I posted this on Madbeanpedals forum earlier, but no response so I am hoping for some help in this forum.
Just finished building a Countdown Phaser from Lectric-FX and I am using a DMM measuring Hz to calibrate it. (This works as expected with Flintlock build also just finished)
I put Clkrange and Maxfre trimmers to "multi turn" ones. Each 22k instead of stock 20k, but I was thinking they should be ok.
After powering up the board measures 9V and 15V where it should.
The TP shows about 1.290 MHz no matter how I turn. It is the same.
Since this was a big project I decided after soldering each component in to check for continuity from its leg to the eye(s) on the PCB where it is connecting to. Also for each of the socket "holes". It was painstaking and made it all take much longer, but I am trying to avoid cumbersome troubleshooting with so many parts.
I cannot swear I did not do any mistakes, but I feel I have at least minimized that part quite a bit.
I also just finished the Flintlock Flanger, by Lectric-FX as well, and here the calibration works. So I can adjust the trimmers and the DMM is showing Hz as expected. Still a bit of tweaking to do, a few more steps and YT videos to check. But that project is moving along.
So I think the gear is OK to use for the Countdown as well.
I have bypass when off and some kind of effect signal when on, but it sounds more like a %^&*ed wah than anything phase-ish.
The OD part seems to work.
Any ideas on what could be the problem, why there is no change when dialing the trimmers?
Multiturn trimmers - are you sure you know which pin is the wiper?
Quote from: puretube on October 30, 2022, 07:40:48 PM
Multiturn trimmers - are you sure you know which pin is the wiper?
I sure hope so. I compared them with the stock ones and ohmmeter first.
On the Flintlock it works and was the same pinout as for Countdown.
I hade the variable one in the middle. Had to bend a bit to fit. The 1 and 3 were opposite of what I expected, but it was quite clear from the meter.
But yes, that might have been an explaination. Will recheck if possible now that they are already soldered in.
"Cocked wah" sounds like the LFO isn't running to me - the flanger is static. So perhaps the trimmers aren't doing anything because they're not getting any voltage from the LFO?
https://lectric-fx.com/wp-content/uploads/2020/09/Flintlock-V.1.3.pdf (https://lectric-fx.com/wp-content/uploads/2020/09/Flintlock-V.1.3.pdf)
Quote from: ElectricDruid on October 31, 2022, 11:15:06 AM
"Cocked wah" sounds like the LFO isn't running to me - the flanger is static. So perhaps the trimmers aren't doing anything because they're not getting any voltage from the LFO?
https://lectric-fx.com/wp-content/uploads/2020/09/Flintlock-V.1.3.pdf (https://lectric-fx.com/wp-content/uploads/2020/09/Flintlock-V.1.3.pdf)
Thanks,
How can I check the LFO?
I was planning on measuring the ICs.
Actually it is the Phaser Countdown with the issue.
Flanger is sort of fine I think (not calibrated yet, but reponds fine)
I will verify the Multi-turns and how they are fitting ito the circut as well.
EDIT: Checked what the ICs are called, but failed to figure out which would be LFO?
I put the 4 pots (OD was not part in the calibration) to fully CCW.
The pictures will show the measurements, and yes I am fully aware of the impossible values in some places. If there is a lead, the voltage has to be the same on both ends.
I can only suspect there are some dynamics going on that throws some values off as time passes and I get to the next IC after that.
But I prefer to write down the values I got to trying to fake things or adjust as "it ought to be". I can re-measure and re-measure until it gets closer, but was a little bit pressed for time.
It is powered by 9V wall-wart. No signal connected. DMM grounded to the Sleeve of Out jack.
There is a "T" (for expression pedal, Tip) I forgot to write in and it was 5,12
Also there are three more points not in the scheme, not on the PCB picture
South of C6: 7,57
East of C7: 7,42
East of C9: 7,49
The TP itself 6,84 but I don't know where that is in the schema either.
So these might be useless info unless you are the designer of the PCB.
Some measurements kept dropping. I waited until they were reasonably stable to take a reading. I marked them as "u" for going up (IC4:p5) or "d" for down (IC4:p6&p7).
On IC5 pins 3 and 8 they kept moving between what seemed to be 2 to 12 volts.
IC12 LM78L15: I checked pinout but that might be wrong considering the schematic. Can't make sense of it, sorry.
I put some ? where I thought things were odd, but gave up after a while.
The schematic is on the bigger side of things and the pin numbers are hard to read, so I will supply the pdf with the schematic in it rather than taking a snap and lose resolution in the process.
In the pics the blue circle is for MAXFRE and the green is CLKRANGE
http://lectric-fx.com/wp-content/uploads/2017/06/Countdown-Phaser-V.1.0.pdf (http://lectric-fx.com/wp-content/uploads/2017/06/Countdown-Phaser-V.1.0.pdf)
(https://i.postimg.cc/B812Ymq4/2022-10-31-20-43-28-2022-10-31-20-32-01-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/B812Ymq4)
(https://i.postimg.cc/WhbgLN29/2022-10-31-21-00-35-2022-10-31-20-32-38-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/WhbgLN29)
(https://i.postimg.cc/hJ9fQ6Dz/2022-10-31-21-21-21-2022-10-31-21-18-56-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/hJ9fQ6Dz)
(https://i.postimg.cc/62tL8dXK/20221031-215143.jpg) (https://postimg.cc/62tL8dXK)
(https://i.postimg.cc/bSvxTprF/20221031-215145.jpg) (https://postimg.cc/bSvxTprF)
(https://i.postimg.cc/WhCGGRvX/20221031-215222.jpg) (https://postimg.cc/WhCGGRvX)
(https://i.postimg.cc/WhhmqNQd/20221031-215227.jpg) (https://postimg.cc/WhhmqNQd)
(https://i.postimg.cc/mzsV7v70/20221031-215233.jpg) (https://postimg.cc/mzsV7v70)
(https://i.postimg.cc/svNcTQpP/20221031-215237.jpg) (https://postimg.cc/svNcTQpP)
(https://i.postimg.cc/LJgVw9Tc/20221031-215304.jpg) (https://postimg.cc/LJgVw9Tc)
(https://i.postimg.cc/KRzf7rgv/20221031-215318.jpg) (https://postimg.cc/KRzf7rgv)
(https://i.postimg.cc/Z0jjyDnM/20221031-215329.jpg) (https://postimg.cc/Z0jjyDnM)
(https://i.postimg.cc/dDQjvm6m/Inked20221031-215304-LI.jpg) (https://postimg.cc/dDQjvm6m)
(https://i.postimg.cc/DJ6QL8vX/Inked20221031-215318-LI.jpg) (https://postimg.cc/DJ6QL8vX)
You placed the (temporary) Jumpers for the setup-procedure as described?
(sorry for the lame question ...)
Quote from: puretube on October 31, 2022, 05:20:44 PM
You placed the (temporary) Jumpers for the setup-procedure as described?
(sorry for the lame question ...)
No worries. Yes first I used a leg and twisted tight, but then I soldered in the stereo jack for expression pedal. I then use a dual crocodile with cable to jumper T R or S R as dictated. Might have missed that doing the readings, but the trimmers do not affect frequency either way.
Quote from: puretube on October 30, 2022, 07:40:48 PM
Multiturn trimmers - are you sure you know which pin is the wiper?
Re-checked again, and I can only conclude they are placed correctly. And I can not see any solder bridges either.
Be sure the socket (jack?) doesn`t have switching contacts that automatically shorten T or R to S when nothing is plugged in ...
(sorry, I know this is lame again - but it can happen [I`m writing for a friend ... :icon_biggrin:])
Quote from: puretube on October 31, 2022, 05:55:04 PM
Be sure the socket (jack?) doesn`t have switching contacts that automatically shorten T or R to S when nothing is plugged in ...
(sorry, I know this is lame again - but it can happen [I`m writing for a friend ... :icon_biggrin:])
Thanks :) It is a "pure" stereo jack (as opposed to the switching kind in the Flintlock Flanger).
And don't worry about asking.
[in the following I`m referring to the .pdf-schemo, coz your pix are too small for my eyes]
LFO = IC5.2+IC5.3+IC5.1, "SWPMOD" controls the LFO-tempo, "SWEEP(-Rate?)"controls the tempo of the 2nd LFO (slower) .
IC5.4+IC6.2 (in combination with the resistance between "R"+"T" of the expression-jack) take care of the correct DC-levels on which the LFO-signals ride.
"Range" controls how much of the modulating LFO-amplitude is going to influence the HF-section (= Depth) and hence the frequency-sweep of the HF (35kHz - 650kHz) which switches the "voltage-controlled pots" IC9+IC10.
"CLKRANGE" sets the upper limit of the voltage chosen with the "Range"-pot that is allowed to modulate the HF.
"MAXFRE" adds a selectable steady DC-voltage to the continuously varying LFO-signal, to limit the absolute max. HF-frequency, when "Range" is at max.
IC7.1+IC8 generate the HF, which drives IC9+IC10 through IC7.2+IC7.3.
Now:
IC7+IC8 seem to work OK, since you measure a HF,
and:
with the fact like ElectricDruid said the "%^&*ed Wah"-sound means the audio-path is OK,
IC9+IC10 seem to show a constant resistance, and can be assumed to work OK.
So: like ElectricDruid also said, it seems the LFO is not modulating (varying) the HF (correctly), or doesn`t swing at all.
Start:
all elcos concerned oriented correctly? (C30, C32, C33, C34, C35, C36, C38).
IC5+IC6 have the correct power-supply-voltage at their corresponding power-pins?
(IC5: pin11 0V/pin4 +15V) (IC6: pin4 0V/pin8 +15V).
Turn all "LFO"+ "HF" (trim-)pots to center-position, then move each of these (trim-)pots one by one slowly left and right, to see if the HF changes at any of these movements.
Quote from: puretube on November 01, 2022, 05:23:17 AM
LFO = IC5.2+IC5.3+IC5.1, "SWPMOD" controls the LFO-tempo, "SWEEP" controls the amplitude of the LFO itself.
IC5.4+IC6.2 (in combination with the resistance between "R"+"T" of the expression-jack) take care of the correct DC-levels on which the LFO-signal rides.
"Range" controls how much of the modulating LFO-amplitude is going to influence the HF-section and hence the frequency-sweep of the HF (35kHz - 650kHz) which switches the "voltage-controlled pots" IC9+IC10.
"CLKRANGE" sets the upper limit of the voltage chosen with the "Range"-pot is allowed to modulate the HF.
"MAXFRE" adds a selectable steady DC-voltage to the continuously varying LFO-signal, to limit the absolute max. HF-frequency, when "Range" is at max.
IC7.1+IC8 generate the HF, which drives IC9+IC10 through IC7.2+IC7.3.
Now:
IC7+IC8 seem to work OK, since you measure a HF,
and:
with the fact like ElectricDruid said the "%^&*ed Wah"-sound means the audio-path is OK,
IC9+IC10 seem to show a constant resistance, and can be assumed to work OK.
So: like ElectricDruid also said, it seems the LFO is not modulating (varying) the HF (correctly), or doesn`t swing at all.
Start:
all elcos concerned oriented correctly? (C30, C32, C33, C34, C35, C36, C38).
IC5+IC6 have the correct power-supply-voltage at their corresponding power-pins?
(IC5: pin4 0V/pin11 +15V) (IC6: pin4 0V/pin8 +15V).
Turn all "LFO"+ "HF" (trim-)pots to center-position, then move each of these (trim-)pots one by one slowly left and right, to see if the HF changes at any of these movements.
Many thanks, will check.
The (trim)pots for LFO and HF Do you mean the 2 stock trims on the pcb, or all 4 (including MAXFRE and CLKRANGE)? Or even also the "external" pots?
All.
(except the OD/Intens-/-ity/Level - don`t worry `bout these, for now).
check the value of R67.
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Thanks
In the instructions I read about R65 and R66 being sensitive to de iations so I measured a few until I found two that matched quite well.
For R67 I didn't go that far, other than verifying it's value (as all Rs) before soldering.
Is R67 also more sensitive to deviations?
Or is it more a case of avoiding 4k7 47k kind of problem?
Will double-check tonight.
You mentioned it was powered by 9v wall wart and then you were checking IC12 lm7815
this is a 15v regulator so should need about 17 or 18 volts input minimum.
I can't see your schematic pics on my phone cause postimage won't expand them.
Can you check you have the cicuit powered correctly. Does the schematic have a bridge rectifier and filter before the lm7815? If so it needs a AC input probably 15vac other wise it needs dc input about 18V
Scratch that... :icon_redface:
https://au.element14.com/multicomp/78l15/linear-voltage-regulator-15v-to/dp/4642557
https://www.ti.com/lit/gpn/lt1054
The pdf schematic shows the 9v input goes through IC11 which is a boost converter this should have higher than about 17vdc on pin 6 which connects to the pin 1 input of the IC12 via the two diodes D6 D7
Pin 3 of IC12 should have the regulated 15Vdc on it. It can also be measure on the positive pin of C45 if its easier to access
Quote from: MP_Quokka on November 01, 2022, 12:08:46 PM
You mentioned it was powered by 9v wall wart and then you were checking IC12 lm7815
this is a 15v regulator so should need about 17 or 18 volts input minimum.
I can't see your schematic pics on my phone cause postimage won't expand them.
Can you check you have the cicuit powered correctly. Does the schematic have a bridge rectifier and filter before the lm7815? If so it needs a AC input probably 15vac other wise it needs dc input about 18V
Thanks
Yes the build is for 9V dc in. Then the circuit pumps up to 15V as needed. EDIT: (Wrong pedal)
Several IC then take VB VC VR etc. Quite a few options set up by the power stage.
Sorry about the pics, I hate that too. I always have to DL first, then I can zoom.
I can post the measurements in text as well, but you still need the pdf schematic and the pins are really hard to read.
Will check your second post later on.
Quote from: MP_Quokka on November 01, 2022, 12:08:46 PM
I can't see your schematic pics on my phone cause postimage won't expand them.
On Android I can click the picture, then longpress and open in new tab in chrome. Then I can zoom. No need to DL.
Quote from: puretube on November 01, 2022, 05:23:17 AM
[in the following I`m referring to the .pdf-schemo, coz your pix are too small for my eyes]
...
Start:
all elcos concerned oriented correctly? (C30, C32, C33, C34, C35, C36, C38).
Yes, and I checked all electrolyte ones for orientation. That is those having - to ground checked out, and the others I checked against one of the "next component points" in the schematic.
Quote
IC5+IC6 have the correct power-supply-voltage at their corresponding power-pins?
(IC5: pin4 0V/pin11 +15V) (IC6: pin4 0V/pin8 +15V).
IC5, p4=15,13V
IC6, p8=14,96V
and the grounds were zero.
Quote
Turn all "LFO"+ "HF" (trim-)pots to center-position, then move each of these (trim-)pots one by one slowly left and right, to see if the HF changes at any of these movements.
I tried with jumping T&R and later R&S respectively. It stays at 1,23 MHz and swings up to 1,25 MHz. Although a bit jumpy it is still a sort of very small sweep, but still a sweeping motion. No turning of any pot seem to affect this except for RANGE which clearly makes it move between 1,225 and 1,285 MHz.
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Marked Yellow Purple Black Gold Brown yields 47R and DMM says 46.8 Ohm, so that should be OK.
Quote from: MP_Quokka on November 01, 2022, 12:41:50 PM
Scratch that... :icon_redface:
https://au.element14.com/multicomp/78l15/linear-voltage-regulator-15v-to/dp/4642557
https://www.ti.com/lit/gpn/lt1054
The pdf schematic shows the 9v input goes through IC11 which is a boost converter this should have higher than about 17vdc on pin 6 which connects to the pin 1 input of the IC12 via the two diodes D6 D7
Pin 3 of IC12 should have the regulated 15Vdc on it. It can also be measure on the positive pin of C45 if its easier to access
IC12 Seems a bit fishy...
If I google it says, looking at the flat side that Left to right is Pin 1,2,3
(https://i.postimg.cc/Ff9npqtr/78l15-pinout.jpg) (https://postimg.cc/Ff9npqtr)
Looking at the PCB marking, that would make the socket match left to right Pin 1,2,3
(https://i.postimg.cc/gwS4D2qs/78L15PCB.jpg) (https://postimg.cc/gwS4D2qs)
(https://i.postimg.cc/WFxnBYyJ/78-L15-inserted.jpg) (https://postimg.cc/WFxnBYyJ)
But when I check connectivity I get connection between Left most "pin 1" and the 15V checkpoint. In the schema to the right.
And "pin3" beeps with D7 cathode.
But in the schematic this is written as 1 going to D7 and 3 going to 15V
Schematic says VI for 1 and VO for 3, but then the numbers again seem contradicting vs the google pinout.
(https://i.postimg.cc/qNB5XSHk/78-L15schematic.jpg) (https://postimg.cc/qNB5XSHk)
I guess I could just flip the 78L15, but would like to know if I am wrong, it won't fry anything...
Kind of a long shot since the build, kit and schematic has been around for quite some time, then I couldn't possibly be the first one facing this...
Shame on me! I typoed wrong pin-numbers to the voltages in reply#11 - corrected :-[
Your supply-voltages for the LFO look okay!
But the "sweep" isn`t as large as it should be.
It`s hard to watch & measure the amplitudes of the LFO-signals with a DMM.
An old analog meter with a pointer would be nice to use. Scope would be perfect.
But maybe you can try to get some max/min voltages reading on pins 7 & 8 of IC5, which should be slowly moving up & down a few volts, when the SWPMOD & SWEEP pots are turned fully CCW.
If they don`t move up & down, the LFOs don`t oscillate.
Quote from: puretube on November 01, 2022, 07:41:54 PM
Shame on me! I typoed wrong pin-numbers to the voltages in reply#11 - corrected :-[
Your supply-voltages for the LFO look okay!
But the "sweep" isn`t as large as it should be.
It`s hard to watch & measure the amplitudes of the LFO-signals with a DMM.
An old analog meter with a pointer would be nice to use. Scope would be perfect.
But maybe you can try to get some max/min voltages reading on pins 7 & 8 of IC5, which should be slowly moving up & down a few volts, when the SWPMOD & SWEEP pots are turned fully CCW.
If they don`t move up & down, the LFOs don`t oscillate.
Ok, will try.
I have an old 1-ch scope I can try. Time to get to know-it.
The DMM is good for Hz measures though.
Any thoughts on the pinout and schematics numbering of the 78L15?
Quote from: matopotato on November 01, 2022, 11:05:41 AM
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Thanks
In the instructions I read about R65 and R66 being sensitive to de iations so I measured a few until I found two that matched quite well.
For R67 I didn't go that far, other than verifying it's value (as all Rs) before soldering.
Is R67 also more sensitive to deviations?
Or is it more a case of avoiding 4k7 47k kind of problem?
Will double-check tonight.
your voltages look right everywhere
if you take into account a fault. see IC5.2 outputs what it has at input, 5V12. see IC6.2 is fed that voltage thru 2 resistors, and reads about 4V. but then that 5V is also fed thru some resistors and your shorting link to the other input, but now only reads bugger all, or SFA. and the output of IC6.2 can only follow its inputs. so - measure the
resistance between pin 14 [? I can't squint them out either] of IC5 and pin 2 [?] of IC6. measure from the IC pin to IC pin, just to make sure.
and with regulators and transistors and IC's - it NEVER pays to try turning them around. get the datasheet for the part in your hand first. then know what you are doing, and you only need do it once.
I thought more pixels meant better resolution. But will re-post pics with more mobile friendly resolution later tonight.
Quote from: duck_arse on November 02, 2022, 03:18:43 AM
Quote from: matopotato on November 01, 2022, 11:05:41 AM
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Thanks
In the instructions I read about R65 and R66 being sensitive to de iations so I measured a few until I found two that matched quite well.
For R67 I didn't go that far, other than verifying it's value (as all Rs) before soldering.
Is R67 also more sensitive to deviations?
Or is it more a case of avoiding 4k7 47k kind of problem?
Will double-check tonight.
your voltages look right everywhere if you take into account a fault. see IC5.2 outputs what it has at input, 5V12. see IC6.2 is fed that voltage thru 2 resistors, and reads about 4V. but then that 5V is also fed thru some resistors and your shorting link to the other input, but now only reads bugger all, or SFA. and the output of IC6.2 can only follow its inputs. so - measure the resistance between pin 14 [? I can't squint them out either] of IC5 and pin 2 [?] of IC6. measure from the IC pin to IC pin, just to make sure.
and with regulators and transistors and IC's - it NEVER pays to try turning them around. get the datasheet for the part in your hand first. then know what you are doing, and you only need do it once.
Thanks, will test tonight.
The regulator flip question is based on google pinout, DMM connectivity test and schematics pin numbering seemingly not matching eachother. I tried to post some pics above, but better pics might show what I mean better.
In your pics it shows the IC12 regulator which looks like its an STMicroelectronics device. This data sheet from RS shows it has "backwards pins"
https://docs.rs-online.com/83f9/0900766b81712999.pdf (https://docs.rs-online.com/83f9/0900766b81712999.pdf)
Pin 1 is Output as traced on your PCB socket. So its probably correct the way the flat side is drawn on the PCB.
Fig 3 in the datasheet has a test circuit, you could breadboard it up and measure the pin voltages to confirm? You would need about 18V or higher supply on pin 3, but should get 15V on pin 1.
I would fit the reg again on the board and measure the pin 1 output and make sure its 15V
Quote from: MP_Quokka on November 02, 2022, 06:41:18 AM
In your pics it shows the IC12 regulator which looks like its an STMicroelectronics device. This data sheet from RS shows it has "backwards pins"
https://docs.rs-online.com/83f9/0900766b81712999.pdf (https://docs.rs-online.com/83f9/0900766b81712999.pdf)
Pin 1 is Output as traced on your PCB socket. So its probably correct the way the flat side is drawn on the PCB.
Fig 3 in the datasheet has a test circuit, you could breadboard it up and measure the pin voltages to confirm? You would need about 18V or higher supply on pin 3, but should get 15V on pin 1.
I would fit the reg again on the board and measure the pin 1 output and make sure its 15V
Thanks, yes I should pay more attentionnto details. I ignorantly thought a 78L15 is a 78L15...
And sorry, forgot to send the values.
Reg pin 1 read 15.02V and goes to the 15V test point.
Pin3 goes to the D7 diode amd has 16.8V. (How the 9v far left make pin 3 get ~17V is beyond my knowledge but that's what a fev caps and diodes seem to do...
I tried to upload new pictures, but no matter what they are still quite small in the forum.
Only thing one can do is click them, then click the picture and open in new tab and zoom in. Tried various settings but couldn't figure it out.
Reposting in unchanged format anyway.
(https://i.postimg.cc/H8j6n14h/2022-10-31-20-43-28-2022-10-31-20-32-01-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/H8j6n14h)
(https://i.postimg.cc/kBQbSh11/2022-10-31-21-00-35-2022-10-31-20-32-38-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/kBQbSh11)
(https://i.postimg.cc/VJzbWB2Y/2022-10-31-21-21-21-2022-10-31-21-18-56-Countdown-Phaser-V-1-0-pdf-Adobe-Acrobat-Reader-64-bit.png) (https://postimg.cc/VJzbWB2Y)
How come we have an LFO sweep voltage from IC5 pin 8 but static voltage elsewhere?
I don't quite follow the sweep control in this thing.
If IC5.3 is the LFO sweep integrator, then IC5.1 is its controlling Schmitt trigger and if so its output pin1 should switch high-low as the sweep integrator changes up/down direction.
For the CD4016 switches doing the phasing, you can clock the Ctrl (control) inputs at any supersonic speed you like, but if the clock doesn't change its duty cycle, the value of the switches in the phase filters remains constant. So the LFO ramp has to change the duty of the 4047 oscillator somehow. The schematic for the 4007 MOSFET array is unhelpful. It needs a redraw to show its internal transistors in the circuit - there are only 6 of them.
Anyway, the Range pot needs to be set so R82 connects more to the output of IC5.3, that is the pot wiper on lug 2 turned to lug 3 if it's wired as per the scheme.
Quote from: matopotato on November 02, 2022, 07:18:31 AM
Reg pin 1 read 15.02V and goes to the 15V test point.
Pin3 goes to the D7 diode amd has 16.8V. (How the 9v far left make pin 3 get ~17V is beyond my knowledge but that's what a fev caps and diodes seem to do...
IC11 magically ~ doubles the input voltage. See fig.20, pg.17 (+fig.12, pg.10)
https://www.ti.com/lit/ds/symlink/lt1054.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667399734411&ref_url=https%253A%252F%252Fwww.mouser.ca%252F (https://www.ti.com/lit/ds/symlink/lt1054.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667399734411&ref_url=https%253A%252F%252Fwww.mouser.ca%252F)
Quote from: puretube on November 03, 2022, 06:40:00 AM
Quote from: matopotato on November 02, 2022, 07:18:31 AM
Reg pin 1 read 15.02V and goes to the 15V test point.
Pin3 goes to the D7 diode amd has 16.8V. (How the 9v far left make pin 3 get ~17V is beyond my knowledge but that's what a fev caps and diodes seem to do...
IC11 magically ~ doubles the input voltage. See fig.20, pg.17 (+fig.12, pg.10)
https://www.ti.com/lit/ds/symlink/lt1054.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667399734411&ref_url=https%253A%252F%252Fwww.mouser.ca%252F (https://www.ti.com/lit/ds/symlink/lt1054.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667399734411&ref_url=https%253A%252F%252Fwww.mouser.ca%252F)
Cool!
I probably put the voltage values on the opposite pins. Makes more sense now.
Thanks.
Quote from: anotherjim on November 03, 2022, 05:38:02 AM
How come we have an LFO sweep voltage from IC5 pin 8 but static voltage elsewhere?
I don't quite follow the sweep control in this thing.
If IC5.3 is the LFO sweep integrator, then IC5.1 is its controlling Schmitt trigger and if so its output pin1 should switch high-low as the sweep integrator changes up/down direction.
For the CD4016 switches doing the phasing, you can clock the Ctrl (control) inputs at any supersonic speed you like, but if the clock doesn't change its duty cycle, the value of the switches in the phase filters remains constant. So the LFO ramp has to change the duty of the 4047 oscillator somehow. The schematic for the 4007 MOSFET array is unhelpful. It needs a redraw to show its internal transistors in the circuit - there are only 6 of them.
Anyway, the Range pot needs to be set so R82 connects more to the output of IC5.3, that is the pot wiper on lug 2 turned to lug 3 if it's wired as per the scheme.
Thanks Jim!
I will have to digest this a bit.
I have to confess though I am still a bit at a loss as to what to try next.
I beleive the pcb and schema is fine, others have succeeded. The components I could measure came out.ok. So something is wrong on my part, my build. Not sure where to start the process.
I can reflow the solderpoints, but as a general indiscriminate action it is a bit blunt and might even risk losening stuff that are ok right now.
Come the weekend I will get the scope up and explore all replies and learn from them.as well.
At one point is suspected the CLKRANGE multi turn trimmer, but eventually got it to measure 0 to 20k. A bit slippery getting the probe points in right.
Scope can tell us a lot. We like pretty pictures of waveforms.
Quote from: anotherjim on November 03, 2022, 07:57:23 AM
Scope can tell us a lot. We like pretty pictures of waveforms.
"Where do you want these scope probings done?"
(... and 'out on Highway 61' is not a useful answer for me...)
Inspecting the top-right "functional diagram" on page 1 of this 4007-datasheet:
https://www.ti.com/lit/ds/symlink/cd4007ub.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667470405163&ref_url=https%253A%252F%252Fwww.mouser.de%252F (https://www.ti.com/lit/ds/symlink/cd4007ub.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667470405163&ref_url=https%253A%252F%252Fwww.mouser.de%252F)
and checking the datasheet of this 4047:
https://www.ti.com/lit/ds/symlink/cd4047b-mil.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667473111601&ref_url=https%253A%252F%252Fwww.mouser.de%252F (https://www.ti.com/lit/ds/symlink/cd4047b-mil.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1667473111601&ref_url=https%253A%252F%252Fwww.mouser.de%252F)
we can identify it working as a free-running astable multivibrator, (IMHO with constant pulsewidth), whose frequency can be varied from ~35kHz to ~650kHzwith a 1M pot between pin2 and pin3. (plus 200Ohm limiting resistor).
Now we can re-draw the HF-generation-section like this:
(https://i.postimg.cc/CdfdswJj/HF-OSC-Countdown-IMG-20221103-123233.jpg) (https://postimg.cc/CdfdswJj)
So IC7.1 is just an ordinary P-MOSFET used as a voltage-controlled resistor.
Correction of the handdrawn schemo: pins4+5 NOT used!
IC7.2 & IC7.3 are just ordinary inverters, wired in parallel.
(the drawing-symbols for IC7 in the orig. schemo are quite, ahemm, misleading ...)
p.s.: the unlabeled pins to the south of IC8 are 7,8,9,12
With a pot (1M) temporarily hooked up to pins2&3 of IC8, AND one end of R89 lifted out of the PCB, your c*cked-wah-sound should morph into phasing, when turning the pot.
Also the frequency of your testpoint should change remarkably.
Try it. This will assure us that only the LFO and its surroundings is the culprit.
(Don`t accidentally short pins while power is on!)
Quote from: puretube on November 03, 2022, 09:02:18 AM
With a pot (1M) temporarily hooked up to pins2&3 of IC8, AND one end of R89 lifted out of the PCB, your c*cked-wah-sound should morph into phasing, when turning the pot.
Also the frequency of your testpoint should change remarkably.
Try it. This will assure us that only the LFO and its surroundings is the culprit.
(Don`t accidentally short pins while power is on!)
Great! Thanks for the effort. Will try during weekend. As well as any verifications I have missed above.
It is good to have a way to verify the LFO being ok or not
Good work PT,
Odd that it's 50% astable. But if the clock frequency is constantly changing, then the on-off times of the switches won't be equal.
Another question is, where do the phase shifter opamps get DC bias from? Usually expect a resistor to feed bias to the +input. On the scheme, if a switch is off, the +input is floating.
Quote from: puretube on November 01, 2022, 07:41:54 PM
...
It`s hard to watch & measure the amplitudes of the LFO-signals with a DMM.
An old analog meter with a pointer would be nice to use. Scope would be perfect.
I got the scope up and running, but right now the swings are very slow so it is either a dot or a line moving a bit up and down...
Quote
But maybe you can try to get some max/min voltages reading on pins 7 & 8 of IC5, which should be slowly moving up & down a few volts, when the SWPMOD & SWEEP pots are turned fully CCW.
If they don`t move up & down, the LFOs don`t oscillate.
IC5.7 is constant on 7.46V
IC5.8 varies on a slow movement between 3.3V to 11.97V
Also tried pin 3 where it moves at a similar slow pace between 2.5 and 12.4V, but here it jumps to those values from a few volts before. So it is not a smooth sweep all through the cycle.
The DMM/Hz sometimes show some more interesting value before going to 0 as I poke around with it on those pins
Quote from: duck_arse on November 02, 2022, 03:18:43 AM
Quote from: matopotato on November 01, 2022, 11:05:41 AM
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Thanks
In the instructions I read about R65 and R66 being sensitive to de iations so I measured a few until I found two that matched quite well.
For R67 I didn't go that far, other than verifying it's value (as all Rs) before soldering.
Is R67 also more sensitive to deviations?
Or is it more a case of avoiding 4k7 47k kind of problem?
Will double-check tonight.
your voltages look right everywhere if you take into account a fault. see IC5.2 outputs what it has at input, 5V12. see IC6.2 is fed that voltage thru 2 resistors, and reads about 4V. but then that 5V is also fed thru some resistors and your shorting link to the other input, but now only reads bugger all, or SFA. and the output of IC6.2 can only follow its inputs. so - measure the resistance between pin 14 [? I can't squint them out either] of IC5 and pin 2 [?] of IC6. measure from the IC pin to IC pin, just to make sure.
and with regulators and transistors and IC's - it NEVER pays to try turning them around. get the datasheet for the part in your hand first. then know what you are doing, and you only need do it once.
IC5.14 to IC6.2 I measure 230.6k when power is off.
Quote from: puretube on November 03, 2022, 09:02:18 AM
With a pot (1M) temporarily hooked up to pins2&3 of IC8, AND one end of R89 lifted out of the PCB, your c*cked-wah-sound should morph into phasing, when turning the pot.
Also the frequency of your testpoint should change remarkably.
Try it. This will assure us that only the LFO and its surroundings is the culprit.
(Don`t accidentally short pins while power is on!)
I hope you can make out in the picture, I lifted the 200R (R89), and inserted a spare 1M between IC8.2 and IC8.3
(https://i.postimg.cc/Ff5tJDDX/20221106-181336.jpg) (https://postimg.cc/Ff5tJDDX)
Unfortunately there was no change to the wah vs phase sound, it remains the same.
Also none of the big pots had any effect except the Intensity which cause some high pitched feedback sound in one of its extremes.
The 1M pot itself lets of a clickish sound when getting close to 0.
The DMM/Hz does not change durin gthe sweep of the 1M pot. Only reaction is when I get close to 0, then it jumped from 1.27MHz to about the double. I naïvely thought there was something to explore so I did the setup again, T&R or S&R plus twisting them trimmers, but sadly no reaction.
EDIT: Anything else to try while R89 is lifted?
I have just built the Flanger also from Lectrix-fx (Flintlock) and that works although I haven't finished the set up yet.
The Flintlock does have a few ICs that are the same and I could try to swap in to the Countdown:
(ICs on Countdown)
IC6: LM1458N
IC7: CD4007UBE
IC8: CD4047UBE
IC11: LT1054
IC12: LM78L15
I doubt IC12 is of interest, but any of the others I could try to eliminate faulty components? (And I am aware this is a long shot)
Quote from: matopotato on November 06, 2022, 12:34:14 PM
I have just built the Flanger also from Lectrix-fx (Flintlock) and that works although I haven't finished the set up yet.
The Flintlock does have a few ICs that are the same and I could try to swap in to the Countdown:
(ICs on Countdown)
IC6: LM1458N
IC7: CD4007UBE
IC8: CD4047UBE
IC11: LT1054
IC12: LM78L15
I doubt IC12 is of interest, but any of the others I could try to eliminate faulty components? (And I am aware this is a long shot)
Out of topic :
I spent a lot of time trying to get the Flintlock perfectly silent, i finally realized it was the 1054. Take it out (only the 1054) and feed it with a 18V power supply. It should be perfectly silent, no more inner whistling.
Quote from: eh la bas ma on November 06, 2022, 01:45:01 PM
Quote from: matopotato on November 06, 2022, 12:34:14 PM
I have just built the Flanger also from Lectrix-fx (Flintlock) and that works although I haven't finished the set up yet.
The Flintlock does have a few ICs that are the same and I could try to swap in to the Countdown:
(ICs on Countdown)
IC6: LM1458N
IC7: CD4007UBE
IC8: CD4047UBE
IC11: LT1054
IC12: LM78L15
I doubt IC12 is of interest, but any of the others I could try to eliminate faulty components? (And I am aware this is a long shot)
Out of topic :
I spent a lot of time trying to get the Flintlock perfectly silent, i finally realized it was the 1054. Take it out (only the 1054) and feed it with a 18V power supply. It should be perfectly silent, no more inner whistling.
Thanks for the tip!
Just take it out? No need to connect any leftover eyes?
Quote from: matopotato on November 06, 2022, 02:13:14 PM
Thanks for the tip!
Just take it out? No need to connect any leftover eyes?
No need, just the IC. You can leave the 78L15 and all the rest. If you ever need to feed it with 9V, all you have to do do is put back the IC in the socket.
See reply #5, where Scruffie confirms it's ok :
https://www.madbeanpedals.com/forum/index.php?topic=33571.0
Reconnect that lifted R89 again. But before doing that, maybe a retry with a test-pot of only 10k or 47k would show a better test-result?
Quote from: matopotato on November 06, 2022, 12:03:44 PM
Quote from: duck_arse on November 02, 2022, 03:18:43 AM
Quote from: matopotato on November 01, 2022, 11:05:41 AM
Quote from: duck_arse on November 01, 2022, 10:14:29 AM
check the value of R67.
Thanks
In the instructions I read about R65 and R66 being sensitive to de iations so I measured a few until I found two that matched quite well.
For R67 I didn't go that far, other than verifying it's value (as all Rs) before soldering.
Is R67 also more sensitive to deviations?
Or is it more a case of avoiding 4k7 47k kind of problem?
Will double-check tonight.
your voltages look right everywhere if you take into account a fault. see IC5.2 outputs what it has at input, 5V12. see IC6.2 is fed that voltage thru 2 resistors, and reads about 4V. but then that 5V is also fed thru some resistors and your shorting link to the other input, but now only reads bugger all, or SFA. and the output of IC6.2 can only follow its inputs. so - measure the resistance between pin 14 [? I can't squint them out either] of IC5 and pin 2 [?] of IC6. measure from the IC pin to IC pin, just to make sure.
and with regulators and transistors and IC's - it NEVER pays to try turning them around. get the datasheet for the part in your hand first. then know what you are doing, and you only need do it once.
IC5.14 to IC6.2 I measure 230.6k when power is off.
That should be IC6pin5 (not:IC6pin2)! (and you`ll probably measure ~22k there).
Duck_arse: use this schemo on page3, which can be enlarged enough to be readable:
https://lectric-fx.com/wp-content/uploads/2017/06/Countdown-Phaser-V.1.0.pdf
If you encounter the voltage-divider (R68/R69) from IC5 output to ground, the ~4V at the resistor-joint seems reasonable.
Thanks @puretube. Will try that and also re-measure.
Really sorry for pics etc coming out so bad in size etc.
Anyone know what I should use to make it user friendlier?
To swap matching ICs between this phaser and the flanger is not useful yet?
I just began to feel a bit sad that all good ideas and suggestions but still stuck.
sorry, I have that pdf at 400% and still can't hardly mahe out the pin numbers.
and no, not pin 5. I was interested in the line from IC5.4 pin 14 thru R67, T+R, R71, to IC6.2 pin 6. I'm not sure the 230k-ish reading fits. I agree 22k from pin14 to pin 5.
matopotato - ALWAYS the power is off for resistance measure. always, otherwise they will be wrong readings.
Quote from: duck_arse on November 07, 2022, 08:30:36 AM
sorry, I have that pdf at 400% and still can't hardly mahe out the pin numbers.
and no, not pin 5. I was interested in the line from IC5.4 pin 14 thru R67, T+R, R71, to IC6.2 pin 6. I'm not sure the 230k-ish reading fits. I agree 22k from pin14 to pin 5.
Ahh - OK, now I understand.
(got the pdf set to 400% too ... :icon_biggrin:)
Yes, the pdf pin-numbers... I needed zoomed printouts and strong light to follow in my continuity tests.
IC5 pin14 to IC pin6 measures 386.8k.
And there is continuity (beeps) between each of the outlined steps between those pins.
Quote from: puretube on November 07, 2022, 05:02:18 AM
Reconnect that lifted R89 again. But before doing that, maybe a retry with a test-pot of only 10k or 47k would show a better test-result?
I found B10k and B50k both or one of them for the test 2.0?
I have tried now with a B50k and a B10k instead of the 1M pot on pin2 and 3 of IC8. But unfortunately there was no change in the wah-ishness going over to phase-ishness.
My last attempt, unless advised against it, will be to swap IC6,7 and 8 between the working Flanger and this Phaser build. IC11 and 12 I see no reason in this case.
After that I have no more ideas.
I am really grateful and thankful for the help, ideas and support I get in this forum. (And not just this build.)
If swapping ICs does not produce anything useful, are there any other ideas as to what I could be or what I could try?
I could of course go over and reflow the joints, but considering all legs "beeped" with eyelets, legs or solder points (last resort) in line with the schema, I doubt that would do much good. Possibly just trying to "fix something that was not broken" brings the added risk of the opposite result.
Quote from: matopotato on November 08, 2022, 04:05:18 PM
I could of course go over and reflow the joints, but considering all legs "beeped" with eyelets, legs or solder points (last resort) in line with the schema, I doubt that would do much good. Possibly just trying to "fix something that was not broken" brings the added risk of the opposite result.
Multiturn trimmers...I can't use them. Did you try with "good" trimmers ? those allowing you to avoid turning in the the void for ever ?
I would change these trimmers first. At least, I would check that their resistance is indeed changing when you turn them, with expected range of values...
Continuity between components and pads isn't enough, I think. If there's a bad trace, you won't notice it this way. Did you check continuity between each components, according to the schems, with the power supply unplugged ?
Take C2 for exemple, did you check that one side rings with ground and the other with R2 ?
Then does R2 rings with C48 and R3, etc. ?
I know this is boring, ridiculously tidious, but the Countdown Phasor will reward your effort, a thousand times I am sure.
Did you try to follow the signal path with an audio probe all the way through the circuit, from IN to OUT ? This could point to some suspicious aera. The circuit is super complex, just ask if you have doubts about the signal path. You need to be sure about it, no loose ends.
On a Lectric FX spectron build, I realized I had no connection between 2 components despite the fact that they were perfectly soldered. A jumper was necessary... I finally found it because the signal stopped in the problematic aera. It's an amazing effect, I am so glad I didn't give up because I hate audio probing and loud pops scares me... You have to do what you have to do, right ?
EDIT: Redited tags to make the quoting as intended.
Quote from: eh la bas ma on November 08, 2022, 08:53:56 PM
Quote from: matopotato on November 08, 2022, 04:05:18 PM
I could of course go over and reflow the joints, but considering all legs "beeped" with eyelets, legs or solder points (last resort) in line with the schema, I doubt that would do much good. Possibly just trying to "fix something that was not broken" brings the added risk of the opposite result.
Multiturn trimmers...I can't use them. Did you try with "good" trimmers ? those allowing you to avoid turning in the the void for ever ?
I would change these trimmers first. At least, I would check that their resistance is indeed changing when you turn them, with expected range of values...
I measured before setting them in, and have also measured now when they are in. They have the marked values on full and react as expected on turning. So I doubt they are bad, and I doubt they are badly soldered.
Quote
Continuity between components and pads isn't enough, I think. If there's a bad trace, you won't notice it this way. Did you check continuity between each components, according to the schems, with the power supply unplugged ?
Take C2 for exemple, did you check that one side rings with ground and the other with R2 ?
Then does R2 rings with C48 and R3, etc. ?
I know this is boring, ridiculously tidious, but the Countdown Phasor will reward your effort, a thousand times I am sure.
Yes, this is what I did when beginning this (and Flanger) project. Every leg sticking out, before cutting, I check connection with the next part(s) in the schematics. Either an eyelet waiting for its component to fill it in. Or the leg of an already soldered component, or if nothing else possible (Cap already in) the solder joint, although I try to avoid this option as much as I can.
So each leg is tested against all the directions the current/signal can take.
It was tedious, and for the Flanger it seems to have been a good investment, but here it did not prevent current issue.
I think still it was worth it, just want to be able to move on from here...
Quote
Did you try to follow the signal path with an audio probe all the way through the circuit, from IN to OUT ? This could point to some suspicious aera. The circuit is super complex, just ask if you have doubts about the signal path. You need to be sure about it, no loose ends.
No, no probing (yet). First I also am not a fan of the pops that sometimes happen. Feels like I might break something. And I have been warned in other posts not to "over-probe" a circuit. So I would need some suggestions of where to probe first. Then I would focus on that instead of following the signal path and risk straying off in any unwanted direction.
Second, I do get signal through in the sense that when the pedal is engaged (OD off) the sound changes. It becomes a bit like a Wah that is stuck. Like mid/upper hump kind of tone. Which led me to believe that the signal goes through the circuit, but does not reach the "phasing" part. And I do not know what part that is.
I am still not sure which IC is the actual LFO. Perhaps the multi stage thing means several ICs together do LFOing. My ignorance exceeds my insights here.
Any tips are appreciated.
Quote
On a Lectric FX spectron build, I realized I had no connection between 2 components despite the fact that they were perfectly soldered. A jumper was necessary... I finally found it because the signal stopped in the problematic aera. It's an amazing effect, I am so glad I didn't give up because I hate audio probing and loud pops scares me... You have to do what you have to do, right ?
Yes, I remember reading this, and as things turned out I had more or less the same problem as you on the Spectron. ;D
The build was also a bit "is it on?" tricky in case the knobs were not "aligned with Venus and Mars" kind of.
In the end I also added a switch to handle different pickups. Turned out really good, but very powerful Envelope Filter that can make things go really strange if you are not careful...
I still feel your oscillations are being blocked by IC6.2. is there any way you can lift the range pot connection to that IC6.2? or - when you rotate the range pot all the way towards the IC5.3 end, does the voltage on its wiper change? increase?
Quote from: duck_arse on November 09, 2022, 08:17:04 AM
I still feel your oscillations are being blocked by IC6.2. is there any way you can lift the range pot connection to that IC6.2? or - when you rotate the range pot all the way towards the IC5.3 end, does the voltage on its wiper change? increase?
Of I lift leg1 on Range, the leg to IC6.2 pin 7, then pin7 has nowhere to go?
Should I short IC6.2 pin 7 to R82 directly? (The wiper R) EDIT: Shorting is opposite I realize...
I will first try yo measure how it wipes.or not.
Any bridging or shorting is proably easier that lifting the pot leg.
I can cut it off an later re solder of course.
The other side of the Range facing IC5.3 pin8 and the wiper (taking whatever from that direction) is ok to keep in, right?
I found your madbean's thread. It's in the Madbean projects section. Scruffie will probably miss it unless you post in Tech Help at Lectric-fx sub-forum.
A complete list of IC's readings will probably make it easier for experienced forumites, more familiar with these ICs.
Quote from: matopotato on November 09, 2022, 08:42:13 AM
Of I lift leg1 on Range, the leg to IC6.2 pin 7, then pin7 has nowhere to go?
Should I short IC6.2 pin 7 to R82 directly? (The wiper R)
I want to isolate the IC6.2 output voltage from the rest of the circuit to see what happens around the oscillator. if you have a spare, you might remove the IC and bend that pin [?14? at 400%] out ...... dunno if that will do it or not.
Quote from: eh la bas ma on November 09, 2022, 08:58:51 AM
I found your madbean's thread. It's in the Madbean projects section. Scruffie will probably miss it unless you post in Tech Help at Lectric-fx sub-forum.
A complete list of IC's readings will probably make it easier for experienced forumites, more familiar with these ICs.
Thanks!
I was not aware/confused.
Will adjust.
Did you try swapping IC7?
LFO=IC5.3 & IC5.1, while IC5.2 adds another (faster) "wobble" onto the main LFO-output, which is at IC5.3 pin8.
Your oscilloscoping seems to show it is working.
(IC5.1 pin1 should produce sudden big voltage jumps, at the same tempo as the max & min of the tri-wave on the main output.
Quote from: duck_arse on November 09, 2022, 09:23:27 AM
Quote from: matopotato on November 09, 2022, 08:42:13 AM
Of I lift leg1 on Range, the leg to IC6.2 pin 7, then pin7 has nowhere to go?
Should I short IC6.2 pin 7 to R82 directly? (The wiper R)
I want to isolate the IC6.2 output voltage from the rest of the circuit to see what happens around the oscillator. if you have a spare, you might remove the IC and bend that pin [?14? at 400%] out ...... dunno if that will do it or not.
The Range pot, wiper voltage when I sweep it more and more "up". (CW) I lower its resistance between leg 3 (pointing at IC 5.3 the out, pin8?) and 2, the wiper and the voltage increases.
It is first around 2V and as I turn it up is oscillates/swings. The low end climbs not too much, to 3 3.5 maybe and the upper end reaches 11.sth in the top before the swing turns back again.
Yes, understand better. IC6 has only 8 pins. And the one from the IC6.2 that is the output reaching Range, leg 1 is pin 7. They have connectivity. I was thinking of putting something like plastic or paper in the socket, but bent the leg anyway.
So pin 7 is away.
I then set it up for test again.
No signal, board powered up, T&R shorted and for a second my heart skipped a beat as the reading is now 0.8sth MHz as opposed to the previous 1.2. But turning either trimmer does not change the value. It flickers in the third digit, but does not feel significant in relation to the problem.EDIT: My bad. had forgotten grounding the dmm...
It is still the same old 1.2sth MHz that floats around a bit so it sweeps, but very short interval no matter how I turn the trimmers
Anything else to explore while the IC 6.2 pin 7 (going to Range) is out?
Quote from: puretube on November 09, 2022, 12:54:18 PM
Did you try swapping IC7?
LFO=IC5.3 & IC5.1, while IC5.2 adds another (faster) "wobble" onto the main LFO-output, which is at IC5.3 pin8.
Your oscilloscoping seems to show it is working.
(IC5.1 pin1 should produce sudden big voltage jumps, at the same tempo as the max & min of the tri-wave on the main output.
Thanks, yes now I just did.
I took both IC7 and later IC8 the 4007 and 4047 but no change to the stuck Hz.
I also put the "phaser ones" in the flanger and it played, so I would think they are OK.
I also put the LM1458 when I was already messing around and still no change.
Also it seems there is no effect or difference if I short the T&R or R&S respectively, the TP shows the same values and behavior.
Checked the El caps orientation, same with the diodes, and the ICs. A few times actually
Quote from: eh la bas ma on November 09, 2022, 08:58:51 AM
I found your madbean's thread. It's in the Madbean projects section. Scruffie will probably miss it unless you post in Tech Help at Lectric-fx sub-forum.
A complete list of IC's readings will probably make it easier for experienced forumites, more familiar with these ICs.
Again thanks,
I opened this thread: https://www.madbeanpedals.com/forum/index.php?topic=34269.0 (https://www.madbeanpedals.com/forum/index.php?topic=34269.0)
I will make a new set of measurements on the legs later on, hopefully during the weekend unless earlier.
Does anyone know or have an educated guess where the TP would be located in the schematics?
Quote from: matopotato on November 11, 2022, 02:15:06 AM
Does anyone know or have an educated guess where the TP would be located in the schematics?
It`s either pin13 of IC8, or pins13/12/8 of IC7. (the latter 3 are combined).
Check if you can see it by the coppertraces on the PCB.
These pins13 should show the same (HF square-wave-form) on the scope,
whereby pin13 of IC7 is inverted (upside-down) compared to IC8`s pin13.
When there is no HF on pin13 of IC8, there also cannot be HF on pin13 of IC7.
If there is HF on IC8 but not on IC7, then IC7 does not work ...
Quote from: puretube on November 11, 2022, 07:02:01 AM
Quote from: matopotato on November 11, 2022, 02:15:06 AM
Does anyone know or have an educated guess where the TP would be located in the schematics?
It`s either pin13 of IC8, or pins13/12/8 of IC7. (the latter 3 are combined).
Check if you can see it by the coppertraces on the PCB.
These pins13 should show the same (HF square-wave-form) on the scope,
whereby pin13 of IC7 is inverted (upside-down) compared to IC8`s pin13.
When there is no HF on pin13 of IC8, there also cannot be HF on pin13 of IC7.
If there is HF on IC8 but not on IC7, then IC7 does not work ...
Thanks, it was neither though. IC8 pin 10 (?!). And you are right about the traces. Should have known to check myself. But you put me in the right area. :)
Will try the other things later on with the scope.
Quote from: matopotato on November 12, 2022, 11:09:21 AM
Quote from: puretube on November 11, 2022, 07:02:01 AM
Quote from: matopotato on November 11, 2022, 02:15:06 AM
Does anyone know or have an educated guess where the TP would be located in the schematics?
It`s either pin13 of IC8, or pins13/12/8 of IC7. (the latter 3 are combined).
Check if you can see it by the coppertraces on the PCB.
These pins13 should show the same (HF square-wave-form) on the scope,
whereby pin13 of IC7 is inverted (upside-down) compared to IC8`s pin13.
When there is no HF on pin13 of IC8, there also cannot be HF on pin13 of IC7.
If there is HF on IC8 but not on IC7, then IC7 does not work ...
Thanks, it was neither though. IC8 pin 10 (?!). And you are right about the traces. Should have known to check myself. But you put me in the right area. :)
Will try the other things later on with the scope.
Ahh - OK! Thanks for looking that up - it tells us, that the TP (from IC8, 10) only shows half the frequency of the frequency which drives the 4016-switches (from IC8, pin13) ...
see fig.1 in the datasheet: https://www.ti.com/lit/ds/symlink/cd4047b.pdf (https://www.ti.com/lit/ds/symlink/cd4047b.pdf)
That means you should read twice (!) the TP-frequency on pin13 of IC8 & pins13/12/8 of IC7.
Now we know the real working-frequency of the "switched resistors" in the circuit.
This is still true:
QuoteIf there is HF on IC8 but not on IC7*, then IC7 does not work ...
*[EDIT:pins13/12/8]
Ok, I returned the DMM with Hz meter since I felt stuck for now. Connected scope for fun and sine tone generator on input jist to see what happens. Set up scope with nice sine wave and then put it on TP. And I get a sqare wave?
The square wave expands and contracts along x-axis. The two shots are sort of at the turningpoints.
I was really expecting something more sine-ish...
Turning them trimmers I see the maxfre affects the square. The clkfre perhaps but harder to tell
So I guess not all my solders were cold after all...
I tried to compare pin 13 of ic8 and 7 and tp.
But the IC pins make a sort of one sided square wave with top being strong and if there is a bottom, very faint. Some settings moving from the tp view to pin 13 on either and thebwhole osc screen goes blank. Out of bounds i suppose.
I will now try to re measure the IC voltages and present in a better way than preciously.
Without signal and why not with signal.
Meanwhile I really hope someone will read this and getnsome nice idea to try based on getting a square vave...
(https://i.postimg.cc/XGZzdV3Q/20221115-201930.jpg) (https://postimg.cc/XGZzdV3Q)
(https://i.postimg.cc/YLYDDbvF/20221115-201945.jpg) (https://postimg.cc/YLYDDbvF)
(https://i.postimg.cc/TpjHrNMM/20221115-202015.jpg) (https://postimg.cc/TpjHrNMM)
(https://i.postimg.cc/3kKf9jYy/20221115-202018.jpg) (https://postimg.cc/3kKf9jYy)
(https://i.postimg.cc/4KyLRJKs/20221115-202027.jpg) (https://postimg.cc/4KyLRJKs)
(https://i.postimg.cc/gxNS7w2g/20221115-202030.jpg) (https://postimg.cc/gxNS7w2g)
Squarewave @ TP is perfect! Expanding/contracting along x-axis is even better!
When the scope shows 2 squares on the screen @ TP, pin13 of IC8 should show 4 squares.
Pin13 of IC7 should also show 4. (Double frequency).
(Turn Range down, and ClkRange to max. resistance, so the square does not exp./contr. too much).
I did another round of measurements. And this time added bigger numbers to the schematic to see where.
To see these pictures on the phone, I find it best to click here, then on the "postimage" page, click again and open in new tab. Then you can zoom and all.
(https://i.postimg.cc/21NRKMDY/schema1.png) (https://postimg.cc/21NRKMDY)
(https://i.postimg.cc/FfmfNTj5/schema2.png) (https://postimg.cc/FfmfNTj5)
(https://i.postimg.cc/zLjyBTjL/schema3.png) (https://postimg.cc/zLjyBTjL)
Measurements
Only power, no signal. T R S not connected. All main pots fully CCW (I think)
"9V" 9,19V
"15V" 15,01V
"TP" 7,07 - 7,10
IC1 TL072
7,47 14,91
7,47 7,45
6,82 7,46
0,00 7,45
IC2 LM348N
7,45 7,44
7,44 7,43
7,45 7,40
14,91 0,00
7,43 7,45
7,45 7,44
7,45 7,44
IC3 LM348N
7,08 7,15
7,09 7,29
7,06 7,22
14,87 0
6,94 7,42
6,97 7,43
6,89 7,43
IC4 LM348N
7,25 7,07
7,26 7,15
7,27 7,10
14,86 0
6,37 6,46
7,31 7,29
7,32 7,41
IC5 LM324N
0,75 5,04
7,44 5,03
2,4 - 12,46 * 5,01
14,90 0
7,33 7,44
7,47 7,48
7,47 3,3 - 11,9 *
* pin 3 and 8 fluctuate slowly across the interval with a full sweep taking 42 seconds
pin 3 tends to "jump" the last 2-3 volts to close to either extreme and then "normal" sweep again.
pin 8 does not "jump"
IC6 LM1458N
4,05 14,96
5,12 8,18
5,13 4,11
0,00 4,12
IC7 CD4007
8,13 14,47
3,74 3,56
4,04 3,56
2,20 14,46
2,09 10,59
10,59 0
0,00 3,56
IC8 CD4047
10,30 (or 10,39?) 14,46
3,74 10,58
8,22 0
14,46 7,18
14,46 7,05
14,46 0
0,00 0
IC9 CD4016
7,05 14,46
6,93 3,55
7,08 3,55
7,03 7,43
3,55 7,42
3,56 7,21
0,00 7,29
IC10 CD4016
2,66 14,46
2,61 3,55
2,48 3,55
2,67 7,21
3,55 7,27
3,55 7,10
0,00 7,23
IC11 LT1054
0,00 9,19
4,52 6,33
0,00 3,43
0,00 0,00
IC12 78L15
_________
/ \
/ \
| |
|____________|
1 2 3
15,01 0 17,0
Quote from: puretube on November 15, 2022, 03:47:16 PM
Squarewave @ TP is perfect! Expanding/contracting along x-axis is even better!
When the scope shows 2 squares on the screen @ TP, pin13 of IC8 should show 4 squares.
Pin13 of IC7 should also show 4. (Double frequency).
(Turn Range down, and ClkRange to max. resistance, so the square does not exp./contr. too much).
Thanks!
Tried again.
This time there is no contraction/expansion, but I might have turned the mainpots or removed T P S or something.
However, previous time I could not see anything sensible on pin 13's
But now I get the square with 8,5 "tops" over the screen (Shortest sweep so could not dial in just two squares)
And on the 13's I get 17 or 16,5 "tops". So that checks out nicely!
IC8 pin 13 and IC7 pin 13 squares differ in as much as one has a broad top and quite narrow bottom, and the other the opposite, as if inverted.
EDIT: IT was the RANGE pot that made it swing. I stuck it now, and changed Maxfre trimmer until I got two squares, then IC7 pin 13 shows 4, with long tops and narrow b*tt*ms.
For IC8 pin13 I have to fiddle with the position to see it but it quickly disappears again, but when I get to see it is as previously but sort of inverted in shape. 4 squares too.
Do you think the square shaped wave is what made the DMM on Hz fail?
Right now I can get the square to change by turning either ClkRange or MaxFre. Different impacts but they do affect it.
I am still not sure if it is enough to make a difference.
Measuring 35 kHz and 650kHz respectively from the scope is a challenge for me I think
And all this is done with to tone generator on (I think) 1 kHz to the input jack.
Anyway, I feel for the first time some glimmer of hope and touch of progress I was not expecting :D
I really appreciate all the tips and support I have gotten so far in this case.
OK, I must say I am quite surprised. I would have liked to edit the title to SOLVED .... and will see if this attempt works or not.
Anyway, I had been using a DMM with Hz setting that I returned last week. (I hope to get to try one more time tomorrow, we'll see). So after the recent post from @puretube suggesting to compare the frequency on TP with IC 7 and 8 pin 13 of each to see if they had double frequency of TP.
I took out the scope yesterday and tried out and it was doubled as suggested, but the wave was a square wave. I now understand that it was the expected shape, and after asking the manufacturer of the DMM, it should be able to measure frequency accurately regardless of shape.
So today I got the scope out again and tried the trimmers. And the frequency changes on the scope notably so I began calculating how many squares a cycle should be for 35kHz and 650kHz respectively. Not very exact numbers, but I managed to tweak Maxfre to the wanted position, then the Clkrange I had to go all they way to one end and it still was not quite right. I felt a bit disheartened first ("this close and still ...") but went back to the other trimmer and after adjusting it again, the Clkrange was possible to fit as well. A few rounds for sure, but less sensitive to set than the Flanger (Flintlock).
Still sceptic to the end result, I plugged it in, And after some knob turning, it actually Phases!
Amazing!
What did I do to make to go from no phase to this, I have no idea. I did lift and later solder back R88. And if that had a weak solder before? Feels a little bit too lucky for that.
I also lifted pin 7 on IC6 and put back, but again would be surprised if that step made it all work suddenly.
I cannot thank enough everyone who helped out with anything from ideas to encouragement. It means more than you might think. Yes, it's just a pedal. But the time and effort put in plus the hopes and expectations suddenly stopping in its tracks. From that point it is easy enough to question your reasons for and competence on building pedals.
First impressions:
I was expecting something different phase-ish.
But two days ago I managed to finish a compressor (Pumpernickel) and I was not overly impressed or excited by the end result.
Today, it sings a different tune all together and will make it on the board(s). (Actually all pedals do....)
So I have hopes that this Countdown Phaser will come through, once it is boxed and tweaking begins.
Only knob I felt didn't have any or much effect is the "Sweep Modulation". I doubt there is another miss, but any ideas on how to set it or what to listen for would be appreciated.
Again,
Many thanks!
I got the Hz meter again. With the scope I was somewhat close like 34kHz and 660kHz (or similar).
Using the Hz meter to adjust as close to 35 and 650 I found that Clkrange never reaches 650, the trimmer hits the bottom. And although adjusting with maxfre "works" it throws off the 35 in the process. So I settled for 34.8 or 34.9 and high 650's.
I guess that will for for my ears at least.
If I had to choose one to nail and the other a bit left to its own, which should that be? Or better to get both as close as possible?
EDIT: And how much does it affect the sound and in which way?
Don`t worry - a couple of +/- kHz makes much less difference than the +/- 10% tolerances of the 1n caps and the 15k resistors in the phaseshift-circuits.
Quote from: puretube on November 17, 2022, 03:48:47 PM
Don`t worry - a couple of +/- kHz makes much less difference than the +/- 10% tolerances of the 1n caps and the 15k resistors in the phaseshift-circuits.
Great ;)
Out of curiosity and to learn more:
In what way would a variation of either affect the sound?