Amp Static

  • Thread starter Thread starter ido1957
  • Start date Start date
ido1957

ido1957

9K Gold Member
Last week it was my mixer - sheesh this is costing me....

Playing last night and had static coming out of the amp speakers. (Marshall JCM900 4100 Head). The best way to describe it - I would play a chord and shortly after the main "sound" the static would develop - not constant but failry consistent. Then the chord and static would stop. No static when unplugged or no chord being played. I kept practicing and it kept happening but was not bad enough to totally ruin the vibe...and not noticeable while playing away.

I will need to take this to the shop... I'm thinking I might be needing tubes again. I think this was a prelude to serious loss of volume and tube redo but I don't remember exactly....

Anybody have any ideas if this is tubes or not?
 
check the soldering on your guitar and guitar cables, a lot of times these solders are weak and can somewhat "loosen" and will cause inconsistencies in your signal which causes buzzing humming, crackling etc.
 
Nope = problem when the guitar plays not when I mute the strings. Checked the cable and it's fine...
 
Sounds like shit tubes but I haven't owned a real tube-eater in years. How long have these been in, was the bias adjusted when they were replaced and how hard do you work 'em?


lou
 
Tubes are about 2 years old so not really old. I just searched for my post about the cost. I only play through it three or four hours a week....so noe excessive.... Seems like it burns through tubes. Thing costs too much to replace so it's nickel and diming me to death....
 
I get this weird shit buzz through mine a couple times per hour when it's on. Not static, but a buzzing sound. Lasts for about a second.

I used to think it was a CB radio or someone's ratty garage door opener. :confused:

It's just this one amp though. Marshall VS265. Got a tube preamp section. I've swapped tubes a couple times. No help.
 
ido1957 said:
Tubes are about 2 years old so not really old. I just searched for my post about the cost. I only play through it three or four hours a week....so noe excessive.... Seems like it burns through tubes. Thing costs too much to replace so it's nickel and diming me to death....
Click to expand...
Two years? Change 'em and find out. I had a Musicman back in the day - basically a Fender Twin clone - that would eat an $80 set of Groove Tubes every six months.


lou
 
Yep - to the shop on Saturday... I need this amp to work....
 
sounds like tube issues

my voxs are good for 9 months for the power, the jcm 900 lasts about a year

assuming 6 gigs a week
 
Sounds like one of the tubes is microphonic (uber sensitive) I'm going to guess a preamp tube (one of the smaller ECC83's/ax7's)

Have a buddy play it while you look at the tubes/and see if any of them are getting brighter/dimmer or cutting out while the guitar is being played. If you can't see without unscrewing the back panel or the tubes have the metal sheilding cases over them, take it/them off so you can see em.

Do yourself a favor and retube it with JJ's.......the more I replace my old Groove Tubes the more I think to myself...damn I've been playing with these turds for way too long. EuroTubes (google) has kits for just about any amp, so you shouldn't need to re-bias once you change em out.

If not......your amp may need recapped (capacitors) depending how old it is. That's worst case scenario
 
Tech checked the tubes on a tube tester and they all seemed okay. But tapping on the tube created a fluctuation and I guess the static. Replaced an EL34 tube and did a thorough cleaning and checkup of all the sockets, jacks and switches. I fired it up for 1/2 hour and seems okay - no static and tone is good. Seems a little louder and more sustain.
He also mentioned that he turned down the voltage from 42 to 35 as 42 is too hot and will burn out tubes faster. Maximum is like 43 or something and 42 is the setting recommended in the specs but that's if you buy Marshall original type tubes - the kind that came with the unit originally - which are long gone so no idea what brand/style. Doesn't seem to have any bad affects reducing the voltage. $204.......:eek::D:)
 
So now I've replaced my mixer, got my amp fixed, now all I need is my Kramer back with it's neck replacement and I'll be done...
 
Welcome to the music "business." A couple of years ago, I was sitting at a table in a honky tonk during one our breaks between sets, and I told the singer/rhythm player, "I'm actually making money, even after buying a new bass!"

He gave me a skeptical look and said, "just for this band, or overall?"
 
You must log in or register to reply here.
Back
Top