What happened to my BSIAB2?????

Started by msb69, August 09, 2009, 10:44:44 AM

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msb69

I built a BSIAB2 last night, fired it up, and it worked great.  So I unplugged the pedal and happily went off to bed.  When I tried out my BSIAB2 this morning, it did not work.  It was all gated and splatty sounding, no matter where I set the trim pot.  Also, as I turn the Gain pot up, at about 2 o'clock there is a slight pop in the sound.

I am using all 2N5457 trannies in it.  They are all socketed.

What could have happened to my BSIAB2 overnight???????


isildur100

Hi,

Could it be that you left it on all night and the battery is now almost dead? Check the voltages.

cheers.

John Lyons

Yeah, that's a good point.
If you wired the battery somehow that left the circuit on
or plugged in... Could be a power issue, that would cause
the gating and not able to bias up....

John
Basic Audio Pedals
www.basicaudio.net/

msb69

I don't think it's a power issue.  My guess right now is that the Gain pot is bad.

Paul Marossy

#4
Quote from: msb69 on August 09, 2009, 07:11:17 PM
I don't think it's a power issue.  My guess right now is that the Gain pot is bad.

Pots don't just go bad sitting over night, they go bad by either being physically damaged by a lot of use or being overheated while being soldered. So you could try a new pot to see if the latter is the case.

Also, check for a cold solder joint somewhere. Maybe it was making a good contact the last time you used it, but not later on.

Or, perhaps one the FETs is loose enough in the socket that it's making an intermittent contact.

msb69

The gain pot feels very "loose" when turned -- the tone and drive pots feel normal.

Paul Marossy

Quote from: msb69 on August 09, 2009, 08:30:10 PM
The gain pot feels very "loose" when turned -- the tone and drive pots feel normal.

Well, try replacing it then...