Install a VVR in Your Guitar Amp!

[C0ldFart]

Greetings fellow VM users.

Have anyone tried this on the VM og something similar.

http://www.youtube.com/watch?v=xV0g3VW_Vfc&feature=sub

[Vinny]

Looks like the VARIAC stuff EVH used???
Never used it, and surely not planning to,looks dangerous messing with voltage!?

[C0ldFart]

No, I don't think so.
The Variac is a huge coil plugged into mains, and feeding the whole amp I believe.

Starving both the B+ and heater elements

I believe it also could run som over voltage into amp.

[KevinOConnor]

Hi Guys

VVR is a poor copy of an early version of Power Scaling.

One of our licenced builders made the mistake of asking Hall to design a PCB for his amp. This gave the opportunity to copy our circuit and the builder's own tweaks to the Marshall audio path.

Have fun
Kevin O'Connor

[Mats A]

Kevin are you the man behind power scaling? Would it be hard to install this on my 1992 Plexi reissue? Are there any people doing this in Sweden where i live?

[C0ldFart]

OK, I thought VVR and Powerscaling was the same thing. But my point is.

Is it possible to modify the Vintage Modern with a "powerscaling" kit?

[SteveD]

It should be possible to modify any amp with a power scaling kit.

[Mats A]

With Power scaling installed will this change the tone in any way when the amp is on full power from what it would sound like if it had no Power scaling installed?

[Beck-Ola]

Hi Guys

VVR is a poor copy of an early version of Power Scaling.

One of our licenced builders made the mistake of asking Hall to design a PCB for his amp. This gave the opportunity to copy our circuit and the builder's own tweaks to the Marshall audio path.

Have fun
Kevin O'Connor

But does VVR work? That is relevant. I've heard one used and it worked pretty good actually.

What is wrong with the VVR? Could a "poor copy" possibly be an improved version to the one copied? Was it a bad design? Or perhaps any competitor's version is "inferior" by virtue that it's a competitor.

Is the version used in the new Marshalls inferior too? Does it have to have two knobs to be a good one? I can see how two knobs would make it more flexible.

If the design was stolen then why not take him to court for copyright infringement?

With all due respect, I didn't hear see any substantive facts in the reply about the VVR, just slags against it which amount to hearsay against somebody selling something similar. This is the first time I've heard anything bad about Dana Hall. I've seen his responses to power scaling questions on some other forum (can't recall which) and he seemed to be helpful and up front. He hasn't been hanging around this forum trying to drum up business so he is probably unaware that he's being attacked. Wonder if he might disagree with this criticism of his product. Maybe it's just a difference of opinions? Just curious.

[C0ldFart]

sooo, is the 2466 a fixed bias amp?

[KevinOConnor]

Hi Guys

Yes, I came up with Power Scaling and the term is my trademark - now part of the music biz lexicon, just like our "detuned" cabinets.

Power Scaling can be applied to any tube amp. Our books show hundreds of ways to implement Power Scaling, as Power Scaling is both a methodology and the goal - not just a single circuit approach. When implemented correctly, the amp's tone will not change from full output down to milliwatts. We only claim what the circuit will actually do. The plethora of builders using Power Scaling is a testament to the fact it does work.

All of Marshall's 50W and 100W amps are fixed-biased, just like everyone else's. In some cases, a beefier bias supply add-on is required to add Power Scaling, as not all bias supplies are equal. There is free info on our site about that.

Some of the copies of Power Scaling - which usually are not full Power Scaling - work as well sonically; the YJM and AFD circuits are examples of this. Hall's circuit tried to economize in areas that made it only suitable for low-powered amps. The current London Power kits accommodate any amp up to 900V B+ and up to 5-600W. Past kits were designed for the bulk of amps and did not accommodate the high-voltage Marshalls or Hiwatts. The VM operates close to 500V so is easily accommodated by our kits. No doubt Marshall will add this feature to the VM either as a new version, an addition to the family or as a replacement.

Part of Marshall's former engineering team ran off with the Rolodex and started up Blackstar. They also had our books and have an undefendable* patent for their variation of Power Scaling. As a one-knob solution, it lacks versatility.

On the good side, all the people copying Power Scaling are helping musicians save their hearing. And... if it didn't work people wouldn't copy it.

*won't stand up in court

I am not here to promote my products - most people know about me, the TUT books, Power Scaling, etc. - and have tried to limit any reference to my own site and writings here. I do want musicians to know what choices they have, and that they can lobby their favourite manufacturer to build products to suit the player's actual needs. It is a win-win situation. Customer feedback lets the manufacturer know what will sell, so they can stay in business. The boutique amp biz basically tests and satisfies these waters, then the big companies see what is successful and can make offerings with less risk.

Have fun
Kevin O'Connor

[C0ldFart]

Kevin, what product would you recommend for my 2466 for a full blown powerscaling?

[Beck-Ola]

On the good side, all the people copying Power Scaling are helping musicians save their hearing.

I appreciate your contributions toward this and Marshall's willingness to begin installing it into their amps. I do appreciate my hearing. One shouldn't have to sacrifice their hearing to have good tone. And then the benefits of a more flexible amp for different venues. All good.

[KevinOConnor]

Hi Guys

If the VM is like most recent guitar amps with B+ just around 500V, then you would need the SF-1 kit to Power Scale it. You might also need the RBX Raw Bias Auxiliary supply kit to get proper performance. The need for RBX depends on how the bias voltage is generated in the amp.

When installed correctly, Power Scaling will not change the sound of your amp except when you set the controls for other operating modes - ones that allow creativity instead of tone maintenance.

If by chance B+ is 450V or lower, then you can use the SB-1, nut still may require RBX.

Have fun
Kevin O'Connor

[BluesMarshall]

So Kevin, What your product does is allow all of us to have cranked amps at low levels and saves the power tubes and all components on the inside?