"Bret Ludwig" wrote in message
oups.com
Arny Krueger wrote:
THD as speced by the manufacturer is not the only
measure of equipment quality. For example, a lot of the
HP equipment would meet spec near their end of life or
the end of life of their tubes. while Heathkit equipment
might meet spec only if routinely maintained.

The HP generators derived from the Model 200 will run
forever, or at least more than one human lifetime.

If you use them a lot, the tubes wear out.

There
are no proprietary parts that are likely to wear out with
normal use.

Tubes have always been proprietary parts. OK, you HP 200C has say a 6SN7 in
it. Which manufacturer's 6SN7 is the right one to use?

If needed the transformers and the tuning
capacitor could be repro'd for far less setup costs than
having a replacement IC taped out, masked and a run made
such as would be needed on many solid state units using
proprietary ICs.

The tube-bigot lie here is that most ICs in good audio test equipment are
standard parts, or can be readily replaced with standard parts.