Volume matched inputs on a preamp?


I'm not quite sure how to ask this - but I'm wondering if there are any preamps that allow you to set the volume by the input so you can volume-match one input to the others.  So many DACs have different output levels, it's hard to compare them.  If you could set the gain by each input to volume match all the inputs - that would be a lot of fun.  Yes, I send digital signals from a single source to different DACs and like to switch between them to see how they may differ.  Tube or solid state doesn't matter, but I'm guessing it'd be easier with a solid state preamp.

Multiple google searches for key words did not turn anything up.  

Thanks!

128x128marlin38

My Audia Flight integrated allows me to set the gain and balance for each input.

Naim’s NAC112 and 112x and Nait 5 do this but they’re possibly their least exciting  amps. I had a Nait 5 but only for a month before trading it. Some people like them I’ve heard.

Oooh.  I think I like that Pallene.  Sounds like it's kinda new, so I doubt there's one out there on the used market.

Thanks all!

Placing variable control on each channel, so that you can adjust them on the fly (so to speak), puts yet another variable resistor (=crap linearity and noise) in the signal path, so a two-edged sword. using two resistors you can do a very clean version, but its fixed. I am borderline on a rampage about DAC manufacturers who totally ignore the convention that stood for like 80 years - line level is nominal 1V rms. Most now are 2-2/12 (150% off!). Some thetas are like 5 vol,ts rms. Insane and overload some inputs.  Guys, Zero dB = 1Vrms. Period. End. :-)  sorry, rant off.

Anyway, long story short, if you have two DACs that you want to even the inputs from, use two resistors (per channel, a voltage divider) either at the pre in or at the output of one of the DACs. To figure out the % drop, measure the output of the two dacs using a test tone (available on the internet, play from your PC USB) and measure the analog output level of each. Voila, you know the difference.

 

I have a "franken Theta" - part theta and part my on design that is pretty excellent. So i soldered the resistors in its output to cut it by 66%. Much better.

 

Oh, the two resistors are stupid low distortion compared to everything else and maybe 10X better than the best rotary potentiometers. Its why i have switched to metal film voltage dividers for all my volume control, period. By making them dual mono i can toss the balance out the window too. revelatory in transparency.

 

A great advance courtesy of 1940s military convention :-)

 

G