Help! Buzzing interconnects on a 1210GR

[MrRadish]

I've been experimenting with different interconnects on my 1210GR, which has standard phono sockets on the back. So far the default Technics cable that came with the turntable and some old Cardas Golden Reference work fine, but both are rather dry and uninspiring. The GR might need the plugs cleaning as its been used in a lot of different places and the Technics might need some more burn in time, but neither is quite long enough for where I want to put the turntable anyway. I've therefore tried some Audioquest cables taken from elsewhere in my system (Tower, Big Sur and Mackenzie) and all of them hum/buzz when used with the turntable, but are silent when used on other components. The Tower and Mackenzie are both the right length and sound better than the standard cable, but the buzzing means I just can't use them.

I have the AQ earthing cable installed too and when I disconnect that the buzzing gets louder, as expected. The right channel buzzes louder than the left, but the left buzzes slightly too. I've tried two different integrated amps and a Rega phono stage, with the same results every time.

Can anyone think why the Audioquest cables buzz but the others don't? If I try a different cable is there anything (construction, design) that I should be avoiding for use with the Technics?

[chris@panteg]

I had some Audioquest ruby and quartz many years ago without any problems, don't know what the problem is, maybe the earth has somehow worked loose.

Try a pair of Mark Grant HDX1's, quite superb, lively and bold sounding with plenty of sparkle, give em a try.

[Bigman80]

I had some Audioquest ruby and quartz many years ago without any problems, don't know what the problem is, maybe the earth has somehow worked loose.

Try a pair of Mark Grant HDX1's, quite superb, lively and bold sounding with plenty of sparkle, give em a try.The Mark Grant cables are likely to be the same construction technique adopted in the troublesome cables so that recommendation is a bit superfluous considering they work fine on the other components.

I've experienced this issue and the problem could be something as simple as the ground isn't making good contact. Try swapping the L+R cables over on each RCA socket and see if the buzz swaps channel. If it does, then there's an issue with the cable, if it doesn't, then you need to start looking at the connection the RCA plug is making with socket.

Give the outer connection (return/ground) a gentle squeeze with some pliers and make sure it's a tight fit onto the socket.

What Audioquest cables are they?

[MrRadish]

The Tower are a year or two old, but the Big Sur and Mackenzie are relatively new. They all seem to make a good contact and have solid plugs that I won't be able to massage with pliers. I do have some older Mark Grant G1000 as it happens but they're not long enough to experiment with.

From further Googling it seems the AQ may only have the shield connected at one end, whereas the others may have it connected at both ends. I'll contact Mark Grant and ask him how his shields are connected. If its different to the AQ cables then it might be worth a try.

[Bigman80]

The Tower are a year or two old, but the Big Sur and Mackenzie are relatively new. They all seem to make a good contact and have solid plugs that I won't be able to massage with pliers. I do have some older Mark Grant G1000 as it happens but they're not long enough to experiment with.

From further Googling it seems the AQ may only have the shield connected at one end, whereas the others may have it connected at both ends. I'll contact Mark Grant and ask him how his shields are connected. If its different to the AQ cables then it might be worth a try.My guess is at construction. Mark will likely be able to make them to suit you.

[Stryder5]

I would have thought you could check the construction visually, depending on the type of RCA connectors. You could also test this with a multimeter.

The screen (if fitted) should be connected to the return on the plug, at the source end.

I experienced this type of issue with no screen connected either end. Connecting the screen at the source end and the problem disappeared.

CD and other sources seem seem immune to any cable configuration.

[MrRadish]

The Big Sur and Tower both use a common jacket, but the Mackenzie is more conventional. I think the relevant paragraphs are the ones below, but I have no idea what they mean in practice:

Asymmetrical Double-Balanced Geometry (Big Sur and Tower)
Purpose designed for single-ended applications, Asymmetrical Double-Balanced Geometry offers a relatively lower impedance on the ground for a richer, and more dynamic experience. While many single-ended cable designs use a single path for both the ground and the shield, Double-Balanced designs separate the two for cleaner, quieter performance.

Triple-Balanced Geometry (Separate Ground-Reference Conductor) (Mackenzie)
Our Triple-Balanced Geometry uses a separate ground-reference conductor, so the cable's shield is never used as an inferior conductor. Whether prepared with RCA or XLR plugs, the cable's three conductors ensure that the positive and negative signals have equally superior, low-distortion conducting paths.


Metal-Layer Noise-Dissipation System (Tower and Big Sur)
It's easy to accomplish 100% shield coverage. Preventing captured Radio Frequency Interference (RFI) from modulating the equipment's ground reference requires AQ's Noise-Dissipation System (NDS). Traditional shield systems typically absorb and then drain noise/RF energy to component ground, modulating and distorting the critical "reference" ground plane, which in turn causes a distortion of the signal. NDS "shields the shield," absorbing and reflecting most of this noise/RF energy before it reaches the layer attached to ground.

Carbon-Based 3-Layer Noise-Dissipation System (NDS) (Mackenzie)
It's easy to accomplish 100% shield coverage. Preventing captured Radio Frequency Interference (RFI) from modulating the equipment's ground reference requires AQ's Noise-Dissipation System (NDS). Traditional shield systems typically absorb and then drain noise/RF energy to component ground, modulating and distorting the critical "reference" ground plane, which in turn causes a distortion of the signal. NDS's alternating layers of metal and carbon-loaded synthetics "shield the shield," absorbing and reflecting most of this noise/RF energy before it reaches the layer attached to ground.


The plugs are cold welded and I don't want to break that, so I can't tell what's connected to what. AQ seem to be saying all the right things (it sounds good to me), but something isn't right on the turntable. For reference I gave the Cardas plugs a thorough clean and put the GR back in again, which now sounds very nice. Turning the volume up with the GR in place produces no buzz or hum whatsoever, just a soft hiss from the phono stage at high volume. I can't afford a longer set of those though. :violin:

[MrRadish]

Yes, but how do I identify a conventional cable? And would that be one with shielding connected at both ends, one end or neither end? That's really what I'm trying to figure out, just to avoid sending stuff back unnecessarily.

[walpurgis]

It's 'normal' to employ coax signal cable for turntable/tonearm leads. It's core and screen, no extra outer shielding. Both ends of each conductor obviously are connected, the core being positive (usually). There should be no hum/buzz due to the cable, unless you have it near a power transformer or A/C motor. Noise could indicate an earthing issue.

The construction of the cable you may want to be using should look rather like this (but not necessarly exactly the same).

http://i67.tinypic.com/15hk744.jpg

There is no reason why you can't experiment with additional earth wires from the turntable and/or arm to the phono stage or amp.

[Bigman80]

It's 'normal' to employ coax signal cable for turntable/tonearm leads. It's core and screen, no extra outer shielding. Both ends of each conductor obviously are connected, the core being positive (usually). There should be no hum/buzz due to the cable, unless you have it near a power transformer or A/C motor. Noise could indicate an earthing issue.

The construction of the cable you may want to be using should look rather like this (but not necessarly exactly the same).

http://i67.tinypic.com/15hk744.jpg

There is no reason why you can't experiment with additional earth wires from the turntable and/or arm to the phono stage or amp.Yes, simple high quality coaxial cable will be fine. Something like RG316 is a coaxial.

There won't be a way to know other than asking the manufacturer.

[Stryder5]

Poor photo, but I guess that NDS that is referred to you can see here.

https://uploads.tapatalk-cdn.com/20180531/ac2019562efe47f68b52689cc13ba971.jpg

You have an outer sheath of polymer
Then the brighter ring you see is a metal braided sheath
Then a fill of carbon loaded polymer
Then a red and white cable sheathed in polymer
In the middle of the two cables is the conductor
You should just be able to see a black circle around the conductors, this is another carbon loaded polymer sheath.


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[allthingsanalogue]

I can confirm that these work perfectly on my SL1200G.

Rega couple 2.

http://hifilounge.co.uk/image/cache/data/rega/accessories/Couple%202/4-399x325.jpg

https://www.amazon.co.uk/Rega-Couple-RCA-Interconnects-1-0m-White/dp/B00CD7HEZ2

[MrRadish]

It's 'normal' to employ coax signal cable for turntable/tonearm leads. It's core and screen, no extra outer shielding. Both ends of each conductor obviously are connected, the core being positive (usually). There should be no hum/buzz due to the cable, unless you have it near a power transformer or A/C motor. Noise could indicate an earthing issue.

The construction of the cable you may want to be using should look rather like this (but not necessarly exactly the same).

http://i67.tinypic.com/15hk744.jpg

There is no reason why you can't experiment with additional earth wires from the turntable and/or arm to the phono stage or amp.

Thanks, I didn't realise interconnects were made like that too. I thought it was just aerial leads, although if it works for aerials then that tells me something. :-)

[MrRadish]

Poor photo, but I guess that NDS that is referred to you can see here.

https://uploads.tapatalk-cdn.com/20180531/ac2019562efe47f68b52689cc13ba971.jpg

You have an outer sheath of polymer
Then the brighter ring you see is a metal braided sheath
Then a fill of carbon loaded polymer
Then a red and white cable sheathed in polymer
In the middle of the two cables is the conductor
You should just be able to see a black circle around the conductors, this is another carbon loaded polymer sheath.


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That's what I was expecting an interconnect to look like, with what I assume are positive and negative cores surrounded by a separate screen (if I've understood you right).

[Stryder5]

That's what I was expecting an interconnect to look like, with what I assume are positive and negative cores surrounded by a separate screen (if I've understood you right).

Yes, I don't totally understand the role of the layers of carbon loading as they are conductive too ( I believe).


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[walpurgis]

That's what I was expecting an interconnect to look like, with what I assume are positive and negative cores surrounded by a separate screen (if I've understood you right).

Screened pair leads are quite common. I have some myself.

[Stryder5]

Why would the screen have to be separate?
In a balanced cable you have two central conductors (+ve phase and -ve phase) and a separate screen, similar to the cable in the picture.
In an unbalanced cable the simplest and most common arrangement is a single central conductor surrounded by a screen.
You can use "two core plus screen" cable (the first type above, as designed for balanced use) for unbalanced interconnects, but what is the best way? Your options would be:

1) Link the two central conductors together so they become effectively a single conductor, then wire it up as a simple screened cable with the shield connected to ground at both ends.
2) Use one central conductor for the signal and the other for ground, and connect the screen to ground at both ends.
3) Use one central conductor for the signal and the other for ground, and connect the screen at one end only.
4) Use one central conductor for the signal and the other for ground, and leave the screen unconnected entirely.

Option 1) would be my choice. There are those who advocate option 2) though there's no justification for it as far as I know. Option 3) has its advocates too, but I can't see any advantage. Option 4) would just be a bit daft.
The AudioQuest cables referred to by the OP which cause problems are probably wired as in option 2) or 3). Simple screened cable would have been better.


Yes, it's conductive and helps to improve the shielding at RF. It's insulated from the central conductors.

There is a carbon loaded layer applied to each conductor if you look closely and read my description, I don't see how it's insulated from the central conductor, unless you are referring to the infill next to the sheath?


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[Stryder5]

There is a carbon loaded layer applied to each conductor if you look closely and read my description, I don't see how it's insulated from the central conductor, unless you are referring to the infill next to the sheath?


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https://uploads.tapatalk-cdn.com/20180604/7bdb43e5ab28cb5f5b72589f98917eda.jpg



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[Stryder5]

Looking on CarboKab website it gives an explanation, whether it's reasonable or foo.....


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[Bigman80]

There is a carbon loaded layer applied to each conductor if you look closely and read my description, I don't see how it's insulated from the central conductor, unless you are referring to the infill next to the sheath?


Sent from my iPhone using TapatalkFrom their marketing blurb somewhere - "The Carbon layer gives the benefits of a Solid core cable whilst retaining the flexibility of a stranded cable"

Personally, I've never hear any benefit from a solid core cable and have always prefered stranded cable. Personal taste of course.

[Stryder5]

We're probably drifting off topic now, but it is interesting.

Bend radius has an effect on signals, hence specifications of minimum radius in Cat xx used in computer networking, I don't know if it's relevant to the signals we are talking about here?

I suggest if anyone wants to expand on this we start a new thread.

Gary

[Bigman80]

We're probably drifting off topic now, but it is interesting.

Bend radius has an effect on signals, hence specifications of minimum radius in Cat xx used in computer networking, I don't know if it's relevant to the signals we are talking about here?

I suggest if anyone wants to expand on this we start a new thread.

GaryCan't imagine anyone will want to chat about that Gary [emoji23][emoji23][emoji23]

Just joking, its way out of my remit.

[Barry]

Sorry, I missed that. Yes, there's a layer of carbon loaded polymer next to each conductor. I don't know what it's for. The manufacturing process may make it easier to have it than not have it - I don't really know.

Suspect it is to prevent tribolelectric charges building up through flexing/handling. Many hand-held microphone cables have a semiconducting layer under the brading, however the Carbokab cables would seem to be too thick for use with microphones.

I have a pair of Sommer Carbokab cables wired for balanced use with XLR connectors. I found the presence of the carbon-loaded layer next to the inner conductors to be a nuisance: it has to be completely removed otherwise the conductors won't 'tin' properly.

[MrRadish]

Thanks for the advice all, I'll try a Mark Grant cable (as 2.5m seems very affordable) and see how that goes.

[MrRadish]

Change of plan - I've ordered the Rothwell Audio interconnects instead as I've not used those before. I've got some of the Rothwell attenuators and they work very well, so I thought I'd give the cables a shot too.

[Bigman80]

I've used some of the cable used in Rotwells "the river" cables myself so you won't go far wrong with these. Not a bad choice at all.
Change of plan - I've ordered the Rothwell Audio interconnects instead as I've not used those before. I've got some of the Rothwell attenuators and they work very well, so I thought I'd give the cables a shot too.