This might be a stoopid question

[Loquah]

If I use a simple RCA splitter cable to connect my DAC to my S.E.X. and Crack, am I correct in thinking that it will halve the impedance and therefore result in higher volume output?

Does it make any difference if the amps are on or off?

[Grainger49]

The DAC will see the two input impedances in parallel.  So 50k ohms.  This is safe for solid state devices and most tubed output stages. 

I did this years ago and didn't have any adverse effects from it.

[Loquah]

So the DAC sees 2 x 100k loads (SEX & Crack) in parallel, making the input impedance basically 50K, yes?

The reason I'm asking is that it sounds OK, but I'm already finding limited range on my volume pots so I don't want to do anything that could reduce this range even a little. Sounds like using a splitter could be reducing the attenuation and that's not helping me.

[Grainger49]

Ok, I'm awake now.  I had misread it as being two sources and one amp.  So I edited my above response. 

Yes, the DAC will see 50k which is just fine.  Most DACs could run into a 10k load with no problem.

But it will not change the volume range.  This goes back to a basic definition.  Elements in parallel have the same voltage across them.  This does not mean a numerically equal voltage it means voltage that comes from and returns to the same source.  This is the case of your DAC feeding the SEX and Crack volume controls.

Your SEX and Crack volume controls will have the same voltage across them.  It will be the voltage of the DAC's output.  That voltage remains the same with one 100k load or two becoming a 50k load.

Both the SEX and Crack will see the same voltage, but double the current will be delivered from the DAC.  It has current to spare in this situation.

By limited range do you mean that you run the volume at 100%? 

[Paul Birkeland]

With a sufficiently low output impedance (under 1000 Ohms), the difference between a 50K load and 100K load will be miniscule (0.2dB of loss for 50K, 0.1dB of loss for 100K assuming a 1K source and a lot of rounding).

[Grainger49]

If you have limited range  on the volume pots you could put an L-Pad at the input of each amp.  This would allow you to use more of the volume pots' ranges.

[Loquah]

Thanks PB & Grainger, that's exactly the info I was looking for.

I am currently building some attenuating interconnects using the L-pad approach so I look forward to trying them soon.