#1
Dear GG&A,

Yesterday, while rehearsing, my Marshall AVT 100 (from 2005) started acting all weird on me. I'll try to describe the problem:

Right after I'm plugged in, I can play normally for about 30 seconds after which I gradually lose output until there is none left. When I unplug the jack and replug it, I have another 30 seconds to play until it starts fading again.

I also noticed kicking or hitting it with my fist has the same result as the unplug-thing.

The strange thing is: I tried with headphones and that output doesn't seem to be affected at all, so there must be a problem with the speaker, right?

I'm kind of afraid because I know it's an amp with a lot of digital stuff in it.


I really love this amp, it's been with me since I started playing the guitar.


So tell me, do I need a new amp?

Kind regards,
Wouter
I fell asleep on my arm once, scariest thing that ever happened to me. I thought it was kill.
#2
It could be just a connection issue, or something much more.

Take it to a tech and have them check it out if you like it that much, or get a Marshall JCM2000 DSL 50/100 for $500 and have a 100x better amp that sounds like a proper Marshall
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#3
Quote by Robbgnarly
It could be just a connection issue, or something much more.

Take it to a tech and have them check it out if you like it that much, or get a Marshall JCM2000 DSL 50/100 for $500 and have a 100x better amp that sounds like a proper Marshall

As a college student, I'm very broke. I would consider buying a new amp, but a jcm2000 would set me back at least $700 and that's without a cabinet. Any other tips though? I play symphonic rock so it would have to be versatile...

Because the AVT 100 is the first and only amp I ever bought, I'm kind of a 'noob' when it comes to amps.
I fell asleep on my arm once, scariest thing that ever happened to me. I thought it was kill.
#4
What is your:
Budget?
location?
new or used? used you will get better gear for your money
home or gig?

Most techs will charge you $50 for a bench fee to look at your amp and see what the problem is.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#5
Quote by Robbgnarly
What is your:
Budget?
location?
new or used? used you will get better gear for your money
home or gig?

Most techs will charge you $50 for a bench fee to look at your amp and see what the problem is.

Budget: I don't know. I think I could manage 500-1000 euros, but that would mean eating crumbs for a few months. I have some gigs coming up, which will bring some money, but still...
I'm in Belgium.
I would prefer new (warranty and services, right? Maybe that's dumb, I don't know...)
It's for rehearsing and gigging.

Don't worry about the tech, I have an old friend who's basically a tech, and he'll do it for a few beers. But with this amp being all digital and stuff, I don't know...
I fell asleep on my arm once, scariest thing that ever happened to me. I thought it was kill.
#6
Look at Jet City on www.thomann.de, great amps and super cheap on Thomann. and get a Harley Benton G212 vintage cab this will set you back €500ish total

Jet City JCA50h €289
Harley benton G212vintage €189

this will do just about any style but super clean jazz.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#7
Sounds like filter caps gone maybe, they're ok when you give them chance to charge, but as you play they aren't filling up properly and run down. Get your tech mate to check those.
Epiphone Les Paul Plus Top
Jet City JCA5212RC (SLO Modded)
Ibanez WD7 Wah
Mad Professor Sweet Honey Overdrive
TC Electronic Flashback Triple Delay
TC Electronic Trinity Reverb
#8
Ok, so I managed to take it apart and take a picture. (Didn't touch anything, and averything is still connected)

Does that tube look ok? I've had it switched on for about 15 minutes before I took the pic.

Nothing seems burned on the inside. No dust pile-ups whatsoever.

EDIT: warning: ginormous picture...


I fell asleep on my arm once, scariest thing that ever happened to me. I thought it was kill.
#9
You can't tell if a tube is good or bad by looking at it. It is getting power though.

The amp needs to be trouble-shot to figure out what the problem is. We can not tell by a picture, there are components that need to be checked with a multi-meter. Unless there is an obvious "burnt area on the board/component.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#10
Ok thanks for the info.
I'll get it to my friend asap, I'll let you know if he can come up with something.

I've been reading into it and I think it's the tube. Even though it's a preamp tube, it's almost 9 years old and has sustained quite some punishment over the years (travel, (extremely) loud playing...).

Fingers crossed!

Thanks a bunch.
Wouter


EDIT: I just noticed somthing: the output only declines when I play loudy.
I fell asleep on my arm once, scariest thing that ever happened to me. I thought it was kill.
Last edited by Lord Waltaa at Sep 20, 2013,
#11
My money would be on dying power transistors in the output or even a simple dry joint on same. If it's the tube it would only happen on the second channel.
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