Countdown Phaser not responding to trimmers

[anotherjim]

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.

[matopotato]

...
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...

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

[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.

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.

[matopotato]

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

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?

[matopotato]

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)

[eh la bas ma]

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.

[matopotato]

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?

[eh la bas ma]

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

[puretube]

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?

[puretube]

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.

[matopotato]

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.

[duck_arse]

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.

[puretube]

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 ... )

[matopotato]

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.

[matopotato]

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?

[matopotato]

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.

[eh la bas ma]

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 ?

[matopotato]

EDIT: Redited tags to make the quoting as intended.

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.

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...

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.

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. 
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...

[duck_arse]

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?

[matopotato]

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?