Schematics needed VTL 120 Deluxe or Ultimate Preamp

[btrail81]

Does anyone have schematics or information on VTL De Luxe 120 mono blocks or VTL The Ultimate Preamp?

Thanks,
Brandon

 

[justanalogue]

Interesting design, like the "floating" PCB with the tubes but not the electrolytics used, should be all radial IMHO, just a matter of taste I guess.
Would love to see the schematics

Willem.

 

[HollowState]

I personally dislike the way those amplifiers are constructed. A vertical transformer mounted over an opening for a horizontal transformer. Cheap capacitors, both coupling and electrolytics. They can't even bother to clean the flux off the cheesy looking circuit boards. And they want you to pay big bucks for that shoddy work. Sorry VTL but that's pretty poor for a professional. And I don't think their circuit isn't anything you haven't seen before. You should be able to trace it out. I'd guess a single triode input to a phase splitter (1st dual triode). Then coupled to a differential driver pair (2nd dual triode). And cap coupled to push-pull parallel 807s.

 

[Chris Hornbeck]

David Manley printed a run of The Vacuum Tube Logic Book in 1988 and Ed Dell at OCSL ran a second edition printing in 1989. These include (rough and general, but enough for many folk) schematics, including yours, and an interesting collection of valve characteristics and curves. Very valuable info in its day, pre-WWW, and worth finding if not too dear.

All good fortune,
Chris

 

[justanalogue]

Thanks Chris,

you can download it for free, just use Google and you'll find it.

 

[ampexperts]

Google takes me to Electrotanya which has the same abbreviated schematic that is in the VTL Book.

Does anyone have a full schematic?

I've got a pair just arrived and the PCB is badly burned and many traces cut and evidence of modifications abound. Gonna be a mess to sort out, even with a schematic!

 

[ampexperts]

Contacted Manley at the advise of another member, but Manley promptly got back to me stating that they don't have documentation for pre-Manley built amps.

This particular unit is pretty badly burned and the traces have been cut in multiple locations. I don't know if some of the cuts are factory approved mods/updates or just what some repair attempt caused. Without a schematic, it would be impractically costly to attempt repair.