I'm new here, but already found lots of good information and thoughts to build me a better amp.
Already one year ago I built a TW express clone with two EL84. It sounds awesome but way too loud for use at home. So I dicided, to give VVR a try. I don't like the sound of MV Amps...
Everything seemed to work well at lower volumes and max. volume, but if the pot reached about middle, I got bad tone with ghost notes and a lot of hum. A friend gave me the advice, to clip out the 12V Zener and it worked! No more hum and bad notes.
Now I really would like to know the purpose of this zener. Is the zener really necessary? Or will I risk some damage?
Thanks a lot...
VVR creates ugly noise
Moderators: pompeiisneaks, Colossal
Re: VVR creates ugly noise
If this is like most of the VVR circuits I've seen, the zener is there to protect the gate (so as not to exceed the breakdown voltage of that oxide) of the MOSFET. If you look at the data sheets the Vgss is usually a fairly low voltage. If you exceed this you'll have to replace the MOSFET as you'll have a short from gate to channel.