Countdown Phaser not responding to trimmers

[matopotato]

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?

[puretube]

Multiturn trimmers - are you sure you know which pin is the wiper?

[matopotato]

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.

[ElectricDruid]

"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

[matopotato]

"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

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.

[matopotato]

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

[puretube]

You placed the (temporary) Jumpers for the setup-procedure as described?
(sorry for the lame question ...)

[matopotato]

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.

[matopotato]

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.

[puretube]

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 ... ])

[matopotato]

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 ... ])

Thanks  It is a "pure" stereo jack (as opposed to the switching kind in the Flintlock Flanger).
And don't worry about asking.

[puretube]

[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.

[matopotato]

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?

[puretube]

All.
(except the OD/Intens-/-ity/Level - don`t worry `bout these, for now).

[duck_arse]

check the value of R67.

[matopotato]

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.

[MP_Quokka]

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

[MP_Quokka]

Scratch that...


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

[matopotato]

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.

[matopotato]

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.