VVR for small cathode biased amps

[tunghaichuan]

The VVR (variable voltage regulator) is similar to power scaling in that it allows you to turn down the high voltage to the tubes without lowering the filament voltage (which damages tubes)

This web site has a point-to-point wired version:

http://yeomansinstruments.blogspot.com/2008/07/vvr-greatest-thing-ever.html

There is also a PCB-based version available from Dana aka UR12, but I don't have his email as the SEwatt board is down.

The benefit is that you get a cranked amp sound at low volumes.

Lowering the plate voltage allows the amp to overdrive sooner, and decreases the wattage at the same time.

From what I understand, the tone doesn't suffer as much as with attenuators.

I haven't tried this yet, but I plan on installing it in one of my Valve Juniors.

tung

 

[Robert]

I am very interested in this topic. I've seen it discussed elsewhere too. That might be the best way to tame that roaring 100 watt Marshall I'll get one day... just so I don't blow the kids out of the windows when I'm practicing.

 

[tunghaichuan]

Robert,

I think that Dana makes boards for fixed bias amps like the Marshall as well. It is a less expensive alternative to Kevin O'Connor's power scaling.

I'll post Dana's email when SEwatt comes back on line and can look it up.

tung

I am very interested in this topic. I've seen it discussed elsewhere too. That might be the best way to tame that roaring 100 watt Marshall I'll get one day... just so I don't blow the kids out of the windows when I'm practicing.

 

[duhvoodooman]

The VVR (variable voltage regulator) is similar to power scaling in that it allows you to turn down the high voltage to the tubes without lowering the filament voltage (which damages tubes)

This web site has a point-to-point wired version:

http://yeomansinstruments.blogspot.com/2008/07/vvr-greatest-thing-ever.html

There is also a PCB-based version available from Dana aka UR12, but I don't have his email as the SEwatt board is down.

The benefit is that you get a cranked amp sound at low volumes.

Lowering the plate voltage allows the amp to overdrive sooner, and decreases the wattage at the same time.

From what I understand, the tone doesn't suffer as much as with attenuators.

I haven't tried this yet, but I plan on installing it in one of my Valve Juniors.

tung

Please let us know how it works on the VJr, Tung--very interested in this one! :AOK: