so i dropped my '74 marshall jmp today...
gimmesometruth27
Posts: 23,168
so i played a gig this evening at a winery. i use a 1974 marshall jmp and a 4x12 marshall 1960 av cab with vintage 30s. when i load in and out i just place the head on top of the cab but perpendicular to it so that the feet on the bottom of the head kind of cradles the top of the cab so i can roll it in and out as a unit. well today when loading out i rolled my head and cab out of the place in the usual fashion and as i was opening my tailgate the cab began to roll away. i grabbed the cabinet handle and stopped it but the momentum on the head caused it to fall off of the cab and land face first on the parkinglot. it hit pretty hard, as the patch cable i use to jump channels was smashed and the inner wire was exposed through the cable sheath. i freaked out. i have been doing this for a number of years and never came close to this happening.
i looked at the head and the only thing on the exterior was a couple of new scuffs but nothing major. i shook the head a bit and did not hear anything rattling around like a broken tube or anything. when i got home i removed the back panel and visually examined it and everything looked ok. i removed and checked and replaced all of the tubes and they all looked ok as well. i plugged it in and plugged in my les paul and noticed a major decrease in volume. i can tell because it is not a master volume head so any decrease in volume results in less gain and is really noticable. the funny thing is that the low e string, a string and d string sounded close to normal, but when i tried to play the g, b, and e strings it was like the amp was not even picking them up, almost like playing it acoustically. has anyone ever heard of this kind of thing happening? i wonder if it might be a preamp tube as they are over 15 years old and are probably about worn out anyway. i was just wondering if anyone had any idea about another cause. i plan on taking to to my tech in a few days. hopefully its nothing too terribly bad or expensive.
i looked at the head and the only thing on the exterior was a couple of new scuffs but nothing major. i shook the head a bit and did not hear anything rattling around like a broken tube or anything. when i got home i removed the back panel and visually examined it and everything looked ok. i removed and checked and replaced all of the tubes and they all looked ok as well. i plugged it in and plugged in my les paul and noticed a major decrease in volume. i can tell because it is not a master volume head so any decrease in volume results in less gain and is really noticable. the funny thing is that the low e string, a string and d string sounded close to normal, but when i tried to play the g, b, and e strings it was like the amp was not even picking them up, almost like playing it acoustically. has anyone ever heard of this kind of thing happening? i wonder if it might be a preamp tube as they are over 15 years old and are probably about worn out anyway. i was just wondering if anyone had any idea about another cause. i plan on taking to to my tech in a few days. hopefully its nothing too terribly bad or expensive.
"You can tell the greatness of a man by what makes him angry." - Lincoln
"Well, you tell him that I don't talk to suckas."
"Well, you tell him that I don't talk to suckas."
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JEFF HARDY AND JEFF AMENT USED TO LOOK THE SAME
"Pearl Jam always eases my mind and fires me up at the same time.”-Jeff Hardy
As for your amp, it could be the preamp, or it could be something simple like a capacitor. I'm not an amp tech, so I can't help you on the specifics. Just hope it's a cheap fix!
i just had my mic stand tip over and crash into my casino last night. putting a nice huge divot in the top horn.
where's that thread about putting stuff away?
good luck with the Amp Tech.
i am hoping its just a preamp tube or something simple. i have not powered it on to do any further troubleshooting because i don't want to risk any further damage.
it had been giving me a funny hum the last few weeks and i had been wanting to take it in to the tech but hadn't gotten around to it. i guess now i have a good reason to get on that huh...
"Well, you tell him that I don't talk to suckas."
It sounds from the description that there is an issue with a tube, which is probably the case. I mean they are one step up from a light bulb. That's what my amp does when the power tubes are dying.
Ouch. I can almost hear that sound and hear that language!
I'm with Paco. Very unlikely a transformer. I can't see where a transformer would cancel out the treble strings. Probably tubes and maybe it loosened up some connections .
If it hit that hard, you might look into replacing all the tubes because they don't like impact and they tend to find the worst times to go when they're injured! Like right when you're feeling it and ripping out your best solo ever!
Don't be mankind. ~Captain Beefheart
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i talked to the amp tech and told him what is going on. he did a quick scan and said he seriously doubts it is a transformer and feels something soldered came loose and its probably the preamp/preamp tubes. he said "since its 34 years old and had some trauma (getting dropped from 4 ft off the ground) i'm going to have to go through it pretty thouroughly..." he is going to call me with an estimate this week some time.
one thing he did find is that the ohm selector was very loose. he said a bad connection there could damage the transformer and blow the whole amp. he said it could also cause some single coil like hum from the cab, which i had been having for a few weeks. he said to "gaffer tape that shit to the chassis so the pins don't come out".. i'll keep yoou guys posted once i hear something.
"Well, you tell him that I don't talk to suckas."
the funny thing is i just had him retube and bias it about 3 months ago. so it looks like i escaped with only a few new scuffs on the front and a $100 go through/retube. what a relief!! i can't wait to go pick it up here after work.
"Well, you tell him that I don't talk to suckas."
"Well, you tell him that I don't talk to suckas."
Yeah that was weak i know
really hope it's not too serious. good luck buddy.
www.cluthelee.com
www.cluthe.com
ampulance lol... i'll find out tomorrow....
"Well, you tell him that I don't talk to suckas."
this is how he explained it to me....he said in vintage marshalls, the third preamp tube is the driver for the power section and tubes. when the 3rd tube socket is loose or bad the alternating current to the power section and tubes is halved resulting is lost power. normally when you rock the guitar volume back the amp cleans up. when the a/c is halved you only get the side of the waves that makes the amp distort going though to the power section so it can not get a clean tone, which is why mine got seriously muddy when i rocked guitar volume back.
he retensioned all tube sockets which fixed the problem. the 15 year old preamp tubes are still good lol....best of all he did not charge me for the repair since he missed it the first time.
i'm really stoked because i think this amp sounds better than it did when i got it. quite possible the best its ever sounded in its 34 years of life. now its nice and loud and ballsy like it should be. hopefully this will be the end of this problem.
"Well, you tell him that I don't talk to suckas."