Warden compressor Vero build help

[duck_arse]

a couple of things - more information please. we can't see the pots and stuff, more photos please. where the layout diagram sez MPSA18 on the left, you seem to have a white wire soldered. why? what? where to?

and, as the MAX1044 takes the 9V in and generates 18V which is then divided down by the 47k//47k to make the 9V for bias, we need the max1044 IN its socket when we do the voltages with the TL072 OUT of socket. all transistors in their sockets, too.

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Ok. As soon as I get home from work I'll take more pics and redo my voltages.

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Here are my socket voltages for the op amp with everything else in place
1, .97
2, .89
3, .34
4, 0
5, 7.01
6, 1.10
7, 1.45
8, 17.8

[duck_arse]

be so kind as to tell us the markings on each of the three caps arrowed, if you would.

with your "18V" reading 17V8, your "9V" should read 8V9 at pin 5, so it appears something is dragging it down. power off again, TL072 out of socket, meter to ohms [power stays off for resistance measures], and probe between ground and pin 1, ground and pin 2, ground and pin 3, ground and pin 5. I still don't like the base voltage on the mpsa.

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From bottom left  104 [100nf], middle 101 [100pf] top right 101 [100pf]
So I powered off my circuit and everything in reference to ground.  Meter set on 200k
1, no reading on any range
2, no reading on any range
3, 34.4
4, 0
5, 29.9
6, 156
7, 156.1
8, 70.6

[duck_arse]

blast, I was hoping for a break on those caps. oh, well.

I hate veroboard.

so, now, see. IF you are 100% confident there is no remaining copper slivers, and all your cuts are clean and tikkety-boo, and IF you are 100% confident there is no unwanted solder bridges between tracks because you ran a knife between them, then we can continue.

in your original photo of the component side, there are parts obscured - I can't say if I can't see, but I don't think any the hidden are the culprit. if you look on the circuit, you'll see every* pin on the opamp has a decouple cap and should read high/open/wandering-to-ground, except for pins 3 and 5. pin 5 has a 47k resistor to ground, so you either read 47k there, or there is a problem. the 10M to pin 3 means we can ignore it, EXCEPT that that pin shows 34k to ground. pins 6 and 7 should read about the same, but open circuit, wandering reading.

I suggest you go through and measure all the caps on [lower] resistance range, see if there is any bulk problems. if none, then maybe try this - measure the resistance from pin 5 to ground as you rotate the pots on that corner of the board. if the reading changes with pot, follow the tracks and find what's wrong. same for pin 5. if you can't see or find, then you'll need to start removing things, like the IC socket, so we can see what is underneath.

just for fun, try these - remove the mpsa and test it on your dmm transistor tester, if it has one, just in case. also, remove the 10M resistor and replace it with whatever else you have - 1M, 2M2, 4M7, whatever, will do for now. and that frankenresistor, pull that out and replace with whatever high-value single resistor you have, 1M will do, 2M2, etc. if the circuit magically springs to life, well and good. if not, leave them in until the circuit does work, then worry about them.

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Ok I tested most of what you said. But I have one question. With measuring the caps on the lowest resistance range, is the circuit off? Do I need to remove a leg of the cap and it reference to ground?? I checked my pots while measuring pin 5 and there was no change. I tested my Transistors and all seemed to read somewhere in the stated range. I replaced the 2.2m frankensistor with next closest value of 2m and imm about to change all 10ms to 1ms and I'll post what I find out. Thanks again for your help. I really do appreciate your time.

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Replaced 10m res with 1m and now I'm getting sound through. Slightly overdrive, way below unity and when I strum hard it breaks up and starts the "splatty, gated" sound" good news all pots work as expected I had to turn my amp 3/4 of the way up to really get a decent signal and it seems like If I use my neck pickup and play lower frequency notes it breaks and gates sooner.

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After doing a little more probing it seems like the dist. Is coming from my sustain pot. Followed the signal all the way there and that's where it starts.  But only when I have it almost maxed out. Now if I can figure out where the volume drop is coming from. I'm still a little confused as to the purpose of the 5089s. I can only pick up signal off of their base. Is this correct?

[duck_arse]

always always always always always power off when measuring resistance. never never never never never never, no exceptions, measure resistance on a live powered circuit, it won't read right.

the reason I wanted you to measure the caps resistances was to see if any were faulty, reading low, some resistance - no legs need lifting. you want them all wobbly high nothing readings, or there is a problem. as all the opamp pins are cap isolated, I was suspecting (hoping) for a bad cap, or a short-y connection somewhere nearabouts. so the reading doesn't matter as long as it doesn't actually read.

a Minor point - m is for milli, M is for Mega. one is 10^-6, the other is 10⁶. those 12 zeros matter.
a Minor point - m is for milli, M is for Mega. one is 10^-3, the other is 10⁶. those 9 zeros matter.

the 5089's are there to turn the led on, is all. when the signal provided by the phase splitter is more than 600mV, the transistor turns on, the led lights, compression ensues. one transistor turns on for signal positive half cycles, and the other transistor turns on for the other half cycle, cause its signal to the base is inverted. the diodes clamp the base so it ignores the negative going half of each cycle. this is the same splitter section used in many enveloped circuits, like the slow-gear, and the dynacomp. you aren't really listening for audio on those transistors, but it will be there to some extent.

you are still looking for the "leaking" around the 18V/9V dividing section, I think. if you have cleared all the cuts and no shorts, and all your caps read like caps should, you might go thru all the resistors and measure for resistance. many some will read lower than marked because they are in circuit, so you are looking for where it doesn't look right, where you can't follow along to something paralleling it. measure all the pots for resistance AT THE BOARD connections, make sure they work right at the board as opposed to at the pot, measure the resistance across the ldr. if nothing shows then, you will have to start taking bits off the board.

oh, and - the emitter of the phase splitter mpsa provides a low impedance unity gain signal from pin 1 to the tone section and the output oppie.

[edit :] phew, and whoops! glad nobody saw that.

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 😂 no worries man. Alright so here's where I'm at I Tested all resistors and just as you expected the higher values were a little low but nothing stood out. Caps seemed to be open readings. Pots also seem to be accurate readings (at the board) I tested  all my traces with continuity  AGAIN and found what must have been a microscopic bridge on the second to bottom row where the 47k dividers were so I cut it AGAIN and when I tested the circuit I had full volume but had HEAVY distortion. I've read a lot about this circuit and a lot of people claim when the sustain is maxed out or the attack is all the way down it does produce some unwanted distortion. Something else I noticed was my led was not reacting at all. So I powered off replaced the 1M with a 10M as the schematic calla for and remembered that the 5089s turn on the LED  as you previously stated. The sockets are a little loose so first I took them out and tested them with a dmm all seemed to be working. I put a small dab of solder on the leg to socket to ensure a connection fire it back up and lost s little volume but the led is reacting again or at least it was for a min or two and then after that only when I strum insanely hard the led would light up and when it got to a certain point of illumination my guitar signal would make a weird popping sound and almost turn into a bit crusher type gated sound. I tested my voltages on the op amp and now pins 1-4 have no voltage through them and pins 5-8 were about the same around 18 on 8 and I believe it was right about 9 on the others If I remember correctly. I know it was over 8v. I'll do some more testing after work. Again thanks for your help.

[duck_arse]

..... and found what must have been a microscopic bridge on the second to bottom row where the 47k dividers were so I cut it AGAIN and when I tested the circuit I had full volume .....

I don't care about anything else, just this.

ok. next step, put all yer transistors in, all yer IC's in, power on and measure all the voltages around the place, opamp and transistors and inverter, post them in sensible order, please.

you could probably fit a second led in series w/ the vactrolling led, and use it as a test/indicator - might not be the best compression indicator, but good enough for test. also, unlikely the 10M value would be a problem if 1M insteaded.

(frankly, I don't know why you would fit transistor sockets on this build - they need no matching or selecting whatsoever - jellybeans to the max. obviously, sockets are a boon for a non-working debug, and give confidence to starter-outers, but my old boss used to say never spend more on a socket than the IC [or transistor] it's protecting. and, see, they proove one more potential point of failure. it's not that easy to kill a modern silicon transistor with soldering unless you really want to.)

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Honestly, I put them in because everything I've read concerning Transistors always said to socket but as I've learned more about this circuit I can see they're not really necessary. Here are my voltages.

1044
1, 9.28
2, 4.59
3, 0
4, 0
5, 0.17
6, 3.5
7, 2 47
8, 9.32

Tl072
.1, 0.86
2, 0.86
3 0.94
4, 0
5, 8.8
6, 9.0
7, 9.7
8. 18.1

Mpsa18
C 12.1
B 4.3
E 5.5

5089 (both)
E 0
B 0
C 14.8

[duck_arse]

well, seeing as your 5, 6, 7 voltages are OK, and your 1, 2, 3 volts are upta shit, and seeing as you replaced that 10M resistor, is there a chance you've jumped one end of it, whatever value it is now, to the ground line instead of the pin 5 line? I'm hoping yes.

if not, another photo or two of your board as it now stands, please.

[moid]

Looking at the close up photo of four pots:


Have you connected lugs 2 and 3 together on the Level and Release pots? Maybe you did and it's not visible... but it might be worth a look. Hmmm just looked at another of your photos and I think you did it for Release, but not for the Level pot. I don't know if that will make much of a difference. Good luck, and listen to everything Duck says; he has saved many of my builds from disaster

Sorry for delayed response I have a 6 month old son and he's not too into pedal building YET  😁

Congratulations, but don't get too upset if it takes a bit longer... I tried for years and my son still has no interest in pedal building, but is very happy for me to build them for him! He makes better sounds than I can, so at least it's nice to hear what my creations can do if someone with talent plugs into them.

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I hoped you were right too but it's in the right spot. I don't see any bridges and couldn't find one with continuity check.

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Have you connected lugs 2 and 3 together on the Level and Release pots? Maybe you did and it's not visible... but it might be worth a look. Hmmm just looked at another of your photos and I think you did it for Release, but not for the Level pot. I don't know if that will make much of a difference. Good luck, and listen to everything Duck says; he has saved many of my builds from disaster

Congratulations, but don't get too upset if it takes a bit longer... I tried for years and my son still has no interest in pedal building, but is very happy for me to build them for him! He makes better sounds than I can, so at least it's nice to hear what my creations can do if someone with talent plugs into them.

On the layout it doesn't say anything about connecting Level 2 and 3 together but I've been looking at this layout, schematic and Vero for like 2 weeks 😂 so it wouldn't surprise me if I've overlooked something obvious. Duck has been awesome. Very patient and helpful. I'm thankful for someone to take the time to help. The only thing my son cares about right now is bottles and naps and I'm okay with that. Couldn't be happier with my little man.

[duck_arse]

it's doing my head in. something's wrong on the opamp. are you swapping TL072 with 4558 or something similar? the 4558 might not like the 10M. but, anyway, something wrong - I'd expect your pin 5 voltage to be best strongest, and pins 6 and 7 to show some meter loading, maybe, but your's shows the opposite.

you need to use the continuity setting carefully, cause it only wants to show low ohms, or doesn't care. we might be looking for a reading outside its range, so you want to stick with resistance ranges, and note stable readings. for the moment, it's back to pulling the opamp and another round of resistance to ground readings, please. pins 1, 2, 6 and 7 should all be open/unstable. if not, you can start pulling up resistors. lift out the far left 10k, then bottom left 22k, the "2M2" - each time check if resistance to ground changes. move to the 10M and those 4 resistors on the right side the oppie then. somethings gotta give soon.

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Ok so my resistances were exactly as you expected so I decided to change that 10M back to a 1M to see if I could at least get signal through again. So I swapped it and checked my voltages
Tl072
1, 4.5
2, 4.5
3, 2.9
4, 0
5, 8.7
6, 8.9
7, 10.44
8, 17.8
Which is a good sign so u plug into my test box and the pedal works great sounding compressor except if I have my guitar volume maxed to 10 it distorts the signal regardless of how low or high the sustain is set but if I dial if back to about 8 it works exactly how it should. Idk if this is the same thing I've read about with people have problems with distortion when the sustain is maxed on their pedal or something different. Like I said my distortion starts early in the sweep of the sustain. Also, if I have my input of the circuit plugged into the input of my test box when I test my voltages it drops them down to where they were previously. Is this normal? And why? If you don't mind explaining.

[duck_arse]

basically, the sustain pot controls the gain of the input stage, the ratio of the leg to ground resistance [sustain + 22k] to the feedback resistance [2M max, parallel w/ ldr + ratio]. obvs, when the led lights on signal peaks, the ldr resistance drops, and so the gain drops. the led will only ever flash, cause it drops the gain to below led-lighting-level each time it lights. leg to ground doesn't go down to DC response, cause of the cap in the leg. so if you crank [low resistance] the sustain pot, you get too much gain, and distortion - but the led lights, etc etc etc. (the second stage "level" pot is also providing gain, the input 10k resistor against the pot value, and is not a standard volume control.)

your build has a problem, tho, in that the opamp voltages aren't right. something is telling them to be not right, and it's not your guitar. when you apply 9V bias to the (+) input, the output pin will follow, and also sit at 9V. because the output has a feedback connection to the (-) input, it also sits at 9V. so pin 5 MUST always be at 9V, no matter what, cause it is connected to the middle of the two resistors from 18V to ground. pins 6 and 7 MUST follow, should be at 9V.

pin 5 is also connected to the 9V by a resistor, so when you measure the voltage at pin 5, the meter looks like a resistor to ground and adds some load, and the measured voltage WILL ALWAYS be lower than the 9V. the MPSA base also follows this rule. because the output provides a low-impedance drive and follows, and feeds back to the (-),  the output voltage measure ignores the meter loading, and so reads the full applied voltage. so if the output pin reads 9V, and the (-) pin reads 9V, it doesn't really matter what the reading at pin 5 is cause the opamp is giving the correct results, because/while you aren't probing across that resistor.

the only two points connecting to DC on the opamp are pins 3 and 5 [and supply, obvs.], and all others are DC isolated with caps. so those other pins should all follow the reference, only, now, none of yours are. so, because feck veroboard makes nothing from here to here without there there over there and around and back as well, we have to find what is messing the voltages, and where, by tracing all the tracks to all the adjacent tracks, and see what is draining all our precious bodilly fluids. I say we, I mean you.

I'll try again. remove from the board the caps 1uF in to pin 3 and out of pin 1, the 100nF [squint value?] in the gain pot leg to ground, and 1uF's in and out of pins 6 and 7. the IC is now totally isolated from the outside world, but for those resistors setting the bias. now power on [oh, and, are you sure your TL072 is good? tested working?] and measure those IC voltages again. if they aren't supply and ground, and supply/2 at pins 5, 6, 7, 1 and 2, and lower at 3, then, we need further resistance probing between traces.