[dvb]

Any experience tube rolling the 12ax7s in the T7 phono stage?

TIA

[zybar]

Dave,

A few people (including Kevein Deal at Upscale Audio who sold me the excellent Mullards you are using) recommended Tungsram 12AX7.

I have heard them described as smooth, dynamic, and very neutral sounding.

George

[dvb]

Thanks for the suggestion, George.  I contacted Kevin at Upscale -- the Tungsrams are $45.00 each, which seems reasonable enough -- unfortunately, Kevin will only ship a minimum order of $150.00 to Canada, and I can't make 45 x 2 = $150.00!  Also, he will only ship FedEx, which has some nasty brokerage fees.   I am trying to arrange with a friend who does business in the  States to have them shipped to her.

In the meantime,  Eli Duttman suggested on Vinyl Asylum that  the JJ/Tesla (supposedly based on a Telefunken) would provide a nice balance to the Mullards -- perhaps because they have a more neutral midrange, so they aren't bloating the rich midrange of the Mullards.  He had liked the JJs in a T6 phono pre going into an all tube ASL integrated

Anyway, Triode Electroncs sells matched pairs of the JJs at about $20.00 for the pair, and ships by USPS air for $5.00.  

Not as good as the Tungsrams, I'm sure, but a fairly inexpensive eperiment to find out if changing the tubes will make a significant difference.

[yeldarb]

I have an AVA 4i and have tried several different 12ax7.  The older pre JJ Tesla's are quite good, as are Telfunken smooth plates.  The Teles are big $ and both are hard to find.  For an affordable tube try the 6681 available at Antique Electronic Supply.  On sale right now and usually GE branded.  In my kit (ymmv) it has smooth mids and highs but a lot more control / punch in the bass.

[dvb]

Thanks for the suggestion.

Do you worry much about matching the pairs in a phono pre application?

I understand that some feel it is not necessary in these small tubes, but, then again, in a phono pre they are handling very subtle signals.

[yeldarb]

I've never noticed any difference and the tubes I use are not matched.  I must not be that critical, or maybe I've been lucky with the tubes I buy.  I would also add that a high quality tube damper (Herbie's Halos is a fine example) made an unexpected level of improvement with my preamp.
There is a much "blacker" background from which the music emerges and "soundstaging" is deeper.  This is a relatively inexpensive improvement, at about the price of a full set of new tubes.

[dvb]

The Tungsrams are on the way, as are the JJ/Teslas.  That should get me started with some tube rolling fun.  It will be tough for the AVA to push the Wright off the block, but I am going to have fun trying.  I'll report back in a couple of weeks.

Thanks to Frank for his excellent reply in the "Saftey Concerns" thread about tube rolling in general.