Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Misc Schematics and Layouts => Topic started by: jhadhar65 on April 01, 2009, 09:20:35 pm

Title: MONSTER VJ (Valve Junior)
Post by: jhadhar65 on April 01, 2009, 09:20:35 pm

This is a simple re-build that I've been asked about.  There's nothing special to it really.  It's basically a stock VJ power supply and power amp mated to a JCM800-inspired preamp.  The basic 800 preamp was modified for a single input jack and some of the component values have been changed to maximize the rock potential (my opinion) of this cool little amp.  The layout is PTP on terminal strips.  Lead dress is very important in this amp.

This design uses the stock transformers and everything has been voiced based on that.  The speaker/cab I used in tweaking it was a small 1x10 and a Weber Michigan 10 ceramic.  If you build this, you'll have to take these things into consideration as far as voicing goes.

The biggest differential feature of this amp is the fact that it has a speaker-emulated line out and a power amp mute switch.  You'll still need a balanced DI, but you can send this one straight into a mixing board or recording console and it sounds really good with no stage bleed.

Title: Re: MONSTER VJ (Valve Junior)
Post by: navdave on April 22, 2009, 01:22:22 am

Pimp your Epi looks good!!

Title: Re: MONSTER VJ (Valve Junior)
Post by: jhadhar65 on April 22, 2009, 08:35:16 am

Thanks!  I gave that particular one away as a promotional thing at a big concert shortly after those pictures were taken.  That was a waste.  It didn't generate me any business, fame, or fortune.  Oh, well...

EDIT:  I just looked at the schematic again and there's an error in the way the output jacks are drawn.  None of them are shorting, but it shouldn't matter to anyone.  The stock jacks, which the drawing is based on, are all mounted to their own little PCB as the pictures show.  As long as they're just left as they are, everything will work out fine.