I have to ask. This is one of the topics I find most interesting. For those using tube amps, what tubes do you prefer in your pre sections? Right now I'm using Tung-Sol 12AX7s in my input stages, JJ ECC83Ss in the lead channel gain stages, and a Sovtek LPS in the PI spot.

Anyone have other preferences in tubes?

Sha,

I think a 12ax7,  and an ECC83 are the same tube,  just different designations.  A 7025 is another designation of that tube.
I have an old tube amp, I'll iventory the tubes (as I forget whats in it now)  and post them here.  I know there are at least 4 12ax7's in there.   

Jim

You would be correct sir. I think 12AX7 is the American designation, ECC83 is the European designation, and 7025 is the military designation. Three names for the same tube. I usually go with whatever the manufacturer calls them, and use whatever I think sounds good.

This may help:
http://www.greenbulletmics.com/VACUUM_TUBES.html

The gain factor of preamp tubes is a good starting point. I love the 5751 preamp tube for a creamier sound and they also sound better when driven hard. They let the power amp tube distortion come through more because they (pre amp) are not distorting as much. Stevie Ray Vaughan used these. They are interchangeable with 12AX7's so you can buy them and try them out. I use these with KT66 power amp tubes for the best guitar sound I have ever found it is just incredible. This combination is what Clapton used during his "Bluesbreaker" years. KT66's are similar to EL-34 (Marshall type tube -English) and 6L6 (Fender type tube-American).
This is my amp, it's not peel the paint loud but it sounds so good and I can try different tubes out with it; I bought Curt's Mad Scientist tube kit with the amp:
http://www.emerysound.com/Superbaby.html
I hope this helps.

gtrjoe

...when "substituting" tubes in an existing circuit, it's actually NOT the tube gain (mu) that's so important, but rather the plate resistance (rp) of the tube.

...there's a rather 'technical' reason behind this, but anyone who's studied "...resistanaces in parallel..." will readily understand WHY the above statement is true.

Well O.K. then....guess that's why I stated "a good starting point." For those of US who have NOT studied....

.....just trying to help - not know it all

While OTM's level of knowledge may dwarf some of us mere mortals, there's no need to take it as an insult. Let's be glad he's so willing to share his knowledge. If he wants to post a book's worth of material discussing the intricacies of how tubes work, I for one will be reading every word.

That said, the original purpose of the thread was to simply find out what tubes others prefer to use. Tone is about preference and in this case at least tubes are about tone. gtrjoe your interpretations of things, which I can only assume is based on what your ears tell you make good tone, are more than welcomed.

In that vein I recently replaced the Sovtek LPS in the PI slot of my amp with a JJ ECC83. It smoothed the sound out a lot without taking away the edge that the Tung-Sol in V1 gives it. Good stuff.