And so I've been using 005 in a couple different new configurations. Original configuration was 005 balanced out to Coincident Statement active preamp, SE (RCA) out to 300B monoblocks. First new configuration was 005 RCA direct out to Coincident 845SET. In this configuration dac is driving amp, 005 digital volume control. This config was not optimum in any sense of the word, digital volume attenuation was around 75% of full volume. While initially impressed by resolution and transparency, tonality thin, timbre off, soundstage, imaging off, no magic, sound quality of cheap dac. Obviously bit stripping going on here, no way this config will come close to exposing potential of 005. My take is dac direct configs can't attenuate volume by much more than 10%, and even then you won't hear full potential of any dac.
Next config was 005 rca out direct to 845 amp in integrated amp mode. Coincident 845 can be used as integrated with built in passive pre, volume control resistor based, or in bypass mode where it is amplifier only. In this mode sound quality challenges original config of Coincident active pre in chain, however, there are differences. The overall gestalt of the non-active pre setup was just slightly to the analytical side of spectrum. 300b amps with active pre is more analog in character, how'd I imagine a ladder dac would sound. The other config is more sabre chip in character. I could also describe 300b with active pre as warmer, in that tonal balance is more toward the lower mid, although I hear it objectively as dead neutra; its only in direct comparison with 845 setup's upper mid centric tonality that I hear it that way. 845 setup has a more wispy, airy character to it, kind of accentuates that area of freq spectrum. 300b setup feels more solid and driven which is the opposite of what I would expect as my 845 excels in comparison to the 300b in those exact areas. And so, the active pre obviously has greater drive, impact than passive in 845. And yet, when listening to 845 with passive I don't feel deprived in these areas. I purposely played a lot of electronica, particularly electronic dance music, plenty of depth in bass, impact and drive, not lacking in objective terms, very involving. More intimate music also excellent with 845 passive, magic of 005 was there in full measure.
At this point, I can't decide which setup I prefer, both are involving and magical. The passive setup may actually be bit more resolving which counteracts the greater drive, impact, more analog sound of active setup. I'm very familiar with the inherent sound quality differences of my 845 vs 300b amps, the differences I'm hearing have much more to do with active vs passive pre's, and specifically the volume control used within, 845 resistor based, Statement transformer based. And so I'd estimate an active pre is not absolutely necessary to hear full potential of 005. I am a firm believer in analog volume control, no digital and no software volume control for me. In relating this to phone users, I assume most headphone amps have passive volume control, 005 will excel here. Now, as to various iterations of volume control and my estimation of quality. Transformer based> resistor based> potentiometers. Pots have tracking issues, noisier than resistor and trans based. Resistor based can be excellent depending on quality of resistors, but resistors vary in tolerance, heat can be issue, and tolerances can change over time. TVC's don't have these issues. So all things being equal I still prefer tvc's based on durability and constancy. So what I'm saying is amp with passive pre (volume control built in, not separate box which needs another interconnect to drive) is great with 005, built in passive with tvc is optimum. I'd also add it's quite a big deal that 005 can drive a passive pre this well. Dac's and phono pre's are not designed to drive amps, they are designed to drive preamps, preamps are designed to drive amps. The purpose of preamps is to amplify low level signals to useful levels for amps. The fact the 005 does so well is due to superior power supply and well designed output stage.