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Positive Feedback ISSUE
january/february 2008
Kennedy on Audio -
Format Wars and Other Musings
by Kevin Kennedy
Odd how the most well considered if somewhat blindly dogmatic decisions can be undone in quick succession. I'm going to share how I have recently become re-acquainted with the sound of vinyl, and discovered that digital isn't just about CDs, PCM, and MP3, that there is this other format which a few far sighted audiophiles (if not the industry in general) has been extolling for exceptional sound quality, and for a rather long time—Super Audio Compact Disk. (SACD)
One of the last things I wrote about was how to build your own PC based media server, and for most of the last two years I have lived with the decision to place most my effort in improving server performance and ripping music to flac format for use on the server. The end result has been entirely satisfactory to say the least, and I have derived endless hours of enjoyment from this approach, not to mention that it is incredibly convenient, fortunately or unfortunately I now realize that I had my blinders on, you know that well known saw—you can lead a horse to water, but….
Vinyl
I had an idea for a new phonostage that I wanted to try. Basically the design used very high transconductance triodes, passive equalization and a very simple circuit path. It performed beyond my expectations which then necessitated a lot of work to freshen up my ancient Thorens TD-125. I ultimately ended up rebuilding the motor control electronics, and fitting the excellent phono jack retrofit from www.analogtubeaudio.de to my SME 3009 Series II arm. I replaced the original SME phono cable with an inexpensive cable I purchased on eBay, this was nicely finished and not too expensive—good for the frugal audiophile like me. See http://stores.ebay.com/Ultimate-Cables for reasonably priced phono, power and interconnect cables. I have only tried the C4 cable which is well shielded, made of silver/copper alloy and sound fine, better than the old SME cables it replaced by some margin—good considering that with shipping it was under $70. Next I decided to upgrade the cartridge, and I just happened to notice a brand new Grado Reference Platinum going on Audiogon for a song—after a quick email and a phone call I got it and after about 25hrs of break in I am again an avowed vinyl fan. It isn't that I ever thought that vinyl wasn't a contender, it was just that CDs and the server were and are so much more convenient, the difference in sound quality on a great LP is hard to contest though..
SACD
We have a little DIY audio circle in this neck of the woods as NNETG (Northern New England Tube Group) and not coincidentally I was talking about the renaissance in analog playback I have been experiencing at the recent get together I hosted. Hosting these get togethers is one of the pleasures of my life. There was significant discussion of the merits of the various digital formats compared to vinyl and to a lesser degree tape. In a moment of rashness I commented that SACD was a format that I had initially embraced enthusiastically—only to be disappointed by the poor performance of my heavily modified Sony SCD-XB770 player. (It was basically unlistenable stock.) One of my fellow members felt that I owed it one last shot, and shortly thereafter I had the opportunity to acquire a lightly used Sony SCD-777ES. I got this ridiculously heavy machine home, struggled down the stairs to my basement lab/listening room and hooked it up, where immediate problems with the mechanism initially resulted in unpredictable player behavior. (Will it load, will it play, will it skip, will it quit... LOL) The sound that finally greeted me in those first moments was (to me) the first convincing proof that I was wrong about SACD… and it left me wondering at the various multi-format players, not to mention my previous player's poor sonic performance—just how many people have even heard a HINT of what this format is capable of doing? The few cheap players I've heard don't do a good job with CDs and seem to be even worse with SACDs. Should anyone out there hear an inexpensive player that even competes distantly with the SCD-1/777ES or better still the Meitner based hardware that Dave R. and others prefer please share the good news.
The available SACD library appears to be far more extensive than the DVD-A libraries available at most vendors, so it does seem like the format is winning against DVD-A at least. Having said that, I am disappointed that there is not more popular music available in this format. There is a very good selection of Classical, Jazz, and even certain popular groups like Genesis and Depeche Mode, and a few new releases by less than obscure country and rock artists, but the pickings are slim. How about Rihanna, Madonna, or Eminem to name just a very few? (No, I'm not kidding.) Perhaps the studio masters aren't good for release in this format, but then again who knows? Sales would be small, but if released as hybrids could be sold alongside or in place of conventional CDs—who knows there might even be one or two young people curious enough to go out and buy a compatible (if lousy sounding) player.
The SCD-1 and SCD-777ES are somewhat notorious for roaching their sled motors, but based on very recent experience with mine I have to suspect that there is more to the issue than the motor which is usually blamed for this.. In the short time I have had mine the intermediate gear in the sled motor gear train has seized twice on its shaft. Exasperated I finally drilled out the center (this is not for the faint of heart, use the smallest metric drill that just doesn't quite fit) and reassembled the mechanism—this seems to be the fix, loading is FAR faster, TOC reads successful, and track to track skip takes no more than a few seconds from one end of the disk to the other, which is as it should be. Loading is silent, no more wailing sled motor.
There are relatively few SACD players that focus heavily on optimizing SACD playback, later universal players tend to have more compromise in their design. My second generation XB-770 does not sound good compared to a standard CD player when playing CDs and is on the low end of acceptable performance when playing SACD—there is no hint at all of what SACD is capable of with this player. Mediocre sound forever would be too kind I think.
Cheap and Cheerful Chinese DACs
A year ago I purchased an inexpensive DAC from an outfit in Hong Kong, a DAC targeted primarily at the Chinese market, which oddly had the option for 120V/60Hz operation. The DAC made by Zhaolu was a model 2.5A which is now discontinued, but may still be available from diykits. See their site for latest offerings http://www.diykits.com.hk/. Including shipping, this DAC cost under $200 and was here in just three days. I didn't expect all that much despite the buzz on diyaudio.com, however the DAC uses good parts and is competently if not exceptionally well laid out. The chip complement in this version is the Crystal 8416 SPDIF receiver and the AD1852. My sole upgrades consisted of disconnecting the rather mediocre headphone amplifier, and replacing the op-amps with LM4562's. All I can say is this DAC is very hard to beat at twice or even three times the price. Very musical and supports everything out to 24 bits at 192k. In fact I like it so much I sold my PS Audio Ultralink II and used the funds to pay for other toys.
My system for a moment in time
Currently I am listening to a set of homebrew Onkens I designed last year using the TS parameters derived by Jean Hiraga, the woofers are the excellent Iconic 515-8G in a set of cabinets graciously constructed for me by my father in law. I'm a lucky dude. The mids are handled by a JBL 4333 mid range horn and the highs by a JBL 2402 annular ring horn tweeter. Cross-overs are second order homebrews using parts from Madisound—their stock coils except for the woofers which have Solen perfect lay inductors, and the excellent sounding and reasonably priced Clarity SA film caps from the UK.
Power amplification is an off-shoot of my commercial 300B stereo amplifier design, and the line stage is the 26 DHT featured in an earlier issue of PFO.
I rehabbed a Mitsubishi DA-F10 stereo tuner per the recommendations of a bunch of the guys at TIC (Tuner Information Center) online.
Next Time
I'm thinking about a couple of really simple tube projects that sound good, and are simple and inexpensive to build. I'll probably have more to add regarding the SACD saga. Hopefully a visit to the Sony service center in Laredo is not in the offing.