Author Topic: Madbean Total Recall question  (Read 374 times)

ckim715

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Madbean Total Recall question
« on: February 12, 2019, 09:09:30 AM »
Hey all,

I built a Total Recall and biased it per the revised instructions (pin 7 and 14/15 of the V571 for Gain 2). It works but...it just doesn't feel right. I can get self oscillation, but that's not until like max feedback. I only get one or two repeats until the feedback pot is at the halfway mark. Any thoughts?

On top of that, I feel like the repeats are very...abrupt? Is that normal? The only other analog delay I have to compare to is the Aqua Boy I built, and the repeats seem much more organic.

Thanks all1
-Charlie

teknoman2

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Re: Madbean Total Recall question
« Reply #1 on: February 13, 2019, 07:10:33 AM »
Post your voltages of the compander (v571).
You should have -4.7 volts on pin 7 of V571 and -13 volts on pin14 & pin15.

Gain 1 and Gain 2 trimmers affect the repeats.
If everything looks right, check the resistors after the compander till the FBK pot (r12,r14,r17,r19,r21,r25,r26,r27,r32,r33).
Cheers,
Panos

ckim715

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Re: Madbean Total Recall question
« Reply #2 on: February 14, 2019, 06:31:11 AM »
Thanks for the assist! Pin 7 is reading -5.6, and pins 14 and 15 are reading -12.95.

Curious as to why pin 7 is running -1 v higher than normal...
-Charlie

teknoman2

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Re: Madbean Total Recall question
« Reply #3 on: February 14, 2019, 07:03:20 AM »
Yeah thats a bit odd, despite that check resistor values of R9, R10, R11 and last R12, R13.

ckim715

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Re: Madbean Total Recall question
« Reply #4 on: February 15, 2019, 07:54:20 AM »
Resistor values are all correct for R9-R13. 68k for R9, R10, R11, 24k R12, 51k R13. This is weeeeird.
-Charlie

ckim715

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Re: Madbean Total Recall question
« Reply #5 on: February 18, 2019, 08:40:47 PM »
anyone else have any insight?
-Charlie