ECC40 preamp

[Hojvaelde]

Hello

I got some NOS ECC40 at Ebay. I want to build a line/pre. amp with those tubes.

Does any have a qualified schematic? Aikido or what else?

Regards


Benny

[andyjevans]

ECC40 is a great tube. I would use the Raleigh Audio design.

http://www.raleighaudio.com/figure_18.htm

[ray_moth]

Can you still get B8A tube sockets?

[andyjevans]

Yep - ebay usually has them. And ECC40s are regularly on ebay Europe.

[aerius]

Originally posted by andyjevans
ECC40 is a great tube. I would use the Raleigh Audio design.

http://www.raleighaudio.com/figure_18.htm

Given the relatively high plate impedance of an ECC40 (around 11k), I'm not sure that a transformer output is the best idea. My ECC40 headphone amp which uses transformer coupled 12SN7 output tubes is already pretty close to the point where frequency response starts getting rolled off on the ends, and the higher output impedance of the ECC40 is only going to make that worse. (sidenote, that's why I mostly use 6BL7 output tubes now with that amp)

One quick change I'd make to the schematic is to use something like the Gary Pimm CCS and use the low impedance mu output from the CCS to drive the transformer. That'll give the full bandwidth and make things sound better.

I've found the ECC40 to be pretty amazing tube, I still don't know what it sounds like since my amp just ends up sounding like whichever output tube I happen to be using. I have half a dozen varieties of ECC40's and they all basically sound the same, the only real difference being that some are quieter and less microphonic than others.

[andyjevans]

I've found the ECC40 to be pretty amazing tube, I still don't know what it sounds like since my amp just ends up sounding like whichever output tube I happen to be using. >>

I think it betters all those tubes like E80CC, 7026, 6N1P etc. It has particularly good treble. It was a famous European tube, used in loads of designs at one point.

[aerius]

I stumbled across the ECC40 at a local electronics surplus shop, I thought to myself "hey, these things look pretty neat, I think I'll get a few and build something". It was only after I built something that I realized how good they were, at which point I bought every last one the shop had in stock.

[kstagger]

I have a pair of Tungsram ECC40s sitting on my shelf and a pair of B8A sockets too... I've been using the EF40 lately - cheap alternative to the rising prices of EF86s...

gotta build something with those ECC40s soon...