Richard Gecko wrote:
I still have original McIntosh Sylvania 7591 tubes, but I heard that
Soviet tubes are now available at low cost. Wonder if they're any good?
By the way, although the tube cage that was original to this amp (and is
seldom available) looks nice, do not be tempted to use it if you have
one. It traps too much heat and will cook the tubes and aging wiring in
no time. Besides, the soft glow of the tubes is soooo nice, yes?

Gecko


Yep, this one came with the new Electro-Harmonix power tubes, they're
labeled 7591A, FWIW. Don't know about how the height compares to the
originals, as Scott mentioned, but they are 3/4" or so shorter than the
transformers.

According to Frank Gow, who I bought the amp from, a real advantage of
the MC225 is that it does not require tube biasing or matching. Don't
know for sure how that applies to the power tubes, but I can't imagine
the old ones could sound any better, this amp is just sweet.

I appreciate the tip on the cover. The amp did not come with it, but I
wouldn't have used it anyway. Like you I prefer the look of the tubes,
I never put a cover on any of my tube equipment, unless it's for live
use or is required to work with a forced air system that needs the
cover.

When I was a kid I watched my Grandpa work on tube TVs and radios. He
installed little fans on every one of them. He would make sure he told
me time and again, "heat is the enemy, heat is what kills vacuum
tubes".

Every old TV my family ever owned had a fan in it eventually. For
years, our standard line anytime anything broke was "Put a fan in it".

I like variety, that's for sure -- I'm using Grant Carpenter's Gordon
preamps that look like they belong in a space shuttle, right alongside
this nice old '60s-something McIntosh amp!

Steve