Balanced Turntable?

[8bits]

I've seen just a few people talking about converting a turntable to a balanced output. I would think it is a good idea if you have a phono stage that is fully balanced and accepts a balanced input as this would help with common-mode rejection.

Googling about it, there are 2 main threads in different forums/times. In one thread, the poster says that it is useless because the cartridge is not balanced. The other is the opposite, they say that the cartridge is actually balanced, so it makes sense.

Is there a consensus here? Can someone with knowledge of this help a brother out?

 

[DrowningNotWaving]

I've seen just a few people talking about converting a turntable to a balanced output. I would think it is a good idea if you have a phono stage that is fully balanced and accepts a balanced input as this would help with common-mode rejection.

Googling about it, there are 2 main threads in different forums/times. In one thread, the poster says that it is useless because the cartridge is not balanced. The other is the opposite, they say that the cartridge is actually balanced, so it makes sense.

Is there a consensus here? Can someone with knowledge of this help a brother out?

With the exception of some Moving Magnet (MM) and Moving Iron (MI) designs that ground one end of the coil, the signal from a phono cartridge is “balanced”. The differences are how that signal is dealt with by the phono preamp.

“Some” tonearms also ground one end of each signal coil.

One can test tonearm wiring fairly easily with a multi meter’s resistance setting. Remove the cartridge first, you don’t really want to apply the admittedly small DC voltage from the meter to the cartridges coil.

It is reasonably straight forward to change tone arm wiring (or tone arm cable wiring) to “balanced” if it isn’t.

All Moving Coil (MC) cartridges are “balanced”.

Hope this helps.

 

[USER]

As with anything related to turntables, there are so many variables at play that every opinion is out there so it is easy to get lost. I was able to modify my turntable to be balanced because it was basically balanced already and all I had to do was change the old rca cables to shielded twisted pair. Luckily I own some incredibly well engineered Denon turntables from the greatest age of turntables, the 1980s. As the poster above mentions this is generally true but with modern turntables being so poorly made, I can't speak for them. I am also using a classic Shure cartridge that is also essentially balanced. All I had to do is remove one of the grounding straps by pulling it out in order to get the respective channel to be balanced.

I would advise you to read these threads for more information and what to expect from the change. A tonearm wiring schematic is also there.

The Secret Society of Lathe Trolls

A forum devoted to record-cutting deviants, renegades, professionals & experimenters.

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https://www.proaudiodesignforum.com/forum/php/viewtopic.php?t=1179

 

[Speedskater]

There are only a few phono pre-amps with a balanced input stage.

 

[sergeauckland]

There are only a few phono pre-amps with a balanced input stage.

Whilst that's true, there are any number of SUTs for MC cartridges that can be easily wired/rewired for balanced inputs. Even with MM cartridges, a 1:1 transformer can deal with that easily. Considering what some pay for a phono stage, another £100 or so for a pair of decent transformers is trivial.

S

 

[8bits]

There are only a few phono pre-amps with a balanced input stage.

And that's my case, I have an ELAC Alchemy PPA-2.

 

[8bits]

Thanks for the help @USER and @DrowningNotWaving !
Very helpful, I will try to do it myself, but my Technics SL1500c will probably be a little more tricky from a bog standard TT as I imagine there will be a PCB attached to those RCA sockets :/

 

[DVDdoug]

This is one of those things that "sounds good" but it's mostly a solution looking for a problem.

Cartridges have coils that pick more hum than shielded cables and if you add a transformer they are also made with coils and a balanced connection doesn't help with that hum.

 

[egellings]

A balanced phono input will be noisier than an unbalanced one due to two amplifying devices used in a balanced input as compared to an unbalanced one using just one such device.

 

[sergeauckland]

A balanced phono input will be noisier than an unbalanced one due to two amplifying devices used in a balanced input as compared to an unbalanced one using just one such device.

Possibly, but not by enough to be in any way audible. In any event if the balancing is done by a transformer, there isn't even the extra amplifying device.

S.

 

[Dant]

With the exception of some Moving Magnet (MM) and Moving Iron (MI) designs that ground one end of the coil, the signal from a phono cartridge is “balanced”. The differences are how that signal is dealt with by the phono preamp.

I'm very curious about this particular case. I assume you mean cartridges like the Ortofon 2M series that ground the cartridge shield to the right channel ground/negative signal? I know the 2Ms let you disconnect that ground. Would that wind up being beneficial for a balanced setup or worse since the shield isn't getting grounded at that point?

 

[thegeton]

Has anyone tried this balanced solution from Pro-ject?

https://pro-jectusa.com/product/pro-ject-x2-b-turntable/

Phono Box S3 B Balanced MM/MC Phono Preamp - Pro-Ject Audio USA

The Pro-Ject Phono Box S3 B phono preamp features discrete & balanced dual-mono circuitry with semi-passive RIAA equalization for low noise & supreme sonics

pro-jectusa.com

 

[RammisFrammis]

I have an Ortofon 2M Black LVB on an arm which allows balanced wiring to the output. The LVB does not short the ground terminals together at the cartridge. The phono preamp is a ProJect Phonobox RS2 which has balanced ins and outs. This combination is the quietest I have ever had and I have to increase preamp volume far past listening levels to hear any hiss at all and hum in completely absent. Also I found that I don't have to use a separate ground wire from the turntable/arm to the phono preamp.

 

[thegeton]

on an arm

What arm?

 

[SIY]

I ran my phono system balanced. Details in my articles “His Masters Noise” on diyAudio and “The Equal Opportunity Preamp” in Linear Audio. It works great, and it was fun to watch people flinch when I’d turn up the volume and touch a cartridge terminal. No hum!

 

[mhardy6647]

^^^ Innerestin'.

 

[RammisFrammis]

What arm?

SME 3009

 

[MattHooper]

My phono stage has ballanced outputs that I run in to the balanced input of my Benchmark LA4 preamp. But it's more for convenience (as I'm running the unbalanced outputs to another preamp). My amps don't take balanced connections, so the benefits would be mostly moot.

 

[aftermast]

I have a balanced setup that runs into the mic inputs of a Motu M4. The cartridge is low output moving coil. Currently I'm using Apple's AU Lab software to digitally equalize (Vacuumsound RIAA AU Unit) and stream to an airplay device.

I would like to simplify this setup by doing the digital equalization on a raspberry pi, but I haven't figured out all the angles yet.

 

[Vacceo]

I saw the adds from Pro-Ject recently and seems like Teac has been building balanced turntables for a while. What advantages do you get from a balanced connection? Extra db? Less noise?