The following is a completely subjective A/B comparison focusing strictly on perceived audio quality of 2 channel music reproduction via digital inputs. Many of the units compared are not equals of technology or price, but only a result of what I had access to and my own curiosity.
My Rotel 1068 burned out and my backup Marantz AV9000 was on the decline. I wanted a new pre/pro and picked up a B&K Reference 30 off ebay for cheap… Disappointed by the lack of detail compared to the Marantz (nevermind the very detailed Rotel), I began an exhausting pre/pro shoot out. All comparisons were done in my own home with the same equipment setup. Only Preamp outputs were used on receiver models.
THE UNITS AUDITIONED
B&K Reference 30
THE REST OF THE SETUP
Focal 826v powered by a Carver AV705x amplifier. All music playback served up by JRiver Media Center, WASAPI Output, via Optical or HDMI where available. All lossless and HDTracks were used.
As my own starting point, the AV9000 has vocal reproduction that is hard to beat. It just sounds very natural. The treble was slightly harsher than the Outlaw, and the bass detail lacking in comparison. The width, instrument separation, and detail was also reduced compared to the Outlaw, 5008, 7701, Emotiva, and T175.*
B&K Reference 30
Very dark, mushy sound. Things just blend together, resolving much less detail. Less natural vocals than the AV9000. Bass detail and control was surprisingly great.*
Dark, confused sound. Very little feeling of width or layers. Probably the worst of the bunch in every way. Bad mid range resonance (blending buzz of midrange sound).*
Wonderfully detailed, smooth sound. Excellent imaging and width, with layers of detail and instrumental separation. Vocals a tad less natural than the AV9000, but much more fun and less fatiguing to listen to.*
Great detail and separation. Very bright, forward sound that was just too harsh for my setup. The Outlaw resolved just as much detail, but with more natural vocals and without the fatiguing sharpness.*
Lacking separation and detail. Voices sound less natural, and highs like snare drums sound harsh and flat. Bass has authority, but lacks detail in comparison.*
Very smooth and controlled, very detailed, great space and separation. More natural sounding than the Outlaw, and vocals on par or better than the AV9000. Slightly brighter than the Outlaw, but never harsh. Space and separation are amazing. Treble is “airy” and wonderfully natural. Bass is less prominent, but very detailed.*
Pioneer cannot resolve as much detail, slightly harsher treble, less warmth…. Less width than T175 and Outlaw. Not bad, not great.*
Very natural vocals. Not as much separation in instruments. Rougher treble. Best receiver I have heard (better imagining than Pioneer). Most hiss at high volume.
slight mid range resonance.*
Great detail and width. Marantz is much brighter than the T175, but has less control of the treble and bass. Makes the T175 sound slightly dark, though I did not hear any more detail in the Marantz. High volumes were harsh compared to the Outlaw or T175, which were more fun to listen to.*
For me, in my setup, the Outlaw 975 was the keeper until I heard the NAD T175. It simply plays the best I have ever heard with my equipment and my ears.
The biggest disappointment was the AV7701. I was shocked how much smoother and natural the T175 was in comparison. It was night and day. It is unfortunately because the feature set and operation is far superior to the T175.
I was very impressed by the SR5008, as it was the best receiver of the bunch and sounded nearly as good as the AV7701. I regret not bypassing my amp and seeing how it performed under its own amplification. If I had purchased it instead of the B&K that fueled this madness, my search probably would’ve stopped there. But once you hear something better…
I wish I could compare to the Rotel 1068 that I enjoyed after the AV9000, but also suspect that the T175 would ruin my fond memories with ease.