VOX AC30 TopBoost and the Hall VVR

[Jack1962]

I installed this Hall VVR the 1st version of this mod , let me first say it was a very easy install , and that's where the fun ended lol This mod is worth the $30 but not a penny more a PPIMV would be a better mod for this. It is a very interesting circuit and I believe if a person(not me) wanted to modify this mod lol it would work just fine . I traced the circuit and made a drawing , and would post it but I doubt ya"ll could read my writing lol

[Willabe]

I believe if a person(not me) wanted to modify this mod lol it would work just fine .

What's it not doing that you would want to modify it to get it to do?


               Brad     

[Jack1962]

I installed it in a customers amp , not one of mine. What I would want it to do is be build with more reliable components and some kind of protection in the event that NTE mosfet burnt or shorted.

[Leevi]

I have installed VVR for AC30 and noticed that a good cooling of the MOSFET is very important.
/Leevi

[kagliostro]

If the mosfet Input and output shorts you have your max B+, not more

il the circuit shorts to ground a fuse before it can prevent further demage

K

[Jack1962]

It's a great idea and works fairly well with fixed bias amps , but my question is would it work as well on one that isn't fixed bias ?

[Leevi]

According to my experiences it works better in cathode biased amps.
Furthermore the VVR circuit is then easier to install since you don't need to regulate the bias voltage.
/Leevi