Will DAC always sound better going straight into a Power Amplifier?

 normal modern DAC will output at min. 2v RCA or min.4v balanced. That is equal to a normal preamp output. Forgetting weird impedance mismatches for the moment, the only job left for the preamp is attenuation. If the DAC has a good relay based rather than lossy digital attenuator, there is nothing left for the preamp to do other than add distortion. If you do have an impedance mismatch, get a passive attenuator

I run direct and completely agree with this - but how does a passive attenuator correct an impedance mismatch? I thought that the problem with passives was that they do not correct an impedance issue the way active preamps do - even unity gain/buffers only preamps. 

 

@majorc,

you are right, however: a passive avoids the additional lossiness of a digital attenuator. Running the Dac at max output reduces the impact of the mismatch

I use an ifi idsd dac micro which has the option of running in direct mode or 2 options for preamp mode - 1 with 0 gain and 1 with gain - when in preamp mode there volume control nob in enabled - is it safe to assume that that is an analog volume control - and if so serve the same role as a passive?

@majorc 0.0 gain or 0.0 db means the DAC is connected straight to your pre-amp or power amp and is not interrupting or changing the voltage from your source.

-db means the gain has been reduced and +db the gain has increased which will decrease or increase the volume by a such a multiple.

Your Ifi DAC probably has a digital volume control but don't sweat it. Only in a more revealing system would it show wanting. It probably sounds fine.

Some folks pointing to output and on the right track. 

Going direct here to 65 watt rebuilt mono block tube amps with the RME ADI-2.

Never looking back. It's super. Definitely worth a look/listen.