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Post by taswegian on Jan 11, 2006 21:17:25 GMT -7
I have some exie NOS tubes in my 66 but the PI is what came with the amp and hasn't been changed since 2003. I realize this is probably too long but what are the tell-tale signs of a PI going bad? Everything still sounds fine. Thanks.
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Post by myles on Jan 12, 2006 12:38:17 GMT -7
Things may sound fine over time but the changes go un-noticed. The PI is a hard worked tube. I change these every output tube change or every other output tube change.
As far as not noticing a change .... a few months back there was a show with Brad Paisley, Sara Evans and a group called Sugerland. I was there for Brad and Sara bu the guitar player from Sugarland was looking over my shoulder and asked a few questions. He had two Vox AC-15 amps that he ran set identically. He said he thought they sounded great. I asked when they were last retubed or looked at and he said "never". I was pretty busy for that two day show but I offered to work on one of the amps. When it was done he compared amp 1 and amp 2 and found them completely different. Even the union guys came to comment at sound check. He asked me to do the second amp but I had other things I had to attend to but gave him a tube set for the second amp.
In any case, during the first sound check Brad said he wanted his MAZ 38 a bit tighter and in less than 15 seconds I had changed the phase inverter from a 135/137 to a 152/155 and he was happy. The phase inveter is pretty darn important.
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Post by taswegian on Jan 12, 2006 16:06:59 GMT -7
Thanks Myles, so obviously I should find a long plate or smooth plate 12ax7 and try replacing it. I think I recall the Doc telling me to try a Tele smooth plate if I had the money. I guess I could throw the 12ax7m from my mini in there and see how that sounds. I seem to recall you suggesting long plates. My other valves are GEC Kt66's (brown base, clear glass) GEC ef86 and Mullard steel based GZ34 (1954) Thanks again.
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Post by jzguitar on Jan 12, 2006 20:11:36 GMT -7
Hey Myles!
I use the JAN GE 5751's for the PI in my Mazerati. What would I ask for if I wanted as much headroom as possible? The one in there now is 95/95. Or would a long plate 12AX7 be the way to go? Man - I wish I was gonna be in L.A. sometime soon. I'd love to pick your brain about my 'Rati. Thanks again for all of your help here!
jz
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Post by myles on Jan 18, 2006 10:44:45 GMT -7
Thanks Myles, so obviously I should find a long plate or smooth plate 12ax7 and try replacing it. I think I recall the Doc telling me to try a Tele smooth plate if I had the money. I guess I could throw the 12ax7m from my mini in there and see how that sounds. I seem to recall you suggesting long plates. My other valves are GEC Kt66's (brown base, clear glass) GEC ef86 and Mullard steel based GZ34 (1954) Thanks again. In the Route 66 the 12AX7M is my favorite PI. I use the SAG-AX7-MPI which is selected off the M's.
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Post by myles on Jan 18, 2006 10:46:43 GMT -7
Hey Myles! I use the JAN GE 5751's for the PI in my Mazerati. What would I ask for if I wanted as much headroom as possible? The one in there now is 95/95. Or would a long plate 12AX7 be the way to go? Man - I wish I was gonna be in L.A. sometime soon. I'd love to pick your brain about my 'Rati. Thanks again for all of your help here! jz 95/95 on whose scale? If this is a VTV scale I'd need to know that. If you want more headroom go to a 12AY7 or for even more a 12AU7.
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Post by taswegian on Jan 18, 2006 14:32:38 GMT -7
Thanks Myles, I might have to order one from you.
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Post by myles on Jan 19, 2006 17:12:55 GMT -7
Thanks Myles, I might have to order one from you. You are very welcome.
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Post by bluzsteel on Jan 23, 2006 20:00:07 GMT -7
I ordered a SAG-AX7-MPI today , I will give my 2 cents in a few days
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Post by taswegian on Feb 27, 2006 1:16:54 GMT -7
Me too!
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