Amp Check Today
- Thread starter smitty_p
- Start date
Walks Backward
Well-Known Member
Ha! Gotta wait until alone to crank it up? Sounds like my neighbor across the road. He'll even hang up the phone when he sees his wife driving up to the house. .... 
Me, well I crack it up at 2am if I feel like it.:dood:
Me, well I crack it up at 2am if I feel like it.:dood:
OP
Ha! Gotta wait until alone to crank it up? Sounds like my neighbor across the road. He'll even hang up the phone when he sees his wife driving up to the house. ....
Me, well I crack it up at 2am if I feel like it.:dood:
Oh, it's not that bad!
Since one of my sons moved out to live closer to work, his room has become my music room. My wife is pretty understanding of my playing.
But, I do try to be considerate for my full-volume...ummm...testing.
Walks Backward
Well-Known Member
Was just picking on ya a bit.
Walks Backward
Well-Known Member
I like to crank it up especially when all my cats are asleep. ....
Then play something in the "Key of Nuge" real loud! They all go nuts and scramble to get to the other end of my little house! It's a riot!
:dood:
Then play something in the "Key of Nuge" real loud! They all go nuts and scramble to get to the other end of my little house! It's a riot!
:dood:
OP
I am partially into my amp check.
Ah, the feeling of air hitting you in the chest!
That is part of the PMI:
* Plug guitar into amplifier and set guitar volume control(s) to maximum. Turn on amplifier and set amplifier volume control(s) to maximum. Play guitar while standing in front of amplifier.
Can pulses of air be detected striking the chest? If yes, amplifier passes this check. If not, replace amplifier with larger amplifier.
Ah, the feeling of air hitting you in the chest!
That is part of the PMI:
* Plug guitar into amplifier and set guitar volume control(s) to maximum. Turn on amplifier and set amplifier volume control(s) to maximum. Play guitar while standing in front of amplifier.
Can pulses of air be detected striking the chest? If yes, amplifier passes this check. If not, replace amplifier with larger amplifier.
OP
Yep. I think you're correct.
Technically, my amp passed the test.
But, I think better results could be achieved!
Must go bigger!
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chilipeppermaniac
Ambassador of Decibels
Smitty, I did an amp check last night. It was not a joyous experience.
My Marshall JMP ,which I speak of freely on here, has once again developed a bug.
The amp does not get a lot of use, yet it seems to keep breaking down. This time I was playing my Lester and the sound coming from the amp was immediate. Once i took if off stand by, it had awful mains moaning and some hiss in channel 1, same but not as loud in channel 2. After twiddling the knobs back and forth, I was able to quiet it down a good bit.
Played it awhile then got a weird little pop crackle noise like when you try inserting a guitar cord in the jack while it is on.
I'd strum again and get no noise, then a little while later it would get sound again. Eventually I swapped guitars and kept same cord and then even while playing the SG, it did the same thing. Sound,,,,,,,,,,,,,then silent this time. I shut it down and checked the fuses on back.
The .5 fuse is good. The 1 amp Mains fuse is cloudy inside .
This is the same behavior the amp ( head) exhibited the past 2 times I took it to a tech. The 1st time, he said it was the power transformer. I had him swap in a new Marstran and the bugger did not return my original 1972 one I could have had rewound.
The next time it failed, blowing fuses again, he told me my tubes were bad so I had him install new ones. He also re-capped the amp and installed pre amp tubes. Once again I did not play the amp for hours on end after getting it back supposedly fixed.
In hindsight, I should have played the shid out of it then took it back to him as I felt it was too noisy after the issues were supposedly sorted out.
Instead I'd plug it in once in awhile and jam for maybe 20-30 minutes and shut er down.
So, as I said, once again, the amp is DOA a bit.
Hopefully I can use my multimeter, acquire a tube tester, get good schematics and books to guide me along with the advice of our electronics educated brothers here, I can get it sorted out.
Too bad I could not trust that tech to get it fixed right the first time and to thoroughly test it before calling me to say it was ready to play x 2 visits.
My Marshall JMP ,which I speak of freely on here, has once again developed a bug.
The amp does not get a lot of use, yet it seems to keep breaking down. This time I was playing my Lester and the sound coming from the amp was immediate. Once i took if off stand by, it had awful mains moaning and some hiss in channel 1, same but not as loud in channel 2. After twiddling the knobs back and forth, I was able to quiet it down a good bit.
Played it awhile then got a weird little pop crackle noise like when you try inserting a guitar cord in the jack while it is on.
I'd strum again and get no noise, then a little while later it would get sound again. Eventually I swapped guitars and kept same cord and then even while playing the SG, it did the same thing. Sound,,,,,,,,,,,,,then silent this time. I shut it down and checked the fuses on back.
The .5 fuse is good. The 1 amp Mains fuse is cloudy inside .
This is the same behavior the amp ( head) exhibited the past 2 times I took it to a tech. The 1st time, he said it was the power transformer. I had him swap in a new Marstran and the bugger did not return my original 1972 one I could have had rewound.
The next time it failed, blowing fuses again, he told me my tubes were bad so I had him install new ones. He also re-capped the amp and installed pre amp tubes. Once again I did not play the amp for hours on end after getting it back supposedly fixed.
In hindsight, I should have played the shid out of it then took it back to him as I felt it was too noisy after the issues were supposedly sorted out.
Instead I'd plug it in once in awhile and jam for maybe 20-30 minutes and shut er down.
So, as I said, once again, the amp is DOA a bit.
Hopefully I can use my multimeter, acquire a tube tester, get good schematics and books to guide me along with the advice of our electronics educated brothers here, I can get it sorted out.
Too bad I could not trust that tech to get it fixed right the first time and to thoroughly test it before calling me to say it was ready to play x 2 visits.
syscokid
Ambassador of War & Peace
So... are we talking about a 35 year old amp?
When you get full sound, are all the tubes lit up properly? Some type of preamp tubes have their heating filaments so encased that its hard to see the light of the heaters. When you lose sound, can you notice if any of tubes are not lighting up?
Every single soldering joint needs to be rechecked with magnification. More than likely, every soldering joint should be reflowed if that wasn't done already... every one!
Also, old sockets might need to have their pin receivers ( or pins ) tightened up.
chilipeppermaniac
Ambassador of Decibels
Thanks, Sysco.
After I noticed no sound I put the amp on standby and removed the back cover. I believe the power Tubes were lit despite me later finding the Mains fuse cloudy inside after unplugging amp and checking the 2 fuses. I cannot say 100% if all tubes were lit to full capacity at full sound like you mentioned but can try to see what I can decipher in the days ahead. I will have to take the covers off the pre amp tubes and turn the amp on. I will check both fuses with my meter and see what they read. I will be checking things out and jotting down the info I observe in order to get going in a systematic, well planned direction. After checking fuses, I will then get the schematic and go from there and report back as time yields data or questions I may have.
Thanks Sys. Also, the amp is 45 years old, not 35. It is one of the point to point JMP 50 watt 1987's
I will post some pics of the top side so we can see the new parts, ( I have almost no issues with the tech replacing caps etc as I know with age caps will leak down and cause problems) This is akin to preventative maintenance on a car. A little prevention can prevent serious damage down the road.
Thanks guys.
After I noticed no sound I put the amp on standby and removed the back cover. I believe the power Tubes were lit despite me later finding the Mains fuse cloudy inside after unplugging amp and checking the 2 fuses. I cannot say 100% if all tubes were lit to full capacity at full sound like you mentioned but can try to see what I can decipher in the days ahead. I will have to take the covers off the pre amp tubes and turn the amp on. I will check both fuses with my meter and see what they read. I will be checking things out and jotting down the info I observe in order to get going in a systematic, well planned direction. After checking fuses, I will then get the schematic and go from there and report back as time yields data or questions I may have.
Thanks Sys. Also, the amp is 45 years old, not 35. It is one of the point to point JMP 50 watt 1987's
I will post some pics of the top side so we can see the new parts, ( I have almost no issues with the tech replacing caps etc as I know with age caps will leak down and cause problems) This is akin to preventative maintenance on a car. A little prevention can prevent serious damage down the road.
Thanks guys.
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chilipeppermaniac
Ambassador of Decibels
These pictures are a little old and not of the best quality. However, I will also take better ones and post them along with pic of the board.
chilipeppermaniac
Ambassador of Decibels
Like this, Smitty
Walks Backward
Well-Known Member
Well I'm sure that the tube amp folks will howl but after years of playing them, repairing them, and dealing with their constant issues I kicked them to the curb years ago. I have had nothing but solid state for several years now. Far more reliable, lighter, flexible, and better than the outdated tubes.
When I began in this hobby, yes, I said hobby, all there was were tubes. In amps, radios, and later TVs. It's all we had. But later I went to an electronic school to learn amp repair and more. I'm big on training. Went to luthier school as well. Trained is beyond the kitchen table tech I think. But anyway, tubes wear out. Generate massive damaging heat. And besides being far too delicate, the amps are heavy and require constant maintenance. So yes, I've abandoned tubes as they're obsolete. Much like the automobile industry switched from carburetor to fuel injection. And the aircraft from piston driven engines to jet. Whether you want to admit it or not, fact is we do evolve. And much like Arnold said in a later terminator film "I'm old. Not obsolete. "
So toss those bottle jobs aside and get a modern and reliable solid state amp and join the current century. Even me, who hates technology, knows solid state is the way to go. Yes, I once was a "no glow, no go" type until I woke up and realized I was living in the past. You may throw your rocks at me and beat your chest calling me an infidel and choose to banish me to the pointless forest, but that still doesn't change the facts.
When I began in this hobby, yes, I said hobby, all there was were tubes. In amps, radios, and later TVs. It's all we had. But later I went to an electronic school to learn amp repair and more. I'm big on training. Went to luthier school as well. Trained is beyond the kitchen table tech I think. But anyway, tubes wear out. Generate massive damaging heat. And besides being far too delicate, the amps are heavy and require constant maintenance. So yes, I've abandoned tubes as they're obsolete. Much like the automobile industry switched from carburetor to fuel injection. And the aircraft from piston driven engines to jet. Whether you want to admit it or not, fact is we do evolve. And much like Arnold said in a later terminator film "I'm old. Not obsolete. "
So toss those bottle jobs aside and get a modern and reliable solid state amp and join the current century. Even me, who hates technology, knows solid state is the way to go. Yes, I once was a "no glow, no go" type until I woke up and realized I was living in the past. You may throw your rocks at me and beat your chest calling me an infidel and choose to banish me to the pointless forest, but that still doesn't change the facts.
chilipeppermaniac
Ambassador of Decibels
Well Wade, I have both types. My bass amp is SS, my 2 small practice guitar amps too. One is a Princeton Chorus and the other a 1x10 Peavey Envoy 110.
Other than that I have 2 heads and 1 combo that are tube. I find it really cool you went to school for training on electronics. I am currently going to the school of fix it yourself due to supposed trained repairmen not doing their job properly and thus having no one else to depend on than my own mind and hands with the diagnosing and verifying of specs, tests, schematic reading assistance from a few of our members here to guide me through it.
Other than that I have 2 heads and 1 combo that are tube. I find it really cool you went to school for training on electronics. I am currently going to the school of fix it yourself due to supposed trained repairmen not doing their job properly and thus having no one else to depend on than my own mind and hands with the diagnosing and verifying of specs, tests, schematic reading assistance from a few of our members here to guide me through it.