Calling on any EH Polyphase 'builders'!

Started by analog kid, May 25, 2006, 03:36:06 PM

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analog kid

I am calling on any Polyphase builders , or anyone who may be able to answer a few questions about the circuit in context to my symptoms,  who may be able to help me out.
Firstly great thanks to Paul Nelson whose Layout and modded schem I have built my 'Phases from. He and I conversed back and forth alot during both our processes of building this project and he helped my a whole lot, great guy! I got the first Version up and going sounded great both in LFO sweep mode and Envelope controlled phasing except the LFO tick was to the point that made it unuable for most app's.  He then went to work on a new layout with extensive decoupling in the lfo's and larger ground planes, etc... to improve upon the tick... with this build is where my prob now lies.
find the layout and schem here: http://topopiccione.atspace.com/PJ17EHPolyphase.html
I had this version going fine as well aside from a fairly large vol boost and still minor tick only in sweep mode, which I couldn't isolate. I messed which a couple mods and such and somethign has happened that I can't remedy.  The ENVELOPE mode is working flawlessly. No tick , BUT the normal phasing was exhibiting a strange , sort of 'clipping' withing the sweep of the phase. Kind of a phasing Hiccup I guess or an accentuated WAH repeating once every cycle with the repat time. I didn't figure what was causing it (tried swapping the LM324, 4013 Flip Flop and CA3140 as well as different opto's)I did have square wave on both the 1458 lfo IC which I take to be the the second lfo , as well as square on pin 1 of the Flip Flop which told me the main LFO is working I guess?  THEN before I could troubleshoot that problem I lost the Phasing AT ALL in normal sweep mode.
I now have NO square wave voltage fluct. on pin 1 of the 4013 Flip Flop.   Tested all 3 Opto's again for proper light resistance and they're good.  so, And here's a  major question I have about the circuit.   The resistance should read flucuating across the outer leads of the LDR side of the Opto's to show the lfo's working as I take it at least. Well they ARE fluctuating resistance when in Envelope contolled Mode , but when in LFO sweep mode they are showing OFF Dark resistance.!! I can't figure what could cause them to be OFF in main LFO mode but ON in Envelope?     secondly are the OPTO"s used or supposed to be in affect for envelope controlled phasing at all. Which mode(s) are the opto's used to achieve effect?
I could well still have a simple problem somewhere ( ie; solder bridge) which as much resoldering I've done on this board. but I have now built this fairly complex build 3 times! And would like some more input on how / when the LFO's and Opto's function.
These Opto's are so rare and disappearing I don't wanna keep swapping them to troubleshoot this , I have already broke the led leads off two of them!!!
sorry so long , thanks for ANY help or theory on this circuit, I can be more clear on the prob in my replies
See the man with the stage fright, just standing up there to give it all his might..

nelson

The optos are working in both the sweep and env mode. No phasing would happen if they didnt change in resistance. It seems your main LFO isnt working and it was before. Check all offboard wiring esp the sweep/env DPDT, make sure no wires have suddenly snapped.  As for your ticking problem it is prob caused by long wires going to the env/LFO DPDT.

The Main phase LFO isnt working and that is your problem. Check the 4013 and the CA3140 voltages. Also check for any shorts around this area.




My project site
Winner of Mar 2009 FX-X

analog kid

Well!"speak of the devil and he just may appear"
I shouldve thought you may be hangin round here.
You're probably right about the light tick caused by wire length and placement. I can really dull it alot just by moving the Rate pot leads far away from the audio path and +15v . as for the DPDT , I had just removed my shielded 2cond wiring from it replaced with stranded single afraid that the sheilds were maybe shorting to something I couldn't see. cheap ratshack stuff!  so I never got to hear the LFO with it wired.
As for the main LFO not working right now, I will look round more but I figured as much since the square wave on Pin1 Flipflop returned back to +14v  :-*
couple questions :
Is the reason the Opto's aren't fluctuating when in Norm position now but in Env. CAUSED FROM the main LFO not functioning  correctly?  because I don't know if I pointed out , They aren't JUST not fluctuating in that mode.. they are showing Dark R' ie; 200k!   Go back to Env.mode and they begin to Fluctuate. Apply 9v out of circuit and they are all good matched around 20k , sound plausible?
and Two.
Getting back ahead of myself. Before the LFO stopped working again. I explained the weird accentuated 'hiccup' in the phase. DO you you have any idea what that may be being caused by?@! because it was the only prob. when both modes were working.! Made the phase sweep just unusable.  the Ross Flanger I have does something similar in it's sweep that I couldn't troubleshoot so I just stole the SAD IC from it. 
Thanks Man.  I will get to pokin and proddin
See the man with the stage fright, just standing up there to give it all his might..

nelson

Quote from: analog kid on May 25, 2006, 05:33:08 PM
Well!"speak of the devil and he just may appear"
I shouldve thought you may be hangin round here.
You're probably right about the light tick caused by wire length and placement. I can really dull it alot just by moving the Rate pot leads far away from the audio path and +15v . as for the DPDT , I had just removed my shielded 2cond wiring from it replaced with stranded single afraid that the sheilds were maybe shorting to something I couldn't see. cheap ratshack stuff!  so I never got to hear the LFO with it wired.
As for the main LFO not working right now, I will look round more but I figured as much since the square wave on Pin1 Flipflop returned back to +14v  :-*
couple questions :
Is the reason the Opto's aren't fluctuating when in Norm position now but in Env. CAUSED FROM the main LFO not functioning  correctly?  because I don't know if I pointed out , They aren't JUST not fluctuating in that mode.. they are showing Dark R' ie; 200k!   Go back to Env.mode and they begin to Fluctuate. Apply 9v out of circuit and they are all good matched around 20k , sound plausible?

The dark resistance of CLM8200/2 is minimum 10M according to the datasheet. Your main LFO is not functioning. The main LFO is the 4013 and CA3140. the 200K will be because the LFO is putting out a constant voltage. Check for a short.

and Two.
Getting back ahead of myself. Before the LFO stopped working again. I explained the weird accentuated 'hiccup' in the phase. DO you you have any idea what that may be being caused by?@! because it was the only prob. when both modes were working.! Made the phase sweep just unusable.  the Ross Flanger I have does something similar in it's sweep that I couldn't troubleshoot so I just stole the SAD IC from it. 
Thanks Man.  I will get to pokin and proddin

I am not sure what you mean by hiccup, sounds like an LFO problem.

You will get it working and learn something in the process. Look at the datasheets for the 3140 and 4013.

Post a list of voltages in the style of the troubleshooting sticky if you get completely stumped.

You really shouldnt be having these problems, the layout works.



My project site
Winner of Mar 2009 FX-X

analog kid

" the dark resistance of the 8200/2's is minimum 10M.."
Yes that's strange. I do remember that on the spec sheet I saw as well as reading a high dark R close to that on the first Opto's I got hold of  ;)  but It is a fact that most all from the batch I procured later that the resistance across the outers of the ldr  reads around 200k when LED is unlit.  So when I see 200k "IN CIRCUIT" I take it that's the full Dark resistance and the LEDs are not shining.     big diff between 200k and 10M huh? what gives I wonder


I believe i've just done so much tsing by way of desoldering and swapping components that I have prob done something to a trace,etc..  I will probably post the voltages of the right side IC's if I'm unsuccessful by tomorrow , but I can tell you off hand the LM324 made me suspicious in that all Voltage pins aside from pin 4 (14v) read appx 6.7-7volts. (12356789 10 12 13 14) IIRC when I had the lfo and both modes working right some of those pins had higher voltage than the 6.6v pins. ie; how many /which pins should be at 6.6? are the LM324 and 1458 NOT part of the main LFO?
See the man with the stage fright, just standing up there to give it all his might..

nelson

The LM324 and the 1458 are part of the Env section.


It is switched out in LFO mode.

If there is no voltage fluctuation on pin 1 of the 4013 check all the surrounding components including the transistors. If it was working before its either a short, broken wire, lifted trace, cold solder joint etc.

My project site
Winner of Mar 2009 FX-X

analog kid

#6
  Ok I decided to post the voltages. I have got both modes functioning , it wasa prob with a lifted trace that I was sure I fixed , the real skinny one on CA3140 connected to "E" and Pin 6.  I am however still stuck with the repeating 'hiccup' in the lfo phase at the end of each sweep. see below   I am sure it's an lfo prob still but WHERE hope this helps you help me.
4558(top dual, all apprx same )
7V
7V
5.7
0
5V
6.5
6.8
14.1V

1458
1 / Square wave 4-7fluc?
2/ 6.6v
3/ fluc.
4/0
5/6.2
6/ 6.2
7/ fluc
8/ 11.5

LM324
1/ 6.7
2/ 7.8
3  6.8
4/  14.2
5/ 6.6
6 7.8
7  6.5
8  6.7
9   7.8
10  6.7
11 0
12 6.6
13  6.7
14 6.8

CA3140
1/ 60mv
2/ 7.5v
3/ 7.1v
4/ 0
5 60mv
6/  6.7v
7/  13.5
8/    8v

Flip Flop
1/  The readings on pins 1,4,6 are strange. for pin 1 I get 7.8v with RATE ccw every time. but when RATE is up to CW I get either 13.8v OR close to 0. very strange I'd figure a short to ground or something but the way the RATE controls vltg....? ???
2/ "pretty much the same as pin 1'
3/
4/ again this is strange w/ RATE off vlt is 3.8v as soon as rate is turned off of ccw vlt goes from 3.5 down to .5v in about 1/10 of rotation stays .5 all the way CW.
but it is .5v always when DPDT is in Env.
6/   appx 2v w/ RATE CCW when turned from CCW vltg drops to .06v
env position vltg reads either .06 OR 11.65v !! short?bad transistor, diode??what gives with this?
7-11/  0
13  13.4
14 13.1
     sorry if hard to follow. the Phasing IS working as well as the envelope section but obviously I;'m still stuck with the odd sounding hiccup at the end of each phasing sweep.  . If set glacially slow it happens just every several seconds , if fast.... " but Always falls at the end of each complete sweep just before it repeats (sort of like you're sweeping a big WAH real quick at the end of each phase sweep)
guess I'm safe to say that this prob is related to something in the flipflop ie; the odd vltg activity on the square wave pin of and other pins of the Flip Flop.  Yes?
ALSO I should note that I had swapped a .1A regulator  in for my 1Amp cause I thought the vltge had dropped from 15v ,have always been getting real warm on this  ??? well I felt the little .1a getting stinging hot on those last flip flop vltgs so I checked the out vltg before disconnecting and to my surprise had dropped to 13.5!! checked again w/ new reg and got the same behaviour on the 4013. but  
why might my reg's be getting too hot and weak in out V.? the 1A I've used in circuit seems to have weakened to 14.7 over long time so I'll keep it in there
.
    THaNKS SO MUCH
  Edit: 
maybe I should reheat joints on filtering caps and all those decoupling caps as there are so many , as wooley suggested his problem with the hiccup in the sweep?
See the man with the stage fright, just standing up there to give it all his might..

woolley

Hi analog kid,
i had a hiccup in my small stone a while back. sounds quite like what you have. wheather it is or not i don't know...
anyway, i also thought it sounded a bit weaker than it used too. the problem was one of the filtering caps had come loose (mounted on a switch for the univibe thing). it would go up up up over down down down round up down round up up up up
so maybe check that..?
good luck

analog kid

#8
ok! I haven't updated you on the problem cause I wanted to take the time AGAIN to triple check everything once I posted those vltgs and saw the strange act. on the FlipFlop.
well wooley was right ON about the cause of the "hiccup"! I looked right away at all filtering and decoupling caps and there was a problem w/ a trace I thought I fixed on the 220uf used to decouple V+ to the Flip Flop  ::)    Yes it's usually the builder/operator, not the design
  So that was the DEFINITE cause of that strange accentuated hiccup at the end of each sweep. Thanks Woolley

So ALL Is working, No tick in Envelope mild in LFO sweep (shielding may be enough)  ONLY  probs are the Oscillation AT the end of RATE pot where the speed is fastest.  as Paul remembers, It goes into a pitch controlled oscillation in just that last little rotation.
SO  Paul , you mentioned before not to concern too much w/ it and that you' d come up with a fix for this if required.(component change, tapering resistor..)  Wondering if you ever found that this was isolated to MY build or that  you did  encounter this problem.  Secondly...and making me think it may be MINE ONLY.   Looking at those odd voltage changes happening only when the RATE is fully on/off? at Pins 1 , 4, 6 of the Flip IC... I checked and that still occurs and....
those voltage changes that I listed when RATE pot was CCW are 'changing' right as soon as that oscillation kicks in!!?
coincedence or tip for troubleshooting the oscillation prob?   ONLY bear in mind the oscill. and  vltg change  I listed as CCW is the FAST end of the lfo  regardless of pot orientation.
-  Square wave on Pin 1 , freezes at 7.6v   when oscillating
- Pins 4 is .54v unil rate pot is full fast and oscillating then jumps 4.5v
-  Pin 6 is .06v "                         "  then jumps immediately to 2v
    this is all w/ DPDT in normal Sweep mode , Pins 6 goes to 12.87v switched to Env.
 
this may points something out
There's also still a fairly big volume boost w/ effect on that I've not been able to find a cause for but I just put a trim on the output.  It ended up taking a 500k turned all the way to get a UNITY gain with bypass.   I wonder if this will affect anything negatively all I notice is maybe a tad bit of highs loss from the trimming down. make sense? If so I wonder if the same resistor/cap trick on a guitar Volume would achieve the same retaining of highs at 'lower volume' ie; trimmer position??
Thanks for the assistance
See the man with the stage fright, just standing up there to give it all his might..