Amp Hum...

[Twitch]

I just bought a new Peavey Classic 30 last week and was thrilled with it...until last night. Last night when I turned the amp on, in my room with now televisions/radios/computers on in the house my amp gave out a low humming noise, similar to that of my single coil strat hum, but this didn't go away when I touched the strings like usual. Anyone have any advice? I'm thinking I need a new cable, but am not really sure.

 

[Fiber-Optics]

Re: Amp Hum...

Hmmm, try different outlet?

 

[Twitch]

Re: Amp Hum...

As in the outlet above this one? Or a totally different outlet in the room.

 

[Curly]

Re: Amp Hum...

I don't know what you can do, but it doesn't sound really serious.

My place has kinda crappy wiring ... in the summer, if I have a fan on, I can hear it through my amp.

Some places just have wiring that's not that great, or there's too much load on the circuit. I have a friend who said his lights would "sag" when his neighbor was using his power tools.

 

[Twitch]

Re: Amp Hum...

Update:

Today when I play and touch metal the hum from the single coils goes away, but their is still a hum from the amp. This hum goes down when I turn the mids or treble down.

 

[echofinger]

Re: Amp Hum...

Get Lew in here. I posted the same question about 4 months back...

For me it meant dropping 20 bucks on a little black box called "The Hum Eliminater".

Eliminates hum caused by ground loops in houses with myriad electrical appliances and/or when you run two amps at once. And it works great, I might add.

 

[Kent S.]

Re: Amp Hum...

A good line filter/surge protector would go a long way towards helping as well, Radio shack has some small two outlet ones that are okay, they help, might solve the problem, might just reduce it ...either way for $15 you'll have a good surge protector.

 

[Twitch]

Re: Amp Hum...

I was thinking surge protecters might help, wasn't sure though.

Here's an update though:

My friend let me borrow a cable from him, this was an improvement over my cable (I've needed a new one for a while) but now I've got other issues with the amp.

I called the store and talked to the guy that worked with me on my amp search, he owns two classic 30's and told me to try it out on a circuit that isn't used as much in my house. Instead, I unplugged my Ipod speakers/alarm clock radio/ipod charger/3 lights out of their respective plugs and tried it again.

Right when I turn the amp on (like before) a small scratchy hum (i guess it would be labeled feedback) starts, then the tubes warm up and this time with the new cable and things unplugged the (feedback?) isn't as loud. So I play for a while and am just messing with the amp, seeing if my problem is fixed. Then I go into the overdrive channel and use the amps presets for the rock lead overdrive tone and while chugging out some Smells Like Teen Spirit and Crazy Train:upset: (they're the only overdriven riffsI remember) the amp started cutting out. It would play, then mute, then play, then mute etc. I got freaked out and turned it off and called the store back. The guy told me to bring it in this weekend so he could have a look at it.

Does anyone know what the problem could be?

Right now the steps I'm taking towards fixing it are:

1. New cable (high quality this time)
2. Surge Protecter (will this help? If I go amp>surge protecter>wall plug)

Also I'm going to hook up all the other electronics in my room onto a surge protecter, and just flip the power on the surge strip off when I use my amp.

Thanks

 

[Kent S.]

Re: Amp Hum...

I was thinking surge protecters might help, wasn't sure though.

LINE FILTER/surge protector ... not the run of the mill power strip ... get something made to combat RFI/EMI ...ask the staff at Rat Shack.
Might help to know if you mains are wired correctly (the wall ), they sell a small checker for that that plugs into the socket, has three leds on it ... real cheap.

All the following should be done
Let the amp warm up first (with no signal ... wouldn't hurt to turn clean volume and pre and post gain to *0*), let the circuit stablize, yes use high quality shielded cable ... could be a preamp tube (power amp tubes are more prone to this) temporarily shorting (a condition where it starts to draw to much current, resulting in hum of various levels, and/or distortion ... even clean), often turning the amp off, and then back on will temporarily fix it (replace tube).
Try it at another house ... If still the same ...
See, tubes tend to get knocked around in transit (shipping to store, trip to house, trip to gigs,etc, ) ... and they don't like that much ... Anyway, if it persists starts hunting thru the tubes ... It don't think the Peavey OEM preamp tubes are a stellar bunch. Some of the internal leads (wires can be routed to close to the wrong things causing hum as well, or they can move getting to close to things). If it still gives you trouble, take it in for servicing, or try to get a replacement from the store, they often order another one using yours as store credit.

All this aside though, it sounds like you need to return that amp and get a replacement.

 

[metallicajs1]

Re: Amp Hum...

yeah try another outlet and maybe a noise gate..

 

[Twitch]

Re: Amp Hum...

Second Update:
Two out of the past 6 times I've played the signal started cutting out, one was because of the bad cable I was using. Also, the static was cut dramatically when I hooked up my ipod speakers/charger, 2 lights, and alarm clock up to a power strip and turned it off, then turned on the amp. Right when I turned my amp on the low static noise started, but not then didn't get louder when the tubes were warmed up enough.

So it isn't really cutting out anymore, it's just the low static noise which isn't from the single coil pickups (since it makes the noise w/o any guitar plugged in).

Is this static a common problem with these amps, or is something wrong?

Edit: Oh yea, I also THINK their is some tube rattle going on. I know this is a pretty common problem with these amps so that's what I assume it is. It normally happens when I play a D# at the 8th fret on the G string, but it also happens elsewhere (just not as bad). If I play the note and hold it so the rattling noise starts, then touch all 4 tubes it goes away, but it doesn't completely go away by just touching one tube.

This IS tube rattle right? And does anyone know if those Tom's Tube Tamers work?

 

[Twitch]

Re: Amp Hum...

Ok here's a final and probably the best update to date:

I found out my cable was causing the cut-outs, so that isn't a problem anymore. The only problems now are:

1. Tube Rattle (I'm waiting for another Tom's Tube Tamer to go up on Ebay)
2. Humming noise

The hum as been outlined before, but here's an update for you. The hum goes up as I turn the treble control up, and down when I turn it down. None of the other controls effect the hum in this way.

 

[Scott_F]

Re: Amp Hum...

Get Lew in here. I posted the same question about 4 months back...

For me it meant dropping 20 bucks on a little black box called "The Hum Eliminater".

Eliminates hum caused by ground loops in houses with myriad electrical appliances and/or when you run two amps at once. And it works great, I might add.

where'd you get that?

 

[some_dude]

Re: Amp Hum...

where'd you get that?

http://www.ebtechaudio.com/he-2des.html

 

[Kent S.]

Re: Amp Hum...

http://www.ebtechaudio.com/he-2des.html

If memory serves correctly, that just breaks the ground connection to one side ... although it may be a small isolation transformer ...for $20 I doubt it though ... some people used to buy them thinking that they'd get rid of single coil hum ... nope. They are real useful little boxes though for home recording problems though.

 

[Kent S.]

Re: Amp Hum...

Tube rattle is more associated with *low* notes, not midrange to high notes ... Never used the tube tamers ...couldn't say .... yeah the treble control action would sound a bit normal if the hum is coming from the preamp, ...why? Because it's hum, which is low in frequency (bass), thus when you turn the treble control up you are turning down the bass also ... so that sounds like it's coming from your preamp. I'd run it back to the store, and/or put new preamp tubes in it, and make sure the power tube sockets are not loose and the tube pin clips are tight ... Btter yet have the store check this. See, if it's under warranty, well no sense in you paying for it.
You might want to check for cabinet rattle and chassis rattle, as those can cause problems to (are all the mounting screws snug ... speaker, chassis, cabinet). Just run it back to the store and explain the situation to the sales people.
Is it a problem with those amps, probably not, most small amps that have some balls to them can suffer from physical vibration problems ..solution more mass, heavier hardware, etc. ...more cost. Plus they can vibrate the heck out of anything around them as well (not just small amps, any loud amp).

 

[B2D]

Re: Amp Hum...

I think your amp hums because.... it doesn't know the words!

*gets dragged offstage with a big hook*