12ax7 subsitute ec808

[Rafa]

Is the ecc808 a 12ax7 susbtitue?
Can I use it in the preamp Im going to build (matchless dc30)?
I found a guy at mi city who sells them and not expensive
Take a look:
http://cgi.ebay.com/2x-NOS-ECC808-Siemens-Low-noise-12AX7-ECC803S-variant_W0QQitemZ190060197521QQihZ009QQcategoryZ67816QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Cheers
Rafa

[JimRayden]

All the info is within your link.

Yes you can use it but the radically different pinout makes you unable to use "the real" 12AX7's in that circuit.

Unless you wire up two sockets in parallel - one with the usual pinout and one with the whacko one.

Here are the pinouts:

ECC808


12AX7


I'm not sure if the gain figures and such are identical, but note that you can only use 6.3V filament supply here, no 12V wiring.

---------
Jimbo

[Rafa]

Well that wouldnt be a problem. Just som slight changes in the power supply
Thanks Jimbo for the info.
Cheers
Rafa

[JimRayden]

http://www.mif.pg.gda.pl/homepages/frank/sheets/124/e/ECC808.pdf

...in case you need more specific info.

---------
Jimbo

[Gilles C]

Check the tubes of this site.

Good tubes at a good price.

http://www.eurotubes.com/euro-e.htm

And I would be curious to try the 12AT7 equivalent, which he says:"....has all the qualities of the JJ 12AX7's"

It was mentioned before that the 12AT7s didn't sound as good as the 12AX7s, so...

Gilles