2. amps-preamps
  3. 1140360469

Preamp Connections - Balanced vs. RCA

I didn't know quite where to put this, so I figured this would be a good spot.

I just replaced my old preamp with a Pass X1, which has the choice of either balanced or single ended connections from the source components. My old preamp was RCA only. So right now I'm using my existing RCA ICs to get to the X1.

I'd like to consider trying some balanced interconnects (rumour has it that the X1 runs optimally with balanced connections), but I'm worried about the voltage delivered to the preamp. My sources (like my D/A) have the standard nominal 2 volts out from RCA and - what is it? - 4 volts for balanced. The thing is that X1, even with the gain set to 4 dB, seems to amplify the signal a lot faster than my old preamp. I'm only using a small portion of the volume control to get the needed volume. If I go to a balanced in on the X1 will that range now be even less since there's 4 volts at the input instead of 2?
tonyptony

Showing 3 responses by tonyptony

tonyptony OP
613 posts
 
Thanks Nsgarch. That makes a lot of sense. I suspect you're right about the inputs being "normalized" RCA Vs. XLR. The X1 does have a gain selection - either 4 or 14 dB. But in the case of 4 dB (which is where I keep it) the midpoint delivers enough of a signal to the amp so that it's plenty loud. I may pick up a couple of used balanced ICs here on the 'gon and try them out.
tonyptony OP
613 posts
 
"i have heard of this with pass pre-amps...if the volume is too high and you cant adjust the "

It's a Boelen modified DSP-7000 Mk.III. I have no desire to change it. You're comment confuses me relative to Nsgarch's. Do you have info that indicates Pass preamps do NOT normalize the inputs? If so that makes using balanced a non-starter for me. I'm thinking I'll call Pass tomorrow and find out for sure.
tonyptony OP
613 posts
 
"i was looking at the x-1 and was advised i would have to reduce the voltage of my dac if i went with it"

Mike, I just got off the phone with Pass. The indicate the inputs of the X1 (RCA and XLR) are indeed buffered and should not require any change in volume depending on which input is used.

"I used a pair of ultimate attenuators between my source and the X2.5 to drop the source gain, for an addition $300"

Rick, do you have a link to these attenuators? I too feel I'm getting too much overall gain between the X1 and my amp, but the only investigation I've done so far had been for the Rothwells, and reports on AA suggest they effect the sound. I didn't realize the X2.5 has such large steps between settings. The X1 is about 1 dB per step, but it and my amp (FetValve 550EXR) still add up to an overall gain so that I can only get through about 1/3 of the total travel before I hit a point that I would not "normally" exceed.
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