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
mikesinger
572 posts
 
you are correct..i put a "if" in my statment.....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..

depending on the system and where you like to have your volume (7 o'clock, 10 o'clock, 1'clock).... if the input sensitivity of the pre is too high is to high and the gain selection wont go low enough....you can reduce the output of your dac and it isnt that hard to do (generaly a couple resistors etc...)

are you sure the output voltage of your dac is 4 volts ???? most sources will have double the voltage of the rca, but not always (electrocompinet dac for instance is 3.3v)...
rgodin
85 posts
 
I had an X2.5, which uses a similar design to the X1. Even at the lowest gain settings I was getting too much volume. I used a pair of ultimate attenuators between my source and the X2.5 to drop the source gain, for an addition $300.

Also, I found that the 3 dB steps on the volume control were spaced too far apart. I was always stuck between too loud and too soft.

I thought the sound of the X2.5 was very good, but the lack of a volume control with small incremental steps just got to me. I replaced it with a Placette Active that had a dual range volume control, each with 127 steps. I like the Placette much better and I can always get the volume exactly where I want it.

Rick
tonyptony OP
617 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.
rgodin
85 posts
 
http://www.tweakaudio.com/Ultimate%20Attenuators.html

You can sometimes find them here used for $250 to $300. That is how I found mine.
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