[sdiy] noise source crap out

[Magus Ship]

Thanks everyone for the advice on this, I swapped out the transistor for a
new one and it sounds great! Better than before.
----------
>From: Tim Ressel <madhun2001 at yahoo.com>
>To: Magus Ship <elmystico at earthlink.net>, synth <synth-diy at dropmix.xs4all.nl>
>Subject: Re: [sdiy] noise source crap out
>Date: Sat, Mar 23, 2002, 12:50 PM
>

>Yo,
>
>I don't think the caps are the problem. Here is how my
>coffee-addled brain would approach it:
>
>Step 1: Check power supplies on the opamps
>Step 2: Ohm out the ground connections
>Step 3: Inspect the board for cold joints etc.
>Step 4: Flex board and listen for output changes
>        --> if you hear changes, re-solder all joints
>Step 5: If you have a scope, look at outputs of amps.
>Look for distortion, heavy dc biases, clipping, etc.
>Step 6: If the opamps are socketed, swap opamps one at
>a time.
>Step 7: Swap the transistor
>
>Questions, queries, posers:
>
>All outputs affected? Or just one?
>Varies after turn-on? Or constant?
>
>Hope that helps.
>
>--TR
>
>*******************************
>When in doubt, gulp a Hexuccino
>*******************************
>
>--- Magus Ship <elmystico at earthlink.net> wrote:
>> "All of a sudden" my homebuilt noise source, which
>> is based on the
>> Electronotes and ASM-1 designs has crapped out. 
>> What used to be a rich hiss
>> has become a futzy stream of what sounds like badly
>> band pass filtered pink
>> noise.  Around this time the ground connection at my
>> power supply became
>> desoldered (unrelated? related?).  My question is
>> whether the transistor or
>> the filter caps to get pink and Random Low Frequency
>> outputs would be the
>> problem.  Is it possible that a transistor that
>> provides good noise can
>> change or crap out over time?  Or is it more likely
>> that a cap or a bad
>> connection in the filters would produce this effect?
>> thanks as always.
>> Gavin 
>
>
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