confused by schem, help!

[tedmich]

Howdy all,

I am a bit confused by the odd way the PV Bravo is depicted in its schematic, and would like some insight into how to isolate certain parts of the amp; ie just the highgain channel, reverb etc.

why? cause I want to clone only the highgain channel, of course the clean channel is just the front end stages of the HG but where could I "snip" the schematic to get rid of all the clean tone stack etc I don't need? Also the reverb which is problematic cause it tends to feedback terribly above ~3-4.

see schematic:
Bravo schematic
thanks in advance!

[octal]

To eliminate reverb:

Remove c24 (coupling cap into the reverb drive ckt) , R29 (resistor feeding output of reverb ckt into the mix). You will not need Q1, U1 and associated components


To eliminate clean channel:

Jumper K2C pins 2&4

Eliminate R19, C13 and all parts left floating as a result.

Jumper K1B pins 2&4

The bottom of the "Ultra" pot and lower connection to C112 should be connected to ground.

Do you still want the "pull for extra gain" feature? If so, you'll still need the K3 relay, control circuitry for it, etc.

I can't read the pin numbers on all the relays- like K1C, but for everything except K3, you should just jumper the wipers to the normally open contacts.


I think that should get you just about there. I may have overlooked a few minor things, but I bet if you drew out a simplified schematic now you'd be well on your way.

You can eliminate Q2, the zeners around it and the circuit driving its gate; it appears to be a muting circuit to prevent noise during channel changes.


Good luck,

Nathan

[tedmich]

Thanks Nathan,

Maybe something like this?

Picasa Web Albums - Ted

[octal]

That looks just about perfect. You did omit C3, which should go from the junction of CR1, CR2 and R5 to ground. I think it would sound a bit like a chainsaw without it!

Nathan

[octal]

Oh, I see one other problem- you have omitted the K3C relay section and associated parts- R100, R65, C10. I think you should be golden if you make these minor corrections.

[tedmich]

Oh, I see one other problem- you have omitted the K3C relay section and associated parts- R100, R65, C10. I think you should be golden if you make these minor corrections.

Thanks Nathan, I'll post clips when the prototype is done; it is a Bravo so it should be close to a chainsaw... but I'll fix the schem.