Installing VVR into Dumble Clone

[buzzer]

Hi,

It's amazing how - behind the times - I get sometimes.

Just a few weeks I was dealing with a Rocktron Alan Holdsworth "Juice Extractor" in order to see if I could bring down the volume of my Ceriatone OTS so that it didn't cause discomfort to my neighbors. It was so noisy it caused discomfort to me!

Then I heard about something that's been around for a while, and would like to get info on it - especially on how t install it on my Ceriatone.

Can anyone here guide me to some sources for vvr's and how to mod it into my amp?

I'll be very grateful.

Buzzer

[skeezbo]

Buzzer,
Are you sure you need VVR? Pardon me if you already know this, but Dumble circuits were designed to produce preamp distortion, and the master volumes work really well to control the volume of that. But they may be a little complicated to use. Are you going for power tube distortion? What kind of sound are you looking for?

Skeezbo

[Structo]

Not sure if you want to build it from scratch or order it from Hall Amplification?

I do know that his fixed bias VVR are only for less than 50 watt amps.

But actually, the ODS style amps have such a good master volume and overdrive that you can play at lower levels and have it sound pretty good.

In fact, I don't really like the tone of my amp turned way up so I am not trying to get that sound.
Just a decent clean tone and a smooth overdrive which is what they were designed for.

Good luck on your pursuit!

[FYL]

A VVR is basically a DC mosfet voltage regulator. You need the VVR3 version ($50 + shipping) in a fixed bias amp, but I'm not sure that it's a good solution for an ODS clone - voltages and currents are too close to the board max and thermal dissipation will be a problem.

Sold by Dana Hall (UR12 here), a really nice person. Check the Hall Amplification site: http://hallamplification.com/main.html?src=%2F#2,2

OTOH, you could use the original and IMO technically better London Power approach and fit a Power Scaling SB-1 kit (C$78 + shipping) with IRFPE50 mosfets instead of the stock IRFP460 - just ask Kevin O'Connor, head solder sniffer at London Power.

http://www.londonpower.com/catalog/prod ... ucts_id=27

Both boards are quite easy to install.

[10thTx]

There are some schematics, pictures and info here:

http://www.el34world.com/Forum/index.php?topic=6899.0

I installed one in an amp that is cathode biased with 5881's and have been happy with it.

I am NOT saying that this will get you what you're wanting with a Dumble amp or that you need one instead of using the mstr vol.
Just relaying some information and my personal experience trying this.

With respect, 10thtx

[rogb]

I have got a VVR3 right here on the desk in front of me, together with a reclaimed computer motherboard heatsink, as I thought I would certainly need one in my 50w Ctone OTS HRM but since finishing my Dlator and using the recovery output as an additional MV, I am not sure whether I need to bother. As the others have said, power amp drive is probably not part of the Dumble mojo.

It is also pretty hard to find a suitable place for the pot, board and mosfet.
I have even installed a 120mm fan in the head cab, all ready to keep the chassis mount heatsink cool

[buzzer]

Thanks for all the replies. In that all of you agreed (along with the manufacturer) that it wasn't necessary - given the way a Dumble (and its clones) are configured as to whether it is necessary.

So, for now, based on your advice, I'm going to cancel this idea, and turn my sights to projects that I should be doing first anyhow.

Thanks,

Buzzer

[Structo]

Yeah, just play with the knobs.
For some these amps are intimidating because they have a few more than some amps.
You just have to experiment with the settings to make it right for you.

And in case you missed it, a Dumbleator is pretty much essential gear with one of these.

[rogb]

Thanks for all the replies. In that all of you agreed (along with the manufacturer) that it wasn't necessary - given the way a Dumble (and its clones) are configured as to whether it is necessary.

So, for now, based on your advice, I'm going to cancel this idea, and turn my sights to projects that I should be doing first anyhow.

Thanks,

Buzzer

Yes Buzzer, should have saved my money there, I reckon. Just build yourself a Dlator, it's fun, pretty easy and the sound is just great! All you need for your build can be found here at TAG

[buzzer]

Hi,

Don't have a Dumbleulator, per se. But heard they were pretty much 'essential equipment'. So, at the time I ordered it I ordered the Ceriatone's version - a Kleinulator.

Thanks,

Buzzer

[Structo]

The Kleinulator by all accounts works well.
It uses JFET's instead of tubes so should be very reliable.

Mike Klein a member here designed it.

Ceriatone now makes a tube powered Dumbleator.