Balanced in phono stages preamp?

Not to beat a dead horse, but you wrote, "Lewm - didn't mean to say that balanced was bad just that there were trade offs." Not only did I not say that balanced was bad, but I was trying to say that I prefer it and why. Also, I was trying to convey the idea that one must be cautious in interpreting what manufacturers claim about their equipment, especially now that balanced circuits seem to be in vogue as never before. Try to find out whether the circuit inside is truly a balanced one (if you care about the issue at all), because in a lot of gear an XLR input or output is derived from what really is a single-ended circuit internally. Many CD players pull this trick by adding a chip at the output, which not only is a phony way to do it but also will likely degrade the sound a bit compared to the SE outputs on the same piece of gear, due to the added active device which is typically a middle grade op amp, at best. Even my former Accuphase DP75 (a $10K cdp when new) and the Sony SCD1 used this approach to obtain a balanced output. For this reason, when someone says they don't hear any advantage to a balanced output, I have to first wonder what they have been listening to.

Anyone have access to a VKP10 schematic? My curiosity is tweaked now, I'd like to see if there is any difference to the balanced input connection downstream of the connectors.

I have a PH2 from Audio Research. It is completely balanced from input to output. A quick look at the schematic and it's easy to tell. The ground runs right down the middle of pin 2 and pin 3. I can't say from experience yet that it sounds better than single ended because I'm running mine into a single ended line stage, but theoretically noise picked up from cartridge output pins throughout a balanced chain will be common mode rejected giving you a lower noise floor and less interference/interaction from outside sources. Good idea given the lower output of phono cartridges

Many CD players pull this trick by adding a chip at the output, which not only is a phony way to do it but also will likely degrade the sound a bit compared to the SE outputs on the same piece of gear

I agree, but would like to point out that since the data on the CD is single ended, any CD player with a balanced output has to "create" the inverted signal in some manner. Some use more DACs, some use inverters after the DAC, but in every case there is no such thing as a balanced CD player from front to back since the data on the disc isn't balanced.

-And since phono cartridges are balanced, it is actually surprising that balanced phono sections did not appear sooner! When we built the first one in 1989, we thought that someone had done it before us, as it seemed the logical thing to do. But apparently the idea of balanced lines was/is foreign to high end audio, which is a shame because they have been so successful for over 50 years in the recording industry.

Balanced lines were created with the intent of eliminating cable problems and differences but the high end community has preferred to throw money at single-ended cables instead. While the techniques has proven successful, it has hardly been economical :)

Balanced operation also gives you lower noise both in the cable and in the circuitry. A differential amplifier, one of the basic building blocks of a balanced phono circuit, has *6db* less noise than its equivalent single-ended circuit! In practice you get a little less than that, but over successive stages of gain this means a lot- 10 db less noise for example in only 2 stages of gain. This allows for greater simplicity (less stages of gain) which translates to being closer to the music.