Nasty buzz on my Roland/Sheraton

**BobD** · 09-06-2009, 08:29 PM

I have a Sheraton II and a new Roland Cube30x. I hadn't noticed this before but when I'm on the clean channel with the volume set to about 9 o'clock and the volume on the guitar all the way up it's pretty much dead quiet. When I turn up the volume on the cube to 12 oclock and the guitar remains at full it's still quiet. But, when I back off the volume on the guitar I get a pretty loud buzz. The buzz seems be worse in the middle volume setting on the guitar but when I turn the guitar all the up it's greatly reduced. Also, when it's buzzing and I touch either the strings or the bridge it greatly reduces it. Any ideas what this could be? Could it be the pots? I'll probably take it to Daddy's tomorrow but I thought I'd get some input here first.

**RAQ** · 09-07-2009, 03:06 AM

This isn't going to be much help really, but at least I can confirm you're not the only one. A buzz, rather than a hum. The problem has all the symptoms of an earthing/grounding one; but I've tried a number of guitars on the 30X - some do it, some don't; and none of them cause problems on my little Marshall 15W. If I carry out any wiring mods I check and remake earth connections as a matter of course, but even guitars I've checked do it. I've tended to live with the problem rather spend (waste) even more playing time on modifications. Some posts have referred to noises on the Cube, but why doesn't this happen in every case, and why on guitars where I know I've made sure the earth lead is OK? Maybe some pups react with the Roland circuitry - but that is taking me out of my electronic depth. I've assumed that, eventually I'll track it down; but I'll appreciate advice too.

**Little Jay** · 09-07-2009, 04:26 AM

ha, I have that also with my Sheraton, on my tube-amps when they are not earthed/grounded. (I have a Cube 30x as well, but for some reason I have not played my Sheraton through the Cube, will try tonight....)

Indeed with the volume full up, there's no problem. Backing off the volume makes it buzz. It's definately a grounding problem, but why it happens to one guitar and not the other I don't know. With my ES175 (copy) with electronics that I installed all by myself, I don't have the problem, though it's the same configuration as the Sheraton. I am going to look at the ground connections in the Sheraton though. All the ground-wires from the picks and pots should be connected to the ground of the input, but also the bridge or the stop-tailpiece must me connected to the earth.

Since it only happens when playing an ungrounded outlet it's not that big a problem with my tube-amps since I always play grounded outlets while gigging. BUT: the Cube doesn't even have an earthed powercord! (at least the European version). So that's maybe why it happens with the Cube...?

EDIT: I googled some more info that could be helpfull:
- http://www.tdpri.com/forum/tele-tech...tone-knob.html
- http://answers.yahoo.com/question/in...8121058AAN5l7I
- http://www.harmony-central.com/Guitar/grounding-faq.txt
- http://www.thegearpage.net/board/sho...d.php?t=588497

**whiskywheels** · 09-07-2009, 05:16 AM

I had the same problem (cube 80), with a brand new peerless guitar. I had to take it back to the shop, but they couldn't find anything wrong, or hear the problem. Fortunately they took the guitar back.
It's a bit of a mystery, but they did say something about the way some archtops were earthed, and they offered to do a custom earthing job to see if that would resolve it.

**BobD** · 09-07-2009, 08:08 AM

Thanks for all the replies. I hooked up my classic vibe Squire to cube and it does the exact same thing as the Sheraton. I'm starting to think it's the cube. I going back to the store today to have them check it out.

**BobD** · 09-07-2009, 08:39 AM

Also, when I plug the cord into the amp and not the guitar it makes a really loud hum.

**RAQ** · 09-07-2009, 09:54 AM

Originally Posted by BobD

Also, when I plug the cord into the amp and not the guitar it makes a really loud hum.

Yes - I think it's likely to do that anyway because the guitar lead/cord acts as an aerial/antenna (the live/hot connector and earth/ground wires will be open circuit until you plug in to the guitar and close the loop). The suggesion that it is an earthing problem makes real sense - it's just tracking it down that's difficult. If the Cube 30 really hasn't got an earth connection that could have something to do with it. Maybe, after saying elsewhere that I've had problems coming to terms with the twin cut-away 335 shape, I'm just going to have to buy a Sheraton for test purposes.

**Gitterbug** · 09-07-2009, 10:37 AM

Have you tried with another cable? Is your guitar jack OK? Sometimes those screw-on plugs come loose and create hum or whatever. Happens more often with speaker cables, though.

There's something strange with the Cube circuitry. I once opened my 60 to check whether another speaker would fit in (nopes). When I put it back together, every note I played ended with a long hiss. "Oh this is for my sin of even thinking the Cube could be improved on," I thought, but in a couple hours the hiss was gone.

**BobD** · 09-07-2009, 10:47 AM

I tried 2 other cables and both still had the buzz. And the guitar jack seems ok. I had a Fender Vibro Champ XD before this cube and I don't remember this problem.

**BobD** · 09-07-2009, 10:48 AM

Are there any other good solid state amps out there in this price range? All I want for now is a good practice amp that has reverb. If I can't find that I might just go for a Henriksen or a Polytone and call it a day.

**RAQ** · 09-07-2009, 11:07 AM

Originally Posted by BobD

Are there any other good solid state amps out there in this price range? All I want for now is a good practice amp that has reverb. If I can't find that I might just go for a Henriksen or a Polytone and call it a day.

I bought the Cube 30 because it got got virtually universal good reviews as a jazz practice amp, and I didn't really know enough about amps to trust my own guesswork. By it's reputation alone the Cube ought to be worth the effort to sort the problem out - but it's amazing how annoying that damn buzz can be. Now it's clear it's not just me, I'll spend a bit more time trying to isolate the problem.

**BigDaddyLoveHandles** · 09-07-2009, 11:07 AM

Originally Posted by BobD

Are there any other good solid state amps out there in this price range? All I want for now is a good practice amp that has reverb. If I can't find that I might just go for a Henriksen or a Polytone and call it a day.

The Phil Jones AG-100 is much nicer than a practice amp, but it is light and small:

CUB AG-100 Guitar Amplifier

While it lists for $608 it's gone for as little as $300 new:

Phil Jones Bass CUB AG100 2x5 Acoustic Guitar Amplifier | Sam Ash Music 1-800-4-SAMASH

It doesn't have reverb but it sounds so nice you don't need one. Or get a good reverb pedal.

**valriver40** · 09-07-2009, 12:05 PM

i had the same buzz problem when i turned up the volume up on the cube 30. i returned the amp and bought a cube 80x and am happy with this amp.

Jazzarian · 09-07-2009, 12:45 PM

Originally Posted by BobD

I have a Sheraton II and a new Roland Cube30x. I hadn't noticed this before but when I'm on the clean channel with the volume set to about 9 o'clock and the volume on the guitar all the way up it's pretty much dead quiet. When I turn up the volume on the cube to 12 oclock and the guitar remains at full it's still quiet. But, when I back off the volume on the guitar I get a pretty loud buzz. The buzz seems be worse in the middle volume setting on the guitar but when I turn the guitar all the up it's greatly reduced. Also, when it's buzzing and I touch either the strings or the bridge it greatly reduces it. Any ideas what this could be? Could it be the pots? I'll probably take it to Daddy's tomorrow but I thought I'd get some input here first.

Ever think of simply leaving the guitar volume at 10? I never back off on the guitar volume.

The volume knob is simply a variable resistor. The more you reduce the volume, the more you increase the pickup's impedance to ground. Just like when you said the amp makes a loud hum with cord connected to just the amp. That's an open circuit, or nearly infinite impedance. Same effect the more you back off on the volume knob.

Some people, like Robben Ford, disconnect their volume and tone pots, and simply use a volume pedal instead for volume changes. Yeah it's essentially doing the same thing, but in a nice metal enclosure with a considerably more expensive variable resistor inside.

Archie · 09-07-2009, 01:43 PM

Originally Posted by BobD

Are there any other good solid state amps out there in this price range? All I want for now is a good practice amp that has reverb. If I can't find that I might just go for a Henriksen or a Polytone and call it a day.

Try a Tech 21 Trademark 30.

**RAQ** · 09-07-2009, 02:08 PM

Originally Posted by Jazzarian

Ever think of simply leaving the guitar volume at 10? I never back off on the guitar volume.

The volume knob is simply a variable resistor. The more you reduce the volume, the more you increase the pickup's impedance to ground. Just like when you said the amp makes a loud hum with cord connected to just the amp. That's an open circuit, or nearly infinite impedance. Same effect the more you back off on the volume knob.

Some people, like Robben Ford, disconnect their volume and tone pots, and simply use a volume pedal instead for volume changes. Yeah it's essentially doing the same thing, but in a nice metal enclosure with a considerably more expensive variable resistor inside.

Thanks Jazzarian - this is very interesting. Tricky stuff impedance isn't it, I've never really understood it, but I get the general idea. I've got an Aria FA71 - very nice 17" with good acoustic tone - better than Emperor Regent I think. I mostly remove pick/finger guards and not wanting to risk cutting the pots into the top I've just left the pots out and plug it in direct ... but I haven't used it on the Cube yet. I'll try it out. I was wondering if plugging direct would cause other problems, but apparently not. It's not really on though, is it, getting something like the Sheraton with all that complex wiring tucked away - and then bypassing it all.

**BobD** · 09-07-2009, 02:57 PM

Well I went to Daddy's. They plugged the amp in behind the counter and got the same problem as I did. Then I took my giutar and plugged it into a Cube 30 thay hout on the rack. It was dead silent. So we plugged mine into the rack and again it dead silent. So I bought a power filter and took my amp back home. Plugged it thru the filter and still there was the buzz. So I moved the amp(3 feet) away from the wallsocket where it was plugged in and move the guitar(3 feet) away from the amp and the buzz was essentially gone. Totally gone when I put the guitar volume on 10.

So I'm not sure whats going on but I think by putting me/guitar away from the amp and the amp away from the socket it will be fine.

**RAQ** · 09-07-2009, 04:50 PM

Originally Posted by BobD

... I'm not sure whats going on but I think by putting me/guitar away from the amp and the amp away from the socket it will be fine.

I just love this forum. I try to join in, but don't know that I can contribute much that's original - in fact I've hit the wall lately and been really struggling. Being able to share problems really helps. Just making progress on something helps. Won't be able to test the Cube for a day or two, but will try the 'no pot' test and spacing the gear out and see what happens. I'm a bit of a gear adict, I admit, but quite often sorting the gear out when the playing gets bogged down encourages the playing again.

**BobD** · 09-08-2009, 08:42 PM

So get this. I plug everything in tonight, same plug, and it's dead quiet. No buzz at all. Even at more than half way up it was still quiet. Totally weird. Maybe something was plugged in on the same circuit in another room. All I know is I'm a happy camper now that I know it's not an equipment problem.

**RAQ** · 09-09-2009, 03:02 AM

Originally Posted by BobD

So get this. I plug everything in tonight, same plug, and it's dead quiet. No buzz at all. Even at more than half way up it was still quiet. Totally weird. Maybe something was plugged in on the same circuit in another room. All I know is I'm a happy camper now that I know it's not an equipment problem.

Well - it's funny you should say that ... I set about trying to reproduce the buzz yesterday (in order that I could then try to get rid of it) and I couldn't do it. Best I could manage was a sort of static crackle by lightly brushing the strings - which, I suppose, if it points to anything, points to an earth/ground issue; but I still don't know what it could be. Main thing though is that this is not a particular issue with your (or my) Cube, and that it can be resolved, even if you're not quite sure how you resolved it. Also - it confirms the Cube 30 as a good home amp, because alternatives can be three times the price. For myself, I think I need to start taking notice of the advice here to take amps more seriously.

Archie · 09-09-2009, 03:45 AM

If there's a light dimmer switch nearby, that could be the cause of the buzz.

**randyc** · 09-09-2009, 11:59 AM

I like the light-dimmer theory.

For broad-band noise, one of the usual suspects is fluorescent lighting on the same mains circuit as the amplifier.

cheers,
randyc

**BobD** · 09-30-2009, 12:45 PM

Thanks for the replies. The buzz came up again last night. I plugged in the guitar and turned on the amp and there it was. So I went around the house shutting off lights and anything else I could find that might be on that circuit and the buzz was still there. So I turned off the amp and disconected the guitar at the amp. Turned it back on and no buzz. I figured, great my guitar is messed up. So I plugged the guitar back in and ya know what.....no buzz. I'm thinking maybe the plug wasn't all the way into the amp jack or maybe the connection in there just wasn't good and removing it and replacing it fixed the connection. Also, when I initially turned the amp on the cable to the plug was mostly wrapped around the cable holder in the back. Could that have been a problem?

**rio** · 09-30-2009, 02:56 PM

I've had the same problem with my 30x from the beginning. It only happens with certain guitars oddly enough. I have been meaning to try adding a 3 pronged cord rather than the 2 prong cord it comes with (i wish they put one on to begin with, I don't get why they would use a 2 prong cord).

**BobD** · 10-03-2009, 03:20 PM

Sorry to beat a dead horse but I was playing this morning and the sound cut out on me. I was on the neck pup as usual and it just cut out. I switched to the bridge and it came back on. Then switched to the neck again and it seemed ok. But when I play softly there is a buzz going on as the notes fade. I know that the switch must be bad cause of the cutting out but could it also be causing this buzzing?