diyAudio (
-   Pass Labs (
-   -   Balanced audio technology VK500/1000: "Single-Ended Bridge" Topology, 450W into 4 Ohm (

tiefbassuebertr 5th May 2011 09:57 PM

Balanced audio technology VK500/1000: "Single-Ended Bridge" Topology, 450W into 4 Ohm
6 Attachment(s)
I read:
A typical solid-state amplifier
will have four or five gain stages, with a feedback loop traversing these same
stages to correct the signal. The VK-500 uses only two gain stagesówithout
global feedback. Unusually direct for any amplifier, this purist signal path is even
more surprising in a design of such high power. The ingenuity of the signal
path is complemented by a unique single-ended bridge topology that allows the
use of superior N-channel MOSFETs in both driver and output stages. The
result is a clear, open sound that breathes life into music.

This sounds like a design from Mr. Nelson Pass.
Also the review about
Balanced Audio Technology VK-500 Reviews
Product Review
Perhaps a transition from a "ZEN"-topology to a "CSPP" (Circlotron)??
Who knows more about BAT's topology?

banat 8th May 2011 06:04 PM

Yes , it is always employed Balanced Bridge / PPP ( Circlotron ) topology inside of this ( Viktor`s ) BAT SS or Tube PP Amp .

Best Regards

tiefbassuebertr 10th August 2011 10:12 PM

are anywhere schematics for download?

mr l 10th August 2011 10:54 PM

like krell, they don't release schematics. good luck!

a.wayne 12th August 2011 12:24 AM

Had a Pr ... not a fan .....................:(

tiefbassuebertr 12th August 2011 06:34 PM


Originally Posted by mr l (
like krell, they don't release schematics. good luck!

I don't need a detailled schematic diagram, only a simlified schematic like that one from the Pass Aleph on page 5 about

Nelson Pass 12th August 2011 10:25 PM

The phrase "balanced single-ended", first used IIRC by Bel Canto, and an
oxymoron if there ever was one, is nevertheless pretty descriptive.

It is likely:

1) Circlotron, either Common-Drain or Common-Source.

2) Two conventional single-ended output stages operated in balanced mode,
either Common-Drain or Common-Source, biased by a CCS or variable
current source.

3) If the product is advertised as lacking global feedback, then it very likely
is a Common-Drain version of 1 or 2


(Fet pin references. Your pins may vary)

All times are GMT. The time now is 05:14 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2