Any opinions on the ECC81?

[lazthegaz]

I am considering using an ECC81 (12AT7) in the second stage of a DIY phono preamplifier. The main reason for considering this type is simply that I've got one in the drawer. However, it looks like the ECC81 is not as frequently used as the ECC83 (12AX7) or ECC88 (6DJ8) so I thought I'd ask you: have you got any personal experience with the ECC81? What does it sound like?

[dhaen]

Have a look at this thread

[lazthegaz]

I did read that thread. My question is not whether they CAN be used. Of course they can, and it should't be too difficult to bias them properly to make a decent amplifying stage.

What I was hoping to hear were opinions of people (if any) who have actually done this and their subjective opinion on the result.
It's just that this tube doesn't seem to be as obvious a choice for an amplifier stage as the ECC88 or ECC83. Maybe it's just overlooked - maybe it doesn't sound particularly good. This is what I was trying to find out about.

I suppose I might just need to try and use my own very subjective ears.

[dhaen]

They sound fine. I seem to remember they are used in the front end of the Bottlehead Paramours, although they use a CCS load to improve performance (hum and distortion).
Like many of these double triodes, it was originally intended for RF work, but they work well at AF too

You might find some more mentions with the search function.

[fdegrove]

Hi,

The VTL phonopreamps used the ECC81/12AT7 quite often as a second stage tube to take advantage of the high mu and lowish Ri.

While I find Manley overused the tube, giving his gear a sonic fingerprint I tend to attribute partly to the ECC81, using a single ECC81 in a phonopreamp would not have that kind of impact IMO.

Cheers,

[SY]

The 12AT7's flaw is noise performance- it's fine for line stage use, but can be a bit dicey in the first hole or two of a phono stage. But once you've got the signal level up a bit, no problems, the tube is pretty linear in the right circuit. I've got a reworked Berning TF10 here that uses the 12AT7 in holes 3 and 4 of a 4 tube phono stage and it seems to work just fine- most of the preamp's noise comes from the first stage (12AX7-based).

[Armin]

we have a lot of ECC81 here in germany, so I tried them in
pre and power amps.
Half of a ECC81 is EC92, for info.
I bild a phono riaa, passive, with half ECC81 in the input, and a half ECC82 or E80CC second stage.
With good results, but some ECC81 are microfonic sensible.
I tried also a ECC85 as replacement for ECC81, this works
fine, but a little less gain.
Also, I used ECC81/85 in as phase inverter/ driver for a EL84PP
amp. But you can find a lot of classic tube amp designs wich use
a ECC81, Excample: Dynacord Eminent.
If you want my phono schematic, please reply.
regards from germany
Armin