balanced output VPI

There is another way to do it as well.

Since your box has a ground post is why you can do this. The signal is actually balanced all the way to the box. All that happens in the box is that the RCAs are connected. The RCAs are insulated from ground.

If the barrel connection of the RCA is not treated as the shield connection (which is the ground post) then you can set up a true balanced line. The only issue you may have is if someone touches the sleeve connection of the RCA while its playing- you may get a buzz at that point.

But otherwise this can be a totally balanced setup. BTW, we offered the first balanced line preamp (MP-1) back in 1989, and this has been one means of making the balanced connection to the phono that we have used since that time. The complete scenario is in our preamp owner's manual, which can be downloaded from our site; click on 'Support'.

The connection:

Ground post = shield of **both** channels, pin 1 on both XLRs.

Center pin of RCA = pin 2 of XLR

ground sleeve of RCA (which is insulated from the ground of the box BTW) = pin 3 of the XLR.

The connections for pin 2 and pin 3 are a twisted pair within the shield of the cable.

The advantage of doing this is that the phono cable will cease to have an effect on the sound (worth doing IOW).

Mordante, the process described by Atmasphere requires that the output end of your phono RCA cable be reterminated with a XLR output. The turntable connection does not change, but you may want to add another ground post wire to allow a separate lead to each channel's pin 1 on the L and R XLR.

Brf, Since Mordante uses a RCA to RCA cable with a separate wire for earth ground, I think Ralph is saying the opposite, that Mordante CAN use his RCA cable and still effect a balanced connection to his preamp. But at the preamp, we need to know what that switch really does, to be sure one way or the other. Further, and even more important, we need to know whether the phono stage itself is a truly balanced device, internally. The presence of the XLR input jack is not proof of that. If the circuit is not balanced, then there is little to be gained by doing anything.

Mordonte, contact the mfg and find out what that switch does. I used a balanced Ayre phono pre amp with both RCA and XLR inputs. The single ended / balanced switch simply grounded the inverting (or negative) signal. So leaving it in the balanced position even while using the RCA inputs gave me connection to both inputs of the phono pre diff amp inputs. Its not the ideal way to do it but electrically it was sound. There was a clear difference in the sound with the switch in balanced vs the single in favor of the balanced. You might be able to tell just by experimenting.

As was said above, having a seperate ground wire is required.

BTW I have a VPI XLR junction box that I got for my
Aries II that I never used if it would work for you should you want to go that way.

TD

What does the manual say?