- Posted by perryc_516@yahoo.com (A) on April 29, 2007 at 15:06:15
I was wondering, which tube brand is the best to use for the CJ PV7 preamp. Current use are Electro Harmonix 12AT7 and 12AX7.My dad said it sounded forward and bright.
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I was wondering, which tube brand is the best to use for the CJ PV7 preamp. Current use are Electro Harmonix 12AT7 and 12AX7.My dad said it sounded forward and bright.
i know that they retube them at the factory (just down the road from here!) with philips JAN's.. used to have such a beast until it had 'catastrophic failure'.. and the phono board fried to such an extent that i couldn't do anything with it! i can't say it ever sounded forward and bright, though-- i'd suspect other than your preamp for that.. what about amp/cabling/sources? hell.. i used mine with an adcom 555ii.. so i know that preamp's not bright!besidedly, though-- if you can find 'em and afford 'em-- put some telefunken smooth plates in the first gain stage.. that'll take the edge off anything-- but lots of good advice in here.. sovtek ax7lps'd be WAAAAY cheaper...
good luck!
d
The EH "house sound" is a bit bright, and when you have two EH it can make it pretty hot.You don't need to spend a bunch of money to make real improvements. I do recommmend a NOS tube for the 12AT7, IIRC c-j used RFT 12AT7s for a while, and I can recommend them. They aren't expensive either.
In 12AX7s, the 12AX7LPS Sovtek is a very neutral and very quiet tube. That or the Tung-Sol reissue would do you well. Both are very reasonably priced.
There is some synergy to be had by mixing different tube brands in your unit, if you want more down and dirty detail drop me a note.
The AT7 is a cathode follower, and for the most part you can sub an AU7 in it's place without any problems. This gives you a ton of options.
Although the AU7 will not have the dynamics of the AT's, it will have a smoother presentation.Stu
Extirpate the EH tubes and get British either the Mullard Blackburn which would be the best tube I think for your problem in both 12AX7 and the 12AT7, even the later production Mullards are probably what you are looking for. Have Dad pony up the cash. They are not inexpensive but the military versions aren't overly expensive KR Audio has them routinely. Or if you like the sound tell Dad to listen to his own rig.
Alternatively find a Phillips tubes made in the Mullard factory (do a search for Mullard codes the Blackburns were acid etched with a B in the middle but search), or get Brimars many of which were made by Mullard. For the 12AX7 you can frequently sub a tube called a 5751 read Joes tube lore under FAQ the gain is lower 70 vs 100 for a 12AX7 , the best are the early versions with triple micas, They are expensive in certain brands but the market has cooled off considerably. The GE 5 Star are fine and abundant, otherwise if on a tight budget the Jan 1980s production is always around and don't cost much more than modern production. Otherwise do what all people do when unsure use a dealer you like to guide you. Shoot me an email I may be able to help you.
