My Power Scaling Box Arrived Today!!

[shredaholic]

For anyone who doesn't know what Power Scaling is, it's a superior alternative to an attenuator. To quote the instructions:

"Power Scaling allows the output power of an amplifier to be varied from 100% down to less than 1% of the full rating. This allows the speaker-amplifier interface to remain intact as this interaction cannot be mimicked. The Power Scale method controls all of the voltages around the Scaled stage(s) to maintain their transfer curve shapes, and thus tone. Controlling all of these voltages means waste heat from the output stage is dramatically reduced as power is dialled down, greatly extending tube life."

more information is available at www.londonpower.com


So not only is power scaling an alternative to attenuation that doesn't sound like ass at low volumes, it makes the power tubes live about as long as a preamp tube. Since NOS preamp tubes last about 30 years, that would mean theoretically I could buy NOS Mullard EL34's and have them last 30 years! Maybe they don't seem so overpriced after all....

Because there's a control to vary the amount of signal going into the poweramp (in addition to the power amp scaling control), you can actually make the poweramp distort more than it would when the amp is on 10. Anyway, here's some pictures :bigthumb:

It's not as big as I expected, which is an added bonus:

note size in relation to an .022uF Sozo cap...

Looks like I've got quite a bit of reading to do. I won't be able to post clips for a while, as I'm right in the middle of exam month so amp work and guitar playing is out of the question!

 

[kevlar3000]

Re: My Power Scaling Box Arrived Today!!

Mullards already last for 30 yrs. LOL I have many tubes over 40 yrs, still going strong.

I personally don't like the idea of having it work for only one amp. When you have 16 of em, it becomes the cost for P.S is far out of reach. My Weber Mass serves me extremely well. Now that I have a few speaker cabs, with different speakers, I am seeing the efficiency of the speaker has much more to do with how lowering the volume sounds. My Swamp Thang, Tonespotter cab sounds fantastic with the attenuator at any setting. Really great. My cab loaded with 60s CTS Alnicos, gets extremely murkier with less volume. I think that has more to do with not pushing the speakers, than it does the Mass itself. I would expect some similarities with any gadget that lowers volume. The speakers either take to it, or they don't.

If I had just one amp, it might be worth looking at. For me, given that I didn't get my amps to play in bedrooms, I think the Mass offers much more flexability.

This post does not mean it may not work out great for you. For multiple amps owners, it may not be the most useable option.

I definately want to hear clips though!!

 

[shredaholic]

Re: My Power Scaling Box Arrived Today!!

Yeah I think that's the reason Power Scaling hasn't caught on, it's also pretty difficult for someone to fit if they've never worked on an amp before. The tone is only supposed to be limited at volumes with Power Scaling by the speakers like you said, but I'm using G12M's which sound great at pretty low volumes. I'm not expecting to get perfect cranked amp tone at bedroom volumes, but it should be an excellent tool for home recording so it doesn't get me evicted lol. Anything quieter and I'd use my Marshall MG100HDFX as that sounds awesome for quiet home practicing.

 

[aleclee]

Re: My Power Scaling Box Arrived Today!!

For anyone who doesn't know what Power Scaling is, it's a superior alternative to an attenuator.

Bold words from someone who does not seem to have any personal experience with the technology.

Hope it works as well as the web site would have you believe. FWIW, most stuff I've heard about it (from people who have PS in their amps) has been good but there are other factors in cranked amp sound that PS does not address.

 

[shredaholic]

Re: My Power Scaling Box Arrived Today!!

Yeah I guess in terms of sound, but I meant it mostly in terms of it's effect on the amp. Apologies, I should have been more clear. What I mean by "superior" is that it's actually kinder to the tubes than running an amp normally, never mind with an attenuator. Also, there should be no risk of blowing an OT from it like there can be with some attenuation methods.