vox top boost pre?

[Arn C.]

http://ampage.org/schematics/vtbpre.gif

Howdy Folks!

In this preamp schematic, there are 3 cap values without the type of value(ex: uf, pf, nf)

These are 500, 100, and 50

Are these all in pf?

Thanks!
Arn C.

[Seljer]

yep, it seems to be picofarads

[Jaicen_solo]

Is this the same Top-Boost that's in the new AC30 customs?? (The ones with MV's).
If so it sounds brilliant! My friend has a vintage AC30 and this new one blows that away, especially for recording because it can get pretty overdriven without being monster loud.
I'd like to see one of these packaged as a pedal, now that would be interesting!

[Doug_H]

Try the Menatone Top Boost in a Can.

[Arn C.]

My friend has a Vox AC30 Top Boost amplifier and I told him the preamp had only volume, bass and treble pots and he said his also has a "CUT" pot.   But I do not see one on the schematic that I posted above.  How can I install this and where?

Thanks!
Arn C.

[MartyMart]

Arn, have a look at www.runoffgroove.com at the English Channel for the "cut" control
setup, I dont use it on mine and can't really see the point on a top boost circuit !!

Marty.

[Arn C.]

Thanks Marty!  I will take a look!

Peace!
Arn C.

[Jaicen_solo]

The Cut control, as far as I can see is a post pre-amp low pass. I think the idea is to have all the harmonics in for the drive stages, but to cut them at the power amp to stop things getting shrill. In my experience, it's a subtle effect anyway. You can only really hear the difference at low volumes anyway, once you start getting power tube grind then the harmonics come back in force anyway.