RM 1.3, Debut Carbon, CA551P, HUM HUM HUM. Please help, I am at a loss now...

E

ElCid79

Audioholic Intern
What a couple of days, sorry that this post is so long...

Yesterday I unboxed my new RM 1.3 and it sure is pretty. I followed the instructions, spending about an hour or two setting everything. Then I hooked it up to my new CA phono and wow it starting humming horribly. Loud loud humming. If I jostled it a little, it would pop. Dead silence, then slowly hum hum hum really loud.

My first thought was the motor causing the issues,

I completely disconnected the motor and moved it across the room. Power supply everything. Still humming. I moved the turntable around. still humming. I changed cables. Still humming. Put the ground into my power conditioner, still humming. Then I was getting exhausted, and kind of giving up.

Then I hook up my onkyo 1200 and it was quiet as a mouse, with no grounding cable and the crappy integrated RCA cables... ZERO hum... So now I am getting slightly irritated.

THEN I realize, that one of the nuts are missing that holds the cartridge onto the tonearm. My thought was, well darn it the cartridge is WAY out of alignment then. Add that to my list of things to do tomorrow.

I noticed a black cable coming off of the tone arm and then into the tone arm. My assumption is that the cartridge receives its ground by directly contacting the headshell, which transfers the ground into the tonearm. Therefor, if I replace that little nut, which would tighten the cartridge, it would improve the ground, and resolve the hum? It didn't work....


So fast forward to today...

I received the new Pro-Ject Debut Carbon today, and while I was unboxing it, I noticed something rattling from inside of the table somewhere. I discovered that the rattle was coming from the RCA junction box. Only two screws hold it on, so that was not a major issue, I pulled it off to see what was up, and lo and behold there was one of the motor mount screws inside of the junction box. How it got there is a mystery. I decided that the wires in there are so small and fragile, that there was no telling what damage could have happened between Western Europe and the US. So I set up an RMA for that one as well. Looks like I am back to the old Onkyo 1200 that my grandfather gave me.

In the meantime, I went on ahead and finished setting this one up as well. I decided that if it worked, I could use it until the replacement arrived.

After following all of the instructions. I plugged it in, and it was the same story, a ridiculously loud obnoxious humming. Just like the RM 1.3.

If I could dissipate static in the tone arm, by touching / jarring it. It would become dead quite for a second. Then start again.

I decided to do a little bit of troubleshooting that I neglected to do last night.

I connected the phonostage into a different input on the receiver. I swapped various cables, using different ones from yesterday. Still the same.

I flipped the wall worts..Same issue...

Finally, I went and grabbed an older NAD receiver that I had, connected the CA to one of the inputs, using different speakers, speaker cable, in a different electrical outlet, with different RCA cables, with a different power strip.... HUM HUM HUM...

Tomorrow I will move that stuff to another power network in the house...

Then I disconnected everything, and plugged the turntable into the phono input on the receiver. HUM HUM HUM....

So is it really a possibility that BOTH of these turntables do not work properly? What could possibly be causing all of these static issues if not the table.

The company that I ordered from is sending me a new turntable, and a new Cambridge Audio Azur tomorrow as one last ditch trouble shooting... If that doesn't fix it, I give up.

Are poor solder points common on these Pro-Ject Debut / RM 1.3? Could it be as simple as a bad ground wire? With both pro-ject tables the hum starts as soon as you plug in the rca cables. The motor does not have to be plugged in, that platter does not have to be spinning. With the RM 1.3 I moved the motor to the other side of the room. Didn't help anything.



What are your thoughts.

So as a review:

Carbon + CA + NAD = Hum.
Carbon + CA + Marantz = Hum.
Carbon + NAD integrated pre = Hum.
RM 1.3 + CA + Marantz = Hum.
Onkyo + CA + Marantz = no hum....





My onkyo 1200 (which strangely doesn't have a ground) is dead quiet.
 
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3db

3db

Audioholic Slumlord
Dumb question.. Have you attached the ground lead from it to the chassis ground of your receiver? I'm on my 2nd ProJect table after having lost the first one to a flood and both performed/perform flawlessly.
 
Last edited:
3db

3db

Audioholic Slumlord
Are poor solder points common on these Pro-Ject Debut / RM 1.3? Could it be as simple as a bad ground wire? With both pro-ject tables the hum starts as soon as you plug in the rca cables. The motor does not have to be plugged in, that platter does not have to be spinning. With the RM 1.3 I moved the motor to the other side of the room. Didn't help anything.



What are your thoughts.

So as a review:

Carbon + CA + NAD = Hum.
Carbon + CA + Marantz = Hum.
Carbon + NAD integrated pre = Hum.
RM 1.3 + CA + Marantz = Hum.
Onkyo + CA + Marantz = no hum....
I'm wondering if the cartridges have been miss wired or are bad? There is no way these tables should hum plugged to power let alone unplugged?
 
Last edited by a moderator:
E

ElCid79

Audioholic Intern
So I used a 16g speaker wire, twisted the two together, and strung that to the phonostage. Still humming. Slightly better now, in that it is not instantaneous, but within 15 or so seconds humming starts. I took another, smaller guage speaker cable and strung it to the power conditioner's ground lug. It didn't change anything, so then I moved it onto the receivers chassis. Still humming. I put the table in the dead center of the room. I just don't get it. I have a wool carpet in there, but any static built up by it should dissipate immediately right? To be certain I took everything into another room, hardwood floors, and tried it in there. Same issue. It gets really bad when I touch the tone arm to lift it out of the cradle. If I leave the room, and let the record play after a few minutes it starts to quiet down a little. Oddly, with the debut carbon the hum appears to be louder out of the left speaker.
 
3db

3db

Audioholic Slumlord
Try everything without the power conditioner in the loop.
 
slipperybidness

slipperybidness

Audioholic Warlord
Are you sure it is a hum (at 60Hz), and not a subsonic rumble?

Have you tried shielded RCA cables from TT to phono input?
 
Whitey80

Whitey80

Senior Audioholic
man, wish i could help you out, my humming woes were cured by grounding to phono stage and power conditioner.
so, basically, Ijust called to say I love you.....
.....and I mean it from the bottom of my heart :D
 

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