Guitar noise....please help
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Posted on Jul 05, 2007 11:23 pm
82Carvin
Member Since: Jul 05, 2007
I have an '82 Carvin that I'm playing through a new Crate V3112 tube amp. With the Crate speaker disconnected, I run the "line out" from the amp to a new Mackie CFX16. At moderate to loud volumes I keep gettin an electronic buzz that starts just after I hit a note and lasts for about three seconds and it sounds like it's going through a phase shifter. I have new cables and have tried different guitars but nothing changes. I know I can mic my amp but shouldn't I be able to run the line out to the mixer? I want to hear the sound through the Mackie and use those effects but still keep the tube sound from my Crate and I don't want to hear different sounds from both at the same time. Suggestions please. I have been dealing with this since my wife bought me this equipment over a year ago and the noise is ruinning my fun. Anyone may e-mail me at [email protected] .........Please
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DiemusikString benderMember
Since: Unknown
Jul 05, 2007 11:33 pm It sounds to me like you may have a grounding or shielding problem somewhere. Make sure you have no TVs, florescent lights or CRT computer monitors too close to the amp or guitar for starters. Are the pickups single coil or humbuckers?
Jul 06, 2007 12:11 am Thanks for the quick response Diemusik. The pickups are humbuckers but remember I've tried different guitars, even my acoustic Takamine gets the noise. In my last house I set everything up in a room with a dedicated electrical circuit with no improvement.
TadpuiI am not a crook's headMember
Since: Mar 14, 2003
Jul 06, 2007 10:23 am Hey man, you don't want to run a tube amp with no load connected to it! If there's no speaker defeat switch on the amp that still keeps a load on the power section, then you'll need a dummy load to hook the speakers to. You don't want to just disconnect the speakers.
NEVER run a tube amp with no load! You'll fry something!
Jul 06, 2007 12:25 pm Thanks Tadpui. Help me understand a little more though. On the back of my amp there's four 1/4in jacks in a row; footswitch, line in, line out, and the 8 ohm speaker jack that runs to the speaker. I assumed I could just unplug that jack and run the line out to the mixer. Do you think that could be causing the noise I hear or were you wanting to caution me about running my amp with no load? And this may sound stupid but could I run a cable from the 8ohm speaker jack to the mixer? Thanks in advance for any more information you can give.
TadpuiI am not a crook's headMember
Since: Mar 14, 2003
Jul 06, 2007 01:30 pm The speaker output of an amplifier is a very high voltage when compared to the voltages of a line-level signal. I don't know the actual numbers but I do know that plugging a speaker output into a line input is not a good idea in the world of guitars, amps, mixers and computers. Something is sure to get overloaded by the big voltage of an amplified signal.
What a mixer wants is either a line level signal (like a CD player, keyboard, or preamped signal) or a mic-level or instrument level signal (like a cable from your guitar or from a microphone). These signal strengths are very low, much much lower than the signal that's coming out of the speaker output of your amplifier.
Putting a high voltage into an input that's expecting a low voltage is usually bad news...something will fry.
What you'll want to do is run the line out of your Crate into a line in on your mixer. See if you can just turn down the master volume and still get a signal out of the line out.
Other than that, some power attenuators act as a dummy load and have a line-out on them so you can get the same signal that would have gone to your speakers and redirect it to a line input somewhere. My THD HotPlate does this.
I would have to assume that a combination of having your speakers disconnected and sending that signal into a line input would be creating the noise, but I can't be sure. I do know that both are a quick way to fry some audio equipment :)
Jul 06, 2007 01:34 pm you don't have anything hooked up to the line in on your head do ya? the phase shift thing makes me think you've got a loop in there somewhere.
Jul 06, 2007 04:03 pm Hey guys. Just to clarify; I do run the "line out" jack from the amp to the mixer. I was just asking about running from the speaker jack in case that was an option. I didn't try that and won't now. Thanks for the warning. As soon as I can I'll try turning down the amp volume and see if I can still get a usable signal to my mixer. I'm wondering though if that will still give me the "tube amp" sound and also if I will get more "hiss" for having to turn up the signal at the mixer. I guess I'll find out and let you know.
For whosyourdaddy -- No, I don't have anything running to the line in on the amp.
Thanks for the suggestions. PLEASE keep them coming if you have anything further. It seems like I have asked so many people and can't get it figured out.
TadpuiI am not a crook's headMember
Since: Mar 14, 2003
Jul 06, 2007 05:22 pm Quote:
I'm wondering though if that will still give me the "tube amp" sound
Definitely not. Most of the lovely sound of a tube amp is a combination of some preamp gain, some power amp gain, and some speaker breakup. By taking a line out from the amp, you're basically bypassing the power amp and the speakers. So you'll be hearing only the preamp tubes breaking up, which isn't really the heart of a tube amp's sound. Its more harsh grit than buttery smooth distortion.
When you try it, you'll hear what I'm talking about...it just doesn't have the same life to it as it does when its combined with power tubes being pushed into distortion and speakers moving air and even distorting slightly.
If you want to record tube amp tone, put a mic in front of a tube amp and crank it up!
The direct out is handy when blended with a mic'd amp, or even for quickly and quietly recording a scratch take or song idea. It may even work well for recording clean guitar tones. But the direct out just doesn't capture the smooth distorted tones of a guitar amp very well.
If you want to record direct, maybe look into a Line6 POD, Boss GT, Behri V-Amp, Vox ToneLab, Digitech RP, or other modeller. They're designed to imitate the sound of an amp in a room and record it direct with no amp involved.
Jul 07, 2007 06:00 pm You're absolutely right Tadpui. The line out to the mixer does not sound nearly as nice as the amp alone. I also mic'd the amp to the mixer and that sounded great as well. Better sound than I've heard in a long time. I didn't really have the problem that I thought I would of having one sound coming from my amp and another sound with effects added coming from the mixer. Makes me wonder what is intended for the line out jack if your not getting a really good signal from it. Thanks a lot for your help and input. That Line6 POD really looks cool. Good reviews also.
