Calling All Guitar Amp Gurus

[phaedrus]

Hi Slutz,

I have been looking for a new guitar amp and I am at the end of my rope. The problem? Buzzing, buzzing, buzzing! We have tried a boutique Reeves, a Fender Blues, the new Gibson handwired amps...I can't seem to find a combo that doesn't have vibrations which would effect recording. I know there could be different reasons why the many amps we have tried are buzzing--damaged tubes in shipping, etc. But after 5 or 6 amps, I was hoping to find a winner (we had three different Gibson amps shipped; ALL had buzzing). So here is the question: do all combos have this problem since the amp and the speaker cab are joined as one? Might it be wiser to get a head and a cab so they are separate--would this help with the buzzing etc? Am I being a perfectionist and chasing a dragon here? Thanks for your thoughts!

P

[BushmasterM4]

Same buzz with different guitars ? How about different power sources ? Have you tried the ground switch. I know its probably stuff you checked, but if its doing it with all the amps, it may not be the amps.

[PVAUDIO]

I've done a lot of recording with matchless combo amps. Even when playing pretty loud i didnt notice vibration...

[phaedrus]

Thanks for the thoughts guys!
I should mention that its not like a hum/buzz--it's actually the cabinet vibrating and making a buzzy sound. For example, if I isolate where the sound is coming from (say, the nameplate, or the grill in the back or on the top) if I press my hand on it, the buzzing stops. But there are internal vibrations too--frankly, after this experience, I don't know how ANY amp wouldn't buzz from sound vibrations--especially a combo. Amps are pushing loads of powerful sound waves and there is a lot of delicate stuff inside the amp, lots of stuff touching other stuff, and places where stuff can vibrate. This sucks!

[GregoryC]

Originally Posted by phaedrus

Thanks for the thoughts guys!
I should mention that its not like a hum/buzz--it's actually the cabinet vibrating and making a buzzy sound. For example, if I isolate where the sound is coming from (say, the nameplate, or the grill in the back or on the top) if I press my hand on it, the buzzing stops. But there are internal vibrations too--frankly, after this experience, I don't know how ANY amp wouldn't buzz from sound vibrations--especially a combo. Amps are pushing loads of powerful sound waves and there is a lot of delicate stuff inside the amp, lots of stuff touching other stuff, and places where stuff can vibrate. This sucks!

Get a Swart Atomic Space Tone Pro and you'll be happy...

[Jonboy79]

I've recorded dozens of combos and never had that problem. Everything from cheap solid states to 3000 dollar boutiques and never anything like you've described. I don't know what your exact problem is but it may not be the amps. Are you setting the amps up off the ground? It's not good to have a combo sitting on the floor as it could cause the floor to vibrate.

[Star Ark]

Have you tried things like unscrewing the grills or even using a lot of tape to hold these vibrating parts down?

If putting pressure on these parts with your hands stops the sound you should be able to recreate the effect unless it is an earthing issue.

[BOWIE]

Are they cheap amps? Inexpensive cabs often suffer from resonant frequencies. Try putting them on a different surface and-or get an angled amp-rack.

[Philo]

Isolate the amp from the ground with a rubber mat or amp stand

Tighten every screw/nut on the amp

Reduce bass frequencies on input with an EQ pedal

In extreme cases, inserting bits of rubber (cut from a mat) or using weatherstripping at the area where the chassis connects to the cabinet can stop vibration

Check for microphonic tubes, especially preamp tubes (you can use a pencil to touch each tube or tube shield to see if it is vibrating)

This diagnosis will work best if someone else is playing, and you can move around and locate the source of the buzz.

Remember that it may be something else in the room, not the amp! My most recent "amp" buzzes were a wah-wah pedal with a loose bottom, a heating vent that vibrated when the volume got loud, and a music stand.

Philo

[Texum]

I'd say that it's quite common to experience some buzzing from certain combos, especially the finger jointed ones. I think I've read somewhere that one boutique manufacturer stated that some buzzing is almost unavoidable, IF you want the cabinet contribute to a classic sound, for example the "looser" sound of old tweeds. I've experienced some of this myself, in my Victoria 5112 (Champ clone), but it doesn't bother me that much, since I believe it contributes to the overall sound, which in this case is rather loose and lively, causing me never to miss reverb on this amp. This lively sound also transfer really well to recordings, IMHO.

In larger combos (Victoria Victorilux, Fender Bassman, Twin, Super, Vibroverb, Matchless DC-30) I've for some reason experienced less buzzing.

I'd also say the chance of experiencing buzzing is overall smaller when using heads and closed cabinets, but that's also a much tighter sound overall, so you'd have to consider that as well.

Is the buzzing the OP is experiencing really that loud? Even with my amps that buzzes a little, it very rarely transfers to a problem on the recordings, even when using room mics.

[Jadestar]

It`s all about the guitarplayer! If he does not play the amp in a cool way it will speak, "bzzz, playzzz mezzz betterzzzzz!!"

Seriously!

[jinksdingo]

Any amp will have a resonant frequency as it is cranked up, just back off the volume a bit or roll off some bass for recording it.

Another source could very well be your guitar as you said you have tried numerous amps and they all seem to have it. Seems logical with the known info.

[elamberth]

What Philo said.

I record a Tech 21 TM 60 regularly, and don't have too much of a problem, i.e. any buzz is far drowned out by the sound of the guitar coming from the amp, so it's inaudible in the recording.

[kafka]

Originally Posted by phaedrus

I should mention that its not like a hum/buzz--it's actually the cabinet vibrating and making a buzzy sound. For example, if I isolate where the sound is coming from (say, the nameplate, or the grill in the back or on the top) if I press my hand on it, the buzzing stops. But there are internal vibrations too--frankly, after this experience, I don't know how ANY amp wouldn't buzz from sound vibrations--especially a combo. Amps are pushing loads of powerful sound waves and there is a lot of delicate stuff inside the amp, lots of stuff touching other stuff, and places where stuff can vibrate. This sucks!

Yes, all combos are prone to this, and it sucks regally. It's a good reason to avoid them (although that's all I have now). It often doesn't show up in the recording, but when you're trying to get things to sound right, man is it ever annoying. It also depends on how sensitive you are to it. Once you start hearing it, your ears will focus on that sound. Hum and cone cry are my peeves now. I've gone through phases where I couldn't stand cabinet buzz. Sometimes you just need to grit your teeth and go with it.

Try tightening and loosening the chassis bolts, baffle board, speaker and reverb pans. You can put a rubber grommet on the speaker. Rubber grommets are a good thing, in general. Make them yourself and insert them liberally between any parts that are held together with bolts. Make sure your tube retaining clips and heat covers are on well. Try swapping them out. Look for loose or old relays. Sometimes the can capacitors will vibrate in their clamps. Even an unused input or speaker jack can vibrate, making a high-pitched sound. Sometimes you just need to place the amp on a different surface or set at a different angle so the vibration is transmitted or dampened differently.

[Paul Hammond]

Have battled that issue many times. There was a run of a couple of different speaker manufacturers where that vibration was in the damn speaker! The free air resonance would cause the cone to create a buzzing sound between F# and A on the low E string played at a reasonable volume. It wasn't the cabinet. The least offending amps in the collection would be the Alessandro Working Dog combos. They are all tested for that exact issue and don't leave until they are tight. Have heard that in a lot of old AC30s. Occasionally Marshall 4X12s but that is usually the dust cap separating from the cone.
When it happens at certain frequencies it can be nerve racking, and yes, as stated earlier sometimes it can be in the room or the room can be causing it. Good luck with eliminating that! PH