Preamp Tube question

[poke01]

I have 3 NOS Phillips Ecc83 preamp tubes, 2 Electro-Harmonix preamp tubes and the regulator stock mesa preamp tubes.
Any suggestions on where to put either or in the V1 through V5 in my 3 channel dual rec.? I know in the end it comes down to taste but just curious if anyone has tried these preamp tubes and in what order. I need to learn how each preamp tube affects the sound overall.

Thanks!

 

[MrMarkIII]

First, if you don't have it, download the manual:
http://www.mesaboogie.com/manuals/3chRecto.pdf
There's a tube tasking chart on page 22. Tells you which tube does what.
Put the amp on standby when switching tubes. It may help to have a small fan to cool them off before handling. It's more an issue with the power tubes, but tubes get warm, so be careful.
Start with the first pre-amp tube. "V1".
Replace it with one of the "test" tubes (NOS Philips, EHX).
Play guitar. Listen.
Rinse and repeat.
One tube at a time, V1 only. The V1 tube affects everything downline, so if you get a good one here, you're set.
You should be able to determine which of your stock of 12AX7s sounds the best in V1. If not, that's good, too. You have a whole bunch of good sounding 12AX7s. Yay!
Then move on to V2. Rinse and repeat.
It might help to have something like an egg carton or some way you can separate the tubes into "good", "better", "best", just to keep track. Take notes, it's easy to get 12AX7s mixed up - they all look alike. Happy hunting!

 

[fluff191]

V1 - Phillips
V2 - EH
V3 - Preferably a chinese tube. The Phillips might cut the top end off the distorted channels a bit too much (they did in my amp). But the NOS are perfectly fine in V3 (they can handle the high voltages of the cathode follower).

Hope that helps.

 

[poke01]

Thanks for the input and the link. I will try both suggestions and see what I get.

 

[Jonberrier]

V3 - Preferably a chinese tube. The Phillips might cut the top end off the distorted channels a bit too much (they did in my amp). But the NOS are perfectly fine in V3 (they can handle the high voltages of the cathode follower)

+1

Those EH tubes are probably Sovteks and they DO NOT handle cathode follower stages well at all. Best avoid putting Russian tube in V3 (the second triode is a cathode follower).