Volume matched inputs on a preamp?

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

marlin38 

Its not listed on the Aesthetix web page but it is the preamp out the Mimus

the base model starts around 5K you can add phono and Dac at any time 

Cambridge evo 150 all in 1 provides level adjustments for each input.

For the multi-channel buffs, the Lyngdorfs do this.. 

Audio Research Ref 6 allows you to set and retain volume on the remote for each input.  A facility I paid for but do not use. Like most of us, I like to put the music on and adjust the volume to suit the programme, my mood, the time of daya, other people in the house and myriad other factors.