Any dual, hi mu triode....

Posted by grhughes on May 25, 2012 at 09:24:45

In Reply to: Is there a lot of difference among 12AX7s posted by peterhh on May 25, 2012 at 08:18:30:

suffers from the manufacturing inequalities and difficulty of making a dual tube in one envelope that is well matched from side to side, ie both tubes, the same transconductance, mu, the same plate resistance, the same cathode current. They can't be made perfect, close but not perfect. Yes, there are differences from brand to brand. It was rumored once that the Chinese were evacuating tubes with foot pumps! I don't know if it was true but it came from a reliable American engineer that did consulting work for the wonderful Red Chinese. The best thing for an audiophile to do is get a transconductance tube tester and check the tubes for mu, ie gain, and distortion. Ray

This post is made possible by the generous support of people like you and our sponsors:

Follow Ups Full Thread

Topic - Is there a lot of difference among 12AX7s - peterhh 08:18:30 05/25/12 (15)

Sonically, Yes, there is a lot of difference among 12AX7 tubes.... - Interstage Tranny 20:19:27 05/25/12 (0)

I guess Joe S's old post answers all my questions - peterhh 12:30:25 05/25/12 (2)

RE: I guess Joe S's old post answers all my questions - Joe Appierto 12:50:04 05/25/12 (1)

Thanks for the link! nt - peterhh 15:37:08 05/27/12 (0)

Any dual, hi mu triode.... - grhughes 09:24:45 05/25/12 (6)

Would you care to divulge..... - Uncle Mike 00:12:09 05/26/12 (1)

RE: Would you care to divulge..... - grhughes 06:48:19 05/26/12 (0)

RE: Any dual, hi mu triode.... - peterhh 12:32:19 05/25/12 (3)

RE: testers - grhughes 12:59:50 05/25/12 (2)

RE: testers also B & K 747 - Mechans 12:52:01 05/26/12 (1)

RE: testers also B & K 747 - Jim McShane 21:36:32 05/26/12 (0)

Every ingredient that goes into a unit makes a difference.. - FenderLover 09:17:54 05/25/12 (3)

RE: Every ingredient that goes into a unit makes a difference.. - peterhh 12:39:49 05/25/12 (2)

Yes sir! - FenderLover 13:24:25 05/25/12 (1)

Thanks! nt - peterhh 15:19:45 05/27/12 (0)

Follow Ups

Any dual, hi mu triode.... - grhughes 09:24:45 05/25/12 (6)

Would you care to divulge..... - Uncle Mike 00:12:09 05/26/12 (1)

RE: Would you care to divulge..... - grhughes 06:48:19 05/26/12 (0)

RE: Any dual, hi mu triode.... - peterhh 12:32:19 05/25/12 (3)

RE: testers - grhughes 12:59:50 05/25/12 (2)

RE: testers also B & K 747 - Mechans 12:52:01 05/26/12 (1)

RE: testers also B & K 747 - Jim McShane 21:36:32 05/26/12 (0)

Any dual, hi mu triode....

Post a Message!