Changing Turntable to Balanced Output

Yes, you have read it. There is a lot more to it than what you have read. Whether it is worth it or not only you will know after having gone to the trouble to find out. For me, it is so far down the list of things I would do, wait a minute let me check. Nope, scratch that. Doesn't even make the list.

No adapter can create balanced.

Phono cartridge output is inherently balanced but one side is often grounded in practice.  However, you would need a phono stage with a balanced input to take advantage of a balanced output from a cartridge.  (I did that many years ago when I played LPs.)

I think if you look at a tone arm circuit it is balanced, why else would it run separate grounds for left and right and a second ground. It is designed to be balanced. The question is do you want noise cancellation tech or balanced, they are two separate thing. The guy to explain the tech side is Mr. atmasphere.

Hey guys, would anything change if I connect phono pre to pre amp with balanced cables I do have that capability ?

Quite possibly. The cartridge is a balanced source to start with- if you have a balanced input on the phono section you’ve got a lot more immunity to the sound of the interconnect cable- it should sound better IOW.

Maybe he will chime in and toss us a nugget or two. :-) I don't use it on a phono but I hear you can.

Happy New Year.

No re-wiring of the tonearm is required. But you’d have to re-terminate the phono cables with XLRs, learn how to do that, and then buy a true balanced phono stage, to realize any benefits.

I have the Modwright PH9.0x which supports balanced outputs but not inputs from the TT, Doesn’t that defeat the whole point of it?

Doesn’t that defeat the whole point of it?

Yes.

Personally, I have thought once or twice to have a balanced phono stage, next to have that phono stage connect to balanced headphone amp, and finally to be heard through headphones wired for balanced operation. Nothing else included in this system. Can't say that it would all pan out, but curiosity still exists.

  OTOH, using a TT to feed a balanced phono stage in and of itself seems troublesome, only to feed from there an unbalanced system.

I could be wrong, but according to highfidelity.pl review of BAT VK-P6SE:

The VK-P6SE is a balanced design, with a passive "floating" RIAA correction circuit, ie after the RCA input the "positive" signal is amplified in one branch of the gain, and the "negative", which normally is shorted to the ground, here is amplified in the other branch. The ground connection is made with a separate cable run from a tonearm.

Does it means even though the cartridge connected to the VK-6SE inputs via rca cable, it still worked as a balanced connection?

BAT VK-P6SE review

balanced shmalanced..........unless all your components are differentially balanced, you will not get the improved performance.

balanced shmalanced..........unless all your components are differentially balanced, you will not get the improved performance.

This statement is false. The Ampex 351 tube tape electronics were used to record a great deal of classical and jazz recordings done by RCA and the like. Its internal circuitry is entirely single-ended except for the push pull output it has driving its output transformer to drive a 600 Ohm balanced line. The input used an input transformer as well. This allowed the tape machine to have microphones a good 150 feet from the machine with no degradation of the mic signal. This was long before an exotic cable industry existed. You might say that the balanced line system itself was the exotic cable industry prior to Robert Fulton creating his first ’Fulton cable’ back in the late 1970s.

Similarly if an input transformer is used with a LOMC cartridge (and the transformer is properly loaded to prevent ringing) then the tonearm interconnect will have far less effect on the sound of the system.

Its arguable that this is the one place you really want to get it right!

The advantage of running a cartridge balanced is of course to minimize any artifact from the cable- meaning an inexpensive cable can sound just as good as one costing 2 or 3 orders of magnitude more!

Now it is a fact that if the phono circuitry is fully differential that there is additional benefit (for example in our phono sections only two stages of gain are required to work with a LOMC cartridge run straight in- you get theoretically 6dB less noise per stage of gain). But balanced lines can be executed with single-ended gear if good transformers are used. Users of SUTs take note! All transformers including SUTs can be used to receive the cartridge signal in the balanced domain.

imhififan, Yes, the circuit of the BAT makes balanced sense, assuming the description is accurate.  If you want to get crazy, ideally you want the conductors of both phases of the signal to be "the same" kind of wire. For an SE IC, the ground side conductor is often the shield itself.  So the positive and negative phases of the signal are riding on different types of conductor, if such a cable is used for a balanced connection. Can you hear that? I dunno.

But some good SE cables do use an audio ground connection via the same wire used for the hot side.  In that case, the shield will not be connected to the audio ground wire, and using such a cable for balanced is "better".

Atmasphere can feel free to correct me if I am in error here.

It’s nice to be able to get the goods, Thanks Mr. atmasphere. I knew you would come through.

Happy New year.. 

Regards

Thanks everyone. I do have balanced out of my phonostage as well as balanced inputs on my Octave V70 Class A amp. I might change out the RCA’s for XLR’s as lean suggested. Not thinking it’s worth it after reading this from the Modwright site:

@audiosaurusrex I don't see anything there that has anything to do with the phono section.

👍Good luck!🙃

"" The output of a cartridge is in principle balanced UNTIL one side (usually the negative) is connected to ground. This may happen at the cartridge (where the (-) side of one channel is connected to a magnetic screen around the cartridge internal wiring..""

Some cartridges came with 3 not 4 pin connectors. I can't find out a " vintage " thread where the normal statement that the cartridge is a balanced design was questioned by serious high technical knowledge oriented Agoners and if I remember J.Carr posted down there and the final conclusion was that in reality the cartridge is not a true balanced design.

I have not the elements about but that " cartridge balanced " could be a little controversiallly. I think that other Agoner in that thread was kirkus along dgarretson. I wish I could find out because is of true ineterest for all of us. Unfortunatelly I can't remember the technoical foundation about but exist somewhere.

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

@atmasphere 

on the second page it speaks to the balanced outs coming from the phonostage. I’m not really sure this true balanced outs because the transformers feed both sidle ended and XLRs. I am relatively new to this.

But some good SE cables do use an audio ground connection via the same wire used for the hot side. In that case, the shield will not be connected to the audio ground wire, and using such a cable for balanced is "better".

Thank you @lewm , that will helps impedance balance on positive and negative lead, made perfect sense!

I’m not really sure this true balanced outs because the transformers feed both sidle ended and XLRs. I am relatively new to this.

@audiosaurusrex Transformers allow you to run single-ended or balanced simply by grounding one side for single-ended, or balanced by letting the transformer winding 'float' (not be referenced to ground in any way) and simply being connected to pins 2 and 3 of the XLR connection.

So to run it single ended you would use a switch or install a jumper to the XLR connection, thus connecting pin 3 to pin 1.

@rauliruegas The old Decca cartridges from the 1960s and 70s had only three pins and thus have to be treated as single-ended sources. They are the only exception to 'all cartridges are balanced' I've ever seen- even ceramic cartridges can be treated as a balanced source. The newer Decca cartridges have 4 pins and are thus balanced.

So, the Edison phonograph is not balanced? Heh heh, there is always so much to learn here.

  Differences between a balanced connection and a balanced circuit (not just an electrical adjustment, but in fact a truly balanced design) are important to remember. That can further muddy the waters by not just accepting that an input may not be true to its suggested nature.

@atmasphere 

The input used an input transformer as well. This allowed the tape machine to have microphones a good 150 feet from the machine with no degradation of the mic signal. 

Do you really believe this. My understanding is that any low signal level cable over 3 metres no matter how whoopdido is going to have high frequency roll off. And what about phase shifts and internal reflections within the cable itself.

I find it hard to believe there is no degradation.

Do you really believe this. My understanding is that any low signal level cable over 3 metres no matter how whoopdido is going to have high frequency roll off. And what about phase shifts and internal reflections within the cable itself.

I find it hard to believe there is no degradation.

@dover 

No- I don't 'believe' it- I know it. I've run similar lengths for microphone signals myself- with no rolloff. Its helpful to keep in mind that a properly set up balanced line system is also low impedance (600 Ohms is typical) and the low impedance aspect allows you to run longer connections.

@atmasphere 

I've run similar lengths for microphone signals myself- with no rolloff. Its helpful to keep in mind that a properly set up balanced line system is also low impedance (600 Ohms is typical) and the low impedance aspect allows you to run longer connections.

I get the low impedance argument, but I still can't believe there is no signal degradation with a pair of 150ft interconnects and no phase distortion across the frequency spectrum. I would agree that in a properly designed balanced system cables are less susceptible to noise intrusion and have less effect than in a single ended system.

Have you measured frequency response and phase accuracy ( across the full frequency range ) in these situations ??

Have you measured frequency response and phase accuracy ( across the full frequency range ) in these situations ??

Sure! I've been unable to measure any loss of bandwidth even with 100 foot cables. To be clear though that means only up to 100KHz. Most transformer systems that operate at line level will only be going about that high- our preamps go higher since they have a direct-coupled output and no need for a line transformer. Phase accuracy in a passive or zero feedback system is entirely dependent on bandwidth. 100KHz bandwidth means there won't be any phase shift below 10KHz.

You might want to consider than in almost any classical recording there is a good 100 feet of cable before the mic signal hits in the inputs of the recording system. Put another way, the bandwidth/phase issue was 'fixed' by balanced line operation back in the 1950s.