[Boatanchors] are all 6550's created equal?

[Todd, KA1KAQ]

On 8/2/05, Eugene Hertz <ehertz at tcaf.org> wrote:
> 
> Hi All, I *might* be in need of a pair of 6550's and I was looking around. Seems that these were very popular with audiophiles.  I was wondering if I bought a pair that were advertised from an audio-related company if they are the same and would work for me (ce 100v).  For example, here is a pair on the eplace that seem reasonably priced... thoughts? epay item# 7340864412
> 
> If they are not the same, how could I tell when a 6550 is usable for audio or RF?

Eugene - 

These are the 're-issue' tubes, a company overseas (Russia or China I
think) is where they are produced. Someone purchased the old
equipment, design, name, and so on to remanufacture these since demand
appears to be high for the original Tung Sol type. I have no
experience with these personally, only the originals. Maybe someone
else will chime in.

I suspect for the purposes of RF, any of the older versions (including
the A) would work fine. 6550s are a fine tube, but they likely get
their pricey nature from the fact that so many older HiFi amps
(McIntosh, etc) used them moreso than being the ultimate audio tube.

Fortunately, there was a spare set with the 100V I picked up and I
purchased 3 good pulls from a listmember. I keep my eyes open for
them, but they're more difficult to find these days. Somewhere I have
a box of pulls with the keys broken off. Seems to have been a common
flaw.

It's probably not too bad of a price in today's world, but I'd want to
hear more about their performance and longevity. Unfortunately, they
haven't been around all that long. Can't beat that shape and look,
though. They look great.

~ Todd/'Boomer'  KA1KAQ