Feedback/Humming When Sampling

i'm having an issue with a feedback/humming noise coming from what seems to be the MPC. when i plug the headphones directly into my phono preamp, there's no sound, but when it's plugged into the MPC, it starts up. everything is grounded as it should be, so this seems to only be happenign with my MPC. i'm guessing that it may be the cord? i had my local music shop make me stereo to 1/4'' plugs but this is something i'm not savvy in so i was hoping for some advice. thanks in advance

first. How are you plugging headphones into a phono preamp? That doesnt sound right.

double check the ground. Just because its grounded doesnt mean its right

check the needles connection

lower your record volume

move the mpc away from speakers

poundaproblem wrote:first. How are you plugging headphones into a phono preamp? That doesnt sound right.

double check the ground. Just because its grounded doesnt mean its right

check the needles connection

lower your record volume

move the mpc away from speakers

my preamp has a stereo headphone line out, which is just a 1/4'' plug, it's meant for headphones.

so with that said, if it wasn't grounded right, i would be hearing that humming through the headphones directly from the phono preamp it seems. regardless of lowering record volume, it seems as though it shouldn't make a difference.

the needle is built directly into the cartridge i have, which is a high output denon, also, i just added that cartridge and even before that one, the issue was there.

lastly, i just tried moving it, which exhausted all the options i know about so i figured i'd have to post here and hopefully figure it out.

any other ideas? i appreciate the help so far

hmmm...

what kind of pre amp are you using and What type of TT

poundaproblem wrote:hmmm...

what kind of pre amp are you using and What type of TT

bellari tube preamp and technics sl-1200

i remember my boy at the music shop briefly mentioning something about certain cables causing some sort of feedback but i honestly dont know if what he said applies to this scenario. what kind of cables are you using on your setup? my phono preamp only has stereo ins/outs

if the cables are crap they could introduce some noise in the signal but I dont know man. Is the unit old? Is the tube in good shape? I have 2 setups. At home I run the TT to a MFC-42 and in the studio I just have a cheesy phono pre. Both work fine and make 0 noise. For my connections I just use a standard red & white set of RCA's

poundaproblem wrote:if the cables are **** they could introduce some noise in the signal but I dont know man. Is the unit old? Is the tube in good shape? I have 2 setups. At home I run the TT to a MFC-42 and in the studio I just have a cheesy phono pre. Both work fine and make 0 noise. For my connections I just use a standard red & white set of RCA's

for cables you would use a cable that's 1/4'' to RCA though right? the MPC is pretty old, i'm gonna try going directly into my profire and if there's no humming, i guess that means it would be the MPC. if it's the MPC, what would i do to fix that?

edit: i hooked it up directly to the profire and the humming is still there, so it must be the cables, unless the preamp only gives the feedback from those 2 outputs.

It sounds like you're getting what's known as a ground loop hum. The problem is that the Bellari has unbalanced outputs. You always run the risk of passing noise down the line with unbalanced connections.

You can try getting a 1/4" Y cable (stereo on one end, mono on the other two ends) and hooking the VP129 headphone outs to the MPC. See if that does the trick (but it probably won't).

Or you could try using an Ebtech HumX, Furman M-8x, or any other power conditioner.

mp3 wrote:It sounds like you're getting what's known as a ground loop hum. The problem is that the Bellari has unbalanced outputs. You always run the risk of passing noise down the line with unbalanced connections.

You can try getting a 1/4" Y cable (stereo on one end, mono on the other two ends) and hooking the VP129 headphone outs to the MPC. See if that does the trick (but it probably won't).

Or you could try using an Ebtech HumX, Furman M-8x, or any other power conditioner.

thanks for the response.. so my first question is what the ideal setup for sampling is if there are issues like this with the bellari. i originally got that preamp becasue i read good things about it. so if i were to have to buy something else, what would you recommend?

other than that, is the only potential fix to use a power conditioner, and is that even guaranteed to work?

thanks for the help

The ideal setup in any studio for any analog connection between two devices is a balanced connection. Its the balanced connection that rejects noise travelling down the cable. But that means that each device on each end of the connection must have balanced inputs/outputs. A growing list of 'prosumer' gear does not. In fact the 1k has balanced inputs but its outputs are unbalanced.

Anyway, most of the time you will be just fine. My setup has a mix of balanced and unbalanced connections. I had a ground loop hum problem a few years back and it turned out that it was my flat panel monitor that was causing the noise. So you may want to try unplugging the power cables on everything but your tt/preamp/MPC (maybe even stuff in other rooms...) to see if that kills the noise. If it does, then plug in one device at a time to see which one was causing the noise.

But if all else fails, a power conditioner will do the trick. That's what they're designed for. In fact I'd recommend a power conditioner regardless of whether you're currently experiencing ground loop problems or not. In my old townhouse, everytime the fridge or air conditioner would power on, I could hear a very subtle click in my headphones. They also protect your gear from blackouts/brownouts/power spikes which can ruin your gear.

BTW: That bellari is a keeper - nice way to warm up your TT before you take samples

Last: there is plenty of info on the net about your problem, just google 'ground loop hum'. I learned everything I know about it when I was trying to eliminate the hum from my system. Oh and if you ever need a bass sound, try sampling that hum and filtering it...

mp3 wrote:The ideal setup in any studio for any analog connection between two devices is a balanced connection. Its the balanced connection that rejects noise travelling down the cable. But that means that each device on each end of the connection must have balanced inputs/outputs. A growing list of 'prosumer' gear does not. In fact the 1k has balanced inputs but its outputs are unbalanced.

Anyway, most of the time you will be just fine. My setup has a mix of balanced and unbalanced connections. I had a ground loop hum problem a few years back and it turned out that it was my flat panel monitor that was causing the noise. So you may want to try unplugging the power cables on everything but your tt/preamp/MPC (maybe even stuff in other rooms...) to see if that kills the noise. If it does, then plug in one device at a time to see which one was causing the noise.

But if all else fails, a power conditioner will do the trick. That's what they're designed for. In fact I'd recommend a power conditioner regardless of whether you're currently experiencing ground loop problems or not. In my old townhouse, everytime the fridge or air conditioner would power on, I could hear a very subtle click in my headphones. They also protect your gear from blackouts/brownouts/power spikes which can ruin your gear.

BTW: That bellari is a keeper - nice way to warm up your TT before you take samples

Last: there is plenty of info on the net about your problem, just google 'ground loop hum'. I learned everything I know about it when I was trying to eliminate the hum from my system. Oh and if you ever need a bass sound, try sampling that hum and filtering it...

do you recommend any particular conditioners?

That Furman that I mentioned above. Its cheap and it does the job. That's what I have. Of course, like anything, if you have more money you can buy a better one, but that Furman is fine.

But again, try unplugging everything but your tt/preamp/MPC first and see if you still get noise.

mp3 wrote:That Furman that I mentioned above. Its cheap and it does the job. That's what I have. Of course, like anything, if you have more money you can buy a better one, but that Furman is fine.

But again, try unplugging everything but your tt/preamp/MPC first and see if you still get noise.

yeah i tried plugging everything in at a different outlet and location and it still was there... is there anything that makes that ebtech any different than the furman?

mp3 wrote:It sounds like you're getting what's known as a ground loop hum. The problem is that the Bellari has unbalanced outputs. You always run the risk of passing noise down the line with unbalanced connections.

You can try getting a 1/4" Y cable (stereo on one end, mono on the other two ends) and hooking the VP129 headphone outs to the MPC. See if that does the trick (but it probably won't).

Or you could try using an Ebtech HumX, Furman M-8x, or any other power conditioner.

+1 +1 +1. I was going to say this. Beat me to it.

JesseHolmz wrote:

mp3 wrote:That Furman that I mentioned above. Its cheap and it does the job. That's what I have. Of course, like anything, if you have more money you can buy a better one, but that Furman is fine.

But again, try unplugging everything but your tt/preamp/MPC first and see if you still get noise.

yeah i tried plugging everything in at a different outlet and location and it still was there... is there anything that makes that ebtech any different than the furman?

I don't recommend Furman. They are glorified power strips. I have a Monster Pro 2500 (which I am not a fan of Monster but this piece is great) that cleaned all of my noise and hum out like you had. Most Furmans only protect from surges if they are the low end ones. And even after a surge you have to replace them anyways. Get something that can handle multiple surges, and will clean the energy to give you a better sound.

Depending on where you are located some places have more problems with energy then others. I live in Texas and the energy is awful here. It causes noise, and even burns lots of equipment out in under a year because of all the lightning storms, and surges.