Manley 440 monos to drive low impedance ribbons?

How long have you had your Scintillas?

Manley are set from the factory for a 5 ohm optimum load and
can be modified to switch to 3 ohms nominal.
The fact that the power is not important, is disputable.
Not as important as the low z capability, yes but part of
the equation. About the Scinnies: drove them in the latest
12 yrs. with Tandberg 3080 (30 amps. peak receiver!!!) in
the 4Ohms configuration (85 dBs) with B&K 200 monos (95 dBs)
Bryston 7b ST (105 dBs). Progressive quality response too.
The best sounding combo was with Spectral 10D pre + DMC 200, which was failing to stable drive the Scinnies (both in the 1&4! Ohms). I kept an eye nopen for the Wolcott 220M's, Kraft 400s /or 250s and the Manley 440/or 500's.
Nobody seem to have tried the Manley/Scintilla combo, so...
why not? The worst,I'll end byamping (passive or active).

John

Jstones, I just don't think that 1/2 ohm impedances and tubes go together in the same sentence.You are going to need a SS amp, or maybe you could use one of those autoformers from Zeroimpedance to help, but I don't know how good those things work. The output impedance of all the tube amps I know of is too high for a 1/2 ohm impedance load. They are all going to go unstable at that kind of load. I would highly recommend researching this before you go blowing up some very expensive amps.

I see. That's of course were I started from, too.
Then, Mr. Henry Wolcott, kindly enough to address
the problem, assured me that:
he thinks that his 220M's (2x175W) are able to properly drive the Scintillas, because, at 0.5 Ohms, his tubes amps will still deliever 70watts to the speakers. Also, reminded me, that "tube watts", count as 3 to 4 times more that "transistor watts" as a given and scientificaly proven fact.
As I didn't have the chance to get a second hand Wolcott,
I assumed that a 2x275W / 2x540W Manley, won't prove less.
Here I might of course be wrong, that's why I was looking
for any possible confirmed opinion. BTW, Ms. Manley thinks
that it's gonna work. What a great lady, she is!
Do you have any hard facts, or (just like me) assumptions?
Thanks,

John

A couple of things...

First of all I think that using tubes on such a low load is an incredibly bad idea. You will be wearing down the tubes and transformers and really overworking the amplifier, and that is assuming that you can get the amp to perform in a stable manner given the impedance of your speakers.

Second, even if it does work and you are able to play anywhere near the listening levels you'll want to attain, it'll sound like garbabe. Tubes don't sound good when they are overworked in terms of the load presented. You will suffer poor bass control, shrill highs, poor tonal balance, mediocre imaging... shall I continue? Even out of two ohm taps (which some amps offer or can be modified to provide) you are talking about a far too challenging load.

Third - I don't care who says what about power output. That is completely irrelevant. We can argue about this until the sun sets. Mathematically you may have plenty of power but remember at the end of the day, watts RMS is a pretty misleading spec all thing considered.

Fourth - why are you trying to do this? Just use solid state. It's going to sound infinitely better in this case, it'll be far more reliable, and you'll be able to play much louder. You will also save yourself a lot of time and energy. Do you realize how much it's going to cost to retube your monoblocks? And you will have to do this quite frequently if you run the amps into half an ohm.

I understand that a lot of people want to run tubes instead of solid state. I am fully aware of the appeal of tubes - I run them myself at home in my own system and many of my customers are tube gurus. However, using tubes purely for the sake of using tubes makes no sense IF they are not going to perform as well as solid state for a given application. When customers come to me I decide what amp will work best for them based on a variety of variables (room size, listening volume, and most importantly speaker impedance) If the customer is open minded and has speakers which will present a realistic load to an amp, I often recommend tubes. But in your case I think it's an incredibly bad idea.

Bear in mind that you really must pick a solid state amp carefully too - a lot of solid state amps will either limit current output or shut down all together into that impedance. Make sure you go with a solid state amp that will run all the way down.