Review: Denon AU-S1 step up transformer

 

Moving back to a low output moving coil has been a real eye-opener.  Yes I had experience with the venerable Denon DL-103R mounted on a rather sketchy VPI HW19 Mark III with a Rega RB300.  But, at least with that system from long ago, I never quite cottoned to the sound I was getting.  I wanted more.  Luckily I found it (some time later!) with the Rega Planar 8 with a Rega Ania Pro MC cartridge.  This combination has quickly become my favorite analog reproducer so far.

My MC step-up transformer is the popular Cinemag 1254 which did its job quite admirably.  Nonetheless I had a nagging thought I could do better here.  Would a passive device, especially something made of wound wire actually make a difference?  I had to find out.  So I read and read some more, trying to find an affordable venue to follow.  I thought of buying some Lundahl transformers and DIYing my own case.  Or I could have gotten anything else, including an active device to give me that additional gain needed for the low 350 micro volt output of the Ania Pro.

Several searches on Ebay and I saw a Denon AU-S1 unit for sale.  It looked extremely well built, more so than my Cinemag "transformers on a box" look.  But finding information on the Denon was, to be blunt, extremely difficult.  It was designed for Denon's once top-of-the-line cartridge, the DL-S1 that cost a princely $1000 way back in 1996.  The transformers themselves are mounted horizontally in the case with padding to reduce vibration.  How much this would work in real life is questionable.

After several audio philosophical discussions a friend, I decided to take the risk on purchasing the AU-S1.  It was the idea that something like this would be of the highest quality given the amount of time and research that a company like Denon can do.  There was only way to find out.  Thankfully the Japanese seller was very quick and I received the transformer(s) in only three days.  The AU-S1 weighs _alot_ for such a small thing.  Build quality was extremely good with gold-plated RCA jacks and (oddly enough) separate grounding lugs for each channel.

 I took out the Cinemags and put the Denon in its place.  Turning the volume up I was immediately taken aback by the amount of hum I was getting out of the speakers.  Moving the AU-S1 around and I was able to get some reduction in noise but still I wasn't happy about it.  It wasn't until I touched my fingers to the left RCA outside jack and then to the ground lug that the hum completely disappeared.  It's the nature of the Rega turntable output connection which doesnt have a separate ground wire.   To circumvent this grounding issue I took a length of solid-core bare wire and wrapped it several times around the left RCA outside lug with one end plugged into the ground lug of the AU-S1.  After that I was hum free!

Well, dear readers, that was a lot of introduction for something that was ultimately bought as an experiment.  How does it sound?  Read on.

Initial impressions were good - solid bass, a "cleaner" view of the soundstage, and just better air. Several records later and a listening session with my audiophile friend and I can say the Denon AU-S1 was a worthwhile upgrade.   

Does it surpass the Cinemags?  Yes.

The Denon reproduces the space around instruments better - such as the horns on Lonnie Liston Smith's Visions of a New World.  This gives the impression of more body and weight.  

And speaking of body, the bass is terrific.  It feels like an extra octave is being recovered - not bloated - but detailed with depth and slap.  Something that was really apparent on Brian Bennet's Voyage album as the excellent bass player provides the space age groove.

Soundstaging is deeper and wider than before.  An example of this is the beautiful Dead Can Dance album Into the Labyrinth.  The second song, "The Ubiquitous Mr Lovegrove," has a moment where the drum shifts left and right, now well detailed beyond the edges of my KEF speakers.  A true demo disc moment.

Overall there seems to be less grain than before.  Why?  I have no idea.  The purity of the copper?  The padding reducing microphonics?  The quality of the transformer windings?  Your guess is as good as mine but the clarity is higher than before and that's all that matters.  Finesse would be a fine word to discuss these SUTs, and given their roughly $700USD price they are a good bang for the buck.  Perhaps, when funds permit, I'll try something more expensive.

Denon AU-S1 Step-up Transformer Specifications
- Ratio: 1:13
- Frequency range: 10Hz-80kHz
- Size: W150 x H70 x D175mm
- Weight: 7.1 pounds

Review: Denon DCD-600NE CD player

 (image from the Denon website)

I still remember the first time I heard a CD player - this was at some teenage party back in the mid-1980s and I was rather impressed how loud it played.  Hey this was before I knew what being an audiophile was.  It was a year later when my dad bought a Magnavox player for his system.  I spent a mighty chunk of change - $22 - buying a Misfits compilation that, sadly, ended up sounding very bright, thin, and irritating to the point where a headache soon came on.  Later, in college, when I got into tube gear, I owned a Theta Basic DAC.   However I still thought my Thorens TD-166 turntable with a $20 Grado Black cartridge served the soul of music much better.

Years later there was a time that I was into digital.  By then vinyl was getting harder to get a hold of and the CD re-issues were pumping out some excellent compilations of rarer groups.  I started experimenting with several DIY modifications and designs.  For example, the transformer-coupled RAKK DAC was one of the better iterations of digital I have ever heard.  But in the end it was analog that won my heart.  Over the years my CD collection continued to shrink while my passion for vinyl increased and became the focal point of my system.

Time marched on - CDs are now ridiculously cheap.  From a purely music lovers point-of-view, they are an easy way to build a music collection, especially compared to the now high price of vinyl.  I decided once again to buy a CD player, hoping that technology has improved the Red Book standard.

But what to get?  I searched through Ebay and Audiogon, looking at several vintage models.  Ideally I wanted something with a digital out so I could experiment with DACs in the future.  Accessories 4 Less came to the rescue with a refurbished Denon DCD-600NE player that featured a 32 bit DAC and AL32 processing that - to quote their website - "expands audio data to 32 bits and uses a proprietary algorithm to interpolate the data and perform up-conversion and sampling, achieving a playback sound that is close to the original source."  So, as my friend likes to joke, "Perfect Sound Forever just got MORE perfect."

The Denon DCD-600NE is a stripped down player and - shockingly - has a metal enclosure.  If you want to use the full functions - random play, direct mode, track programming, etc, - this is where the rather large remote comes into play.  Digital out is via Optical - not ideal - but this may point to a future Schiit Bifrost 2 DAC upgrade.

So how does this little beast sound?  Initial impressions weren't the best.  There was a forwardness to the sound that was tiring, along with a sense that, compared to even my lowly Dual CS5000 turntable, that 20% of the musical information was just missing.  What I mean are the spatial cues were gone, rendering the voice and instruments as very two-dimensional.  A good reproduction system should have depth along with breadth, transporting the listener to the mind of the producer, or with some classical recordings, to the venue itself.  Instead the Denon reminded me once again why I prefer vinyl for home listening.

After a few days of break-in I decided it was time for some comparisons against two different turntables along with some general impressions.

The forwardness was reduced but there is no other way to say this - this budget Denon still sounds like digital.  Compared to the same LP, the CD is missing reverb cues; either the room or artificial.  An example of this is Willie Nelson's Stardust.  The body of the acoustic guitar is gone, leaving just the top layer of the guitar notes.  The "black background" sounds uncanny but not in a good way.  It's like a black hole of information - nothing is there! - compared to the warmth and fullness of analog which captures the space of the room and the size of the instruments.  It feels as if the music has gone through some kind of horrible clinical ward, stripping off the flesh of the music and leaving only the bones.

Now that does sound like a harsh review.  To be fair some CDs were better than others, like a few Chet Baker albums in my collection that sounded quite good.  Jazz is usually well-recorded but I still preferred my LP versions - even with my second turntable, a budget Dual CS5000.  At least with analog my brain connects to the music and I can relax.  With digital I am still gritting my teeth and feel uncomfortable with the overall presentation.

Maybe a DAC will bring some improvements.  We shall see!

System:

• Audio Research SP8
• modified Eico ST70 with 6AR6 tubes
• Cardas Neutral Reference interconnects
• KEF R500 speakers
• Dual CS5000 turntable with an Ortofon OM20 cart, aftermarket Shibata Stylus
• Thorens TD309 with Ortofon 2M Bronze