Its now nearly 6:00 in the evening here in the UK and I've been listening to both amps all day with a wide range of music. I thought I'd got the amp until Monday but it looks like I'll be out all tommorow so I'll have to cut my comparison short
I feel confident I have a good idea of the sound of each though. It doesn't take days and days to form an opinion. These are also just opinions based on comparing each amplifier in my system and room so please don't be offended if they don't neccessarily agree with your own experience's, chances are you don't own the same kit, don't have a room dimensioned and constructed the same as mine and your preferences are also probably different.
My comments about the AKSA posted at the very beginning of this thread stand.
When this amplifier is used with very revealing electronics it sounds cold and removed from the performance compared to the AKSA even with the best recordings I have - Chesky et al. Extremely accurate for sure and you always feel that your not missing a thing no matter how loud you play. But when I swapped back to the AKSA a lovely sense of musical pace, layering, smoothness and rhythm was very obvious that the UcD simply didn't have. I should note that it never sounded harsh nor grainy even when driven very hard.
Dynamics on the UcD are great, massive attack, good speed (not the equal of the AKSA though) and a general feeling of control right through the frequency range. The AKSA on the other hand is smoother but equally dynamic *provided* the volume is kept to sensible levels.
Bass on the UcD is much better than the little 55N+ but as Hugh already pointed out its 400w into 8ohm vs. 55w and that's nearly 8 times more power on tap. Elaborating futher on the bass; its got a real sense of power, punch and definition. I'm using ATC SCM7's which are only 83dB sensitivity although they are 8ohm. I know from experience these like power and lots of it 150-250 is recommended by ATC. The UcD has absolute control over these speakers at all times. If you read back to the first post on this thread my thought's on the AKSA bass is there, suffice to say it isn't a UcD700!
Soundstaging on the UcD is average to good. The presentation tries a little too hard though and it comes off as unatural and synthetic compared to a direct comparison with the AKSA. When listening to music recorded in a venue with natural acoustic's the AKSA absolutely destroys the UcD in everyway, much more natural and the reverberation, decay and layering are so real as to be palpable on the AKSA - you feel like you are there and not just listening to a facsimile. You hear all this on the UcD but its presented in a less believable way.
Imaging on the UcD is a big WOW! Soundstaging and imaging are often confused and maybe I'm guilty of that but for me soundstaging is the ability to relay the event, acoustics and overall space of the sound whereas imaging is how well defined and dimensioned individual aspects are within this soundstage. The UcD may suck a little with soundstaging but boy does it know how to image! Even with the most complex of mixes you can follow an individual sound and it remains stable, focused and coherent in respect to the rest of the performance. The AKSA on the other hand is a tad blurred in comparison on very complex material and you have to listen harder to make out what seems to come naturally and without strain from the UcD.
Detail on the UcD and AKSA are around about the same but again I'd definitely give the edge to the AKSA in providing those details with more 'electricity' whilst maintaining a sense of absolute calm and smoothness that the UcD doesn't quite do in the same manner. Its just a difference of presentation and someone's favourite could be easily swayed by preference - I prefer the AKSA here but I do rather like the UcD also. Overall I'd say its down to personal preference rather than absolute superiority of one machine of the other.
The speed/pace of an amplifier is a rather daft idea on the face value. Afterall how can one amplifier be quicker than another? Its all down to presentation, system synergy and tonal balance which really defines how fast an amplifier sounds and the AKSA is perhaps the ultimate amp on the planet in this regard. Its massive speed allied with an effortless smoothness is a huge paradox but one that is utterly alluring and not easily forgotten. There's no way the UcD can even hope to hold a candle to this.
To sum up:
First off, the UcD700AD is a good amplifier and anyone who owns one should be proud. In the right system I imagine it can sound fantastic (my friends for example). However in my system it just doesn't work as well as the AKSA. Maybe the combination of extremely revealing frontend, studio monitoring speakers and the matter-of-fact delivery from the UcD just doesn't gel well for musical enjoyment. I imagine for monitoring and mastering its a doozy though since you can hear everything and know exactly what is going on and what's wrong with a mix.
The AKSA is an audiophile product, proud to be coloured and all the better for it when it comes to actually enjoying music rather than just listening to music.
Whats clear is Hugh has masterfully crafted these colourations into something that bridges the gap between the recording and the original live venue. Is it accurate? Not in respect to the recording no but it does bring you closer to the original spectacle and surely this is what enjoying music is about?
This little test has been great fun and its only cemented my opinion of the AKSA. I suspect that when I do the comparison to Greg's SKA things maybe somewhat closer but as far as 55N+ vs. UcD700AD, I'd take the AKSA for my system any day.
Now to order an 100N+
Hugh are you listening? I want an 100N+, like, yesterday.
