I evaluate a DS with Bridge II and RedCloud installed. I am using the DS as preamp to my mono blocks.
I experience an increasing harshness when have chosen the low level output level (-20 db) instead of the normal output level.
Has anyone else have the same experience?
Or do I just imagine… 
//Stefan
Welcome, Stefan!
The attenuator changes output levels by adding a shunt resistor to the signal ground. Engaging the 20dB attenuator is akin to turning the volume down by 40. The analog attenuator is there to allow you to lower the noise floor by 20dB if you normally listen at volume setting of 60 or lower.
The sound should be the same with and without the attenuator engaged but some feel they can hear a difference. You may be one of these listeners. If leaving the attenuator out sounds better to you, by all means do not use it. 
Thanks Elk!
The reason I tried to use the low level its because my mono blocks a quite sensitive, without the -20db the volume settings will not be higher than 30-40.
//Stefan
Harshness isn’t normally something I hear about as a lacking in the attenuator - as Elk says, it’s just adding quality shunt resistor with a relay so it shouldn’t affect the signal much.
I’m not sure how the attenuator “burns in” compared to the rest of the DAC, but things like “harshness” change quite a bit during burn in and the DS takes a long burn in (100’s of hours.)
Great thanks for the answer!
The DS has been playing for 150 hours. I need to have patience…
This is interesting. I run my Direct Stream DAC direct into a Musical Fidelity M6 power amplifier. For the last couple of years, I’ve generally used the “low” output setting, meaning that the volume control is usually set between 60 and 80, and there is no audible hiss from the speakers - even when no music is playing. This seems ideal. However, I have, at various times, tried the “high” setting - mostly because, with my Oppo Blu-ray player, even a volume setting of 106 can be insufficient.
In the past, I haven’t noticed any sound quality benefit from using the “high” setting, but, inspired by the original post, I’ve revisited this issue, and the “high” setting now seems much better than “low” - more dynamic, and, at the same time, smoother - particularly on vocals. Could this be related to Redcloud? Of course, the trade-off is that there is some background hiss - though not enough to be noticeable when music is playing. Also, the volume setting is now typically between 20 and 30 (except when the Oppo is playing).
Stefan and jb - I have the same impression. I’ve mostly been running without a pre since Redcloud, and had the attenuator in for a while. It seemed “flatter” sounding and a bit wooly, and when I went back to high it seemed to go away. Haven’t done any vigorous testing though. Don’t really need to.
I just realized, “flatter sounding and a bit wooly” is a pretty good description of an in burned in DS. Perhaps in some of these cases the attenuator’s resistors haven’t burned in yet and a little more time with it engaged would help. (On the other hand, if you’ve been using the attenuator all of the time, clearly it’s already burned in.) Just a thought.