Power Scaling

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wally19840
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Joined: Mon Mar 10, 2008 1:37 pm
Location: USA

Power Scaling

Post by wally19840 »

I would like to start a new thread about power scaling. What is the most popular scaling circuit to use in a build. What are the pros and cons of each circuit also.
Thanks
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greiswig
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Re: Power Scaling

Post by greiswig »

Since power scaling isn't used much in Dumble circuits, I'd suggest you start the thread in the Technical Discussion section. Good place to search, too.
-g
John_P_WI
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Re: Power Scaling

Post by John_P_WI »

Why not head over to powerscaling.com and ask the man, KOC, himself?

If you are interested the London Power SB circuits will work with 100 watt amps and can be easily switched with the clean and over drive channels.
brewdude
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Re: Power Scaling

Post by brewdude »

I have used the VVR from Dana Hall (ur12) in three different amps, all with great results. It works great in a relatively simple amp that utilizes power amp overdrive to get the tone that one seeks.

However, the Dumble style circuits seem to be all about pre-amp overdrive/distortion and they use a very effective master volume. I find that there is no need to power scale my D'Lite. Its fairly easy to dial in a great sound at low volume.
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rogb
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Re: Power Scaling

Post by rogb »

I have used VVRs twice, both on 5w SE amps. They are very useful, especially with an MV.

In D style amps, if you use a Dlator, it is IMO unnecessary, as you can use the output pot as a global level control (in series mode).

I use it on the 50w and the 5w with great success. I put a VVR and MV in the 5w and it does work great, especially for recording, but using the Dlator is just easier, and smooths the sound too.

If you haven't built one, go ahead, it's easy, especially with all the great help on here :D
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renshen1957
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Re: Power Scaling

Post by renshen1957 »

wally19840 wrote:I would like to start a new thread about power scaling. What is the most popular scaling circuit to use in a build. What are the pros and cons of each circuit also.
Thanks
Hi,

London Power has different types of power scaling, DC Power Scaling (which uses any pot can be used being interfaced by PVIs) and their Super Budget (which uses a 2watt military spec pots).

I agree with John_P_I, KOC would be worth your time to make his acquaintance and his ideas. He has been by far one of the most accessible electronic genius I have met to date, and very generous with his time.

KOC possesses a wealth of knowledge (not only on Powerscaling) that is time well spent exploring. I originally purchased his TUT 3 book (on building amps, Vol. 4 and 6 are on Powerscaling) and his writings on the subject of grounding (galactic grounds, decoupling, etc,) DC_standoff voltage for heaters, and board layout changed how I build amps. This was before www.powerscaling.com came into existence, I subsequently purchased every book in the series. plus a few others by KOC. I pre-ordered his book on HiFi notes.

Dumble's power stage is more of a Hi-Fi power stage (no power tube distortion) and the preamp generates all the overdrive/distortion.
I will point out having the option to lower the voltage on the power tubes does have applications during recording, extends the life of the power tubes, and the PS can used to make Power Amp distortion at low level (an added tonal palette not normally associated with Dumble amps) is a great feature.

One doesn't need to be burning up power tubes at 100Watts of power when recording, especially if you are recording at home or apartment at two in the morning. when lower wattage (i.e. 1/2-1 Watt) will sound just as good.

I joined the ampgarage forum after reading TUT 6's Dumble chapter. Unlike vols. 3 and 5, The Ultimate Tone vol. 6 isn't layout and full schematics. Like his other books in the series, KOC explained quite a bit about the hows and the whys Dumble did what he did in his amps (even the goop) plus other ways to achieve similar results.

Best Regards,

Steve
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