slamson00 Posted December 21, 2014 Share Posted December 21, 2014 Hello. Recently bought a brand new Epi Hummingbird pro and love it! I have never had an acoustic electric guitar so I picked up my acoustic amp to play around with at home. I picked up a Fishman Loudbox Mini 60w and a Fender Acoustisonic 15w to try them both out at home and see which one I like best. I noticed when I plug the Hummingbird into the Loudbox mini, when you turn the volume up to a normal level there is a pretty noticeable constant electronic "hummmm" that comes out of the amp. The guitar sounds beautiful through the amp when you play, but when coming to rest the hummm is back. Its not terribly loud, but enough that you can definiately notice it. Turn the gain or bass up, the hummm increases. turn it back it decreases. So I plugged the guitar into the Fender acoustasonic and the same "hummmm" is basically not present. It is there but very very low and nothing above what I would consider normal for a solid state amp. For comparison to what I'm used to my Epiphone 335 plugged into a Fender Frontman is quiet as can be when not being played. I actually plugged my Hummingbird into my Frontman amp also just to see if a "humm" was present at rest and it was quiet as well. I did change cords around on the Hummingbird and the different cords don't effect it when plugged into the Loudbox. Now if I grab the end of the chord where it is plugged into the guitar, the humming goes away with the Loudbox. I called the local guitar store where I had my new Epi Hummingbird set up and the action lowered and they said that constant "hummm" coming out of the loudbox is considered normal. They told me sometimes pre-amp guitars like the Hummingbird don't always mix with every amp out there, and then you will get this "hummm" as I have described. Part of this is the amount of power that is built into the Loudbox mini (their comment). They told me when you have a pre-amp in a guitar stacked on top of a amp this can happen. You have to play with the settings and mix to find the sweet spot. Still I expected the Loudbox Mini to be more quiet at rest then the Fender Acoustasonic especially because of the price difference. Perhaps that was a bad assumption on my part? So my question is there something wrong with the pre-amp on my Hummingbird or could the ground be bad? Like I said when I grab the end of the cord where it goes into the guitar the humm on the loudbox goes away. But the humm is not present when I plug the Hummingbird into my two other amps. Looking for suggestions on what to do? Or should I just get used to the "hummm" being there on the Loudbox Mini and tell my OCD to take a nap. lol Any info or suggestions are appreciated. Like I said I am new to all this so trying to learn as I go. Link to comment Share on other sites More sharing options...
cliffmac Posted December 21, 2014 Share Posted December 21, 2014 Maybe a ground wire loose inside the guitar? Link to comment Share on other sites More sharing options...
slamson00 Posted December 21, 2014 Author Share Posted December 21, 2014 You know a loose ground wire on the guitar was my thought too, but was playing around with the amp and guitar setup more this morning and I wound up fixing the problem (although technically don't know what I did). lol I wound up just moving the amp to another room and plugging it in there. the amp was always dead silent without the guitar plugged in. But this time when I plugged the guitar in it stayed silent! Good results. So now I know its not the guitar. It was either the outlet in the wall or physical location in my music room (amp next to something causing interference when the guitar is plugged in). So I took the guitar back to the music room and tried and put it in the same location it was before but tried a different outlet. Now the humming came back. Sooooooo....perplexed...i decided to change the physical amp location in the music room. I switched positions with my fender amp. PLugged it back in with the guitar plugged in....this time dead silent!! We had a winning combination!! I am now very happy with the results. So something in my wall in the corner of my room where I had the loudbox plugged in was causing the humm only when my guitar was plugged in. But once moved to the other side of the wall, still using the same outlet with the guitar plugged in....was dead silent! I'm confused....but hey not arguing with the results. Any thoughts on what was going on? Needless to say that amp will not go back in the corner of my room. Now I can enjoy the beautiful sound of the Hummingbird through the loudbox without interference. Sounds just as I was hoping it would. Link to comment Share on other sites More sharing options...
Cougar Posted December 21, 2014 Share Posted December 21, 2014 So something in my wall in the corner of my room where I had the loudbox plugged in was causing the humm only when my guitar was plugged in. But once moved to the other side of the wall, still using the same outlet with the guitar plugged in....was dead silent! I'm confused....but hey not arguing with the results. Any thoughts on what was going on? There are many fronts in the war on hum. I know Tweak has a good article: The War on Hum that likely contains an answer or two. It pertains to "home studios," but the concept is the same.... Link to comment Share on other sites More sharing options...
Flight959 Posted December 28, 2014 Share Posted December 28, 2014 I dont have pre amps on my acoustics but I have a similar problem with my electric guitars through my amp. The room in which I play has a dimmer switch for the lights. Doesnt matter if there down low or on full...the hum is unbearable... Other sockets in the room must be on a different electrical loop as there are no issues with them. Regards Link to comment Share on other sites More sharing options...
milod Posted December 28, 2014 Share Posted December 28, 2014 I don't have either of these two, but I've used my little Kustom AE amp and the potential problems are identical - as are the potential solutions. The notch (anti-feedback) filter control on the amp, along with the phase switch on the guitar's preamp, should be messed with to find the two more likely sources of guitar-based "hum." That's to a degree, and your Fishman manual has the info on that amp, resonance in the Loudbox. External hum tends to be less likely on any amp nowadays if plugged into a properly grounded wall plug - assuming that wall plug isn't served by various other potential hum-creators that can affect an amp. m Link to comment Share on other sites More sharing options...
TommyK Posted January 3, 2015 Share Posted January 3, 2015 What Milo said. You're gonna have to move. Or.... install a dedicated circuit for your music room. Having said that.... Since moving the amp cabinet changes the state of hum your amp is picking up an RF frequency from somewhere as if it had an antennae. Continue to use the 'sweet spot' in the room for amp placement. You might be able to use some sheet metal to shield the amp in your preferred location in the room. My son was having trouble with interference with his entertainment center. It cropped up after he got new neighbors in the adjoining apartment. Turns out it was caused by a wireless router the neighbor installed on the adjoining wall. A sheet of metal applied to my son's side of the wall (behind a picture), opposite the neighbor's router, is all it took to block the interference. The current movement to a 'wireless' world is sure to create more challenges. You know, some solid electric guitar pockets, where the electronics reside, are shielded with foil. I wonder if shielding the inside of the amplifier cabinet with metal foil might be a fix too? Just be sure to not short out the circuitry. Link to comment Share on other sites More sharing options...
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