Rocket preamp tubes

[paulster]

The Chinese 12AX7 and JJ ECC803S tubes seem to fare pretty well in cathode-follower positions and have a good reputation as far as new glass goes.

I haven't personally tried either though, as I like NOS, but I'd certainly be looking at these if I needed new production for V2.

RJ - The Tung-Sols will be quite happy in the PI as well as V1; it's only as a CF that they exhibit the problem.

[martin manning]

Does anybody know much about the Reissue Mullards? The review on these was also good but I'd like to add some real world credibility to go along with that review.
Otherwise it seems like the nod goes to the Sovtek 12AX7-LPS or the JJ.

My recent experience with the Mullard RI in an ODS is that they are microphonic and noisy. The JJ 12AX7S I have are better on both counts, particularly on the microphonics.

[jelle]

The sovtek LPS is a long plate spiral filament tube. This one has been reported on many occasions to be very sensitive to elevated cathode voltages. JJ's are not going to break the bank.

[FYL]

It's a real shame about this element of the design because they're a really nice sounding tube as far as new production goes, but suffer this problem and also are prone to massive heater hum after a period (which I work around by using DC).

Same cause: poor cathode to heater isolation.

Most Saratov-sourced 12AX7s suffer from the same problem because they are *not* real 12AX7s but copies based on the 6Н2П-ЕВ, which originally uses a different heater arrangement.

[jelle]

FYL,

Great info! Do you happen to know which Saratov produced ones are not based on that 6Н2П-ЕВ?

Jelle