motu ultralite output

[totheiotragi]

so...

i currently own an imac connected to a motu ultralite mk2 connected via balanced cables to focal cms 40 monitors. the focals are on the +4 db sensitivity option as suggested for pro audio. the main outs volume of the motu is way too loud and on many occasions the sound is distorted even when the volume on my monitors is in its lowest setting. if i turn down the main volume on the motu at around -6db or even lower, the distortion subsides.

i have checked the focals with the headphone output of a retina macbook, at full volume and there is no sign of distortion.

i contacted the motu tech assistance and to cut a long story short the suggestion was to simply lower the volume. i argued that in order to have a bit perfect stream with no loss in resolution the volume should be at 0 db. they insisted that "lowering the volume of the ultraLite lowers the strength of the signal. It has no effect on the quality". i asked again.

"so you can confirm that the master output of the motu isn't digitally attenuated hence lowering the resolution and changing the bit stream but that it controls the analog signal like an external volume knob would do? "

and they said that yes, "lowering the master output does not effect the resolution or bit stream".

is this really the case? can someone else confirm this? any other suggestions on how to quieten these loud outputs without resolution loss is appreciated. i considered buying something like spl volume 2 or tc electronics level pilot (way cheaper but i 've read some nasty comments about stereo image on low volumes, crackling etc) but if the motu main volume does the same thing without problems concerning the audio signal, that would save me some much needed cash.

thanks in advance

[mikehalloran]

Turn it down.

[crduval]

Yes I believe that volume knob controls volume post D to A conversion. I have had to play with volume a few times to eliminate distortion - the first time it happened I got a little freaked out thinking that I had recorded distorted audio without knowing it, but it was only the output amp on the ultralite.


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[totheiotragi]

thanks for the replies
.

[Karl Hungus]

I now use a stepped attenuator between my Ultralite mk3 and my (powered, input @-10) DynAudios for this very reason. Despite their confirmation, to my ears, the bit stream resolution is most definitely compromised when you 'turn it down' via the master level knob. With a desire for more dynamic mixes in the box, I feel that I have to have the master level at 0db.

Regarding volume controllers: none of the digital ones I tried held up at 'low levels' (as per the OP's research), meaning the stereo image was compromised and artifacts were introduced. I tried them because of price. My first cheap analog solution was a Presonus HP4, which despite cheaper components, introduced a minimal amount of garbage into the signal and had 4 additional headphone outputs which came in handy.

Currently, a home made high quality stepped attenuator has me satisfied but still not fully understanding what 0dB on the MOTU means other than 'not digitally attenuated'. I understand that the physical output is +4dBu and that pairing that with my powered speakers is a very 'noob' setup that leaves me with little control over the insane volume levels. An attenuator has allowed me to achieve mixes that translate decently well to professional systems with much more headroom.