How much head noise is normal??

Haha yeah that's normal man. That's extremely common in the 5150/6505 as well. Get a noise gate (I prefer ISP) and it'll silence that crap :)
 
The hiss sounds normal but the weird backround noises are not.

99% of the weird extra noises are caused by a preamp tube gone bad. That's nothing to worry about, because with a high gain tube amp, that's like breaking a guitar string etc.

Noises like the ones on the clip are usually caused by microphonic tubes. You can find out which one of the preamp tubes it is by turning the amp on and tapping the preamp tubes with a pen. If you hear the tap through your speakers, then that is the tube you need to change.

Preamp tubes are usually pretty cheap, 10-20 bucks a piece (of course there are some NOS tubes that are over a hundred bucks a piece) but generally speaking it is not a huge investment. I always have spare tubes at home in case a tube craps out in the middle of a session.
 
thanks...so i fire up the head as i would for normal playing and then tap each of the 4 Ruby tubes with a pen see if that tap is amplified? right?
 
Yeah pretty much.. you'll hear the glass sound of the tube amplified really loud and kind of hollow. It's not a bad preamp tube 99% of the time... They do cause noise but keep in mind tube amps are more prone to pick up signals from fans, dryers, computers, cell phones, etc. So check to see if anything of that nature is near where you jam. Also, a noise gate can go in front of the amp or in the FX loop.
 
16S said:
thanks...so i fire up the head as i would for normal playing and then tap each of the 4 Ruby tubes with a pen see if that tap is amplified? right?
Click to expand...

Nope, the 4 tubes are power tubes, there is a cover on the back of the amp and behind that one, you have your (five) preamp tubes.

Yep, you need to have your amp on as if you were playing.
 
I checked the pre amp tubes by tapping them with a pen. You could hear a very slight tap sound through thr cab (gain on 3) with all of them except one: the one on the far right (if looking at the head from behind) This one made a very loud clunk when tapped......so does this mean anything???

Any help appreciated.
 
Only the 5150/6505 combo has built in reverb ;) And I'm pretty sure Peavey uses a solid-state buffer for its FX loop (which is why it sounds so much more better and more transparent than the loops on a Recto :Smug: ), so I'm pretty sure it's 4 preamp tubes and a phase inverter.
 
Yeah, I've just come to the conclusion that tube amps are tempermental bitches that will bark and sputter every now and again, like an old carbuerated muscle car - doesn't necessarily mean there's anything wrong with 'em, they're just snorting, inefficient brutes!
 
the hurricane i can except but this is random crackles...

I read an article that says when the amp is crackling remove one pre amp tube at a time until you find the one that is the culprit for the noise and replace that tube. Can you do this reasonably safely with the amp switched on?
 
NO NO NO NO NO - I'm not 100% certain it would be damaging (but I'm pretty sure it would be), but more importantly, they get so fucking hot, you'd regret that decision real fast!
 
16S said:
I checked the pre amp tubes by tapping them with a pen. You could hear a very slight tap sound through thr cab (gain on 3) with all of them except one: the one on the far right (if looking at the head from behind) This one made a very loud clunk when tapped......so does this mean anything???

Any help appreciated.
Click to expand...

The far right tube (viewed from rear) is V1. This is the first tube in the chain and is responsible for most (80-90% maybe) of the distortion. It is setup quite hotter than the other tubes so when tapping it, the resulting sound will possibly be louder than a similar tap on the other tubes. If it is a loud clunk though, then it could well be a dud tube. Swap this tube with the one next to it (and even the middle tube) and repeat the tap test. See if the resulting sound is similar.

The fourth tube from the right is used for the effect loop and the fifth (left side) is the PI. They are not labelled (look closely on the preamp board) sequentually 1 - 5 Right to Left.

Check out below link for details (or look at the preamp board):
http://www.fjamods.com/5150Models.html

V1 - Gain Stage 1
V2 - Gain Stage 2
V5 - Gain Stage 3
V3 - Effect Loop
V4 - PI
 
GuitarHack - thankyou that is very useful to know!!!
when i did the tap test the bloody amp wasn't even making any crackle noise: it was behaving itself WTF! Typical.
Anyhow as soon as it starts crackling again i will be straight on it with some valve swapage tests and i will also do the swap you recommend to see if tube at V1 is dud.
thanks again!
 
...the latest in this annoying saga is as follows:
6505 was crackling and popping randomly on red and green channel. I removed v1: still crackling, i removed V2 as well: still crackling, then i removed v5 still crackling...now pissed off.
Emailed Peavey....waiting for a reply...

A question for you guys please could someone tell me if you get a loud click/switching pop if you switch the effects loop in/out with the footswitch when no cables are connected to the FX send/return?
thanks
 
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