Total Recall working but not quite there

[claytushaywood]

So i dont have my shop setup right now.  All my stuff is in storage for a little while.  i had a madbean member get into my total recall and bias it up.  Its now working and it sounds pretty good, but its not quite there.

all voltages are good.... but
There is a good deal more noise than a real deal DMM.  It isnt boxed up yet, but I really didnt think that could make a giant difference on a circuit that isnt high gain.  Maybe?

The guy that biased it said that there was some stuff about changing the values of r10 and r11 for the compander... however, I cannot find anything on the forum about that

He also originally said that I had a noisey compander and he replaced that when biasing the delay, but maybe to try the sa571?

It should be noted that there are now tl072's instead of the 4558's as an attempt to lower noise.  Not something I really wanted to do as I just wanted the OG DMM sound, but it was an attempt.

It sounds like this... there is definite extra noise which kinda reminds me of a pt2399 delay without enough high end filtering.  As the repeats continue and fade out it sounds like the beginning of the attack of the notes (on the repeats) are shaved off a bit.  Like as it continues to repeat the attack of the original note gets cut off.  I know there is some magic to the repeats of an original DMM, and i know what theyre supposed to sound like.  this is subtle but it is different.

Any help would be greatly appreciated.  I am almost positive there are no cold solder joints.  All caps are correct, resistors could be off but I dont even know where to start on that.  That would be a CHORE!  If anyone has any ideas on resistors that may be the wrong value that would be a great help to start from.

Thanks!!

[chordball]

Which BBD's are you using? Also, what compander is in there now? Have you taken voltages to see if you need to rebias the compander? Also, what method and equipment was used to bias the circuit? Maybe it's not quite right.

[LaceSensor]

I found a lot of trial and error to get mine sounding good, helped to have a MN3008 EHX big box to just dial it til it sounded like that

Dont be afraid to have a tweak of the trimmers, in my opinion

[czapa tranzystor 2]

I have two Total Recall (one proto) and work wery wery good with my diy power supply.Trim gain half position,maybe not good regulator? must LM7915 not 7815.
I don't now
regards

[Scruffie]

Have you read the posts about the documents set up procedure being wrong? That could cause more noise as the gain ends up being set too high.

Also, you say the attack gets cut off, in the reissue DMM this was based off there's a minor change over the vintage model, a 1M5 resistor on the expander portion of the compander in parallel with the 1uF cap, this works as a light gate, removing that might help with that aspect.

Of course if you have a resistor wrong in the low pass filters that would change the cut off frequency so you should check the values of R12-17 and R21-29.

[claytushaywood]

ill check those resistors as mentioned above.

in response to other posts.  the voltages are good.  i am using xvive mn 3005s with ne571 compander. 

whete are the posts about the original viasing documentation being wrong?

i had a forum member bias it up and he said he couldnt get it any better and that boxing up would help get it better or make it easier to bias to perfection.  is there any truth to that?

and to scruffie what part of the expander and should i try to remove?  and would that be just a straighr removal or replace something with a jumper?

thanks yall!  sorry for late replies i am constantly having trouble with email notfications.

[claytushaywood]

so I thought I had it sounding pretty dang good- but not im second guessing again- too much noise- the repeats arent as weird- but its just not nearly as absolutely gorgeous as a real DMM- it sounds good, but not amazing.

Where are the documents for the "improved" or "correct" way to bias this pedal?  i cannot find them for the life of me!

[Scruffie]

so I thought I had it sounding pretty dang good- but not im second guessing again- too much noise- the repeats arent as weird- but its just not nearly as absolutely gorgeous as a real DMM- it sounds good, but not amazing.

Where are the documents for the "improved" or "correct" way to bias this pedal?  i cannot find them for the life of me!

http://www.madbeanpedals.com/forum/index.php?topic=21643.msg214280#msg214280

[lincolnic]

I guess the build doc never did get updated.