Another 5 Watt amp - The Valve

[K.E.B.1281734147]

Check out Carl Verheyen playing this cool studio / practice amp.

http://www.youtube.com/watch?v=GSsPorSlfQg

Official Website: http://www.the-valve.com/amps.html

Sounds killer to me. Anybody here about these yet?

[Swoop]

Certainly looks and sounds great. Trust the Italians to come up with a sexy and coherantly designed amplifier. Not cheap though, which is to be expected. It really is a boutique amplifier, being point to point hand wired. This store in the Netherlands stocks them.

 

http://maxguitarstore.com/store/index.php?searchstring=The+Valve&image.x=0&image.y=0

 

835 Euros = $1120US. That's for the little 5W 112 combo. Pretty darn expensive, but it certainly sounds really nice.

[m-theory]

Sounds awesome, but I think they're on crack with those prices. And, why are they calling power scaling "an attenuator?"

 

Trust the Italians to come up with a sexy and coherantly designed amplifier.

Where's the long history of awesome, vintage Italian guitar amps? ;-)

[jefrs]

Sounds awesome' date=' but I think they're on crack with those prices. And, why are they calling power scaling "an attenuator?"

 

 

Where's the long history of awesome, vintage Italian guitar amps? ;-)[/quote']

 

Probably because it is an attenuator, like a Master Volume is... potentiometer = voltage divider = attenuator.

 

In the clip, it sounds just like a Laney Cub 10 which has Tone, Volume and Gain i.e. it has an MV too, and it is a lot cheaper. Plus the Cub10 does sound awesome, and I have played one.

 

But hold the front page... Laney have made the Cub12R for £279 also with a low power 1 watt input

 

http://www.laney.co.uk/show_prod.php?prod=cub12r I smell a BJ beater...

[m-theory]

Probably because it is an attenuator, like a Master Volume is... potentiometer = voltage divider = attenuator.

Power scaling lowers rail voltage. It is neither a master volume nor an attenuator.

[K.E.B.1281734147]

I agree. It is pricey. Still like to try one. :)

[jefrs]

Power scaling lowers rail voltage. It is neither a master volume nor an attenuator.

 

Power scaling could mean anything. As a proprietary method it does drop the HT rail, that alters sag too, but I don't think the term has been trade marked. This power scaling could be called attenuation of the HT rail supply. Which leaves these descriptions open to linguistic abuse by copy writers. I suspect that this amp uses attenuation of signal at the power stage, because they use both terms, and it is cheaper.

[m-theory]

Actually, power scaling, attenuators, and master volumes, while all utilized as methods to reduce the amp's overall volume, are most definitely NOT the same thing. In the same sense that not all rectangles are squares, not all methods of attenuation are, in fact, reactive or resistive load attenuators.

 

Power scaling utilizes a mosfet to effectively reduce rail voltage, for the most part without mucking up the tone of the amp. That includes sag. The point at which bias is affected is extremely low. On the amp I tested, it equated to a knob setting of about 9:00, which was a tiny fraction of the overall output of the amp. At that point, you could definitely hear and feel a difference in the amp, but at any point above that, not at all, other than that the speakers don't move as much air.

 

A master volume allows you to drive the preamp section harder while keeping the output section low. This results in a VERY different sound and feel than simply cranking the amp.

 

An attenuator, in guitar lingo, utilizes either a reactive or resistive load to reduce an amp's overall volume at the output, before it reaches the speaker. This definitely changes the tone and feel of the amp, somewhat.

 

So, while it may be TECHNICALLY acceptable to label all three methods as being "attenuation," the fact is, they are each quite different in methodology.

 

Here's a paragraph from Ben Fargen about power scaling:

Power Scaling is a technology developed by London Power, headed by renowned tube amp innovator and author Kevin O’Connor, that controls voltages inside the amplifier, allowing for continuously adjustable power output. Power Scaling reduces power, and thus volume, enabling the amp to produce power tube distortion at reduced volume levels, freeing you from the need for an attenuator.

 

"freeing you from the need for an attenuator"

 

Again, they're all technically rectangles, but not necessarily all squares.

 

Here's a really good Q&A page from the designer. I do believe that the term "power scaling" is, in fact, trademarked, btw.

 

http://www.londonpower.com/pscaling.htm

[jefrs]

All squares /are/ rectangles, but if you want to obfuscate, they're quadrilateral tetrahedrons too.

 

 

Whilst London Power permits their technology to be used under patent licence, it is unclear whether their trademark 'Power Scaling' runs to Italy, Canadian law does not, it would be difficult to trademark that in the UK because it is common terminology. However, "London Power Power Scaling" is protected technology. Using mosfet and other such to regulate voltage in power supplies is common practice.

 

A correctly placed MV can keep the same feel to the amp, but at lower volume from the output section. The output section is typically designed to run clean, especially if one has a 'clean' channel: few big amps deliberately run their output section dirty, that comes from the pre-amp. We do perceive a difference when an amp is cranked up, but mainly because that's the way our ears work, we do not have a linear tonal response to volume: we want more bass at low volume and more treble at high volume. A 5 watt amp does not get into the high-volume stakes, a MV will tame its output most adequately, plus it is very cheap.

[m-theory]

A correctly placed MV can keep the same feel to the amp, but at lower volume from the output section.

If you truly believe this, why mess with tubes at all? The front end of any tube amp can be very accurately emulated with FET circuits, and if all you want is clean at the output, you can do that far more efficiently with mosfets than tubes. You'd also have infinite "power scaling" and far fewer maintenance issues, if any.

 

A 5 watt amp does not get into the high-volume stakes, a MV will tame its output most adequately, plus it is very cheap.

A MV, even if PPIMV, doesn't work nearly as well at maintaining the tone of an overdriven amp at a lower volume level, it's not at all unique in a rather congested marketplace, and it's not much cheaper than a power scaling circuit, truth be told. I'd say that there are some very good reasons why they chose to go with power scaling on a 5 watt amp, but still don't agree with them obfuscating with their knob label!