Help with Hifi Hum ?

[andrewc]

Anyone here use a turntable ?

I've just got round to fitting a new cartridge to my tonearm and am now getting an alarmingly loud hum and a high pitched noise.

Previously I've run a moving magnet cartridge into a Graham Slee Era Gold  and never had any problems.

As I'm now using a moving coil I've put a Graham Slee Elevator into the mix as well (had this for a while but have never used it)

I thought it could be my diy interconnects but swapping them for known good ones hasn't helped either.

The PSU's are on the floor away from the kit, cables are as separate as possible, earth wire is going to the connection on the back of the Elevator (moving to the earth on the phono stage or the earth tab on the mains block didn't help either)

Disconnecting the earth wire gets rid of the hum but there is still a high pitched whining noise.

Cartridge sounds very good but the unwanted noise is annoying!

All advice welcome 

[clifftaylor]

You seem to have sorted the hum (earth loop) - have you tried taking the elevator out of the equation? (I assume this just boosts the M/C output). Overall, this sounds like an earth related problem.

Edit: Or the cartridge is borked 

More Edit: Or the Elevator is borked. 

[andrewc]

Cartridge is brand new, but bought from Japan so no local dealer.... and I'm a cack handed numpty at fitting them, but I don't think it's that,

Elevator & phono stage were bought* from a mate who reviews hifi when he isn't doing cycling tours, he had no problems with it but I've got an email out to him.

There is no hum with the earth disconnected , but I'm not sure it's OK to leave it like that.

I've got the elevator and amp at an angle to each other which seems to have reduced the high pitched noise to a very low level. It's just audible when not playing music .

* His favourite charity got my cheque, I got a very good phono stage at a nice price.

[numbnuts]

I use to get an earth loop with my tape decks, the way I cured it was to take the earth out of each plug wire them all together and put them into one plug i.e. tape deck 1 to tape deck 2, tape deck 3 and so on

[Lonewolff]

I don't know much about HIFI stuff, but I do know about ground loop issues (from CCTV installs). We have little boxes called ground loop correctors to get rid of 'hum' (shown as vertical bars on the image, but I assume its the same idea). Maybe you can get something similar for HIFI setups.

[pcolbeck]

The recommendation used to be to remove the earth connection from all the plugs bar one in a HiFi stack then they all earth through that one and you get no hum. These days you need to be carefull and remember that any piece of equipment that connects top the rest optically will need a separate earth.

[andrewc]

Using the cartridge into the phono amp with the earth connected causes no hum but is obviously too quiet.  Put the Elevator back in and use the earth & I get noise!

I've finally just left the earth wire hanging, twiddled the capacitance settings and it sounds fine.