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Don Foreman
 
Posts: n/a
Default Anyone need a tube tester?

On Sun, 01 Jan 2006 03:47:18 GMT, "Tom Gardner"
wrote:

See it your buyer wants to buy my copy machine. I still have a box of
negative paper for it and 2 quarts of developing fluid...I forget what they
call the process but it 'kinda worked. I also have a CP/M computer with
SSSD 8" floppy drives and a 9" mono composite monitor, hand built-worth
more! I also have a TUBE TESTER!

Gunner, here's the phone number for BFI in your area:XXX-XXX-XXXX If you
call them, I will too.


There are some audio guys and musicians (guitar amps) that *WANT* that
"tube sound" and pay large to get it.

I thought that was fetish bull**** for quite a while. After finally
studying the matter rather than smugly hooting, I now see why "tube
sound" really might be more pleasing to some or most. It's not the
same as the gold plated power plug stuff which is utter bull****.
Tube amps don't intrinsically distort any less than silicon amps,
but they do distort differently -- and the difference in relative
strengths of various harmonics (distortion) is more "musical" to
some ears. One key to this is "balancing" some of the tubes,
particularly the output tubes which often run in matched pairs. A
good transconductance tube tester would be very useful for selecting a
best-matched pair out of a bunch of found tubes. The cheaper
emission testers were really only good for weeding out dead or
near-dead tubes at the drug store. I don't know which flavor Gunner's
is, but being B&K I'd suspect that it's a good one. If there's
something on the meter that says gm, bingo. Gm is
transconductance.

Don Foreman -- who is struggling mightly (while whining miserably and
bleating pitifully) to learn to use microcontrollers and program in
C, but designed tube circuits many moons ago and still has the RCA
tube manuals.