Powerful Tube Amp for SF Strads?

I know were are talking about absolute "reference" level speakers and components here, but I'm surprised that with this many suggestions and responses so far, no one has recommended simply trying Paul Speltz Zero Autoformers to increase the impedance seen by Llyod's amplifiers.

They can be used to double, or even quadruple, the load seen by the amplifiers. As a result, amps that "run out of steam" may often handle previously impossible speakers without breaking a sweat. In many, many, systems, insertion of the Zeros not only remove the impedance issue, they are undetectable from a sonic standpoint. Give the FAQ a read.

Not saying they are guaranteed to work in every situation, or even this particular one, but for $450 in the naked version and $950 in the boxed, it is a far cheaper, and easier, experiment than all the fantastic amps being suggested. And even high-powered tube or solid state amps can still benefit from seeing a higher impedance.

I know this sounds like an ad, but I haze no connection to the company, professional, financial, or otherwise. Just passing on a little suggestion from the world of high-efficiency speakers/low-power SET amps and OTL amps.

Hi Darkmoebius. Thanks for your thoughts! I do not know this product and will look into it. I know that Musical Fidelity has their superchargers which sound like they do the same thing but "supercharging" amps. I do not know the technology but I did see at least two reviews which were both a little mixed on the success. (Basically, more grunt and volume...but a loss of the refinement from the original amp standalone). Your recommendation may well be better solution. Thanks again.

Tuboo,

What power cords are your Antileon owning friends using? I have read PAD Dominus Ferox which is my goal. I think Gryphon use Siltech? Someone else recommended Transparent Ref PCs...I do love their reference speaker and interconnects which run throughout my system. Thanks for your advice!! Lloyd

Hi Lloyd,

Zero's are nothing more than impedance matching transformers(actually autoformers - just a primary instead of the primary & secondary in transformers). They serve exactly the same function as output transformers in tube power amplifiers, which are used to match the impedance of the output stage to the speakers.

Paul Speltz seems like a great guy from his postings and is extremely proud and confidant of his product. It probably wouldn't be difficult to get a trial out of him. He also can wind custom Zeros for specific situations,if I remember correctly. Although, yours is a fairly basic one.

Of course, excess power and headroom are always a good thing with all speakers, especially medium to low efficiency ones. So, in the end, you may need 100-300+ watts to fully realize the potential of your Strads on dynamic passages. Even then, though, the Zeros would help.

the Dominus in itself is a great PC but the next level Anniversary easily betters it. if you crave for speed and resolution i would however not pick Purist cables as first choice.
the SF speakers benefit greatly from Fast-Authorative- Speed and Resolution amps and cables. remember it is all in the match :-) i would first settle in with your Dominus, take your time and eventually try another PC.

the Speltz autoformers are a solution to a problem for sure.
personally i see no reason to go OTL first and put in Speltz Autoformers later because of bad speaker impedance.
why not choose 'good' speakers first?
i don't say the Autoformers don't work or don't sound good.
but to me it's like towing a caravan behind a sportscar and using slick tires still. well something like that.

i think high wattage as per definition is not a sign of a 'good' amplifier. and you don't need 300 watts to drive the 93 dB Stradivari.
you rather need 50 superb watts. the first few watts count most.
high wattage may be a sign of capacity but it says nothing about quality of powersupply nor authority.
big & heavy amps says nothing about authority and control too.
as a great example the little Cello Encore 50 amplifiers look like little sigar boxes and weigh nothing. i would dare to say these are more powerful sounding then many many amplifiers be it 300 or even 1000 watts.
the 'little' FM 111 monoamps would apply very nicely too.
or the 'little' Boulder 800 series. these amps would get any SF speaker on their knees :-)
don't let specs and size or even marketing 'the bigger the better' mislead. it may account for in many cases but not per definition.

now the big Gryphon is big and heavy for intrinsic reasons. it is one of the few true class A amps out there and this means big heatsinks and so acres of heat dissipation alloy. pure Class A rules be it SS or tubes.
once again congratulations on your Gryphon and Stradivari match and looking forward to read your experiences on Gon.