Power Scaling is Flawed?

[mooreamps]

heckofalot easier

You people are insane (just kidding).
The ditzy broads I play to every weekend can't tell what amp I have and don't care!
Anyway, I power scale all the time, I use big amps for some gigs and smaller amps for others.
Sometimes I use a master, sometimes an attenuator...still a heckofalot easier than installing a power scaling kit into an amp.

If I offered my device as a mod, I would do the work. Although, I would prefer to licence someone else to do that for me..

-g

[Mark Hammer]

I re-read what I wrote, and wanted to emphasize that while the amp may produce more distortion of some types at low power output, the speakers merely "misrepresent" the audio signal, and do not distort in the sense of adding harmonic content, until much higher power levels. That doesn't make the result sound any better, but it is important to clarify what sorts of corruption of the intended audio signal arise from which sources under what conditions.

I agree with others (and said so in the original post) that alternate speakers for varying power-scaling ranges is probably the ideal solution.

And to underscore what Steve notes, I had one of the first-issue Peavey Classic amps in the early 70's. It was a 2 x 12" hybrid combo that I believe had a tube power stage and solid-state front end, much like Music Man amps of that same era. Decent quality amp for the money at that time, but the speakers were simply awful. One personality for volume settings less than 4, and an entirely different personality for anything louder. Made it next to impossible to memorize tone settings identified during practice and apply them to gigs.

[Ptron]

You people are insane (just kidding).
The ditzy broads I play to every weekend can't tell what amp I have and don't care!
Anyway, I power scale all the time, I use big amps for some gigs and smaller amps for others.
Sometimes I use a master, sometimes an attenuator...still a heckofalot easier than installing a power scaling kit into an amp.

Seems like a capital idea to me! Ever go to a gig and for whatever reason (not knowing or misjudging the room) find out your amp is too big/small for the place? Or something about the PA is bigger/smaller than you thought. Or the soundguy won't mic the amps or s/he makes you turn your amp down? What about the folks that don't/can't have multiple amps?

You're right though. No one in the place will know or care. But hey, a lot of us here are pretty OCD about this stuff aren't we? Hell, you see the discussions around here about what type or brand of cap to use where? Makes me feel sane.

Oh, I don't get the speaker issue. Speakers are 25w on the low end anyway aren't they. Maybe 15w.

If you wan't some drive but can only have the vol of a 5-10watt amp you only have so many options and seems to me power-scaling is probably as good (and hopefully better) as any of them.

[mooreamps]

Is Power Scaling Flawed ???

Maybe it is. It would seem Mickey still has me tagged as a "trouble-maker"

Of anyone more capable of supporting "their cause", they give ya the boot. Maybe it's time Kevin calls his dog off me.......

-g

[TD_Madden]

Mickey?

[Arthur B.]

I don't see EF86s having enough balls to drive any available output transformer

I'm quite sure it'll deliver enough power to compensate for the transformer losses, but the load impedance would have to be scaled up, possibly in the hundreds of ohms.

[Enzo]

And you are just now bringing all this up again after SIX MONTHS because...?

[d95err]

Interesting thread this. I thought I'd chime in with some of my Powerscaling experiences. I have a 15W "18W-ish" amp that I powerscaled using the original Mickey C shematic from the 18W-forum (I've since bought TUT4, so now I know how it works too...)

First of all (contrary to the first post of this thread) noise is reduced a lot when dialing power down. Not just relative to the amount of volume reduction, no much more than that. I suspect that this is because with lower voltages and lower currents in the poweramp, there is less interference between the wires and components. I.e. if you record the amp at high and low power levels and play back at the same level, the low power recording would have significantly less noise (hum, bzz, hisss, ...).

The Fletcher-Munson effect, speakers and low power and so on, is the same for all volume reduction methods. It would be better to create a separate "Low volume" thread to discuss how to deal with this, and what equipment or amp mods would be useful to improve low volume playing.

As for the question - "why use Powerscaling when 99% of the audience can't tell the difference?" Well, YOU can tell the difference, and that's what really matters...

(And you can replace "Powerscaling" in the sentence above with virtually any fine piece of musical equipment - vintage guitars, "Boutique" amps, high quality cables, custom shop pickups...)

[kg]

after 20 years of screwing around with guitars and amps, i say fuck power scaling.

why?

because it will never work.

every time i pick up any guitar it sounds different, i feel different, and i play different.

i have learned to embrace the fact that playing softly (ie in my basement while my 3 year old is asleep) sounds completely different and demands different technique than playing loudly (ie in my garage with the BAGA at full tilt bozo).

the big lie about power scaling is that it should have been called a tone control, because that's what it is... just like the volume knob!

(incidentally, that's the reason why my amps never have labels or scales on the controls. why bother? it just sets you up for disappointment.)

jm2c
ken

ps. take "fuck power scaling" as no offense to KOC: i cut my teeth on some of his books and he's always been cool to me over the years.

[Steve Conner]

fuck power scaling... no offense to KOC

Most quotable thing I've seen on Ampage in years You've probably guessed that I agree with KG on the issue, though.

One thing I've been working on for a while now is upward power scaling, for when you have a tube amp that sounds good but isn't loud enough. I got the idea when playing with an old 3 watt Selmer Corvette. I replaced the old 8" radio speaker in it with an Eminence Beta 8 and actually preferred the tone. Now I have a 3 watt amp with a speaker that can handle 100w, hmmm....

[d95err]

One thing I've been working on for a while now is upward power scaling, for when you have a tube amp that sounds good but isn't loud enough.

Go read all about Super Scaling in The Ultimate Tone 4 then...

[d95err]

after 20 years of screwing around with guitars and amps, i say fuck power scaling.

why?

because it will never work.

every time i pick up any guitar it sounds different, i feel different, and i play different.

i have learned to embrace the fact that playing softly (ie in my basement while my 3 year old is asleep) sounds completely different and demands different technique than playing loudly (ie in my garage with the BAGA at full tilt bozo).

the big lie about power scaling is that it should have been called a tone control, because that's what it is... just like the volume knob!

(incidentally, that's the reason why my amps never have labels or scales on the controls. why bother? it just sets you up for disappointment.)

I don't think Kevin has ever claimed that Powerscaling is a panacea that solves all problems and results in perfect tone in any situation. What he does claim (rather boldly) is that Powerscaling works better than other volume reduction methods.

Tell us why you think Powerscaling would be worse than, e.g. Attenuators, mastervolume in a non-master amp, screw-tube-amps-I'm-using-a-POD or any other low-volume solution.

[Steve Conner]

No, I think the onus should be on power scaling fans to explain why it's better than the other methods mentioned. Turning down a volume control is the industry standard way of making something quieter, and power scalers are a minority challenging this.

I've never read any of K o'C's books, but my proposed "super scaling" involves a switch that interposes a dummy load, master volume, and solid-state power amp, between the Champ's output and its speaker. I'll hide all of this to test my hypothesis that transistors only sound bad when you know you're using them

[d95err]

No, I think the onus should be on power scaling fans to explain why it's better than the other methods mentioned. Turning down a volume control is the industry standard way of making something quieter, and power scalers are a minority challenging this.

OK, let's compare a stock 5e3 to a powerscaled 5e3. Let's say we want a nice crunchy sound at low volume. Which amp do you think sounds more consistent when turned down? The stock one, or the powerscaled one?

Most of the so called "flaws" attributed to powerscaling I see here apply exactly the same to master volumes, attenuators and so on. So, any constructive discussion needs to focus on the actual differences in tone between the methods.

I don't think there is an ultimate way of reducing power, but from my experiences, powerscaling works best. I've used my ears to determine that, not theory.

I've never read any of K o'C's books, but my proposed "super scaling" involves a switch that interposes a dummy load, master volume, and solid-state power amp, between the Champ's output and its speaker. I'll hide all of this to test my hypothesis that transistors only sound bad when you know you're using them

Go read the book and you'll find out why tapping off a resistive dummy load is not the best way to preserve tone, and how to do better. Super scaling can be done both with tube or solid state.

[kg]

I don't think Kevin has ever claimed that Powerscaling is a panacea that solves all problems and results in perfect tone in any situation. What he does claim (rather boldly) is that Powerscaling works better than other volume reduction methods.

it may very well preserve MORE of the original tone, but that's really subjective.

what you cannot take away is the fact that it is an interesting way of controlling output power, albeit more complex than previous methods.

i will never bemoan a circuit that promises flexibility and/or a wider range of tones on the pallate, and that (to me) is the proper way of thinking about it.

Tell us why you think Powerscaling would be worse than, e.g. Attenuators, mastervolume in a non-master amp, screw-tube-amps-I'm-using-a-POD or any other low-volume solution.

i don't think it would be worse at all.

... it is just different.

but, at the foundation, to expect the same tone/sound/effect/emotions/etc out of an amp that's putting out 1/10th or 1/100th the original power is ridiculous.

is driving a 400hp car at 10% throttle the same as driving a 40hp car at 100%?

is swinging a 12lb sledgehammer lightly the same as swinging a 6oz tack hammer swiftly?

maybe it's because i've been playing out of a truly large musical instrument tube amp for close to 10 years now that i've come to terms with what i'm talking about--there is SO MUCH DIFFERENCE between room response, cabinet response, speaker response, ear response, output transformer response, output tube response, etc, with different power levels, that trying to achieve a consistent tone across all of it will inevitably end in failure and disappointment.

again, i love kevin. i think he's an asset to the community, and i want to say that i have never found his claims or words to be negligent or misleading. i just think that people have unrealistic ideas about the perception of power and sound that no amount of electronic ingenuity can fulfill.

jm2c
ken