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Re: why poeple alway talking about dynaco ST-70 ?

Posted by ToobWiz (M) on February 21, 2005 at 03:27:46

In Reply to: Re: why poeple alway talking about dynaco ST-70 ? posted by lovetube on February 21, 2005 at 01:43:47:

lovetube,

With all due respect to Sparks, whether an ST-70 sounds good is based on opinion, as is I suppose, nearly everything in audio :-)

The ST-70 once was a cheap way to get into tubes, but with thecurrent demand for decent ones, it is no longer. Nowadays it is *much* easier to find a good Fisher, Scott, HK, etc. receiver (or amplifier) which will give you *much* better sound than anything Dyna made (original design)nas they are better designs.

The Dynaco circuit is so common because it was CHEAP to build or rather supply to builders, and likely rather profitable. It *measures* OK when the input/PS tube isn't aged.

If you want an old PP amplifier, none of which *really* sound good by today's standards, then Eico, Lafayette, and some others made amps with better circuits (cull Knight, only a very few of their amps had OPTs that were up to the job, though their circuits were quite as good as the others) and they are available cheaper (with some exceptons. F'rinstance, an Eico HF-87 or 89 is tons superior sonically to anything Dyna made, and when brought up to date, sound (and measure) much better than a Dyna ST-70. However, IMHO, they are all fuzz machines regardless of what you do to them, if you keep the original circuits, even the best of that crowd *maybe* excepting Eico). You can put a cross-coup;ed phase inverter (at some no small expense) into any of them (along withh cood caps and resistors, plus extensive PSU upgrades) and get about as good as PP gets.

Sparks is correct that the Dyna OPTs were very good, generally. So were Eico's and those of the receiver (and power amp) manufacturers mentioned above. I rewired a Fisher X-100-B to triode output with no NFB, and redesigned PSU, and extensive cap and resistor upgrades, and oh yes, passive phono amp and different driver design :-) and had about as good as PP can get. It would have cost a fortune without my "junk box" being available. It was still a "minor fuzz machine", but it got a lot of compliments as to sound quality. I'm now modifying it to a DRD SE 2A3 (don't ask; I'm rightly regarded as a madman :-)

Why are ST-70s in such demand??? Nostalgia, pure and simple. That's the answer to your question.

Cheers/The Fader
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