RCA connectors can't carry a balanced signal. You need to use cables with XLR connectors to support balanced.
Balanced vs. Unbalanced Inputs
I am trying to upgrade to a differentially balanced phono stage to compliment my Pass XP-22 pre and Pass X250.8 amp so as to minimize long cable artifacts and benefit from CMR. I do understand the it is the circuitry and not the input connection that determines wether a signal is balanced or not. I am looking at both a Pass XP-27 and AR Phono 3SE as possible options. Both have RCA inputs plus a ground post only. No XLR inputs.
As far as my understanding goes, a balanced cable must have 2 signal conductors, a hot (+) and a cold (-) PLUS a ground for EACH channel. So, I sent an email to Pass Labs as follows:
".... I want to confirm that there are TWO signal conductors PLUS a ground for each channel. Specifically, on each of the RCA inputs, do the center pins and the shields carry the hot (+) and cold (-) signals respectively while the grounding wire/grounding post becomes the tone arm/turntable chassis ground connection common to BOTH channels? "
This was the response:
"No. RCA shield and ground lug are contiguous connections."
But on the pass website is the following:
"In order to minimize ground loop issues Pass Labs never manufactures equipment with signal ground and chassis ground contiguous."
When I email Linn about their pseudo balanced LP12 T cable they responded with:
"All Linn arm cables are terminated with a 5 pin DIN connector with the center pin being arm ground, which on an LP12 is also used as the chassis ground. This is separate from the left and right channel grounds and hots which are on the other 4 pins."
Again, there is no (+) signal to be superimposed with an inverted (-) signal separate from ground for CMR. I Do have a technical background but I am not well versed on circuit design so please forgive my ignorance. I did get some very helpful advice from a member here, however, the further I inquired with the manufacturers the more confusing it became. As of now I am wary about emailing AR for fear of even more confusion. If anyone has any advice on how to proceed I would really appreciate it. Thank you all so much.
Bruce
As far as my understanding goes, a balanced cable must have 2 signal conductors, a hot (+) and a cold (-) PLUS a ground for EACH channel. So, I sent an email to Pass Labs as follows:
".... I want to confirm that there are TWO signal conductors PLUS a ground for each channel. Specifically, on each of the RCA inputs, do the center pins and the shields carry the hot (+) and cold (-) signals respectively while the grounding wire/grounding post becomes the tone arm/turntable chassis ground connection common to BOTH channels? "
This was the response:
"No. RCA shield and ground lug are contiguous connections."
But on the pass website is the following:
"In order to minimize ground loop issues Pass Labs never manufactures equipment with signal ground and chassis ground contiguous."
When I email Linn about their pseudo balanced LP12 T cable they responded with:
"All Linn arm cables are terminated with a 5 pin DIN connector with the center pin being arm ground, which on an LP12 is also used as the chassis ground. This is separate from the left and right channel grounds and hots which are on the other 4 pins."
Again, there is no (+) signal to be superimposed with an inverted (-) signal separate from ground for CMR. I Do have a technical background but I am not well versed on circuit design so please forgive my ignorance. I did get some very helpful advice from a member here, however, the further I inquired with the manufacturers the more confusing it became. As of now I am wary about emailing AR for fear of even more confusion. If anyone has any advice on how to proceed I would really appreciate it. Thank you all so much.
Bruce
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- 39 posts total
- 39 posts total