Kevin’s
www.diycable.com Exodus Audio “Demo Amp” (2-channel UCD400AD version with the Hypex HG Supply & soft start) listening and use comments.
Well the Post-CES traveling demo amp has come and gone from casa Tracy and it is time to share my thoughts with fellow Circlers.
Executive summary
Very good sounding amplifier packaged in a solid case built to a high standard while avoiding posturing excess such as ½” thick milled faceplates. The sound is powerful and clear especially excelling in the bass, pace and rhythm departments. Versatile hookup options and well behaved in system. Very high value at the $1800 price.
All the gory details
I had the Exodus Audio UCD400 amp for 10 days so I was able to accomplish a more in depth demo than possible at a show or dealer showroom. Of course that is less than the months an owner or reviewer might live with the amp so we can consider these observations as in depth but hardly definitive.
The amp was listened to using the following speakers:
- Fostex F120A based fullrange (89 dB/W/M)
- CSS WR125S based fullrange (85.6 dB/W/M)
The above at various times with and without help in the bass from:
- Subwoofers using four TC Sounds TC2+ 10” drivers in two enclosures
Comparison amps included
- Modified Hafler DH500 (subwoofer only)
- DIY 2A3 SET
- Spectral DMA-50
When used with a subwoofer the front end of the system included a Parasound AVC-1800 surround sound pre-amp (analog by-pass mode used for SACD & DVD). When auditioned in a stereo only environment a DIY pre-amp based on Nelson Pass’ “Bride-of-Zen” design was used. In both the 2.0 and 4.1 systems primary source was my modified Sony DVP-NS900 DVD/SACD player. Source material included CDs, SACDs, DVDs, and high definition video from digital cable.
My primary agenda for signing up on the demo program was to evaluate how the UcD modules function as a subwoofer amp. My secondary agenda was to hear how the UcD performs as a traditional stereo amp. In addition to the personal amps listed above I have heard the NuForce amp in my system and Tripath based BelCanto designs at dealers and the Carver Pro Tripath amp I used in a client’s home theater driving the subs. I also use a tweaked Sonic Impact Tripath based amp in my office system.
When the Exodus Audio UCD400 amp arrived it made a favorable impression even before it was plugged in. The casework and power supply are heavy enough that one needs to be careful picking it up or you will tweak your back. The case is built to tight tolerances with good fit and finish. Personally I like the stainless steel ‘X’ on the front panel better in person than it looked to me in the pictures posted on the web. The quality of the case is well up to high-end standards from both functional and pride of ownership viewpoints. No attempts are made to play the metal sculpture of the month game so beloved by Krell and other boutique players seeking status along with (or over) performance. Around back we find both RCA and balanced XLR connections for inputs. WBT clone 5-way terminals for output and IEC power inlet jack completes the backside. Also included were diycable.com power cable and RCA-XLR signal cables, these were used for all my listening.
Kevin wisely councils to do the initial power up using less expensive speakers to rule out shipping damage, so I set aside my F120As and jacked in the CSS based units. These are in a ¼ cubic foot bass reflex box. It was immediately apparent the WR125S really, Really, REALLY liked the big power of the Exodus Audio UCD400 amp. The WR125S equipped system benefited from the extra volts and amps available compared to the 2A3 SET amp. First disk up was the stereo SACD of Santana ‘Abraxas’, I like this because I have loved the music (and the girl on the cover) for decades and the high frequencies recorded on this disk are very revealing. Among the first questions about a class-D amp we ask are ‘what are its highs like’ so it was a natural selection to reach for a disk full of Latin percussion. The first track ‘Singing Winds, Crying Beasts’ begins with an intro by the band’s drummers playing all their little brass toys. I would be willing to bet these were recorded up close with vintage German tube condenser microphones or maybe even RCA ribbons because on a good system one can hear all the little metallic textures resulting from what the cymbals and bells are made of and how they are being hit. The Exodus amp passed this test with flying colors revealing a wealth of intricate natural detail. When the rest of the band kicks in the UCD400 amp nicely tracked the jump in dynamics. Soon I dropped out of audio geek mode and relaxed back just grooving along through 'Black Magic Woman/Gypsy Queen' and 'Oye Como Va'. As track four began I had reverted to audiophile mode and got up to switch disks to hear the amp with different music. Before I had stepped away from my couch the first strains of 'Incident At Neshabur' poured out of the speakers and I was jerked out of audio geek mode and the music lover just started dancing. Silly, goofy 50-year old man dancing alone to the Latin groove laid down in 1970. Time machine time with the dial set to way-back. This experience and the other cuts listened to that first night cemented the very positive first impression the Exodus Audio UcD400 amp made. One aspect I value more and more is a components ability to aid the system in getting me emotionally connected to the music and the artists who created it an aspect the UcD400 continued to score highly in all through its stay.
After the first night using the UcD400 amp as the main system amp I moved things around to test it on subwoofer duty. Here it replaced my tweaked Hafler DH-500 250 wpc @ 8 ohms amp. In both cases the stereo amps were fed the 0.1 bass signal out of the AVC-1800 through a 1:2 splitter so one channel of the amp feeds each subwoofer box separately, i.e. the amps run in stereo not summed or bridged mono modes. Surround sound listening used the Fostex F120A based speakers running on 2A3 SET power for front channels L & R, phantom center, oneZ rear channel speakers, and the above detailed dual subs.
After setting levels with a SPL meter and fine tuning by ear initial listening included the concert DVDs Eagles 'Hell Freezes Over' and Talking Heads ‘Stop Making Sense’. During my time designing and installing home theaters these were our go-to disks for demo and judging systems. While hardly reference after one has heard them over and over on systems up to $80,000 worth of Meridian 800 series they become something of a personal benchmark. What I was looking for here is for the amp to control the subwoofer drivers so that they stay out of the way of the music while going about the business of making bass. In other words the ability to make tuneful deep bass while avoiding the dread droning of all too typical one note subs. A good subwoofer system is essentially invisible until called upon. In the case of the Exodus Audio UcD400 amp driving the quad of TC Sounds TC2+ 10” drivers good subwoofing on the music side was achieved. With the Eagles disk the rock bass and drums had good timing and impact. The small string orchestra backing the band was reproduced naturally with no subwoofer blur obscuring the cello and other low midrange and acoustic bass instruments. Confirming good damping and bass tone with the Eagles disk on went the Talking Heads to check out the slam and boogie factor. The live concert movie ‘Stop Making Sense’ captures the Heads at the height of their considerable powers. Featuring two drummers and synthesizers there is plenty of musically compelling rock bass to exercise any system. And songs like 'Burning Down The House' just beg to be cranked to "11". One word can describe that part of the listening session. Fun. It was big fun. That is a big part of what this hi-fi deal is all about, right? When we forget about dissecting the sound into its parts and the system recedes into the background while a significant performance is brought back to life. And this performance BOOGIES. As always this disk called for turning things up. With the Exodus Audio UcD400 amp driving the bass along even the little 3WPC of 2A3 power on the mains (set to ‘small’ to use the AVC-1800 DSP crossovers) were sufficient to achieve silly levels all the while grooving to the tunes.
Having shown itself capable in the musical bass department it was time to bring out the home theater artillery. And I mean actual recordings of artillery. I have always loved a good tall ship sailing story. So Russell Crowe staring in 'Master and Commander, the Far Side Of The World' is just my cup of tea. The adventures of the men who explored the world using little more that oak and canvas always sets my imagination alight. Of course with the exploring also went the fighting and that brings us back to the subject at hand. For 'Master and Commander' the sound design team recorded actual breech loading navel cannons from museums firing cannon balls through large oak beams simulating the ship's rigging. Mixed in with the other sound elements during the battle scenes the effect is stunning. On a good system in a good room the canon fire pressurizes the room with the most amazing impacting bass from subsonic frequencies on up to the cracking of splintering oak as the shots rip through the rigging. The last home theater I was hired to design featured the ASC system to acoustically treat the walls, floor, and ceiling. The de coupled and damped room along with the two big bass traps hidden behind the screen resulted in a sound environment any audiophile would adore. In that room with dual TC Sounds TC2+ 12” drivers the 'Master and Commander' battle scenes are amazing. What was really impressive about the Exodus Audio UcD400 in my home system was the degree to which it could replicate that experience in a normal living room open on one end to the dining room and the other to the entryway. With a little extra gain we got dang near pressurizing the whole downstairs of my house!
So the verdict on the Exodus Audio UcD400 amp in subwoofer duty for both music and movies is A+.
Later in the week I invited my audiophile buddy Leo over for a listening session. He is pretty well set in the personal system department with Magnepan Tympanis driven by Audio Research SP6+M100 monoblocks gracing his living room. As you can see Leo is an avid tube guy, he is also a longtime reader (as am I) of ‘the absolute sound’ and that magazines rave over the Nuforce 9 has our interest peaked on the subject of class-D amplifiers. For the evening I reconfigured my system as stereo only using the heavily modified stereo outputs of the Sony DVP-NS900 CD/SACD/DVD player into the BOZ preamp then the power amps feeding the Fostex F120A alnico full range single driver speakers. We started listening to the Exodus Audio UcD400 amp then swapped in the Spectral DMA-50 for comparison. Music (and formats) used for our evening of listening included:
- Blood, Sweat & Tears self titled album (Stereo SACD) tracks 'Variations On A Theme By Erik Satie' and 'Smiling Phases'
- Gershwin 'Concerto in F for Piano And Orchestra' (Classic 24/96 DAD)
Before discussing the results of Exodus Audio UcD400 vs. Spectral DMA-50 let me say a few words about the Spectral amp and Fostex F120A based speaker used.
Spectral (
http://www.spectralaudio.com) marketing is very low key with little advertising and few review loaners going to the magazines so many of you reading this may have never heard of Spectral. The underlying design philosophy at Spectral is ultra-wide bandwidth. In the case of my DMA-50 the full power bandwidth is DC to 3 MHz. Many amplifiers claim DC response, the term is almost as misused as “dual mono”. As typically used it means there is only one DC blocking capacitor or a DC servo in the signal path. Not at Spectral where they are too hard core purist for that. When they say this power amp is DC coupled they mean it, so if the pre-amp or source feeding it has a few mV offset we see volts of DC on the speakers terminals! Likewise at the top end it really will pass MHz signals at full power. The thinking here is only be removing a subsonic low cut filters and extending the supersonic high cutoff do they achieve maximum transparency. More details of their design philosophy can be found at the above URL. My DMA-50 is a precursor to the DMA-100S in the same 1U high form factor. All solid state with MOSFET outputs it is good for 80 watt per channel at 8 ohms. The DMA-50 was produced in the mid-1980s when it sold for circa $3500. So comparing the Exodus Audio UcD400 vs. Spectral DMA-50 we are putting the UcD400 up against a unit selling for several times its cost for a fraction of the power.
The Fostex F120A equipped speaker used is a new mini-monitor design of mine. The box is a bit less than ½ cubic foot bass reflex. Just placed in service while very revealing it does have a tendency to go ‘over the top’, that is at times one hears a narrow band resonance(s) being excited into harshness. Exactly what is going on here remains to be discovered and designed out. Chief suspects include the amount of damping in the box, lashed up internal wiring, and insufficient driver break-in. Ninety percent of the time this prototype speaker delivers the amazing musical textures and inner detailing which makes alnico worth the considerable up charge. That and the phase perfect coherence one gets from 100 mm class full range drivers acting as virtual point sources.
We began listening to the Blood, Sweat & Tears disk using the Exodus Audio UcD400. 'Variations On A Theme By Erik Satie' was just plain lovely. This is another song which starts featuring the percussion section and again the delicate highs had a fragile very live quality. The next cut on the disk is 'Smiling Phases' (I always thought it was Smiling Faces, somebody was being cute with the spelling) and here the big BST horn section lets it rip. This was not a successful moment as the reproduction got harsh enough that we winced and I jumped up to swap disks! On to the Gershwin Concerto in F on 24 bit 96k DAD disk still with the UcD400 amp. This was fine reproduction. Lots of orchestral color and good transparency, we settled down and just listened through the piece for enjoyment.
Next up the Spectral DMA-50 was swapped in place of the UcD400 and the Gershwin Concerto repeated. By the time the third note sounded Leo and I looked at each other and just grinned. It was that immediately obvious that the Spectral still has the goods and we had moved into another level of transparency. As we listened it was easier to pick out the various sections of the orchestra and hear the details of individual players. It was getting late but before we called it a night we returned to the offending crescendo on the Blood, Sweat & Tears disk. It still got harsh when the horn section let loose but this time it was bearable.
So I like my Spectral better than the UcD400. Lest you get the wrong impression I also like it better than the Krell, Levinson, Proceed, Meridian, BAT, and Classe superamps I have direct experience with. The Exodus Audio UcD400 performs in that class for a fraction of the usual entry fee.
My final listening sessions were solo on the last Sunday the UcD400 spent in Tulsa with the WR125S based speakers.
Material used included:
- Igor Stravinsky conducts Le Sacre Du Printemps (The Rite Of Spring) (Stereo SACD)
- Quincy Jones 'Q's Jook Joint' (CD)
The Stravinsky is not audiophile candy, the sound is rather dark. Listening one wonders if the original master tape is lost or damaged or if it was just another mediocre recording of a towering master talent. Regardless it is Stravinsky conducting Stravinsky and the Rite is one of my favorites. Again the synergistic pairing of the UcD400 and WR125S was demonstrated to great effect. Powerful music through a powerful amp into drivers designed for power worked a treat. The masterpiece just swept me away.
I pulled out the Quincy Jones disk because it is both a music lovers and audiophiles treat. A-list talent recorded through cost no object equipment by artists who can hear the difference. Listening to ‘Back On The Block’ or 'Q's Jook Joint' you can just hear so plainly that we are in a great studio using tens of thousands of dollars worth of microphones through a hundred thousand dollar console. And oh how Mr. Jones can pick the material and talent. The first cut on 'Q's Jook Joint' is a great hi-fi tester. The scene opens with a queue of people milling around waiting to get past the doorman and into Q's Jook Joint. Shaquille O'Neal plays the doorman and as the anxious patrons talk to him and each other a good system really makes their voices distinct. The scene must have been recorded on a Foley stage with a great stereo mic because we can hear the gravel of the parking lot under their feet and if your system is really tuned up just so you can hear that they are lined up and the head of the line at the right side is closer to us and trails off into the depth of the stage at the left. The music is leaking out of the building as the wannabe patrons see if they can get by Shaq. The UcD400 revealed all this. We manage to talk our way in and as we get through the door the music surges as a full on big band plays ‘Let The Good Times Roll', and man do they ever roll.
As an audiophile I reached for 'Q's Jook Joint' as one last test of the Exodus Audio UcD400 transparency and imaging capabilities. A test it passed with flying colors. As a music lover I kept listening to the disk just grooving on the tunes. Ray Charles makes several appearances in the sound bites which tie the disk’s tracks together and singing for us. It struck me that now he is gone. Just as with the Stravinsky the UcD400 was greatly aiding the brief reincarnation of a lost artist, No not lost, make that departed as the point is in both cases the gear took me back to be in their presence again. An emotional response was elicited and the artist’s intent more completely experienced.
Needless to say it was with some regret that I broke down the system and packed up the Exodus Audio UcD400.
My conclusion is the Exodus Audio UcD400 is a very good amp and a great value. The only misstep it made was when partnered with a high efficiency prototype speaker known to get out of hand, even driven by a 2A3 SET amp! The unit’s limits were only revealed when compared to a very radical tweak amp which cost twice the Exodus Audio UcD400 2006 price when it was new in 1986! The Exodus Audio UcD400 was equally at ease at sub-watt levels reproducing a tiny brass bell or at it's limits with home theater artillery. Buy one quick before Kevin comes to his senses and doubles the thickness of the front panel and price.
