On Fri, 9 Nov 2018 17:06:12 -0800 (PST), wrote:

On Friday, 9 November 2018 23:05:29 UTC, Ralph Mowery wrote:
In article ,
says...

Tubes are a whole 'nuther thing. It looks like there is a lot to
learn about tubes. How specific types work, which can be substituted
for which, etc. Which are best in new production because NOS tubes may
not be any good. And are often more expensive anyway.
Any more advice and suggestions are welcome.



Most NOS tubes I have dealt with seem to be fine. I have some tubes
that are very old and no problem with them. Many can be bought for a
few dollars if you look around.
I have a ham amplifier that has the origional tubes in it from aound
1975 or older. They still put out the rated power.

I have 1930s tubes still in occasional service.

If buying old, there are plenty of crap tube amps to choose from. And some good ones. And some major winners.

As for power, speakers have gotten less sensitive for good reasons. If you're sure you need a ton of volume, look for (1960s) domestic speakers in big cabinets & try tem out. Don't touch large pre-war ex-cinema stuff, fidelity still had a long way to go.

If you buy modern, look for large woofers & cabinets, horns for mid-range. I'd also look for piezo tweeters but not everyone likes them. Those 4 features are as efficient as they get (with reasonable equipment).


NT
The only speaker that I know of that had piezo tweeters that sounds
good is the Dahlquist DQ10. Dahlquist put an 8 ohm resistor in
parallel with the tweeter and crossed it over above 10 khz. The normal
way of hooking the tweeters directly to the speaker input results in
horrible distortion.