5687 tube

[croccodillo]

Hi,

I found some Haltron (England) NOS 5687 tubes in a local shop, at a low price: are they good?
Can be used to drive a SE KT88?

Ciao,
Giovanni

[Eusebius]

Only last night I was listening to a 300b SET using 5687 in two stages as input and driver, and it sounded fine. I believe the 5687 has been used in a few high end SETs, even by Zander if my memory is correct. Don't have any schematic links, but I'm sure others will oblige.

[croccodillo]

Thanks for the answer.
Another question:
the same shop has some russian (no brand) 6N6P/ECC99, what about these tubes?

[phn]

Those, too, are fine tubes. A Russian tube to keep an eye out for is the 6N30/6H30. Look what they use in in the finest tube amps out there, like those by Ken Shindo. Usually that's a pentode. But when triodes are used, it's frequently low Ra triodes.

[dsavitsk]

Originally posted by croccodillo
I found some Haltron (England) NOS 5687 tubes in a local shop, at a low price: are they good?

5687's are teriffic tubes. Generally pretty linear, and not real tubey sounding. Plus they have a low plate resistance (~2K) so they can be used in a grounded cathode configuration as a line stage or driver very easily without the need for srpp.

Originally posted by croccodillo
the same shop has some russian (no brand) 6N6P/ECC99, what about these tubes?

Also a teriffic tube. Perhaps a little warmer than the 5687? These you can get on ebay for about $3 per, but are almost the same tube as the above mentioned 6H30. Even lower plate resistance on these.

I use both of these tubes with a plate load CCS as a gain stage for a DAC with passive I/V (http://www.ecp.cc/5687_module.html) and both work very well.

[widowmaker]

Originally posted by croccodillo
Hi,

I found some Haltron (England) NOS 5687 tubes in a local shop, at a low price: are they good?
Can be used to drive a SE KT88?

Ciao,
Giovanni

I have few pcs. 5687 RCA (IV 1964)... and they sounds very ordinary...
russian doble triode 6N6P sounds much better!