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Please be positive and constructive with your questions and comments.

No decay...

by diplowave on Fri Sep 29, 2017 3:22 am

Hi, x0xerz'! When have a decay potentiometer that doesn't work where can it come from? I have already checked the potentiometer and several things on the env, 4066, Q36, Q37, Q38 are OK.
There was the VCF out of service but i found out where the problem came from, Q21 was burned, however the decay i do not know why it is not working...

diplowave
 
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Re: No decay...

by rv0 on Fri Sep 29, 2017 7:20 am

the decay can be very subtle / do nothing depending on position of other pots.. sure?

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Re: No decay...

by diplowave on Sat Sep 30, 2017 3:51 am

Thanks rvo, yes i'm sure because i have already built more than 10 x0xb0x, so i know a little bit.
I know that the decay is more blatant with the envelope and that one does not hear it when there is accent everywhere on the sequence. I know 303's behavior.

So i listened a little more to the synthesizer and i noticed that the potentiometer accent acted like a volume potentiometer. It's abnormal. Let me explain:
When NONE accent is programmed on the sequence, if i increase the accent potentiometer, the volume increase, this is abnormal because there is no accent programmed on the sequence. So i think if the decay does not work, it comes from an accent problem that is constant and should not be.
From what i hear the accent also seems to me inactive on the VCF and acts only as an additional volume potentiometer. That said the accent does not completely cut the volume if one goes down.
I did not specify, it is not an x0xb0x but a TBX303, but the circuit is quite similar, there are some little differences, but it looks great.

diplowave
 
Posts: 83
Joined: Wed Aug 21, 2013 9:49 am
Location: France

Please be positive and constructive with your questions and comments.