Posted by Bluzharper on April 13, 2001 at 21:54:29:
In Reply to: 12AX7/12AU7 swap posted by David on April 13, 2001 at 20:13:55:
: Can anyone tell me if I can replace a 12AX7 tube with a 12AU7 without any concern ?
You should have no problems if thats the pre-amp tube in a guitar amp. The amplification factor on the 12AX7 is 100% the factor on the 12 AU7 is 17% this will allow you to turn up the volume with somewhat less feedback and it should not hurt the amp. Great for harmonica not so great for guitar. Good Luck..