Azabache white noise problem

Started by nate77, March 13, 2014, 12:01:27 AM

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nate77

I've built and azabache from ROG with a pcb from th customs and everything seems to work as it should but I get a massive amount of white noise that only moves with the volume pot. I can't figure out for the life of me why. It is unusually high, despite the low gain nature of the effect. It sounds great but it largely unusable with the crazy high noise floor. I know this isn't common with these. Any thoughts?

PRR

It isn't a low-gain circuit. Gain well over 1,000, huge.

So something isn't working right.
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midwayfair

Double check all your ground connections against the schematic.

We're going to need voltages and pictures, too:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
My band, Midway Fair: www.midwayfair.org. Myself's music and things I make: www.jonpattonmusic.com. DIY pedal demos: www.youtube.com/jonspatton. PCBs of my Bearhug Compressor and Cardinal Harmonic Tremolo are available from http://www.1776effects.com!

Keeb

I built one on a home etched board (the layout from ROG) and it doesn't have that issue. I didn't use shielded wire, just made the wires long enough to fit the layout that I wanted to use. I did get some "ghost notes" (like a saturated transistor sound that followed the note played) because I couldn't get one j201 to bias according to the instructions, with the stock trimpot. When I changed the trimpots to 50K it biased fine and that issue was gone. I blamed it on my j201s... (If anyone reading this think my solution was brute and not as elegant as possible. Simply a cure of symptoms rather than of the cause.  I would gladly listen to suggestions. But, as I understand engineers say, it's "close enough for practical uses").

So to conclude: your issue is not normal - but fixable! Like the others have said, voltages and pictures would help.

nate77

Thanks guys. When I first built this it was very high gain and I had heard on another forum that it was supposed to be low-mid gain, which honestly was what I had expected. I replaced my j201s with 2n5457s to reduce overall gain but the white noise is still ever-present. I'm having a tough time with posting pics but I just got some advice from another forum member here on how to post them. I'll get pin readings soon and work on pics. Thanks guys