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amp problems....again

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EMB5490  
19 Jun 2009 22:19 | Quote
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hi, i have a jmp '77 100 watt super lead, well im getting an overtone, ghost note, w.e im getting it, and its pissing me off, i have new caps, new tubes, what else could be causing this, also when i turn it on i get a soft sumble/inconsistant static, even with nothing plugged in, even sith standby on. i lightly tap the side of it, and it goes away. any ideas? i havent had it bias'ed. could that be it? any ideas wouldhelp alot. thanks
Ozzfan486  
19 Jun 2009 23:56 | Quote
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Idk. Phip probably knows.
Phip  
20 Jun 2009 05:30 | Quote
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Ahhhh Little buddy, my guess is the static is a bad ground or solder connection somewhere in there or perhaps a dirty/sloppy tube socket. Not much you can do about that without some tools and technical experience. The ghost note, I'm not sure. Maybe it is time to have a technician take a look at it.
Phip
EMB5490  
20 Jun 2009 08:27 | Quote
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i haave as i said i brought it in for the tube/caps change and it eliminated the high frequency squel but not the rest...
Phip  
20 Jun 2009 09:07 | Quote
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Ok, i misunderstood. Still, if the guy stands behind his work he'll be happy to give it a second look. It might be something simple that he/she didn't tightened up when putting it all back together. Sometimes we miss things when reassembling and we are happy "make good" on a job and appologize for any inconvenience.
EMB5490  
20 Jun 2009 10:00 | Quote
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nah, i forgot to mention i had the same problem before i gave it in. it just went away and came back last month.
EMB5490  
20 Jun 2009 20:05 | Quote
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i took a vid of it, how do i upload a vid from my videos without youtube?
Phip  
20 Jun 2009 20:34 | Quote
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you don't,
but you could email it to me.... phip1@verizon.net
or we could use messenger, or is this for the whole group?
You would need a website that will allow you to store videos and put a link to it here but this forum doesn't have a method of posting a video directly that I am aware of.
some sites that allow file storage are
http://photobucket.com/
or
http://www.4shared.com/
EMB5490  
20 Jun 2009 20:47 | Quote
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there we are. listen VERY closley you can hear it, trust me im not hitting hard, im lightly tapping it.
EMB5490  
20 Jun 2009 20:50 | Quote
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at exactly :11 or :12 you can hear it. thats the amp, put in earplugs to hear it or put your ear up close to the comp and raise the volume.
Phip  
20 Jun 2009 20:55 | Quote
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well I didn't hear it go away when you tapped, if anything it sounded like it got worse. Am I right about that? It sounded like a slight hum to me.
sounded like you gave it a pretty good whack at the end Elliott. Go easy on that thing. You could make it worse.
Anyway in this particular video it sounded to me like you did NOT succeed in getting rid of the hum with your tapping. Is that correct?
Phip  
20 Jun 2009 21:03 | Quote
Joined: 23 Dec 2007
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yeah that's a hum. sounds like a bad ground possibly or even a wire came loose off of one of the control knobs. There is also a possibility of a "leaky" tube (recitifier).
Problem is I don't thing there is much you yourself can do about this problem. If it were me (technician trained in not getting electrocuted) I would take off my watch, remove the cover and GENTLY tap each tube to see if the problem corrected itself. If not, I would gently tap the circuit board next. And i would use a plastic device to tap with so as not to get a shock. But we are talking about a novice (no offense)and I don't want to see you get zapped. But we have had this discussion before so...................
Phip
oh and the hand i wasn't using i would have behind my back so that I don't touch any metal and ground myself, providing a path to ground, increasing the potential for serious injury.
Phip  
20 Jun 2009 21:13 | Quote
Joined: 23 Dec 2007
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And to all members......
I may sound like a fussy old man and some of you may think I am a bit too worrysome, but I will guarantee you THIS. These larger amps (or any device that plugs into a wall outlet) is capable of deliving HEART STOPPING AMPERAGE! If you think it's just some stupid little thingy that you plug your guitar into and it makes nice sounds, then take some advice and get your stupid f*cking hand out of the thing!
I like you guys and don't want to attend your funeral. yeah, i know, "but phip, i've done it a hundred times before". Good for you. make one stupid mistake and bye bye. Be careful my friends!
telecrater  
20 Jun 2009 21:32 | Quote
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Are you sure it's not a cord or guitar?

I've read about the cap's in the tube amps hold a charge for years. I've also read that they hold enough voltage to kill you easly. I think your best bet would be to take it in and and a trained tube amp tech look at it.

Don't mean to sound blunt but, you have decided you wanted vintage equipment and this is the by product of that decision. This is not going to be the last time it happens either, parts fail and you have a 30 year old amp, more are bound to fail.

Best of luck to you
EMB5490  
20 Jun 2009 22:07 | Quote
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in response to phips first 2 posts. nah the phone was really close to my hand, im very delicate with it. it went away like the second the video stopped lol. and no i never try to fix my amp myself, if i screwed it up itd be 1700$ of my own moneyim waisting. im brining it to an amp genius. jack k. he builds amps from broken down amps and makes then sound better then ever. hes amazing.

yh i didnt even have it plugged into my guitar or pedalboard.

as i said i never touch the thing myself alway jack.

ik more are bound to fail, for all i care its worth it. i get the greatest tone outta it. as long as the amp works im happier then anything new. it sounds great.
Phip  
21 Jun 2009 04:59 | Quote
Joined: 23 Dec 2007
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Elliott,
Wise decision!
Be sure to ask Jack what the solution was. I'm betting on a faulty tube socket or bad ground!
Phip
EMB5490  
21 Jun 2009 06:41 | Quote
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i will, check out his site, its awsome, im not even like a promoter of him, his amps r just that awsome.

he has a "frankenstien" amp from parts from a broken plexi, broken bassman, broken jmp, and other amp parts from other broken amps, and truthully sounds better then them.


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