Mods, I apologize if this is in the wrong spot - I gave it my best guess.
My Cure is a fantastic amp for me, it does exactly what I need - so my issue isn't with my amp. At home, it's dead quiet, and on several gigs it's been perfectly well behaved. Where I have issues is in our rehearsal space, and in a few select spots we play, where the power is particularly dirty.
Our rehearsal space is the most extreme example, and our other guitar player and bass player both have the same issue. All of the amps have wicked hum...it's not volume related or gain related, and no one in our band has single-coils. For whatever reason, the PA doesn't seem to have hum issues - only the instrument amps.
Maz jr.18 nr. Mrk II studio. Blackout Maz jr. 18 studio/reverb. Blackout Ghia 110 model. Gibson Traditional les paul/figured trans cherry. Suhr classic pro/Sherwood green/rosewood/v70's. Suhr classic pro/fiesta red/rosewood/60lp's. Hgwy 1 series texas tele(modded). Fender players strat.
i played a lot of gigs with no power conditioners years ago. things to look for are dimmers on lights, florescent lights, and neon lights. we would try to plug our gear into circuits/outlets that don't have any of those things plugged in. we would ask someone at the venue if they knew if the stage outlets were on their own circuit. if there are any of those things plugged in and turned on near the stage (or same circuit), we would unplug them or turn them off.
Are your amps on the same branch circuit as the PA? Any motors on that circuit? Is the hum continuous or does it switch off and on?
I'll have to look into what's on the same circuit - that's not a question that I knew to ask, but I'll certainly be asking now.
The hum is continuous, and is especially noticeable from the two guitar amps. It disappears entirely when the guitar volume is off - which in my head says it's as likely to be a proximity issue as anything, but in the rehearsal space, no fans, no fluorescent, no neon, nothing with a motor that I'm aware of - the building itself is 1950's era, and we share it with a document storage company, and a small church.
If it’s a 1950’s building, is the electrical three wire (ie three prong plugs)? I lived in a house that age and all the original wiring to two wire with no ground. You could get some big grounding issues and ground loops. This is the wiring that can also give you a nice shock from a mic or even guitar strings.
If you mute the guitar and it disappears, you found your entry point. P90's and other single coils are more notorious for picking stray interference up like that, too. Humbuckers are not immune, but the effect can be greatly reduced. Inferior cable (and jacks/plugs) can be at fault, too. But, turning the guitar down and it disappearing means it isn't coming through the power line and directly emanating through the amp. Thus, power conditioners aren't going to help you with that.
Like others have said, dimmers, motors (moving stage lights, for example) can have an impact. Large power feeds for the stage equipment close by, etc. Also, some power line garbage can actually reverse-feed back through the ground and chassis...and to the jack, etc. Good luck on rearranging the stage wiring in a venue.
AS for rehearsal space? If an industrial area, there's the same potential. All that said, it won't hurt to add a true power conditioner that uses a very large transformer wound to keep the ac line voltage stable and filtered. That small tester someone listed won't measure line garbage, but it's a real good safety item to let you know it's safe to plug-in. Better yet, get a cheap digital meter ($20 or less) that can measure and tell you what voltage your ac is to begin with. If can vary all over the place.
Here's some more food for thought. Pedals, pedalboards and power supplies. I once had a nasty buzz that was very very low, yet it really bugs me if not pristine clean. One day I set out to find what pedal on my board might be creating it (if any). It was a Pedaltrain PT1 with an ISO5 supply under it. I had a direct box on top about 2" or so from the supply under it. Bingo! Moved the DI to another spot and clean again! Why? A good DI or a Wah pedal has a transformer in it. The ISO5 is a switching power supply. It emanates a high frequency switching interference that most pedals won't "see"...unless they have an inductor (or transformer) inside like a wah, etc.
So, assess your pedal situation, if any. Remove all pedals and just use guitar and amp in practice and note any differences.
Overall...noise is a bear to eliminate at times.
One more source...if your amp is old enough and some oxidation is occurring at the speaker jack/chassis mounting connection. Had that in a Jaz20/40 one...needed to pull the jack...clean off the inside chassis at the mounting hole...reassemble and all was fine.
My point is this...in the quiet places, is it really dead quiet or is there a very very low hum, etc. that you think might be normal? If the latter, it's not...the amp can be made completely quiet. If there's any noise at all...i.e. hum that's very very low, that can indicate you still have an issue it's just that issue gets abused in the noisier environment.
Post by thatstatuemoved on Apr 4, 2018 7:02:09 GMT -7
All great advice above. I have a Furman power conditioner that I hauled to every gig I went to. Mine is a big unit and I do not know if it is even still made. A lot of places we played had wanky electrical issues. My take on the Furman was that it helps to keep the electrical current consistent and always made me feel like my amp was not at risk for low power and surges which can wreck internal components in an amplifier. Never had an issue using the furman. I cannot recall if it helped with hum--I do not think it helped much in this area. One thing I did find was that cell phones can cause weird noises in your amp. I always put mine in airplane mode and had band mates do the same.