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Checking back in after an absence-- life gets a little crazy sometimes. I've had a few other big projects to work on and not a lot of occasions to pull out the big guns (mostly teaching these days, no gigs in a while), so my 5150 was on hold until recently.
I checked the amp through different speakers (as well as a different amp hooked up to these speakers) and everything seems to be in order there. I think my problem is definitely within the chassis.
I changed the tubes in the amp on Saturday. I brought it to the luthier I've been studying with-- we tested the old tubes (they were reading well into the "replace" zone on the tester... 80-100 mOhms, lower for the power tubes) and put in a set of 5 Electro-Harmonix 12AX7's, and a matched pair of JJ 6L6GC's. All of these had strong readings before going into the amp.
I also pulled out the chassis (before replacing the tubes) to see if anything was noticably destroyed inside the amp-- a botched modification or leaky caps or anything else of the sort, but nothing stood out. This is, of course, to my untrained eye.
After I put the amp back together, I fired it up and my volume issues were resolved. The 5150 was as loud as it should be, although it still lacked much of the body and low end to the tone like before.
Now here's where it gets weird.
I put the amp in my trunk and drove back home. I fell asleep and it stayed in the trunk for a couple of hours in 30-40 Fahrenheit weather. Brought the amp inside and left it alone for a few hours to get back to room temperature. I plugged it in today and got... nothing. Tried 5 different cables, no dice. The only sound I could get was some loud fuzz (think poor television reception, not Big Muff) for about 5 seconds when the amp was turned on, and again when it was turned off.
On a random whim, I tried plugging the guitar in through the FX return and to my surprise, I was blasted with some full volume noise.
Check this out-- I get a clean, reasonably normal sound when I play through the effects return, but NONE of the knobs do anything. No EQ, pre or post gain, resonance or presence. I didn't think to test the reverb and I can't fire it up right now as it's REALLY loud. I can't switch channels, either. I only get the rhythm channel.
All of the new tubes light and heat up. The pre tube farthest to the right seems to be a little cooler than the others but that might just be me.
So my guess is that between the cold weather and the round trip-- from my basement to my car, across town,from my car into the workshop, up to the workbench, and back-- a connection snapped somewhere at the beginning of the signal chain. Or is this indicative of a different problem? I am SO confused I'm considering switching to acousic.
@Gribnick- I haven't heard of Jerry but maybe I'll try to get in touch with him. I haven't really had any amp work done in the past-- I'm still looking around at different places. I was considering making an appointment with Voodoo out in Utica (a couple of hours away) and just having the thing overhauled but it would cost me more than I paid for the amp to begin with.
I checked the amp through different speakers (as well as a different amp hooked up to these speakers) and everything seems to be in order there. I think my problem is definitely within the chassis.
I changed the tubes in the amp on Saturday. I brought it to the luthier I've been studying with-- we tested the old tubes (they were reading well into the "replace" zone on the tester... 80-100 mOhms, lower for the power tubes) and put in a set of 5 Electro-Harmonix 12AX7's, and a matched pair of JJ 6L6GC's. All of these had strong readings before going into the amp.
I also pulled out the chassis (before replacing the tubes) to see if anything was noticably destroyed inside the amp-- a botched modification or leaky caps or anything else of the sort, but nothing stood out. This is, of course, to my untrained eye.
After I put the amp back together, I fired it up and my volume issues were resolved. The 5150 was as loud as it should be, although it still lacked much of the body and low end to the tone like before.
Now here's where it gets weird.
I put the amp in my trunk and drove back home. I fell asleep and it stayed in the trunk for a couple of hours in 30-40 Fahrenheit weather. Brought the amp inside and left it alone for a few hours to get back to room temperature. I plugged it in today and got... nothing. Tried 5 different cables, no dice. The only sound I could get was some loud fuzz (think poor television reception, not Big Muff) for about 5 seconds when the amp was turned on, and again when it was turned off.
On a random whim, I tried plugging the guitar in through the FX return and to my surprise, I was blasted with some full volume noise.
Check this out-- I get a clean, reasonably normal sound when I play through the effects return, but NONE of the knobs do anything. No EQ, pre or post gain, resonance or presence. I didn't think to test the reverb and I can't fire it up right now as it's REALLY loud. I can't switch channels, either. I only get the rhythm channel.
All of the new tubes light and heat up. The pre tube farthest to the right seems to be a little cooler than the others but that might just be me.
So my guess is that between the cold weather and the round trip-- from my basement to my car, across town,from my car into the workshop, up to the workbench, and back-- a connection snapped somewhere at the beginning of the signal chain. Or is this indicative of a different problem? I am SO confused I'm considering switching to acousic.
@Gribnick- I haven't heard of Jerry but maybe I'll try to get in touch with him. I haven't really had any amp work done in the past-- I'm still looking around at different places. I was considering making an appointment with Voodoo out in Utica (a couple of hours away) and just having the thing overhauled but it would cost me more than I paid for the amp to begin with.
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