Removed the Master Volume on my 81 Vibrolux

I am not familiar with the Craig Anderton MV, there are different types of MV and some sound much better than others. As you found out just putting a MV in a vintage Fender doesn't make it into a Marshall or a Boogie, and I don't really know why you'd need one on a Vibrolux Reverb, they sound great stock IMO.

Sounds like you got your mojo back!

 

Have you tinkered with mini amps at all? that's where I'm at, way too afraid to try repairs or mods on larger amps. (That and I am without the knowledge.)

There are guys on youtube doing some neat stuff already. As for me I just got my first Fender mini amp powered by a 9v. My plan is to attach a cheap, but good sounding pc speaker to it and wire it all in a cool box. I have an old chair in the garage with this bamboo mesh backing that would look killer on an all-wood amp. I plan to make knobs of wine corks soaked in some kind of resin.

 

I'm a fan of the Trainwreck Type-3 master volume because it's super simple and adds no capacitors to the signal chain. It's easy to temporarily alligator clip the MV into an amp and try it before doing any soldering or hole drilling. With a push-pull pot you can get a combo MV/Vox tone cut. Pull up for a master volume, push down for the high cut tone control.



For new build amps my favorite MV of all time is the Frondelli master volume. It's similar to the Lar-Mar but doesn't require the 2.2M bias safety resistors.

 

The article was December, 1982...
The Anderton mod was essentially the same bad idea (IMO) the Frondelli, but there's no accounting for taste, and people like what they like. The PI goes to the pot wipers, providing a constantly changing load on the circuit, not to mention the changing time constant. I believe it truly represents what most people don't like about MV mods. It was one of the first mods that I did to my '74 Princeton. Pre-internet, like you said. I thought, "Hey, this is cool." Not for long. That was back when Princetons and Champs were practice amps that no one wanted. Drill a hole in the faceplate? why not....D'oh!

A Fender is best left alone. It does what it does all by itself.

 

A master volume is always going to change the load, power tube bias, grid leak resistance, grid stopper resistance or something else.

I like the Frondelli master volume because it adds no capacitors, keeps bias voltage and grid leak resistance constant and allows the load and grid stop resistance to vary. Turning down the MV add grid leak resistance which helps reduce blocking distortion. The Frondelli MV will not leave the power tubes with no bias voltage with a pot failure, even without tack-on safety resistors. No MV is perfect but I think the Frondelli is best.

 

This is somewhat an old post, but you seem to have good experience with the Frondelli master volume, so I'm asking you anyways.
I was wondering if you had some tips for implementing a Frondelli MV in a project I'm working on.
Would this be an acceptable approach for a cathode biased solution?

first post btw
Thanks

 

I have tried I think 3 of the popular 4 MV's in Fender style amps. Tone sucking devices for sure.

 

Moen, that MV will work just fine.

 

thinkin about doing a Hoffman Plexi & it has a Master Volume pre inverter. would a post inverter be the better way to go? as in, no pre inverter MV, and only the Lar-Mar post inverter MV

 

I've been thinking about doing one to my '68 custom vibrolux. Which Master volume type did you have on there?

 

Went down that moding road myself. What I figured out was if you want an old Fender to do Boogie or Marshall stuff. Just buy a Boogie or a Marshall. Or a modern Fender like a Pro Sonic for that matter, too bad they stopped making those. Point is there's a whole lot out there that does that sort of thing so why mess up an old Fender?