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Ah I know the guy Dave Watson, used to jam with him. He is a draughtsman by trade, was self employed in that back in 2008 when I last spoke to him. Modded one of my amps once. Self taught.

I've oft looked at his amps, and like the base principles he employs (valve type, circuit type etc)....but one thing EVERY modern amp builder should get their heads around is power scaling. To compete properly, at any boutique level, amps need to have power scaling. The parts are only worth a few bucks, but it's the actual implementation that's tricky. For those at Tronfest they can hear John Gilmores power scaling in my AC30.

was talking to John last night... he mentioned that you near made his head explode with the last thing you had him do.. I guess that was it

rocklander wrote:was talking to John last night... he mentioned that you near made his head explode with the last thing you had him do.. I guess that was it

erm... IB...

*UNIQUE* wrote:I've oft looked at his amps, and like the base principles he employs (valve type, circuit type etc)....but one thing EVERY modern amp builder should get their heads around is power scaling. To compete properly, at any boutique level, amps need to have power scaling. The parts are only worth a few bucks, but it's the actual implementation that's tricky. For those at Tronfest they can hear John Gilmores power scaling in my AC30.

I've heard mixed results about power scaling so I'm not actually won over by it. Besides, there's no substitute for actual volume, you need the trousers flapping in the breeze of an overdriven speaker cone.

Unique, you mean like http://www.hallamplification.com/main.html?src=%2F#2,2 ? They seem to get good reports from Express-style amps.

BG wrote:

*UNIQUE* wrote: I've heard mixed results about power scaling so I'm not actually won over by it. Besides, there's no substitute for actual volume, you need the trousers flapping in the breeze of an overdriven speaker cone.

Just turn the scaling unit to full

65 Amps and my AC disengage the circuit completely when wide open...but who wants to hear ear bleeding AC volume in a small bar? Asides from me? So there is an application for it...and the naysayers usually haven't owned/played an amp with it correctly utilised.

For anyone interested in how well it works try a 65 at Ryans...they've nailed it.

@rocklander - John doesn't seem to return my phone calls anymore...and pulls his curtains when I drive past? Weird.
@alan - yes, that concept...I used london power EL84 version (obviously). Not a simple task, and there's plenty of bullshit surrounding it (some of those amp guru's we talked to in the USA were painful...self important etc)...John stuck to it and implemented very well. Amp is incredibly usable now.

*UNIQUE* wrote: usually haven't owned/played an amp with it correctly utilised

Some of the naysayers have been amp designers... some people are quite scathing about Kevin o'Connor.

imo O'Connor has good and bad points . Some information in his books is just incorrect (and he's yet to offer any addendum for the series ) and they are imo too expensive and some aren't particularly well written, but he is approachable, helpful and has replied to the queries I've put to him.
His books were however pioneering in the field of guitar amp design for serious amateurs and pros. I reckon in balance he's been a good influence on the field.

Btw I think the term powerscaling is proprietary to London Power. More generically the technology is referred to as VVR or variable voltage regulation.

BG wrote:

*UNIQUE* wrote: usually haven't owned/played an amp with it correctly utilised

Some of the naysayers have been amp designers... some people are quite scathing about Kevin o'Connor.

I don't blame them...speaking with Kevin is like trying to communicate with Yoda after he's consumed half a bottle of Absynthe.

I think amp designers probably should look at 65 Amps and take Kevin out of the equation, in terms of looking at a working principle.

but it still comes down to that basic flaw that all attenuation suffers from, whether its a hot plate, ppimv or power scaling (Tm), you've taken the speaker out of the equation. And all of these methods suffer to an extent anyway even without the speaker - not one is entirely satisfactory, tone is diminished in some way. Even Kevin o'Connor admits this.

If you were that bothered about hitting the audience with a wall of sound, you'd be using a 2 watt Firefly

Just sayin PPIMV works for me, might try power scaling (Tm) on my next build though.

BG wrote:

*UNIQUE* wrote:I've oft looked at his amps, and like the base principles he employs (valve type, circuit type etc)....but one thing EVERY modern amp builder should get their heads around is power scaling. To compete properly, at any boutique level, amps need to have power scaling. The parts are only worth a few bucks, but it's the actual implementation that's tricky. For those at Tronfest they can hear John Gilmores power scaling in my AC30.

I've heard mixed results about power scaling so I'm not actually won over by it. Besides, there's no substitute for actual volume, you need the trousers flapping in the breeze of an overdriven speaker cone.

Finally someone has said it, Its just not the same without the punch and all!!!

I was talking to Rich at Rivera, they have a new Attenuator out, but it is suppose to operate differently or something. Also will not damage your amp. I would like to grab one but no funds at the moment..

BG wrote:but it still comes down to that basic flaw that all attenuation suffers from, whether its a hot plate, ppimv or power scaling (Tm), you've taken the speaker out of the equation. And all of these methods suffer to an extent anyway even without the speaker - not one is entirely satisfactory, tone is diminished in some way. Even Kevin o'Connor admits this.

If you were that bothered about hitting the audience with a wall of sound, you'd be using a 2 watt Firefly

Just sayin PPIMV works for me, might try power scaling (Tm) on my next build though.

Will you admit then that PPIMV has the same effect as scaling does on a speaker?

Having had PPIMV's and compared to scaling/VVR - no contest...I pick VVR. My TopHat still has a PPIMV however, which works pretty good.

And lets call it, as Ears suggests, VVR....because that's what it is regardless of the minor tweaks to circuits, or some mad tube theorists brand.

And no arguments from me - in the studio, for full on rockin tone, that speaker has to be working hard, so everything is cranked. Live performances to smaller audiences requires a different approach. To get an AC30 cranked tone through a Celestion Blue (which by nature almost sounds like its working hard all the time) at a gig friendly volume is something that I had previously thought was impossible. Not so.

OP - anyone heard that 6V6 amp he has on there now as his "best amp"?

Tonemaker wrote:

BG wrote:

*UNIQUE* wrote:I've oft looked at his amps, and like the base principles he employs (valve type, circuit type etc)....but one thing EVERY modern amp builder should get their heads around is power scaling. To compete properly, at any boutique level, amps need to have power scaling. The parts are only worth a few bucks, but it's the actual implementation that's tricky. For those at Tronfest they can hear John Gilmores power scaling in my AC30.

I've heard mixed results about power scaling so I'm not actually won over by it. Besides, there's no substitute for actual volume, you need the trousers flapping in the breeze of an overdriven speaker cone.

Finally someone has said it, Its just not the same without the punch and all!!!

Look, let's clear this up. You cannot beat the sound of a Marshall stack operating at the sweet point (as a representation of any amp/speaker array working at their respective peaks), but there is a place for controlled volumes when you give a fuck about the customer.