BSIAB 2 Technical Questions.

[ilya-v]

I got a few question that'll help me and other understand and tweak the BSIAB to perfection.  

*According to GGG schematic.

1. What resistors form RC filter with C2 and C7? is it 500k (1M / 2)?

2. Instead of tweaking the C7/C2 can I add/change a cap in parallel to R10/R3, will it be the same effect?

3. The Coupling Caps (C4, C12. etc..) form RC filter with what resistors? (in a tube amp with the Plate resistors).

4. Is making R3 and R10 higher will have the same effect as switching to a lower gain jfet (j201 to 2n5457)?

5. I tweaked my tube preamp to perfection, will copying all the RC filter, Dividers, Bypass Caps of the gain stages
to the BSIAB yield the same tightness/clipping response, or are the jfets distort/clip in hugely different way?

I had more but I'll need to remember them.

Thanks.

[ilya-v]

Anyone have a good understanding in jfets mu-amps?

[Talon5051]

Anyone have a good understanding in jfets mu-amps?

This may help.
http://www.runoffgroove.com/fetzervalve.html

[ilya-v]

Thanks Talon.

I've already read the Runoffgroove site in the past.
It very informative but is not answering my questions.

In the mu-amp (bsiab) there are few caps that I don't see how they form a RC filter, because there is no resistor to form it with.

Everybody says lower this cap to make it thinner, BUT what resistor this cap interacts with to make a filter (C2,C4,C7,C12)?
I want to put it in the RC filter Calculator and calculate the cutoff frequency myself.

[gght]

Find a guy that goes by liquid or liquids.  I think he knows the circuit at least as good as Ed!!!

[ilya-v]

bump.

Liquids can you help me on that?

[Davelectro]

1. What resistors form RC filter with C2 and C7? is it 500k (1M / 2)?

Yes, the two 1M resistors in parallel.

2. Instead of tweaking the C7/C2 can I add/change a cap in parallel to R10/R3, will it be the same effect?

Not the same effect but similar. Both methods change frequency response for sure.

3. The Coupling Caps (C4, C12. etc..) form RC filter with what resistors? (in a tube amp with the Plate resistors).

They form an RC filter with the impedance (gate-to-ground resistor) of the next stage.

4. Is making R3 and R10 higher will have the same effect as switching to a lower gain jfet (j201 to 2n5457)?

Yes, but a lower gain jfet will also have a greater clipping-free input.

[ilya-v]

Thank you Davelectro.

I socketed the whole pedal today, its time to experiment.