2. amps-preamps
  3. 1178225663

12AX7 vs. 5751

I'm getting my first tube pre (Counterpoint 7.1) this week or early next week, and of course I have start fiddling with it ;-) I've been reading Joe's Tube Lore (http://www.audioasylum.com/audio/faq/joes-tubes.html) and the 5751 caught my eye, however I see statements like "lower gain that the 12AX7" and lower "mu" (what is mu?). Anyways could I use the 5751 tubes in my Counterpoint without causing any damage? altavistaaudio.com mentions nothing about the 5751.

thanks
greenp3
davt's avatar
davt
505 posts
 
I use a matched set of 5751 NOS RCA from 1959 in my Belles 21A preamp. I went to them from Mullard 12AX7. I found no audible difference in gain with my system. I found the RCA's to provide a little more air and detail between instruments, a little more depth of soundstage and very nice extention and tightening of bass. I got these from Vintage Tubes and have been very happy with the upgrade.
casouza
239 posts
 
5751s will work fine on a 12ax7 line stage.
OTOH, on a phono stage, you need all of the 12ax7 gain.
Good luck
Ag insider logo xs@2x
hoopster
184 posts
 
Typically you can use 5751s where 12ax7s are called for. The 5751s having less gain just gives your volume control a little more flexibility, ie you can turn your volume control without a little adjustment giving you a big volume increase as 12ax7s give in some applications. With my preamp there is a noticable difference in gain between these two tubes. 5751s were speced for the military and are very rugged. They also sound very nice, IMHO. I too like their air and detail and I would add bass response. Just to make sure, send altavista an email, they are the experts on Counterpoint equipment.
More to discover