"Jon Yaeger" wrote in message
...
Hey Mike,

Drop me a line when you're ready to dump your 10B. I've always lusted for
one of those . . . . .

A good buddy of mine left a 10B on the curb, figuring that no one could
work
on it. He told me that he cried after I sent him some e-bay completed
auction figures . . . .

I'm surprised that Mr. Morein stopped his perpetual duel with Mr. McCarty
even momentarily to opine on an audio-related matter. (I thought I'd
never
say this, but we're probably better of when he sticks to "outing" Brian).

I don't quite agree with Bob. In general, my SS tuners had better
selectivity than the many tube receivers that I tried. My "gold standard"
was the ability to pick up WCLK, a wonderful local jazz station owned by a
Clark Atlanta U. Only a DH-330 could find and lock on it.

I agree with the above statement. Is there some misunderstanding as to what
I said?
The DH-330, of which I've had two, was inferior to several FM tuners I
continue to own.
It was almost state of the art in mono mode, but markedly inferior in
stereo.
And I'm generally a fan of Hafler gear. Hafler was a local legend, and I use
Hafler amps extensively.


However, some of the tuners - especially the Sansuis - had a pair of
Nuvistors in their front ends and actually overloaded at times. Atlanta is
crowded as hell with mediocre (or worse) FM stations; there weren't so
many
around when these things were originally sold.

Nonetheless, the Nuvistor equipped gear would pick up stations I never
heard
before, and many that were apparently beyond the capability of the SS
DH-330.

I bought a ragged Sansui 1000 recently, and raided it for the trannies. I
am building a separate amplifier around Welbourne Lab's Dynaco ST-70 kit,
designed by Alan Kimmel.

If I have a bit of time I may try to reconstitute the Sansui's FM
circuitry
and substitute a crystal filter IF stage that I've been saving for years.
And maybe I'll also add an RF attenuator to reduce the overload and see
what
happens. But that's project #24.

- Jon


Nuvistors had the lowest noise figures of any production tube, but by
the nature of thermionic emission, have a higher noise figure than a good
FET.

I won't challenge your claim that your Sansui nuvistor tuner outdid the
DH-330, because it was far from the ultimate in tuners. It used a VCO analog
locking scheme, which made performance in crowded areas inferior to modern
tuners, which employ digital synthesis.

The 10B is doubtless better than many decent FM tuners. I don't see how
it could compare to the best solid state twenty five years later - ie, the
Onkyo T9090 mkII, or one of the other DX favorites. No prejudice against the
magnificent design work; but vacuum tubes operating at 700C have a much
higher equivalent temperature than a cool semi.

Overloading by itself is not an indication of sensitivity. It's another
aspect of design. If AGC is applied to multiple stages, the tuner will have
greater dynamic range. This was not frequently done.