I guess my first question would be about your turntable Interconnect you are using...Is it Shielded?? |
"This noise is also dependent on the volume; the higher the volume the louder the noise"
Now thats a revelation. Harvard grad?
Bob |
Try grounding preamp to center screw in AC outlet, that sometimes works. You can also try lifting the ground by using a cheater plug. If you try the latter a further step having nothing to do with hum is to ground down or file off the bigger prong so it can be inserted either way. One way usually sounds better than the other. |
If you are using a tube power amp, there may be hum originating from the amp or the tubes. Also, as mentioned above, definitely check the polarity of each component, and interconnects. Cable quality and placement are also important. There may be a ground loop. I was able to get rid of one source of hum with using a battery phono preamp. Good luck! |
Sounds like a potential grounding problem. If your tonearm interconnect has a ground wire, connect it to the ground screw (or a chassis screw if the pre doesn't have a dedicated ground screw). Then, get a ground lift plug and put it on the AC cable of your Power amp. Leave the ground on your preamp AC plug intact. Try that and see what effect it has. I've found more than once that leaving the Preamp grounded and lifting the ground on your power amp will resolve most grounding and hum problems. |
Acoustat6-Yeah, nice. The guy's trying to explain, in detail, his issue, and he's mocked for his efforts.
I'll assume you're a Community College graduate, so I'll explain this like I'm talking to a six year old: believe it or not, there are 'hum' issues that are steady-state, with no volume differential dependent on gain. Hence, the OP's clarification.
Hope that helps... |
I've had this problem a lot on various vinyl rigs I've tried, and I think this is a pretty common issue. I've had varying success in eliminating it and am hardly an authority, but here are some things I'd suggest:
- check the ground from your table to the preamp - make sure it's good and solid.
- check whether the position of your table with respect to your preamp makes a difference and relocated it accordingly.
- get some Craig DeOxit contact cleaner and apply it to every contact in the signal chain - headshell connections, interconects and ground.
- make sure the TT ground connection goes to your tonearm as well as the TT subchassis.
If you can't hear it from your listening position at normal listening levels that's good, and if you can get it cleaned up so you can't hear it at above normal volume levels (ie from your seat, with nothing playing, volume setting higher than normal), you may have to be satisfied with that. This is because you may reach diminishing returns, and IMHO this is just the fact of life with certain arms, cartridges, preamps, and the combination of them. You're likely to have more of this hum on vinyl than with CD or other inputs, even under ideal conditions. The alternative is swap components.
PS - johnbrown - good on you for calling out acoustat6. |
Frepec,
How far away is Your Preamp from the Turntable?
My Rig has a Hum issue... In My
case the phono stage is a
seperate tubed unit,
& the power supply is remote (3+ feet away from the cartridge). However the Tubes are right below the T.T.
cartridge gounded at the Phonostage.
So maybe It is the Tubes causing the Hum? |
First, do you hear the hum ONLY on phono? If so, I agree with the notion that it most likely has to do with grounding between your preamp, tt, and tonearm. I am having a similar problem with my newly set-up Technics SP10 Mk2/RS-A1/Ortofon MC7500 rig. I normally run a Lenco/Triplanar/Koetsu combo that has absolutely no hum issues. With the SP10 et al, I get a volume-dependent hum, probably just like what you are experiencing. The SP10 is in a slate plinth which is absolutely not grounded. So far, grounding the RS-A1 tonearm to the preamp (an Atma-sphere MP1) did no good. My next plan is to ground the SP10 to the MP1. The MP1 is a true balanced circuit, and I have never had hum issues of any kind before, so I think I've got to blame the new rig. Let us know what happens if you take some of this advice. |
Thanks for the help, even Bob (acoustat6). I guess that was a little redundant. And, by the way Bob, it's Princeton. Just kidding. Let me bring you up to date. Some of you have asked about my cables. Using Tara Labs ISM cables though out. However, the tone arm cables are not plug-in type so they are what came with the 'table. They are shielded, RCA. The 'table is $5000.00, with arm, so I am assuming the wire is better than say lower end but obviously not top of the line either.
I have the tonearm grounded to the BAT PK5 phono stage which is a tube unit. The phono stage is two shelves below the TT as is the Preamp (Mcintosh MC2200). There is very little audible noise on CD mode. By removing and reinstalling the arm ground wire to the phono stage, I was able to lower the phono noise level to about half of what it was. Must have been a sloppy connection. My dealer says that if I can't hear the noise from the listening chair, don't worry about it. It is not annoying but I was interested in what causes this noise and if it is possible to get rid of it totally. From the replies I just read it appears to be a grounding issue. It also appears that I probably can't get it any quieter than it is now, which is acceptable.
Thanks again to all who replied, including Acoustat6. |
I don't think this has anything at all to do with cable shielding. Cables pick up RF, not "hum". The term hum implies a 60Hz monotone. RF can include radio reception, hf hash, etc, but not hum per se. |
I am also hearing a low level hum, but mine happens as soon as I connect any device. I've tried some of the fixs I've seen here: started by disconnecting the balanced inputs to the power amp (Threshold T-100) and there is no hum, so that means its not from the speakers.
Then I disconnected every component. As soon as I connect any device, (EAR 834P; tube CD plyer no matter what) I get the hum. I've tried cheater plugs, ground wires. Can't figure it out.
Any ideas? |
