a recent Hum addition to my amp

andy__woods · February 10th, 2006, 02:52 PM

Hey guys, I've got a VOX AD15VT amp. I've had it a couple of months now and really love it. No problems with it at all until yesterday. I often like to play sitting on the couch in the dorm room, with the amp right next to me, so i can mess with settings and whatnot. Well, last night there was a very apparant hum coming out. If i turn the gain down, it goes away, but I didn't change my settings at all after Praise band on wednesday (when there was no hum).

The only thing I can think of is that when we were coming back to the dorm, my roommate was carrying the amp and accidently hit it into a wall. There was a small gouge taken out of one of the corners but I didn't think anything of it. Now I'm wondering if something came loose on the insides. Any thoughts?

Wally · February 10th, 2006, 06:53 PM

Andy, could we have a few more specific details, por favor? With nothing plugged in and controls on zero, is there any hum? (I'm thinking not, right?) Now turn the tones up. As you raise the gain and volume, when does the hum occur? If the hum occurs once the amp is generating signal and increases with volume/gain increase, I would think that you have a bad connection, possibly the result of the bump and probably bound to occur anyway. This is symptomatic of most modern PCB builds, and would require some tech time on the bench for repair.
If the hum does not occur with no instrument plugged into the amp, then your hum is pickup induced or possibly indicative of a bad connection at the jack when the guitar is plugged in.

hankseiz · February 13th, 2006, 03:37 PM

If I have to use a 2-prong adapter on my Bluescube it hums. Plug it directly into a 3-hole outlet: Presto. No hum.

Wally · February 13th, 2006, 06:18 PM

Quote:

Originally Posted by hankseiz

If I have to use a 2-prong adapter on my Bluescube it hums. Plug it directly into a 3-hole outlet: Presto. No hum.

Trick from the old '2-prong' days...flip that two prong plug around and the polarity will be corrected and the hum disappears.....however, the danger does not.

February 10th, 2006, 02:52 PM	#1 (permalink)
andy__woods Tele-Afflicted Join Date: Sep 2005 Location: Michigan Age: 23 Posts: 1,180 60 Photos	a recent Hum addition to my amp Hey guys, I've got a VOX AD15VT amp. I've had it a couple of months now and really love it. No problems with it at all until yesterday. I often like to play sitting on the couch in the dorm room, with the amp right next to me, so i can mess with settings and whatnot. Well, last night there was a very apparant hum coming out. If i turn the gain down, it goes away, but I didn't change my settings at all after Praise band on wednesday (when there was no hum). The only thing I can think of is that when we were coming back to the dorm, my roommate was carrying the amp and accidently hit it into a wall. There was a small gouge taken out of one of the corners but I didn't think anything of it. Now I'm wondering if something came loose on the insides. Any thoughts? __________________ -- Andy "Woods" Crowder --

February 13th, 2006, 03:37 PM	#3 (permalink)
hankseiz Tele-Meister Join Date: Mar 2004 Location: Clifton, NJ Posts: 162	Using a 2-prong adapter? If I have to use a 2-prong adapter on my Bluescube it hums. Plug it directly into a 3-hole outlet: Presto. No hum.

February 10th, 2006, 06:53 PM	#2 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 4,212	Andy, could we have a few more specific details, por favor? With nothing plugged in and controls on zero, is there any hum? (I'm thinking not, right?) Now turn the tones up. As you raise the gain and volume, when does the hum occur? If the hum occurs once the amp is generating signal and increases with volume/gain increase, I would think that you have a bad connection, possibly the result of the bump and probably bound to occur anyway. This is symptomatic of most modern PCB builds, and would require some tech time on the bench for repair. If the hum does not occur with no instrument plugged into the amp, then your hum is pickup induced or possibly indicative of a bad connection at the jack when the guitar is plugged in.