When were the best tube amps made?

@atmasphere 

Tis ever thus...

I keep flirting with the idea of getting a valve integrated for my nearfield set up which has 4 ohm monitors. My current integrated is superb.

I am odd coz i love integrateds

Since I've gotten mentioned in these discussions I'll cite a few good tube examples.

CAT has a superb reputation and I've heard this from other tube designers I know and respect.

David Berning is a genius. His ZTOL circuit is one of the few real amp inventions in decades and his amps are special.

And I'm biased(pun intended, since the designers were good pals) towards the now, defunct Melos amps. Tube monoblocks with over 400 wats in triode and 25 watts class A and a damping factor 0f 20 from tubes, all from just 4 output tubes is something special. And the 400 watt rating is one pulled back from higher ratings for reliability.

And I know I'm missing at least a few other good tube amps.

Hi @atmasphere ,

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

Regards,

Alex.

@alexberger

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

I haven’t tried the Chinese 6SN7 that get good ratings (note some of their alternate sub types may draw more heater current!). But the Russian Tung-Sol and EH have a number of advantages:

• Can be easily sourced for low noise and tight matches
• They measure VERY high for transconductance compared to vintage 6SN7. These make GREAT drivers for power tubes.
• The Tung-Sol GTB are rated for much higher plate voltages and dissipation - versus vintage 6SN7GT and VT-231 (and certainly 5692) - which some circuits require. A GT tube in a true GTB slot will not last as long. There are some vintage GTA nd GTB tubes and they can be quite nice, but they don’t have the full-on "sweet tone" of the best old GT’s

In my VAC amps I find good vintage 6SN7GT sound best in V1 slots (I like various Sylvanias, Hytron, and Tung-Sol round plates best, followed by Ken-Rads and then RCAs last). But the Russian Tung-Sol GTB are just hard to beat in the V2 driver slots. They rock there. In V1 slots, the Russian tubes lend a bit too much of a solid-state like quality to the overall sound.

For preamps, old vintage 6SN7 tubes are very hard to source to be quiet enough. Microphonics is a particularly big problem there.

So yeah, as per @atmasphere , it just depends :) 

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

The Linlai 6SN7 is really impressive. I'm familiar with the KenRad, which is one of the best vintage types. Our customers report that the Linlai is actually a bit better- combining the best of the vintage 6SN7s with none of the weaknesses, which is a really strong recommendation! We've had a few in the shop and I really couldn't fault them. I didn't like the globe version- the glass itself is resonant so if the tube were to develop microphonics the glass will exacerbate them.