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dcstep
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Balanced Turntable Interconnects

Most tone arms have either two RCA outputs or a DIN output. Most of the TT cables that I see have either RCA plugs on both ends or DIN on the TT end and RCA on the pre-amp end. (Plus a ground, of course).

Why don't you see "Balanced" or "XLR" connections on the pre-amp end? I suppose it has something to do with cartridges being unbalanced, but I'm not certain. Does anyone know for certain why this is the case?

Dave

dbowker
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Re: Balanced Turntable Interconnects

The balanced setup, while still debatable as to how much it matters, only really works when it's from one end to the other, as it were. To my knowledge no cartridge has been designed to work with balanced cables. You'd need it to go through special balance leads, etc. Plus, from everything I've read it's when you have very long cable runs that you get the most benefit and you pretty much want your 'table as close to your phono pre-amp as possible due to the extremely low level signal coming out of the cartridge. I try and have mine using 1/2 meter ICs.

CharlyD
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Re: Balanced Turntable Interconnects

There are four output pins on almost all phono cartridges; two pins for the left channel and two pins for the right channel. This configuration is inherently balanced. I don't know how most turntables wire these signals to two unbalanced outputs, but it would seem that the best configuration would be to keep the low sides independent until they reach the preamp. A fully balanced connection would be far more preferable due to its inherent noise rejection. I can't understand why that configuration is not more common.

dcstep
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Re: Balanced Turntable Interconnects

I use a short TT cable, combined with a high output MC cartridge, so noise isn't really an issue, at least when the ground is behaving. However, those using low output MC cartridges thru a step device really do have to worry about noise. Yet, those step up devices tend to be unbalanced.

I just don't get it, so I think that I'm missing some basic fundemental about cartridge to amp interface.

Thanks for the help so far.

Dave

dbowker
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Re: Balanced Turntable Interconnects

You make some good points. A question for Michael Fremer?

Elk
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Re: Balanced Turntable Interconnects


Quote:
There are four output pins on almost all phono cartridges; two pins for the left channel and two pins for the right channel. This configuration is inherently balanced.


Are cartridges truly balanced, or do the simply share a common ground?

I have heard for years that cartridges are inherently balanced but never understood how this is the case.

KBK
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Re: Balanced Turntable Interconnects


Quote:

Quote:
There are four output pins on almost all phono cartridges; two pins for the left channel and two pins for the right channel. This configuration is inherently balanced.


Are cartridges truly balanced, or do the simply share a common ground?

I have heard for years that cartridges are inherently balanced but never understood how this is the case.

The center tap, or ground, floats. The signal is generated by magnets, ie coils moving in fields, etc. The center tap finds itself, on the fly. It is inherently perfectly balanced and cannot create signal that is 'out of balance'. The system 'floats' positive on the one signal, the exact opposite (mirrored) on the other.

When terminating, you provide the 'x' or 'ground' in XLR separately. X=ground, L=line, R=Return.

There is an excellent thread on 'balanced phono sections' on the forum 'vinylengine'. Using a transformer can extend that through to a MM phono section with balanced inputs. Most times, if stock, the cable needs be a balanced design for the tonearm, and the transformer as well. It is possible to change just the cable and maintain the RCA jacks on the transformer and the tonearm cable, but it is not an optimal situation. One just has to be sure that the cartridge/tonearm cable/transformer/cable are not utilizing any 'proper' grounds. Just floated ones. The utilized proper ground for the entire XLR mess is to be perfectly functional throughout the electrical signal chain, but not connected to what is normally a 'ground' (outer ring) on a standard 'line level' RCA jack, as is the case in the vast majority of audio gear that has three prong AC plugs and utilizes 'single ended circuitry' and RCA jacks.

Elk
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Re: Balanced Turntable Interconnects

Got it!

Thanks, KBK - great explanation.

Are there any phono preamps that accept this balanced signal? Other than cost, is there any disadvantage in doing so?

dcstep
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Re: Balanced Turntable Interconnects

Thanks KBK, that makes perfect sense.

This is that kind of thread where Stereophile is real good.

Dave

CharlyD
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Re: Balanced Turntable Interconnects

The Atmasphere MP-1 features balanced inputs for everything, including phono. An interesting discussion of this architecture can be found in this thread on Audiogon.

dcstep
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Re: Balanced Turntable Interconnects

Nice reference. I'll surely talk with Jeff Rowland about this issue before I install his phono card. I love the idea of removing what seem to be the last vestage of noise in my system, the cartridge/pre interface.

Dave

Elk
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Re: Balanced Turntable Interconnects

Cool! Thanks, CharlyD!

mrlowry
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Re: Balanced Turntable Interconnects

Ayre and Boulder both make phono states that are fully balanced. I've heard the Ayre P5xe in a couple of systems and the performance is outstanding. The Boulder 2008 I've only heard in one system for a short period of time but the system as a whole was extremely impressive.

KBK
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Re: Balanced Turntable Interconnects

I mention the transformer, as I use low output MC's ONLY,as I've found after having about 25 +1k MM to High out MC's to very Low out MC's--that the low output MC's always sound the best. That is--- specifically if one uses transformers to up the output and inject that into a MM input. I've gone through and modified about 100 or so phono sections and analyzed (in my limited way) the entire situation and listened quite closely, for specific things.

Every time, the low output with transformer has won out with respects to sonic quality.

My biz partner is using the high output top Grado cartridge right now, so hey, other opinions exist! In all honesty, I feel my statement is true, but only if all things are equal-which they invariably are not.

KBK
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Re: Balanced Turntable Interconnects

This from EAR on transformers and low output moving coils:

An

mikeymad
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Re: Balanced Turntable Interconnects

Interesting thread... thanks.

I was always curious about balanced for TT's. First thing, I like XLR connectors. They are solid when clicked in properly.

I was looking at the PSAudio phono stage that had balanced outs. And was wondering 'how balanced is it?', with the RCA standard inputs. But it looks like it can be possible.

Cheers,

haroon
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Re: Balanced Turntable Interconnects

Hi:

Victor Khomenko, principal and designer of Balanced Audio Technology, (BAT) wrote about this subject at,

http://www.audioasylum.com/audio/general/messages/9/97386.html

http://www.audioasylum.com/audio/vinyl/messages/3/31747.html

http://www.audioasylum.com/audio/general/messages/9/97513.html

Regards,

Haroon

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