Just got a batch of 50's-60's 12ax7's

[skhan007]

I just got these and can't wait to try them in both my 1987x Marshall plexi reissue and my GDS 18 watt 1974x clone. I was wondering if any of you have any opinions on the following 12ax7's and recommendations (phase inverter position, first gain stage, tone stack, etc.).

L to R:

1. Black plate RCA dates to Sept. 1957
2. Grey plate RCA 1960 43rd week (Oct.)
3. Long plate Bogen by Mullard dates B9A, Blackburn Jan. 1959
4. Telefunken made in Germany, unknown date. On the top it has a "913" stamp
5. Zenith made in Holland (Amperex, I think), unknown date. Has "6 21" stamp

http://i69.photobucket.com/albums/i57/skhan007/DSC_0003-12.jpg

[Timbre Wolf]

I recommend you try them out, yourself, one at a time, and in various positions. That experience will be exponentially more valuable than my (or anyone else's) opinion on which you'd like where. That's a good set to experiment with. Please post back with your results.

- Thom

[rockon1]

Try them and see. The Mullard long plate would be best served in the V1 though IMO. Its warmth and clarity and openess are hard to beat. Bear in mind long plates are better in heads than combo's due to vibrations.
I take it you cant see/find the etch code on the zenith? Bob