Flintlock Flanger not Sweeping

[duck_arse]

At this point I would suspect a mistake with some component value, .....

.... desolder every capacitors and resistors from this first build, measure them carefully before resoldering them with extreme caution on a brand new board.

don't make me type, it hurts my back.

no sir, you can't have both, either good components on the old board, or ALL NEW components on the new board. it makes no sense to wave your hand over the old board, no matter how much you re/test the parts, and say they are right for a new build. not to me, anyway.

I'm afraid I didn't look all [only the last] movies - that would have been my download allowance for a month! sorry.

I was thinking again about finding where this is going wrong, thought it migh make sense to pull all the ICs outta the sockets, and then fit just the oecillator and voltage refs section, see if they are sane or not. then you could add the 4046 or whatever it is, see what happens.



owwww.

[matopotato]

I'm afraid I didn't look all [only the last] movies - that would have been my download allowance for a month! sorry.

No worries, not much to see anyway I think. If I find something interesting I might try again.

I was thinking again about finding where this is going wrong, thought it migh make sense to pull all the ICs outta the sockets, and then fit just the oecillator and voltage refs section, see if they are sane or not. then you could add the 4046 or whatever it is, see what happens.

I take it the voltage refs are the 7815L (IC7) and the LT1054 (IC11).

Pardon my ignorance: I've tried to figure out which one works as the oscillator and some posts point at IC4 LM1458, but it is an op-amp. Or oscillator is perhaps not an IC as such, but what an IC can be doing.
MN3007 IC10
CD4049  IC9
CD4047 IC6
CD4007 IC5
are the other options I think.

If I pull all the ICs out except the power stage ones, will there be any signal processed at all? It seems some of them would out would cut the circuit.
Or should I keep the 4558s in all the time? I have a vague memory of pulling one and the signal went all silent...

[pacealot]

That was probably IC2, as I remembered that it generates (or rather buffers) VB, which is required by IC3 and IC12 as well as the JFET. When I was first testing the voltages on mine, I had all the chips out except the LT1054 (which I ultimately ditched to run it at 18V) and the 15V regulator IC7, and I was very confused about why I wasn't getting a Vref of 7.5V until I realised that!

You might be able to test the oscillator section without it, however — that might be beneficial for troubleshooting, or possibly not...

[duck_arse]

Pardon my ignorance: I've tried to figure out which one works as the oscillator and some posts point at IC4 LM1458, but it is an op-amp. Or oscillator is perhaps not an IC as such, but what an IC can be doing.

don't make me type! opamps is building blocks. make a outhouse or an airport runway, just depends how you lay them out. the three pin voltage reg is an opamp configured just so. an oscillator can be an opamp schmitt trigger to say "on" now, "off" now, followed by an opamp integrator to say charge up, charge down. or a comparator, or a reference - is the output higher than the input? etc. or, even, you can amplify a signal with! filter with! buffer, even.

in the flintlock, IC4 IS the oscillator. but it needs a Vref, which is derived via IC2. that is fed from IC7, which regulates what IC11 generates. so those are all you need to test the oscillator for whether it oscillates or not.

IC8 messes about with voltages to provide stuff to the cmos 4007, which feeds the phase locked loop cmos 4047. that provides yes and no outputs, which the 4049 cmos buffers/inverts tb drive the IC10 bucket brigade correctly. and that HUGE mess of opamps across the top of the circuit are amplifiers, filters, mixers, rectifiers, choppers and god knows whatall, but they are all just opamps.

you don't need any part of the audio chain to test supply and oscillator function.

[matopotato]

Pardon my ignorance: I've tried to figure out which one works as the oscillator and some posts point at IC4 LM1458, but it is an op-amp. Or oscillator is perhaps not an IC as such, but what an IC can be doing.

don't make me type! opamps is building blocks.

Sorry. I did try to google, but i didn't feel I got any clear answer. So I asked. Now I know this piece of information and I am thankful for it.
In my ignorance I thought op amps were "just" amplifiers. It seemed the most common use of them I had encountered thus far, and I took the name as a definitive hint.
I will use them for my next shed for sure (assuming shed count as outhouse. Sort of)

in the flintlock, IC4 IS the oscillator. but it needs a Vref, which is derived via IC2. that is fed from IC7, which regulates what IC11 generates. so those are all you need to test the oscillator for whether it oscillates or not.

OK, so I pulled all the other IC out. (Kept the transistor though). And then I wasn't sure what to do. The signal went out of course so the thumping noise was no longer there. So I measured everything again. See separate post.

you don't need any part of the audio chain to test supply and oscillator function.

OK, let's hope measuring the pins will tell something.

[matopotato]

I pulled out IC1 IC3 IC13 IC12 IC8 IC5 IC6 IC9 and IC10
I kept only IC2 IC4 IC7 and IC11

IC2
5.01
5.01
5.00
0.0
7.44
7.44
7.46
14.88

IC4
5.86-8.06    14.85
8.15           7.93-8.56
7.20-8.06   7.46
0.0             7.46 
(I am guessing the variations on pins 1,3 and 7 are the oscillations)

IC7
15.10
0.0
17.95

IC11
0.0      9.5
4.62    6.49 (Squealed when I measured it...)
0.0     3.55
0.0     0.0
I thought it would produce around 18V somewhere, but the IC7 gets its 17.95 anyway. So I might have missed something, but I measured twice the IC11


And just for the archaeologists or good measure while the DMM was all fired up: (none of these have anything in the sockets so no pin measures, just socket measures)
IC1
From 7-ish to around 0.6 steady drop, but slower and slower
same as above but from 7 to 0.58
6.79
0.0
6.68
7.35
7.39
14.88

IC3
7.20
Dropping when measuring but recovers when not. Sort of stable at 6.38
7.41
0.0
7.46
7.19
7.21
15.09

IC5
0.0   15.10
0.0   0.0
0.0   0.0
0.0   0.0
0.0   0.28
0.0   0.0
0.0   0.0

IC6
0.0     15.10
0.0     0.0
0.0     0.0
15.10  0.0
15.10  0.0
15.10  0.0
0.0     0.0

IC8
7.29-7.96
4.48-7.70
4.11
0.0
6.04
1.71-1.86
0.29
15.09

IC9
15.10  0.0
0.0     0.0
0.0     0.0
0.0     0.0
0.0     0.0
0.0     0.0
0.0     0.0
0.0     0.0

IC10
14.96  14.82
0.0     14.82
7.39   0.0
1.02   0.0

IC12
7.46
7.43
7.46
0
7.46
7.46
7.43
14.85

IC13
7.39
7.41
7.46
0.0
7.37
7.45
7.45
14.88

As I put the ICs back into circuit, I removed some of them one at a time and turned the pedal on. Probably not bringing any clarity to the problem, but here it is anyway:
IC10 out, there is still the thumping although at a much lower (overall) volume level
IC9 out, there is less thumping, but still there
IC6 out, pretty quiet.
IC5 out a squealing noise so not able to tell anything about the thumping.

I did something similar with the other Op Amps but it was sort of inconclusive or obvious. Removing one and it went pretty quiet.

There is one kind of thumping that is almost "always on" at a slower pace. But the noisy one is at a faster pace and the on I am referring to above.

[duck_arse]

sorry, I wondered about this in the interim, I should have said that having only the oscillator and volts stuff was ONLY to confirm the oscillator workings. none of the audio section will be of any use. you should apply your oscilloscope to the osc opamp output pins, 1 and 7, and one SHOULD show a square/pulse wave, and the other a triangle/leaning saw wave. work those nearby pots and observe the effect.

and that jfet - what type number is it, where did you get it? have you had all the IC's in before but removed the fet at any stage? I'm wondering if the thump stops if just that is missing from circuit.

[matopotato]

sorry, I wondered about this in the interim, I should have said that having only the oscillator and volts stuff was ONLY to confirm the oscillator workings. none of the audio section will be of any use. you should apply your oscilloscope to the osc opamp output pins, 1 and 7, and one SHOULD show a square/pulse wave, and the other a triangle/leaning saw wave. work those nearby pots and observe the effect.

No worries. I understand the audio would be out, but since I had everything up, I thought I'd might as well measure just in case someone would ask.
The scope next. IC4 pins 1 and 7.
I got a mind fart and measured pin 8 as well, and it shows an interesting pattern, on the other hand I had to increase the sensitivity a bit to see it, so it might not be relevant at all.

Pin 8




Pin 1 (Quite square IMHO)


Pin7 (And quite sawtoothy, also IMHO)


So if this was the task to check, I'd say the oscillator is doing its job.
Now, I did not remove all the other ICs this time, but since the shapes were already as you described them I thought this would be good enough for a check.
Of course I'll re-do it with the ICs out as prescribed, just type the word.

and that jfet - what type number is it, where did you get it? have you had all the IC's in before but removed the fet at any stage? I'm wondering if the thump stops if just that is missing from circuit.

It is 2N5457. I got it with the kit from Das Musikding. I understand they are hard to find, but so far their kits have had the parts they say it should. I have right now a something else temporarily an SMD that was supposed to be equivalent. Not sure which one in the end. Marked W6D or o space and then U but googling it does not bring back any memories. So I skipped it for the original one 2N5457.
There is no effect to the problematic thump if it is in or out. Seems the Flanging is not affected either strangely enough. I would have expected it to have some impact.
I had a BF244A to try with as well (different pinout), but same thing. No impact to the flanging or thump with it in or out same as the original  one.

[duck_arse]

pin 8 is DC supply. and what do we know about DC supplies? yes, that's right - they should look like a flat straight line.

what sensitivity setting are those pin 8 pics at, and is yours a 10:1 probe? the supply to an osc will hop about with each state change [as you will discern from the timebase settings matching], but if too much hopp, trouble.

[matopotato]

pin 8 is DC supply. and what do we know about DC supplies? yes, that's right - they should look like a flat straight line.

what sensitivity setting are those pin 8 pics at, and is yours a 10:1 probe? the supply to an osc will hop about with each state change [as you will discern from the timebase settings matching], but if too much hopp, trouble.

Peaks around 25-30mV
In comparison to 9V it ripples around 0.3%
It does not sound like the root cause of the problem to me.
I realize now it was all probably irrelevant and had been better left out.

Not sure what to try next.
There are some pin bendings left if I remember. Will try that.
But if the square an tooth look OK for IC4 thus far, what could be the next thing to try?
I have swapped by now I think all ICs and FET for other ones I have, or equivalents.
Except for the BBD MN3007. But so far I felt the thumping was still present even with the BBD out.
Will recheck.

[matopotato]

I ordered a new 4558L to test around with. Will see if that reveals anything.
I was wondering if a broken Electrolyte cap in the power section could be causing the thumping? Or be part of the problem.
Is there any way to check that without desoldering/replacing them?
I poked a bit with the DMM and any values I get are just useless since they are in circuit. The fact they have minus direct to ground does not change that. I guess when caps are in there is not much an old DMM can do.

[duck_arse]

use the cro, Luke. and by cro, I mean oscilloscope, just in case. probe IC2, which should have nothing but DC voltages, see if there is any pulse or poit or glitch. probe IC8, half will be DC, other half will be DC shifting about with the oscillator mixed. probe IC7, it should be DC, no glitches. probe VA, probe VB, probe VC, should be clean and flat.

listen to the thump and watch the oscillator output on the cro. does it follow or is it something different? if follow, you need to find how/where it gets into the audio - if not follows, you need to find where generated. I don't envy you the task from this distance.

[matopotato]

I am trying to probe around with the scope.
I have an almost flat line on IC2 pin1 but it shifts up and down with the rhythm of the flanger thump wobble.
Top to bottom is about 20mV to 35mV. Trying to get the shape on screen makes thw sweep so slow that i get the dot rather than a curve which is harder to determine its shape.
I can imagine a hint of a ripple on the DC might happen if adapter is not perfect. But  hanging to battery made no difference.
So since IC2 wobbles with the flanging I tried the IC11,
And on pin 2 I get a strong square wave. On pin 7 a forward leaning saw tooth., and an audiabke squeal.
I thought the IC11 was pure DC, so surprised to see those shapes there. On IC4, the oscillator makes sense.
So it would seem to my untrained eye as if the circuit was "leaking back the signal" to IC2.

IC8 same as IC2, and pin 7 with amplified signal same as IC2.

IC7 also a flat line that wobble sup and down, as if the flange-thump is superimposed somehow.
So following the DC in, it is quite flat and non wobbly until the junction of D8 and C33 where it is a square wave with fixed bottom(s) but the tops wobble with the flangethump.

Same for VA VC VD and VR.
I am not sure if this is wrong or not.
IC11 again.
The C37 is omitted as per build instructions, which would have pin2 the only feed to C33. Pin 8 is nice flat DC.

I got a new fresh spare 4558L and I swapped current IC2 for it. There might be a sloght difference in the wobble frequency, but could well be my mind playing tricks with me.
I let the new one try all 6 4558 locations, but nothing changes.

I have already tried a different 1054 IC11. Could D8 be part of the problem?
Can I test by hooking up another in parallel or do I have to desolder the old one?
Unless it is a futile test of course.

Feels like the Apollo 13 trou lesgooting rescue or the air scrubber was easy peasy in comparison. But the stakes were a bit higher...

[duck_arse]

the Apollo 13 trou lesgooting rescue

trouserleg? what now?

now as you know, I can't have the build docs, because they kill my computer, so what do they say about C37?

I know not much about the charge pump IC's cause I've never used one, but waveforms on their pins will be oscillations of various types until after the diodes and smoothing caps, so at D9/C34 is should be flat flat flat DC.

Same for VA VC VD and VR.

well there's yer problem. if the "15V" is not thump-free, then VA,C,D,R will all be transmitting carp to all the audio biases. and that can't be good.

back to taws, then. and if this all hinges on that bloody C37, you are in BIG trouble. pull all the IC's out,  all the IC's out, except IC11 and IC7. test for flat and clean on the input and output of the IC7, which will "clear" them for the moment. if there is any thumping or ripple on the IC7 out, you have bad IC's there. you might try loading down the +15V with a 1W 330R or 390R to see what effect it has on the supply. otherwise, put the IC2 in, see if the VA,B, etc start thumps. if not, put also IC8 and search for thumps. if none, put IC4 in as well, see if any thumps.

or - put IC2 in, test for thumps. then add in some of the audio sections, IC1 or 3 or 12 or 13, and see if they have any thumping pins. put those four in and see if there is any thumping. then add the IC4, see what happens.

urgh. flintlock. carefull when you stir the cryo tanks.

[duck_arse]

The frequency can be increased by adding an external capacitor (C2, Figure 12, in the range of 5pF to 20pF) from Pin 2 to Pin 7. This capacitor will couple charge into CT at the switch transitions, which will shorten the charge and discharge time, raising the oscillator frequency.

from the TI LT1054 datasheet. so, what harm can it do? try tacking a ceramic cap from pin 2 to pin 7, 22pF will do, and see what happens.

[matopotato]

The frequency can be increased by adding an external capacitor (C2, Figure 12, in the range of 5pF to 20pF) from Pin 2 to Pin 7. This capacitor will couple charge into CT at the switch transitions, which will shorten the charge and discharge time, raising the oscillator frequency.

from the TI LT1054 datasheet. so, what harm can it do? try tacking a ceramic cap from pin 2 to pin 7, 22pF will do, and see what happens.

So a 22p at C37 makes the thumping audio louder. The squealy additional sound I got/get from probing IC11 pin7 gets audiable throughout (without probe), so imho it made things worse.
With 22p in and probing pin7 the frequency of the squeal changes to lower and sawtooth seemed to hav higher amplitude.

Congrats to the Ashes btw.

[matopotato]

the Apollo 13 trou lesgooting rescue

trouserleg? what now?

Yes, trou lesgooting is Svedish for causing more trouble than you resolve. Or it means the keyboard on mobile phones was not designed for people with normal sized fingers.

now as you know, I can't have the build docs, because they kill my computer, so what do they say about C37?

The have it in the BOM saying "OMIT" and in the schematic it is listed with 22pF. I did some 22pF testing see previous post above.

I know not much about the charge pump IC's cause I've never used one, but waveforms on their pins will be oscillations of various types until after the diodes and smoothing caps, so at D9/C34 is should be flat flat flat DC.

Same for VA VC VD and VR.

well there's yer problem. if the "15V" is not thump-free, then VA,C,D,R will all be transmitting carp to all the audio biases. and that can't be good.

back to taws, then. and if this all hinges on that bloody C37, you are in BIG trouble.

Somehow I feel that I am. Regardless.

pull all the IC's out,  all the IC's out, except IC11 and IC7. test for flat and clean on the input and output of the IC7, which will "clear" them for the moment. if there is any thumping or ripple on the IC7 out, you have bad IC's there.

I'd say all others out, then it is nice and flat.
The IC11 pin 2 shows square-wave of 80ms period and just over 0.8V peak to peak

you might try loading down the +15V with a 1W 330R or 390R to see what effect it has on the supply.

Not sure how to do that, connect the R to ground?
I have no 1W Resistors either only 1/4W ones.
I have a bunch of 70's resistors, but no idea of their wattage. They are probably carbon. Old and brown and vintage.

otherwise, put the IC2 in, see if the VA,B, etc start thumps. if not, put also IC8 and search for thumps. if none, put IC4 in as well, see if any thumps.

IC2 in, all is well.
IC8 also well
IC4 probably OK. There is a slight wobble on VA, pin8. About 2mV. The "flat line" does this wobble. On the line are also tiny peaks, very short and perhaps 4mV from flat line to its top. Looks like ----^------

or - put IC2 in, test for thumps. then add in some of the audio sections, IC1 or 3 or 12 or 13, and see if they have any thumping pins. put those four in and see if there is any thumping. then add the IC4, see what happens.

OK, removing IC4 and doing 1,3,12,13
As I put one of them in the V:s check out flat line. Repeat for 1,3,12,13
Then IC4 and it is still flat I would say, with a tiny hint of wobble on all of them, but it is around 2mV or less. And no ^ as I could see

urgh. flintlock. carefull when you stir the cryo tanks.

So trying the remaining ones.
With IC5 (4007) out there is a loud squeal.
With IC6 (4047) the wobbling is about as gone as with them all out.
EDIT: not sure what I meant above. But IC6 seems to be the common denominator for the wobble to appear.
I tried with removing IC10 and IC9 respectively and the wobble seems to appear with IC6 in.
I had another 4047, so I swapped, but the problem is the same, so I doubt it is the IC itself. In the other pedal the 4047 works and does not cause any unwanted noise.
But I have no idea if it is actually significant or if something close to IC6 could be the cause.
I should mention that the wobble with IC6 in propagates over to IC11 and the square wave that was stable does wobble like the other places.

There is one difference between the schematics and the actual PCB wiring, The C-RANGE trimpot to the left of IC5 and IC8.2 has pin 2 drawn to R52 and VC IC8 pin8, but in reality the C-RANGE pin2 goes straight to pin3 and R54.
I didn't figure this was anything since the PCB is as it is. I would suspect a misdrawing of the schematic over a misprinted PCB for only my case.

I have tried probing the signal path before and I ended up with soon after IC1.1 and I think the Diode square, but hard for me to say where the fed back signal joins in with the clean.
Might try one more audio probe to see where it goes, but I doubt it would clear anything up.

[matopotato]

Here is the intended home



If nothing else, it is a picture. And some of you like pictures.

[matopotato]

I did some audio probing again.
I find four states: No sound, Clean sound, Flanging with the thump-wobble and Some faint rudimentary flanging where any thump or wobble is hard to tell if it is there or not.

The clean audio is there until and including the junction of IC1 pin1, R4 and R9. Also until and including IC3 pin 3.
The Flanging with thump-wobble begins at the other side of R9 (jct with R10) including the D1-4 diodes. Also at the Drain of Q1.
Where IC3 pin1 and R17 meet there is sound with rudimentary flanging. Also at R22 and R21 junction.
The No Sound (or too faint) is R16 R17 and IC3 pin 2 junction. Including the Threshold pot.
I did a bit of random poking on the other pots but most of them were silent, (except Enhance) so that might be a case of me probing wrong since there is signal on the OUT and the pots turning affect that signal, so they are doing something in the signal path.

I somehow doubt this brings any clarity to the source of the problem.
My current guess after attempting the suggestions form duck_arse as per above is that the power section is OK.
But at some point when all is in place, it get affected "back" somehow.
The ICs 1,2,3,4,7,8,11,12 and 13 seem to be doing ok when it is only them.
When adding the "Flange producers" IC 5,6,9 and 10 the problem is introduced, and IC 6 seemed to have the bigger impact although swapping it for another 4047 did not change anything.
Measuring around IC6, although all parts are already "in circuit" I do get pins 4,5,6 and 14 at around 15V (slight swing between 14.5 to 14.7 though). I get ground connection to 7,8,9 and 12.
pins 2 and 3 have 2M2 between them corresponding to R58.
Pin 3 and IC5 pin 11(?) har 47R between them corresponding to R57.
But pins 1 and 3 show 180p and trying to reach C26 legs, same thing. I am aware that this might mean nothing since it is a cap in circuit. Also my DMM is not the best on small caps. Still, is 180p measured vs 27p in schematic something I should try and swap out?

[matopotato]

I have no 27pF around, but I have 22pF. Does that mean I should up the R58 to 2.7M? (2.2M * 27pF = 2.7M * 22pF).
Or better try to get hold of 27pF.
Unless of course I am wrong in that the Cap could have been broken-ish.