Humming problem!!!

[Bernard]

Another thing to try is to connect a piece of wire between any metal on the chassis of your TT and the ground on the phono box.

 

[Questy]

I hooked up a wire to the motor like you said and it decreased somewhat but not much.

 

[Questy]

I had a sub hum and had been using a "quality" cable to connect it to my pre-amp and it turned out to be the damn cable. So, I would change the interconnects as well as any power cables that you can change. Just to ANYTHING else... does not need to be a high quality piece, just something different so that you can check to see if that makes any change.

The sub does not hum at all unless the phono is on therefore it is from that not the interconnect. Changed all interconnects except for the one on the table as it is permanent and no change.

 

[Bernard]

I hooked up a wire to the motor like you said and it decreased somewhat but not much.

The motor may well be isolated from the chassis, so try it again with the wire connected to a screw on the chassis.

Another thing to try is disconnect all wires from the cartridge and check for continuity of each wire to the phono connectors.

 

[risabet]

Does the Phono Box have a three prong plug? If so try cheating it with a 3 to 2 adapter. Connect the TT ground to the phono box and the PB to the preamp. Does this help? If not try various grounding combos until you find one that works. Don't give up. I spent a month once tracking down a ground loop.

 

[Questy]

The motor may well be isolated from the chassis, so try it again with the wire connected to a screw on the chassis.

Another thing to try is disconnect all wires from the cartridge and check for continuity of each wire to the phono connectors.

Thanks. I will try this. Could you tell me how to go about disconnecting the wires as I am not familiar with this. Do you just pull them out one at a time?

When you say "chassis" do you mean another part of the table besides the motor?

Excuse my lack of knowledge but I am new to analogue.

 

[Bernard]

Thanks. I will try this. Could you tell me how to go about disconnecting the wires as I am not familiar with this. Do you just pull them out one at a time?

The wires are connected to clips that slide on to the cartridge pins. You just slide them off the cartridge pins. Take note of where each wire goes before disconnecting it.

When you say "chassis" do you mean another part of the table besides the motor?

Yes.

I am assuming you have an ohmmeter to verify continuity.

 

[Questy]

Going to Montreal on Monday and am bringing the table and phonobox with me to be checked. Luck would have it that I have business there so I hope we can resolve this as vinyl really sounds as good as you all say it does! I am quite blown away at this price level and will most likely go up in the future. I think my CD player and server will be on vacation for a while!:music:

 

[tonepub]

if it stopped humming when you unplugged the turntable from the phono box, there is nothing wrong with the phono box or the connection between the phono box and your amplifier.

Next try plugging the table into the phono box, via the interconnects, but UNPLUG the turntable from the wall. If the hum comes back when you plug the turntable's AC power back into the wall then that's where your problem is.

Another thing you can do to potentially track down the ground problem (perhaps one of your outlets is improperly connected, you may need an electrician), is to run the turntable's ac plug through a long extension cord to another room and get it on a different ac circuit and see if the hum gets better or worse.

It's not the phono box.....

 

[Len44]

I also just tried grounding to the preamp and amp and that did not change anything.

Is it possible you can try a better ground? Wall socket, perhaps? It worked for me...

 

[Questy]

if it stopped humming when you unplugged the turntable from the phono box, there is nothing wrong with the phono box or the connection between the phono box and your amplifier.

Next try plugging the table into the phono box, via the interconnects, but UNPLUG the turntable from the wall. If the hum comes back when you plug the turntable's AC power back into the wall then that's where your problem is.

Another thing you can do to potentially track down the ground problem (perhaps one of your outlets is improperly connected, you may need an electrician), is to run the turntable's ac plug through a long extension cord to another room and get it on a different ac circuit and see if the hum gets better or worse.

It's not the phono box.....

I have tried all you mention except unplugging the table. As for the part where you mention to plug it into other sockets, that I did also and no change. I had all my house rewired 3 years ago during renovations and had dedicated 20 amp breakers installed for my listening room with no other connections so I don't believe this is the problem. I also did NOT use any type of surge protector as well and that also did not change anything. Very strange!

I will try unplugging the table (don't know why I did not think of that before!!) and will see if that is the problem. If not, as I said, I am bringing it with me next week to the dealer and he is going to check it out. Nice to know it is not the pre but in a way I wish it was because that would be very easy to bring next week on the plane!!!.............by the way, I got clearence to bring it on board based on dimensions of the box and weight. Thank God it is not a table like most of you have here on this panel as mine is only an entry model and I will say again, I can only imagine what a table 5 times the price would sound like!! Already I like it better than CD's!

 

[Questy]

I unplugged the table and there was no difference! The hum was still there! I will have it checked.

 

[spectral]

This still sounds like a ground loop somewhere. I had the same, and broke it by attaching the single wire shown below to the phono preamp's ground lug (suggestion by Ayre factory) - the arm's ground wire was also attached to the phono's ground lug. I then reduced it even more by plugging the preamp directly to the wall - apparently, the MIT Z Strip that everything was plugged into was causing this ground loop.

 

[Questy]

This may sound like a dumb question but where did you plug the wire into the table? In other words I understand to use the phono preamp ground but to what on the table?

 

[risabet]

This may sound like a dumb question but where did you plug the wire into the table? In other words I understand to use the phono preamp ground but to what on the table?

The third wire from the tonearm cable should be attached to the phono preamp also, in most cases. The phono pre should then be attached to the preamp or integrated or what have you. If the Int. or pre-amp doesn't have a phono ground post, you'll need to ground to a screw on the chassis. You may need to scrape off some paint to get a good connection for the ground. Click on the doc for a little line drawing.

 

[MiTT]

Exactly as Risabet says. You should have some sort of a ground connection at the j-box on the turntable (see the red wire in the photo below). If your table has a fixed cable coming off of it there would be a third conductor in the cable terminated with a spade lug most likely.

 

[Questy]

Thank you all for your kind help so far with this "frustrating" problem

On the Pro-Ject Debut III table, the interconnects are fixed to the table. On the connecting end, there are the right and left plugs as well as the ground wire with a spade. I have this hooked up to the Pro-ject Phonobox and the ground as well. I have tried to take a second wire from the phonobox ground to the power amp and that did not change anything.

I am wondering if during the cartridge change they performed before sending the unit, something was not hooked up properly for grounding. I find this unlikely because the store that did this, does it all the time so error in that area would be most likely minimal but I guess you never know.

Should I have a look and under the table inside the enclosure to see how the wires are set up? There has to be some simple solution to this but I am very new at the analogue thing and all is not understood.

Thank you everybody

 

[spectral]

To verify that the turntable is properly grounded use a multimeter to assert connectivity from the arm (anywhere on the metal) to the phono's ground lug. The arm acts as the shield for the 4 cartridge wires. If you find that it is grounded properly then this would strengthen the ground loop theory.

 

[Bernard]

Another thing to try, if you have not done so already, is connect the ground lead from the phono cable to the preamp instead of the phono box.

 

[Questy]

Well, I have been playing around and have done a lot of changes to where I plug in my gear and have gone with one main electrical connection. I then reversed both the phonobox and tables A/C connection and that dramatically decreased the hum! It is still present but very week in comparison and I have to turn the volume almost full way up (with no music of course........500watts!) to hear it. Of course I would like to completely eliminate it but maybe this is the best I can do! You cannot hear it at all during playback or between songs so I guess I can say 95% problem solved!

Thanks everyone for all the advice!