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Weird hum issue. Please help!

Angry Possum said:
Process of elimination. Try swapping out your cartridge, if you have an extra. It could be a bad ground in the cart or defective cart,,,maybe the ground on the cart is bad?. I would give that a try most definately. Simply because a cartridge is an amplifier and would most definately be a causation in that medium with regards to grounding issues.
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I just swapped it out for another cart (Original rega one that came with it. Got a Naga 110 installed). Though the noise did not change at all. So probably not the cart.

classic carl said:
I recently was given a turntable by a friend to check out for him. One of its issues is a hum in one channel. I can change the volume of the hum by moving or twisting the RCA cables. These cables are almost 40 years old. If you can do the same with your cables, the issue is probably bad cables. How old is the Rega? Is your hum in both channels or just one?
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Unsure as I bought it used. But roughly 5 years, I'd say. The hum is in both channels. Twisting the rca cable does nothing. Touching changes the way the hum sounds.

Mr Boochie said:
I was wondering, with turntable turned-off, could you temporarily short (with DVM probe) the LEFT, then RIGHT channel posts (in the back of the cartridge) to ground. Either the ground post of the cartridge or a grounded probe from the pre-amp? Then, listen for changes in the hum level --- maybe with headphones? Changes in hum would indicate poor shielding within the cartridge? :idea:
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I tried another cart, as Angry Possum suggested. Rules out the cart, right?

Nashou66 said:
The part highlighted leads me to believe it might be a house wire grounding issue. Do you have one of those plug in device that check proper house wiring polarity?
One outlet might be reversed with neutral on hot/load. Is it possible to flip the Yammys plug in the socket or the Rega's ?
Also where is the Rega's power plugged in? The wall or the Amp? Try both, and even the Elgato. That is try them all in bite the wall outlets and then the amps outlets and a combination of both.
Keep notes on what your connecting where and its results.

nashou
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Unfortunatly I do not. All I got is that electrical testing screwdriver. I did try to reverse the plugs though, with no changes.
Regas power is plugged in a power strip. Same as the amp (amp has no outlet). I did try to connect the rega to the wall separately, same with the amp. No changes.
I do not even have to plug the rega in at all to get the hum.
 
Nashou66 said:
The part highlighted leads me to believe it might be a house wire grounding issue. Do you have one of those plug in device that check proper house wiring polarity?
One outlet might be reversed with neutral on hot/load. Is it possible to flip the Yammys plug in the socket or the Rega's ?
Also where is the Rega's power plugged in? The wall or the Amp? Try both, and even the Elgato. That is try them all in bite the wall outlets and then the amps outlets and a combination of both.
Keep notes on what your connecting where and its results.

nashou
Click to expand...

May need temporary cheater plug, to find culprit device or outlet.

https://en.wikipedia.org/wiki/Cheater_plug
 
hankspencer said:
I did try to connect the rega to the wall separately, same with the amp. No changes.
I do not even have to plug the rega in at all to get the hum.
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Sounds like the soldering of that RCA cable to the Rega, needs to be ruled-out. Can to see where the cable is soldered to the turntable? Maybe, a cold-solder. Frequently happens with RoHS solder these days. :idea:
 
The cables go directly into the tonearm from the bottom. Can't see any soldering without dismantling the thing, I guess?
I might be able to find an old tt next week and will just switch it with the rega to know for sure its the rega.
 
hankspencer said:
The cables go directly into the tonearm from the bottom. Can't see any soldering without dismantling the thing, I guess?
I might be able to find an old tt next week and will just switch it with the rega to know for sure its the rega.
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Yeah, do this first. :thumbsup:
 
Do you have another power strip to try? Or just go directly in to the wall with the amp and the Rega only?

Nashou
 
Yes, tried a different strip and also with the rega in the wall and amp in the wall at the same time. What I also tried just now is using an extension cord to plug the amp and rega into a wall outlet in another room. Also I did switch off the fuse for the room the setup is in, to switch off power for every device that might be causing interference.

No change.
 
do you have a Multi meter to do a continuity test from the head shell wires to the RCA plug end, Signal continuity and GND continuity.

All Continuity from TT GND to RCA plug GND. There should be continuity there if its done right. I find that summing all the GNDs on any TT works to eliminate hum.
 
Try running a wire from the ground pin of the amp to a real ground. It would help to know if your outlet is wired correctly - the little testers that plug in to determine that are only $5-7 iirc. For a temporary ground, strip off enough insulation to wrap the wire around the ground pin of the Rega plug, assuming your outlet is actually grounded.
 
So I just tired running a cable from the ground post on an outlet to the amp. Result: Hum was the same, like with the Elgato connected (low hum, but still there) and disconnecting the Elgato or connecting it, didn't change the hum anymore. So indeed is the Elgato helping in grounding.

Though I'm unsure if that is advisable at all: I also tried running the cable to the Rega directly and connected it from outlet post to ground cable. Hum/buzz was even worse than having the ground cable disconnected from the amp. Probably expected?

Angry Possum said:
Have you tried a different outlet all together. In another room perhaps? I know it sounds crazy.
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Yes, I did. Didn't change anything. Even took out the fuse for the room.
 
hankspencer said:
So I just tired running a cable from the ground post on an outlet to the amp. Result: Hum was the same, like with the Elgato connected (low hum, but still there) and disconnecting the Elgato or connecting it, didn't change the hum anymore. So indeed is the Elgato helping in grounding.

Yes, I did. Didn't change anything. Even took out the fuse for the room.
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I can dig the Freudian slip. :oops:

Now, it looks like you or some tech will need to access the RCA terminals inside that turntable. My bet is the problem is in the soldering and/or placement of these terminal ends within the turntable.

If you find that these interconnects are the problem, you may want to consider trying to install separate RCA jacks on the turntable. This will allow you to easily substitute cables. DIY wiring would have to be neat and secure, to prevent another hum issue.

Good luck, with the further hunt! :thumbsup:
 
Unfortunately Rega has not made it easy for us tinkerers and home repairers. The tiny tonearm wires seems to soldered to a small round pcb inside the pillar where they connects to the rca.
But it seems that at least it should be possible to carefully disasemble and have a look to see if all wires are soldered ok and maybe asess further course of action. Do it at your own risk of course.

This guy has some pretty decent pics of how it works:
http://www.aqvox.de/REGA 250 300 Tonearm mod humm-free remove signal groundrega_mod.html
He also seems to have removed the black ground wire o reduce hum. Don´t know if that may work for you.

A quick test without disassemble could be to carefully touch/bend the rca where it goes into the pillar to se if something happens to the hum.
 
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T68 said:
Unfortunately Rega has not made it easy for us tinkerers and home repairers. The tiny tonearm wires seems to soldered to a small round pcb inside the pillar where they connects to the rca.
But it seems that at least it should be possible to carefully disasemble and have a look to see if all wires are soldered ok and maybe asess further course of action. Do it at your own risk of course.

This guy has some pretty decent pics of how it works:
http://www.aqvox.de/REGA 250 300 Tonearm mod humm-free remove signal groundrega_mod.html
He also seems to have removed the black ground wire o reduce hum. Don´t know if that may work for you.

A quick test without disassemble could be to carefully touch/bend the rca where it goes into the pillar to se if something happens to the hum.
Click to expand...

Thanks, for link. This was an interesting statement. I've never used a DVM on a cartridge, but have read about using one (even here, on this site). :(

Attention, never use a meter, if the cartridge is connected, the coils can burn out.
Always disconnect the cartridge clips before connecting a meter to the tonearm wires.
Never connect a meter to the cartridge!
 
Mr Boochie said:
Thanks, for link. This was an interesting statement. I've never used a DVM on a cartridge, but have read about using one (even here, on this site). :(

Attention, never use a meter, if the cartridge is connected, the coils can burn out.
Always disconnect the cartridge clips before connecting a meter to the tonearm wires.
Never connect a meter to the cartridge!
Click to expand...

That is only if you use a higher powered one like the old analog meters. those send a higher voltage through the problem than the newer DMM.

Nashou
 
Got around to try another turntable (very cheap plastic one, called Fisher MT-9055), but the result is exactly the same like with the rega: connected to amp, there is noise. Less noise (only on very high volume) with the Elgato dock connected to the amp. The turntable has a ground cable too. Makes no difference if connected or not.

So are both turntables bad, or can I cross out the turntable as a noise source?
 
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