Vox Virtuoso schematic?

[spy]

I'm trying to bring back in life a late 60's solid state Vox Virtuoso amp! But, I can't find anywhere the schematic, only if I pay. Does anyone have it?

[DrGonz78]

Well according to the VOX Showroom the Virtuoso used the same preamp circuit as the Conqueror, Defiant & Supreme. So it says on the site...

http://www.voxshowroom.com/uk/amp/virtuoso.html
The VOX Showroom - The VOX Virtuoso Control Panel

Here is the schematic for the preamp and it can be found around the net.

[spy]

I've seen this, thanks but I need the power amp and PSU, too.

[R.G.]

You may have to trace them out. They will almost certainly be very similar to the Defiant.

[spy]

I'll check it out RG! It seems that there's nowhere a schematic for the Virtuoso.

[R.G.]

You may well be the first to reverse engineer it and put the info out for others.

Having seen the way that Vox did designs in the UK about that time, I would be very surprised if it was radically different from the other contemporary amps. They liked to do variations on a theme.

[spy]

I'll be very glad but I have never use any program for drawing schematics!

[R.G.]

Don't use a program, use a pencil.

[loudthud]

A reprint of the original schematic is in the deluxe edition of Jim Elyea's book, Vox The JMI years. It's copyrighted but I have re-drawn it

[loudthud]

I posted that schematic on late Saturday night but Spy hasn't logged on since Friday. Oh well, I sent him a PM.

I was noticing that there is no voltage feedback on the power amp, only current feedback. The other solid state Vox amps from that era are the same story. There are 50W and 100W versions. I think that is the earliest example of current feedback I can remember. There was a Shure Vocal Master PA that used current feedback, it sounded bad unless you used their speaker columns. Can anyone else think of an old example of current feedback from the 60's or earlier?

[spy]

loudthud, really thanks for this! I was too busy the last month, now I'm back! The schematic will be very helpfull to complete the full service of this little beast!