| Author | Message | ||
     TJ Koch (avman9) Username: avman9 Registered: 06-2009 |
I bought a 12AX7 P.I. HD-130 about a month ago and I really love the amazing glistening clean tone it puts out, however, after reading around the net about these amps, I think I may have discovered an issue with mine. The pre-amp starts to break up with single coils with the pre volume at about 2 and with humbuckers at 0.75, no matter the master volume. This just seems off to me. Knowing that MM amps can be "drama queens" when it comes to mechanical problems, I decided to get some info just in case there is something sinister lurking in my amplifier. Any help would be appreciated. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I think you got this posted in the wrong section, but I'll post anyway. I would check to see if it's been re-capped FIRST, then start with the normal stuff. My 2-10 does pretty much the same thing. I was GOING to go in and work on the front end a little to tame the preamp down but just decided to use the second input instead. It's lower gain and should clean it up some. Also, you should have the bias checked if it breaks up THAT early. You mught have the amp running beyond saturation and ready to go chernobyl on you. | ||
| TJ Koch (avman9) Username: avman9 Registered: 06-2009 |
Thanks Mike. Yeah I noticed that the section was called "Website questions" AFTER I made the post. My bad. Anyways thanks for the info. I don't think that it's in three mile island stage, I always check the heat output after long periods of use. Just standard power tube heat and the transformers are cold as ice. Also I made a mistake in the last post, it breaks up at 1.75 with humbuckers, not 0.75. I just want to be able to achieve that legendary clean volume that the HD-130 is known for. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Look in the back and see if it has amperex tubes in it instead of sylvania's. They will also mush up faster than the sylvania's. I'd try the second input and see what happens. | ||
| TJ Koch (avman9) Username: avman9 Registered: 06-2009 |
Yes the second input helps a ton. I was afraid it would kill the overall volume, but it really didn't all that much. The amp has sylvanias all around. Gray labeled 6CA7's and a green label 12AX7A. Thanks for the info Mike! |