Using XLR for Phono out


Hi folks, I am setting up my stereo on paper first and have an interesting question. I have bought a PS Audio GCPH phono preamp. It has RCA inputs for phone but output
can be RCA or XLR! PSAudio states their amp is all balanced. I am using a VPI JWM tonearm that has direct RCA outputs. I am using XLR from preamp Cambridge 840E to my Marklevinson 336. Should I use the XLR phono output to the preamp too? Thanks, Rique.
spaninc
Romaxim, I was planing on connecting RCA to XLR adaptors on the output of the VPI JWM tone arm when I realized the
GCPH has only RCA for inputs. However, outputs from this amp are true XLR so I guess that part is solved by default
Buddy,
using adaptors (XLR RCA, or what ever) with *any* phono-cable is one big NO NO!
So my advice: DON'T!
BTW, the GCPH wants to see a single ended (RCA) input, and only then it is converted (via OP-amp) into a differential signal and further handled like such. So the GCPH is not fully differential from input to output (kind of demi-differential :-)
It is this OP-amp chip XLR conversion at the input that makes some purist cringe, and some not bother to use the XLR output (unless desperately in need of the extra 6dB I mentioned earlier on)
Greetings,
Axel
VPI arms can have either a junction box that accepts XLR cables, or one that accepts RCA's. If your equipment is REALLY balanced from input to output as Ayre stuff is, with no electronic trickery in the circuit to make the single ended circuit balanced, there will be a definite advantage in using balanced from cartridge to speakers. The difference is not subtle, if and only if you have the proper gear to accomplish this.
The type of plug does not determine whether a connection is balanced or not. I am using a "balanced" connection from my cart. to my fully differential phono pre. However, by choice, I am using RCA plugs. Why? XLR plugs fitted on my OL arm would not fit through the arm pod on my Nott. table. Balanced or single-ended is a function of the circuit topology, not the type of plug used.
Dear John, Can you cite me a reference for your statement that "transformers have some of the highest CMRR ratings"? This might be true if a transformer is properly implemented at the front end of a balanced circuit. But when transformers are used at the in- or output of an SE circuit, as is often the case, I don't see how you would get any CMR.