madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Philosopher on May 12, 2014, 11:51:32 AM

Title: sea urchin volume drop
Post by: Philosopher on May 12, 2014, 11:51:32 AM
i have a big problem with volume drop, i checked every value, solder bridges 3 times, changed 12k to 47k and added the volume trimmer at the output but no luck, i can hear the delay but i have to crank up the amp , very very big voluem difference? any suggestion;?
Title: Re: sea urchin volume drop
Post by: midwayfair on May 12, 2014, 01:27:14 PM
Quickest way is probably to use an audio probe to see where you're losing signal so you can narrow it down. There shouldn't be a volume drop in this circuit, so you either have a wrong part value or something else wrong, assuming you're building on a verified layout.
Title: Re: sea urchin volume drop
Post by: Philosopher on May 12, 2014, 03:21:31 PM
i built it before, i had no problems. İ've checked 3 times, changed op amp, 2399 and regulator 2 times still same, which caps or reistor are diretcly influence the volume? i assume its c8 and r5?
Title: Re: sea urchin volume drop
Post by: rullywowr on May 12, 2014, 05:55:29 PM
I had a similar issue with my "Jules Caverne" version of the DBD.  Ensure the feedback loop resistors are the appropriate value.  R3 and R5 on the Sea Urchin schematic are likely suspects.  I had a 180k in R3 by accident when prototyping my layout and my volume was lower than unity.
Title: Re: sea urchin volume drop
Post by: Philosopher on May 12, 2014, 05:57:29 PM
my all values are correct, i checked 3 times. and changed r5 12 k to 47k and added volume trimmer at the and but no luck, i will go with audioprobe, or rebuild again.