Humming problem!!!

[Questy]

I decided to buy an entry level table to see if I enjoy the sound of vinyl and got myself a ProJect Debut III with an Ortofon 2m Red cartridge and ProJect Phonobox II USB. It sounds wonderful for the price except I have some buzzing and an annoying hum when I turn up the volume. At the advice of the dealer, I have moved it all around as far as 18 feet from any transformers, wires etc.............and still no change. I did cure some of the buzzing from dimmers but some is still present.

To make a long story short, I have been trying for a week non stop to find the source but to no avail! I have no surge protectors hooked up to it, have tried different plugs, turned the plugs in opposite directions but nothing seems to work. It is probably nothing major but I would like to know if some of you have experienced similar problems????

HELP!

 

[tonepub]

Unplug your table from the Phono box and see if the phono input still hums.

Sounds like a ground loop issue between the table, preamp and phono pre.

 

[Questy]

When I unplug the hum is gone!

 

[Bernard]

Do you have the ground lead from the phono cable connected to anything ?

 

[Questy]

Yes I have it connected to the ProJect Phonobox. I am quite baffled as to what to do as I have tried everything. Sounds like a ground problem but I don't know what else to do! I may just return all the gear and forget about it as it seems after much Internet research that this is a common problem with turntables! Is that correct?

 

[Bernard]

it seems after much Internet research that this is a common problem with turntables! Is that correct?

No, this is NOT a common problem with turntables. I have not had the problem wih any of the turntables/tonearms/preamps I have had.

Have you tried disconnecting the ground between the turntable and the phono box?

A possibility is that the ground lead is broken somewhere, so with a meter check for continuity between the lead and a metal part on the tonearm.

What do you have the phono box connected to ? You could try connecting the ground lead to it instead of to the phono box.

Don't give up yet. I once had a ground problem in a power amp that I built, and it took me a few days of investigation before I found the cause and fixed it.

BTW where in Canada are you located? There are a number of people here spread all over who could perhaps help you in person.

 

[FOUNTAIN]

Hey Questy,

Sorry to hear about your troubles with the new phono stage. I too just went through experiencing a similar situation when I brought home a different phono stage and had the dreaded hummmmmmmmmmm! Let me make a couple of suggestions and hopefully this will aleviate your problem. First ground the tonearm to your preamp/reciever assuming it has a three pronged ac plug which contains a ground. You may have to loosen a screw on the chassis if a ground lug is not provided. Also, make sure the project is not located too close to your amp, give at least a foot or two of seperation. If your equipment is located in an enclosed cabinet take your phono stage out and place it somewhere outside so it is not trapped inside with your other componets being bombarded from their power supply. Another tip would be to look at what your cables are running next too. If the TT cable, that goes to your phono stage, is running alongside power cords or worse yet coiled up with them then this small leakage will be amplified in the phono stage giving a hum. Keep your cable run fairly short from the TT to the phono stage and the output cable short as well. You will need it long enough to at least get it away from your amplifier, but not so long that it exceeds 10 or more feet. This of course is not a hard and fast rule but it can attribute to noise if the cable is too long. You may even try grounding the phono stage as well to the preamp, but this did not work for me. Good luck.


Glen

 

[Questy]

No, this is NOT a common problem with turntables. I have not had the problem wih any of the turntables/tonearms/preamps I have had.

Have you tried disconnecting the ground between the turntable and the phono box?

A possibility is that the ground lead is broken somewhere, so with a meter check for continuity between the lead and a metal part on the tonearm.

What do you have the phono box connected to ? You could try connecting the ground lead to it instead of to the phono box.

Don't give up yet. I once had a ground problem in a power amp that I built, and it took me a few days of investigation before I found the cause and fixed it.

BTW where in Canada are you located? There a number of people here spread all over who could perhaps help you in person.

When I disconnect the ground wire from the Phonobox, it hums much more and not the opposite. The box is connected to my system preamp in the auxillary input as I do not have a dedicated phono input on my Bryston BP-25. Maybe I should try grounding it to that as well. Never tried this yet!

 

[Questy]

Hey Questy,

Sorry to hear about your troubles with the new phono stage. I too just went through experiencing a similar situation when I brought home a different phono stage and had the dreaded hummmmmmmmmmm! Let me make a couple of suggestions and hopefully this will aleviate your problem. First ground the tonearm to your preamp/reciever assuming it has a three pronged ac plug which contains a ground. You may have to loosen a screw on the chassis if a ground lug is not provided. Also, make sure the project is not located too close to your amp, give at least a foot or two of seperation. If your equipment is located in an enclosed cabinet take your phono stage out and place it somewhere outside so it is not trapped inside with your other componets being bombarded from their power supply. Another tip would be to look at what your cables are running next too. If the TT cable, that goes to your phono stage, is running alongside power cords or worse yet coiled up with them then this small leakage will be amplified in the phono stage giving a hum. Keep your cable run fairly short from the TT to the phono stage and the output cable short as well. You will need it long enough to at least get it away from your amplifier, but not so long that it exceeds 10 or more feet. This of course is not a hard and fast rule but it can attribute to noise if the cable is too long. You may even try grounding the phono stage as well to the preamp, but this did not work for me. Good luck.


Glen

I have done what you said and actually had the table 20 feet away and no difference. I moved around the cables as well. I think the table is either defective or a ground wire in the arm is not right somewhere. I am at the point of sending it back to the dealer.

 

[Questy]

Forgot to mention that the table is mounted on the wall isolated from noise and components not that this would make much of a difference in my case.

 

[FOUNTAIN]

Just to clarify and make sure we are talking about the same thing. In my situation it did not matter how far I moved the TT, but rather moving the phono stage away from the other componets and power cords a couple of feet, or more sometimes, did my hum finally go away. Have you moved the phono stage away from your componets as well or just the TT? Have you also used shorter/different interconnects just to make sure that the problem isn't with the length or shielding of the cable? Hope this helps.

Glen

 

[FOUNTAIN]

When I unplug the hum is gone!

After re-reading and seeing this then it may either be the TT or the cables connected between the TT and phono stage. I would try the other tips mentioned as well, but if by disconnecting the TT from the phono stage, which is properly grounded(?), and the hum goes away then it would seem to be either of the two items mentioned above. How long is the interconnect between the TT and phono stage? Is this an aftermarket cable or is the tonearm prewired with a cable?

Glen

 

[Len44]

Have you tried connecting your ground lead from the TT directly to a known good ground?

Just a thought...

 

[kach22i]

I once long ago lived with an increasing hum with my old turntable. I was renting in an old building, sometimes there was a browning hue coming from the light bulbs.

I upgraded my turntable but the problem remained.

I moved into a newer apartment and the problem went away.

Don't forget the master ground to the whole building, if that's bad, then everything after it will act funny.

I had the power company fix the ground on my house, can't say it fixed anything with the stereo because there was nothing wrong. I can say the lights in the house are whiter and not so yellow brown.

 

[Questy]

After re-reading and seeing this then it may either be the TT or the cables connected between the TT and phono stage. I would try the other tips mentioned as well, but if by disconnecting the TT from the phono stage, which is properly grounded(?), and the hum goes away then it would seem to be either of the two items mentioned above. How long is the interconnect between the TT and phono stage? Is this an aftermarket cable or is the tonearm prewired with a cable?

Glen

The interconnect is only 2 feet long and is of high quality and shielded. The table has its own connection with the ground wire included. I cannot change them.

I have moved the Phonobox far away and no wires are anywhere near the power cables or any other wires. Is it possible that some noise is normal? I will have to change my dimmer switch as well................anyone know which kind I should get?

I also just tried grounding to the preamp and amp and that did not change anything. All my gear is plugged into there own 20amp breaker directly to the box so I am thinking it is definitely not current related.

 

[FOUNTAIN]

Is it possible that some noise is normal?

Not from the listening seat. If you have the volume up to listening level without a record playing and you can hear a little hiss then that's usually ok, but the hum should not be heard. I can hear a little hum in mine with my ear up to the speaker when volume is up to listening level, but if I move back 2 or three feet it is not audible. I would like to get rid of even that, but I'm not sure it's possible when dealing with such a tiny signal that gets boosted by so much. Keep us posted of what transpires. Good luck.


Glen

 

[Questy]

Not from the listening seat. If you have the volume up to listening level without a record playing and you can hear a little hiss then that's usually ok, but the hum should not be heard. I can hear a little hum in mine with my ear up to the speaker when volume is up to listening level, but if I move back 2 or three feet it is not audible. I would like to get rid of even that, but I'm not sure it's possible when dealing with such a tiny signal that gets boosted by so much. Keep us posted of what transpires. Good luck.


Glen

Thanks..................I'm still trying and I would quit if the sound (besides the hum) was not so darn good!!

 

[FISH_MAN]

a loud noise floor is one thing and a ground loop is another.you should be able to fix the ground loop and improve the noise floor with a better pre amp and cartridge ...
don't give up analog is the way to audio bliss who did you buy your TT from?

 

[Questy]

I bought it from Codell Audio in Montreal and they are great. Of course they think it is fixable as I also think but it is hard to find the ground loop!!!!!!! The hum is less than initially I started with and audible only at high volumes but never the less still present. I do not hear it during normal listening in my chair. A friend of mine has the same table and no noise. I bought it with a better cartridge that was installed before being sent so maybe there is something there but they do this all the time so who really knows!? I am brain dead after a week of non stop worrying about this!

 

[Pcar928fan]

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.