The wiring is the same whether to balanced or unbalanced, it's just the connectors that change.
A balanced phono stage has, all things being equal, a 3 dB higher noise floor.. for the simple reason that the input signal seen by the + and - inputs with respect to ground is only half the the full voltage, while an unbalanced input sees the full voltage. (each input has 6dB more noise (or 6dB less signal for the same gain, if you prefer), but some of that noise cancels at the output together with the common mode noise, end result +3 dB)
Where low input noise is the primary concern (and for a phono stage, it should be) unbalanced is the preferred circuit topology.
The motive is to run the whole enchilada balanced: re-re, reamp, ower amp. Is what i do, my rime TT has re-installed balanced outputs, yet to see a 2d standard-issue model.
Not unusual if one lives in the balanced zone.
I published a balanced Phonostage in Jan Diddens Linear Audio Volume 0.
Yes, the wires are the same but you need other connectors. Non of the wires from the cartridge should be connected to ground, only the shield.
It's not even important to use different connectors, the standard RCA plug & socket works just fine as long as it's not earthed anywhere - if the electronics are fully balanced.
Our fully balanced RTP3D preamp has three phono inputs:
1. balanced XLR
2. balanced REDEL/Lemo, our house preference - simply the best sounding audio connector we have found
3/ a floating RCA socket which makes a perfect interface with 99% of good MC cart RCA equipped tone arms And even if the cable is a shielded unbalanced cable, as long as it's not grounded, I've never had any hum or other problems.
WoW started this tread couple of weeks ago and now loads of imput.
I have been running myne balanced for a while (LAC suply and passive RIA no caps on signal pat job whit silver revired arm)
Sound beter than what I had before but is one of those multy leghed critters job
so I was asking why not a balanced Pearl (may see Papa reply).
main advantages to me no noise from the input cables and just one resistor to adjust the gain
At present I am vorking on a balanced F5 but once done I was loking for a fully balanced set up.
Joachim Gerhard I am sorry I missed the Article can you drop me a link to it please?
Bksabath, here is my original schematic. The version shown was for a very demanding customer so it has some very expensive parts in it.
What is not shown is the servo. For more details i sugest you do youself a favour and get you a Linear Audio Vol.0. That bookzine has a lot of other interesting articles.
The servo shown there works only when you transfer balanced into unbalanced at the output. I designed a new servo that holds the DC offset to less then 1mV, single ended and differentially and it will be published in a follow up in Vol.1 i hope.
As soon as we have stuffed the new PCBs and tested them, i will also publish the changes on my MPP thread. Jacco, thanks for the enthusiatic words. From my point of view it´s a classic.
P.S. concerning the noise, when i compare balanced to unbalanced, balanced has a 3dB noise disadvantage provided we use the same amount of input devices, BUT it is much more robust in terms of hum pickup, so in a realistic setup it may be less noisy overall.