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Old 12-18-2006, 01:43 PM   #1
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BSIAB built...question on some strange voltages

I just built a BSIAB II using the PCB from General Guitar Gadgets. Schematic is here. The circuit works and sounds pretty good...the distortion comes on really quick but I used a linear taper 500K drive pot so that should explain that. All other values were per the layout/schematic except I used a 100ohm source resistor instead of 120ohm on Q3.

My question is on some slightly strange voltages on two of the trannies (based on the BSIAB II build instructions on the GGG site). Q3 has the exact same voltage on the source and drain (about 1/2 V+) with very low voltage on the gate. Q5 also has the same voltage on the source and drain (adjustable through the V+ range with the 100K trim-pot) with about 1.1v on the gate.

The unit doesn't sputter, it distorts pretty well...and a lot, tonality is good, it has plenty of drive and volume...plenty, and it decays well...no 'fizzing out' when a note decays.

Are these voltages anything to worry about? It does seem to work fine but I'd hate to not see the full potential because of some mistake/problem. Any help appreciated. Thanks.
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Old 12-18-2006, 02:59 PM   #2
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Probably best to ask that question at the diystompbox forum (http://www.diystompboxes.com/smfforu...php?board=2.0), where the overwhelming brunt of experienced BSIAB builders reside. They will be able to provide more assistance.
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