A/DA Flanger does TZF?

[moosapotamus]

analog kid - I don't really have any additional insight on your IC1 questions, either. But, I am really glad that you've taken on the challenge and are posting all your findings. Great stuff. Thanks!

Also... Grip, and anyone else - I'm glad to host any additional ADA stuff that you've created. Send it my way and I'll add it to my ADA Flanger page.

I'm hoping to be able to steal enough time to finish up my layout this weekend. 

Thanks!
~ Charlie

[Gripp]

More info: It looks like we'll soon have a public schem of the flanger, scroll down to the October 28th update
http://www.adadepot.com/.
The links don't work now but maybe they will if they're serious about making them free for download.
/Pelle G

[StephenGiles]

Blast, I squandered $2.50 on those circuits

[Dave_B]

Blast, I squandered $2.50 on those circuits

Same here.  I'm not sure why he's making them free.  It was one of the better schematic deals, IMO. 

[analog kid]

Thanks Gripp for chiming in on this and explaining the Revision combo being used here!
 

I have no idea what your problem might be with IC1B apart from an error in the pcb layout. Have you tested "as you build" as I did or did you just stuff the whole board first ?

Nope, I just very carefully poplulated the whole board, then checked it against the layout and schems for errors and bridges from the etching then went to town! Disconnecting the Gate after all was populated is the most sectionalizing I've done and I'm gonna reconnect it now I think.  I'd sure hate to work backwards diconnecting section by section now and hope I'm not needing anything too drastic  but Is there Anywhere you'd recommend me measuring/probing to check that any section is working optimumly? I'm not using a scope btw. I have to say ANY advice and help from you is more than appreciated here , and all others for that matter.
  Do you believe though that it IS a problem in IC1b based on those voltages or the audio probing results I tried to describe?  I'm just not smart enough to know if in fact those pins 5,6,7 ARE supposed to be behaving in such a way when probing signal.
  see I am getting good hot flanged signal from it now , seems very close to working right.   In fact the only issues I am having seem to be that in Auto the sweep is very abrupt and uneven when at Faster speeds. ( I don't know if some more extensive biasing could be done or some more precise trimming.... Or if it's result of an actual problem)  And the problem that I would think is the result  IF there's a problem in IC1... a problem with the ENHANCE controls....
  Concerning ENHANCE, Regardless of (T2) enhance trim's setting I can't turn  Enhance up past 1/2-3/4 without going into full blown FB!!     Shouldn't  I be able to calibrate (T2) to allow the Enhance to be turned up without causing this? So long as T1 is within "bias range", Enhance can't be turned up!! I've tried minimizing it by tweaking other (clock) trims but as long as T1 biased , the Enhance can't be turned up regardless of any other settings.        Mind you this is something to work around by tapering the pot to the useable range of Feedback but if it's due to a problem elsewehere.....

OT:  Can't help but think the reason for those Schems,etc...going to FREE has alot to do with the thread about them awhile back : )  Eeek! $650 , those were some expensive factory doc's but I believe it

[StephenGiles]

Could be an error in the feedback filter.

[puretube]

I never liked un-de-coupled combined biasing of BBDs and surrounding opamp-circuitry...

[Gripp]

Care to expand PT?
The way i see it only the preceding opamp stage and the BBD share the adjustable bias in the rev3. The following opamps are all on the buffered 1/2 V+ bias line.

I just don't get the feedback loop and diode limiting in the rev3 schem, the feedback being introduced on the buffered 1/2 V+ bias line and the diodes being ahead of the feedback control.
I do get that this bias line essentially is ground for ac signals so it is a diode to ground clipper, but I don't see how it relates to the feedback line.

Best!
Pelle G

[puretube]

I`m looking @ the schemo in reply#7,
and to me it looks like being passed towards IC2b

[Gripp]

Ok. Then we have to wait for the public rev3 schem. The one in reply#7 isn't the one we've been building from.
Thanks anyway!

[Gripp]

Oops!
Spoke too soon.
The dry/wet mix (output) opamp (here also IC2B) is indeed getting bias from the bias trim in the rev3 too, passed from opamp in front of BBD (IC1B) along the dry line.

[analog kid]

 I'm glad we've got these bright minds here thinking about this. I've faith it'll get sorted out for sure now.

just don't get the feedback loop and diode limiting in the rev3 schem, the feedback being introduced on the buffered 1/2 V+ bias line and the diodes being ahead of the feedback

I don't get the way this setup works either, OR why it's the only version that it's configured this way. It makes me wonder what would happen(surely couldn't hurt) if I was to try and change the diode limitiing/FB loop to the setup used in other versions? Since it's connected directly to the area of the circuit and IC that I'm having some issues with it does make some sense to consider IMO. but what do I know.   I also bring this up because I distinctly remember reading a post ( I can't find it now but think it was older) where it was said that the early Rev and Rev 4 FB/diode setup seemed to work better for some reason.   This could stand to reason since it looks like it's the config they started with , attempted to change it in Rev 3 , then went right back to the original setup for Rev 4. 
I am really kind of stumped on the problem with T2 not letting me  adjust ENHANCE pot control range to let it be turned up high , unless it's being caused by something wierd about this configuration?
Again I am getting flanging and really beautiful flange tones as well as some nice chorused sounds at slow speed settings. But at any substanial speed it's obvious that the Sweep is extemely uneven (detuned and abrupt ) I also remember reading Steven where you had a problem with very uneven sweep at one point, though I'm aware the cause could come from many areas.
  I did try raising the value of C28 connected to Pin 9 LM324 from .0047 to .1uf  as suggested in the Irwin schem to see if it smoothed it out but to no avail.
??

[puretube]

I can see rev3 schemo on moose`s site, but I can see no part values...
where do you get them from?

maybe "enhance" is 100k?

or just make "enhance-trim" larger?

[Gripp]

Just discovered that Moose has them all up on his website. It's in a zip but anyway.
http://moosapotamus.net/IDEAS/ADAflanger/ADA%20Flanger%20Archive.zip
In here there are both schem and partslists.

The partslist is the HTML file made by Bill B during his tracing of the ADA (is for rev3).
Some errors in the partslist, R32 and 33 changed to 22k, IC3 should be LM324 and Q1 is most likely a 2N4393.

Now in the one we're working with, only the audio path and CV/LFO is from rev3, BBD and clock is from http://moosapotamus.net/IDEAS/ADAflanger/ada_MI_1024.jpg
The problem seems to be somewhere in the audio so.

Thanks for looking PT, it really means alot and is a great opportunity to actually learn something!

[analog kid]

if you opened up the zip archive ( ADA Flanger Archive . zip ) scroll down halfway to the ada.html parts list file, this contains part #'s and values for the version I'm working with, just BEFORE changes to incorporate the SAD.so the whole audio path at least should match what you're lookin at Rev 3.
  I'm sure it's possible that the Enhance pot could be a different value,as I've not gotten parts values for other ADA REV's. 
But just in case I didn't explain the behavior well, the way the Enhance control is working now, It is going into full blown feedback at least 1/2 rotation even if it's trim is down fully ccw. don't know if i"m seeing it right on the schem but  larger values for these pots wouldn't give even more avail FB?  sorry if I'm confused and misunderstood 
Frustrating thing is the Sweep problem, Feedback can be used at least!  just too much too early in rotation and can't trim back,   The issue I'm most concerned with is the sweep, I'm so far from a smooth sweep right now , it's sounds more like an ATARI game effect! haha      There has to be something I can look for in the LFO to tell me what's  causing the sweep problem, without a scope.  Obviously problems with IC1 wouldn't be causing the sweep issue(would it?)  There's a 13.9k that M.Irwin has added with decoupling cap off pin 9 of SAD, that struck me as an awful precise value and I used a 14k, no reason would need be exact is there? just lookin for anything that I may have caused in my build.   IF the sweep would smooth out on this thing I'M THERE !!!!
ALSO : 
I found the quote about diode limiter configuration (which I mispoke on earlier, this layout is setup like Rev 3 already, Rev 4 is as shown in the Irwin/Giles schem. and I don't know how rev 1 and 2 are , which gets back to this quote FROM Steve Giles btw..)

I think at Mike's suggestion I replaced the diode network on the input with the simpler limiter network on one of the earlier versions. Good luck.
Stephen

Do you happen to remember what the configuration was (like Rev 3 , 4 or different than either) , or what the intended benefit Mr. Irwin recommended it was? I am very curious about this.

[puretube]

looking at a "revx"-schemo, searching the parts in a "M.I."-mod by "S.G.", looking up the values in a "B.B."-html in a "M"-"zip" makes me mad...

enuff window-hopping  

[Gripp]

Totally understandable. Things will get better.
I'm in a state of madness where "looking at a "revx"-schemo, searching the parts in a "M.I."-mod by "S.G.", looking up the values in a "B.B."-html in a "M"-"zip" actually sounds like a perfectly sane, coherent and understandable statement

[puretube]

all for a non-obtainable chip... 

[analog kid]

Oops   Gripp beat me to directing where you can find the parts list while I was typing forever! And once again, did a much better job explaining the particulars than I could / wink : )
Yes thanks so much for taking a look at this purtube, Steven....etc..  and yeah sorry about directing you to a never ending supply of windows to open and close !!  Of course I have all this stuff printed and you couldn't imagine the awful mess and paper juggling I've been performing the last week or two. Aarrghhh

[StephenGiles]

.....and all the while the seasons outside are changing, wives & girlfriends get angry with the amount of attention given to the holy grail of flangers and not to them, bags are forming under eyes.........