Home DigiTech Forum GNX Forum Achive GENERAL General Discussion and Chatter

Tube amp hiss (normal or not)?

<div style="displaynone">fiogf49gjkf0d</div>Does anyone have an opinion about this? I have seen some say it is normal, others say not. I want to do some recording to my GNX4 from a tube amp. Is low grade hissing from the speaker normal with all tube amps? I just brought home a Mesa/Boogie (traded in a Fender Hot Rod because it was too hot for home on low volume setting and it buzzed too much). The Mesa does hiss a little. For the price, I would have thought it would be completely quiet.

Comments

  • No...you should be able to eliminate this noise.

    Another member just tried a new Mesa Roadking and complained it made lots of noises. This stuff comes from a lot of reasons, and you have to rule out the problems one by one until you find the source.
    A new amp in the store thats making noises is just plain incompetent store techs. At least you find out right away...who not to go to for help or service.

    My guess right off ...is a tube or tube socket problem. These things get shipped with the tubes still in them. It may survive shipment this way, but tubes do get rattled to death, or loosened in the sockets.

    A modest \"hum\" is likely a preamp problem. These tubes are generally noisy anyway. You can purchase \"low noise\" preamp tubes, but they are pricey. I'm not sure what tubes you have, but a preamp is generally the 12AX7's. If you are not sure of what you are doing...it is highly recommended you let a tech inspect and repair your amp. Especially a high end amp like a Mesa Boogie which has lots of tubes and circuitry.

    With the power off, first check that the preamp tubes are set firmly in the sockets. Power up and check. ...still humming? One tube may be noisier than others. Try reversing the order. You want to get your noisiest preamp tube farthest away from the power tubes. Use a spray cleaner on your connections too. Mild corrosion could also be the culprit.

    This is one of those subjects that is hard to diagnose over the internet. More exact info is needed. There can be many other problems causing noise. I'm just saying a low volume hum is generally a preamp issue.
    Poor house grounding, cheap cables, lousy guitar shielding, corroded or damaged connections, area interference...(lots of cables or stompboxes, computer, etc.nearby) to a defective part in the signal chain....and other etc.'s etcetera.
  • It sounds like you are talking about two differen't things. All audio electronics have a noise floor at which you will hear hi frequency hiss. Depending on the quality of the design of the gear can partially determine at what level you will hear it. It can also be caused by bad gain stucture. Are you driving the input enough? It can also be caused by impedence mismatches between the output and input of two interconnecting devices. Hum is usually associated with a grounding problem or a high power source inducting noise into an audio input. Is your power transformer laying on top of your guitar cable? Of course tube problems can also cause
    hum and noise issues. Hi frequency buzzing is usually caused by induction
    of RF or a lower power source being to close to an audio input. Do you have single coil pickups to close to flourescent lights or a computer monitor? May also manifest itself as a bad connection or grounding issue.
    An electronic component going bad may also cause excessive hiss.
    This is all just food for thought, but if it is just hiss, I would focus on gain structure first. If it is buzzing or hum then you may have other issues.
    If your not sure, have a tech go through the amp.

    Jamminmj
  • A Bro has a Mesa Roadking...and it's quiet.
    It's the string Bikini- no tan line- tight looking HOT BABE model. :cry:
    I LUST... 8) :P :oops: 54.gif


    MesaRK.jpg
  • Mmmm...that rig's a moist-maker... :shock:
  • <div style="displaynone">fiogf49gjkf0d</div>The noise is a low shhhhh (like the sound of running water) like you tell a child to quiet down. It happens even with nothing plugged into it (no guitar cable, no fx loop, no cable from mixer or GNX4). I had the power plugged into a surge suppressor. I just tried it direct into the outlet and get the same thing.

    The noise gets louder as I turn up the master volume on my clean channel. It also gets louder (is louder than the clean) as I turn up the master volume on my dirty channel.

    I have not tried reseating the tubes or anything like that. Being a novice at this, I'm a little reluctant to mess with the insides of stuff. But, I can try.

    For what I paid for this, I think it should be quiet. No shhhhh sound. I could end up carting it back to GC, but I'll call Mesa first.

    I do really want to record into the GNX4 with this amp. It is far better than the Hot Rod Deluxe I traded in.
  • I've not had Mesa's or anything expspensive? BUT everytube amp I've had or played thru has had an Idle Shhhh sound the louder you turn the gain or the Master the louder the Shhh get's This noise to me did not seem so Alarming as it's not real loud or anything Like was already said probably the noise floor of the amp? If this noise is excessive I would susspect a preamp tube. After you try reseating tubes & check & see if the amp quites down Try replacing the Pre amp tubes 1 at a time till you find the noisy tube. BUT as I said at least in my finite experence some idle Shhhh is normal at least for me and Amps I've played around with.
  • <div style="displaynone">fiogf49gjkf0d</div>I called Mesa and the techie also said that the quiet shhhh is normal.

    Thanks for the input.
  • :D Alrighty then. :lol:

    A tube amp is louder than a solid state amp, and it does sound louder in say a bedroom vs. a larger area. I don't hear my Carvin Belair out in my living room which has a cathedral ceiling, near as much as in my bedroom/studio.

    My TV is actually louder on mute than my tube amp. :P

    If you don't have to touch your amp...y-e-t...:D ...you will. Tubes will need to be replaced eventually. When my Carvin showed up at my door from San Diego via UPS Ground, I had to replace two preamp tubes right from the start. I only have 9 tubes to massage though. 5- 12AX7 preamps and 4- EL 84 power tubes. I keep extra tubes in bubble wrap, stashed in the cabinet.

    Carvin003.jpg

    I disconnected the 2- 12\" Celestions and run this through my Crate 4x10 closed back cabinet. This is my perfect combo. One day I plan to chop the cabinet down and turn it into a regular head, and just eliminate the speakers altogether. They are just dead weight.

    I don't like this through my GNX4 at all. Basically all I use on this is just a Screaming Demon wah-wah...that's it.
    I use a Crate Power Block through a 1x12 Crate cabinet for the GNX4. Solid State just seems to work better. I'll be happy to know how you like your tube amp through the GNX.
  • Manitou wrote:
    Another member just tried a new Mesa Roadking and complained it made lots of noises.

    Yep that was me! :P :lol:
    The Roadking I tried didn't really hiss or anything like that. Instead it popped and crackled when you pressed buttons/switches etc, turned knobs and even when you bumped the cab it was sitting on. It didn't hiss - it wheezed! Like Tou said, the obvious thing to do would be to go through the amp item at a time and eliminate causes, I could rattle off half a dozen reasons why it was doing it. But I couldn't be bothered doing that to a new head that costs north of 5 grand here in OZ. Instead it should reflect the money it costs.

    But for what its worth, the Stilleto and F-50 I also tried were a bit hissy - only when quiet though. To me they just acted like a normal tube amp, no different to my JSX.

    But don't worry Gstrickler, once you're on stage with an aggro drummer you won't be able to hear ya Mesa hiss - just cymbal sheen!! :lol::lol:

    By the way Tou, sweet shot of that Roadking...and it doesn't make noises! He's a lucky man! :D

    BBoo.
Sign In or Register to comment.