Hello Quad people,
My 1985 invention of the recording device which eventually was named Colossus by my partner (The late Brad Miller) changed the audiophiles distaste for CDs to ultimate praise for the media. My device, which was capable of recording 4 audio channels at the same time, when connected to a Harmonia Mundia digital standards converter, corrected all of the digititus problems that had plagued the CD system.
The following is the J. Gordon Holt article followed by Jon Atkinsons comments and my reply, which opened up a can of worms for the CD player manufacturers. This was a time before commercial Sigma/Delta A to D and D to A converters. The manufacturers loved successive approximation A to D and D to A converters. The big deal at the time was oversampling which was a numbers game between manufacturers and had little to do with real sound improvement (Nyquist was a pretty smart guy). These converters had offset and linearity factory adjustments which when done accurately would yield only 14 to 15 bit CD playback performance.
Any way enjoy the reading of these articles as they bring back fond memories for me.
Sidebar 2: Colossal Reviews
BEETHOVEN: Sonata No.32, Op.111; Sonata No.21, Op.53 ("Waldstein")
Tibor Szasz, piano
Bainbridge BCD-6275 (CD). Leo de Gar Kulka, eng. & prod. DDD. TT: 58:03
MOZART: Piano Concerto No.13, K.415; Overture to Lucio Silla, K.135
Jeremy Menuhin, piano; George Cleve, 1987 Midsummer Mozart Festival Orchestra
Bainbridge BCD-6273 (CD). Leo de Gar Kulka, eng. & prod. DDD. TT: 36:58
PROKOFIEV: Alexander Nevsky, Lieutenant Kijé
Andre Previn, Los Angeles Philharmonic
Telarc CD-80143 (CD). Jack Renner, eng.; Robert Woods, prod. DDD. TT: 63:37
RACHMANINOV: Sonata for Cello and Piano, Op.19
Steven Kates, Montagnana cello; Carolyn Pope Kobler, Bösendorfer piano
Bainbridge BCD-6272 (CD). Leo de Gar Kulka, eng. & prod. DDD. TT: 40:42
THE SOUNDS OF TRAINS, Vols. 1 & 2*
Bainbridge BCD-6270, -6271* (CDs). Brad Miller, eng. & prod. DDD. TTs: 60:45, 50:14*
If you read my article in these pages about recording the Cumbres and Toltec Scenic Railway steam trains (Vol.10 No.1), you may recall the mention of Colossus. Colossus is the name of a new digital recording system which designer Lou Dorren claims to be different from every other digital system in several ways, none of which has ever been disclosed to us. I had a chance to listen to some tapes made on it shortly after writing the C&TSRR article, but since they were made with a completely unfamiliar microphone (Mobile Fidelity Productions of Nevada's own design) and featured mainly the sounds of trains, airplanes, and other sources of potential ear damage, I couldn't really tell anything about the recording system, except that it had the kind of low end I expect from any respectable digital audio. A sonic evaluation had to wait until I heard Colossus on more familiar terms—that is, with music recordings. Now, that time has come.
Colossus is not yet in commercial production, but By the Numbers—the firm that's promoting it—has had several prototypes made up, and has been loaning them out to recording companies that might appreciate what's special about it. Telarc, Sonic Arts, and MFPN are three such. (Actually, MFPN is a partner in By the Numbers.) In recent weeks, we received for review four music recordings made with the new systems, and all but one feature bowed string instruments, which happen to be one of the most stringent tests for a digital recording medium.
First, to the amusical recordings. As you might guess from their titles, these are sounds of trains—steam trains. Although MFPN's Brad Miller likes to pretend that his business is recording sound effects for film and TV post-production, his recordings would seem to belie that. Brad simply likes the sound and mystique of steam trains, and he records them for maximum emotional effect. That some of the recordings may be usable for foley (footnote 1) work is coincidental; many of the train recordings are marred for that purpose by excessive use of the whistle, which adds a romantic aura to the sounds and shows off the infinitely varied reverberant nature of the surrounding terrains, but will rarely suit the needs of filmmakers (who usually prefer separate recordings of train and whistle, mixing them to taste).
So forget the filmmaker, and think of these as what they really are—evocations of the romance of old-fashioned railroading—and you have a couple of very atmospheric and effective records to be listened to for sheer enjoyment. The sound, by the way, is extraordinary, with incredible dynamic range—much wider than that of any music recording—and some of the deepest low end ever committed to any recording. (Listen in particular to Track 8 on Disc 1. If your system has good LF extension, the visceral pressure from one of the sounds on that track may drive you screaming out of the room. It makes some listeners dizzy.) A cautionary note, though: Like many digital recordings of amusical sounds, The Sounds of Trains discs are potential system busters, partly because of their tremendous dynamic range, partly because most cuts start out with the almost-dead silence of the outdoors just before the locomotive becomes audible in the distance. Don't set your volume control any higher than you normally do when listening to music, or the first whistle blast could take out your midrange drivers, power amps, or both.
The imaging is poor until the train arrives at the speaker positions, but then is pin-point precise. I suspect that this is due to the fact that Brad Miller has mixed the two rear channels—the original recording was on four tracks—into the front.
Now to the musical material. The Tibor Szasz piano disc is an excellent recording of slightly idiomatic but immensely satisfying performances of two Beethoven sonatas, recorded sequentially and without edits—the closest it is possible to come to a live performance without actually having an audience in place. Having myself recorded, many years ago, the Op.111 with another virtuoso technician, I'm aware of the difficulties of many sections of this work; I stand in awe of Mr. Szasz's prodigious ability to sail through them without apparent effort. But apart from the fact that the sound of this recording is a little more transparent and much leaner in balance than most piano CDs, it is hardly a dramatic illustration of what Colossus is all about. Likewise the gorgeous reading of the Rachmaninov sonata, but that one does gives us more of a clue than the Beethoven, because it's the most natural-sounding CD recording of a cello I've heard; by comparison, others seem to present too much of the instrument's normal guttiness.
With the two orchestral recordings, we have something completely different. All symphonic CDs to date have suffered from a greater or lesser degree of a peculiar, and peculiarly digital, grundginess (digititis) elicited mainly by massed strings—cellos and violins—and also to a lesser extent by male chorus. It is conspicuously audible on some discs, only slightly audible on others, and while I have never been particularly horrified by small amounts of it, some listeners find even the slightest trace intolerable. They are in for two shocks when they listen to these discs.
Shock No.1 is the Telarc. So proficient have the Telarc engineers become that, regardless of what orchestra they record where, their symphonic CDs have a distinctive and immediately recognizable sound. They tend to be rather fat and bass-heavy, and distant, with lots of reverb and amazingly amorphous imaging. Some of their sound has always included an element of typical digititis, varying from slight to obnoxious. (Yes, it's on all other symphonic recordings too, but most have so many other things wrong with them that a small overlay of grundge hardly merits comment.)
Telarc's first Colossus recording, believe it or not, has no digititis at all! It is totally clean, amazingly liquid and transparent, and seemingly finer-detailed than previous Telarcs. All instruments sound more natural than before, and harmonics seem to "hang together" more convincingly. Cymbals sound like brass rather than like escaping steam, cellos have bite without exaggeration, while massed violins are amazingly clean. When combined, all these things have several unexpected effects on my reaction to other aspects of the "Telarc sound."
First, I found the performances of the music much more involving than usual. This Nevsky is, in fact, the first Previn performance for Telarc that literally stood my hair on end—my acid test for any recorded performance of this kind of music. And Kijé has animation and humor coming out its seams! I have been so consistently disappointed with Previn's Telarc work that I find it hard to believe that he was suddenly seized with inspiration for this latest effort. I must attribute a lot of the change to the recording, which—even though the listening distance still sounds like 80' or so—seems to bring everything into sharper focus than before. Second, I became aware for the first time that the Schoeps mikes Telarc uses have a slightly aggressive steeliness to them. Re-listening to some other recent, pre-Colossus Telarcs verified this, although this steeliness is less evident on them than on this recording because it tends to be obscured by the veiling so conspicuously absent here.
And listening, for comparison, to Leo Kulka's Mozart recording (below) confirmed the presence of this steeliness on the Telarc. The effect is exciting, but not very musical, and becomes rather fatiguing after a while. Nonetheless, this has to be counted as the best-sounding CD Telarc has ever done. The dynamic range is awesome, yet effortlessly clean. No LP could possibly do this. Telarc, you're onto something; buy, rent, or steal a Colossus, and stick with it. But, dammit now, get yourself some sweeter-sounding mikes and move in closer. In your own way, you're doing exactly what CBS and RCA did for 30 years: sacrificing a lot of great performances to a cowardly adherence to what you believe to be a "commercial" sound.
The one symphonic recording on the Bainbridge label was produced and engineered by Leo de Gar Kulka, whose Sonic Arts records were the first digitally mastered LPs that didn't sound like digitally mastered LPs. Leo must be the most underrated recording engineer in the business today, as this Mozart recording is, quite simply, the best-sounding orchestral CD I have ever heard. Tony Faulkner has never come close!
The rarely played "lightweight" Concerto No.13 is a charmer, as is the disc filler—a little gem of an overture from an opera nobody's ever heard of—and both performances are delightful (though the "filler" hardly fills the disc—36:58 is pretty short shrift). The recording is an example of how all acoustical music should be recorded. First of all, it was done at a performance, with an unusually attentive and quiet audience, and has the spontaneity and excitement that often result from that. It is recorded from a natural-sounding audience perspective, and is refreshingly free from the billowing ambience that seems de rigeur these days for any "audiophile" recording. And instead of cutting to dead silence between movements, the sound has been allowed to carry over with faint audience rustlings and hall ambience, adding a greater degree of realism to the recording than one might guess. Finally, there's applause at the end, which is something I heartily applaud (footnote 2). The applause sound, by the way, is very realistic.
Imaging is about as tight and solid as one hears at a live concert, and there's a nice feeling of space surrounding the instruments. And although the piano sounds a little more distant than the instruments at left and right, the balance between piano and orchestra is perfect throughout; neither ever overpowers the other, and you can easily follow all the solo lines during the most tumultuous tutti. There are a few of the inevitable live-audience coughs (though they're all quite muted), and the performances aren't as technically perfect as the plastic-perfection product we are accustomed to buying, but there isn't a single flub here that's bad enough to impair the enjoyment of these buoyant, spirited performances.
The difference between this CD and Telarc's Nevsky is in the instrumental timbres, which are far more natural on the Bainbridge disc. They suffer from the "affliction" which bothers audiophiles when they listen to real, live instruments: There aren't enough highs. In fact, the highs are just about perfect on this Mozart disc, unless you're steadfastly seeking hi-fi instead of musical realism. (The main stereo mikes, by the way, were Neumann TLM-170s, which were top-rated in a listening evaluation of professional mikes reported in the April, 1984 Recording Engineer/Producer.) The only real flaws on this disc are a couple of fairly prominent noises during the program: a click at 4:04 into the 3rd Concerto movement, and a plop at 1:26 into the overture. (These were on two different pressings, so they're obviously in the recording.)
So, what do I conclude about Colossus? Is there any indication from these recordings that Lou Dorren's system is basically better than other digital recording systems? I would say, emphatically yes. There is an ingratiating ease, a liquid transparency, and an incredible delicacy about the sound of all of these recordings that I have never before heard from any other recording system, digital or otherwise. The massed violins on the symphonic recordings don't even sound like analog tape, which has its own unique kinds of distortion (footnote 3); they sound very much like real massed violins. The difference is hard to explain and impossible to illustrate unless you actually buy some of these CDs, because massed-violin sound as natural as this has never been available on a recording before, even from D-to-D. These recordings sound more like a live direct-microphone feed than any I have ever heard. In other words, I believe Colossus is a major technological breakthrough, destined to change the way most of us feel about digital in general and CD in particular. (See this issue's "As We See It.")
As for these recordings, all are excellent, but the Bainbridge Mozart/Cleve/Menuhin recording is more than that: It's a landmark in musical fidelity. This is one recording that every high-end audiophile with a CD player must own.—J. Gordon Holt
Footnote 1: "Foley" is film-production terminology for sound effects added to a soundtrack after original filming.
Footnote 2: I hope, though, that the major record companies never adopt it as SOP; you know as well as I do that they'll abuse it, tacking "Bravos!" and "Encores!" onto dull performances the way TV sitcoms hype dumb jokes with hysterical canned laughter.
Footnote 3: The worst is scrape flutter, which in its own way does as much damage to massed violins as digital aliasing.
Article Continues: John Atkinson Comments »
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Colossal Reviews
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Manufacturer's Comment
The Colossus of Audio:
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John Atkinson Comments, from May 1988 (Vol.11 No.5)
In Vol.11 No.4, JGH enthusiastically reviewed a series of recordings made with the new Colossus recording system (p.153). The reason for his enthusiasm was that these recordings totally lacked any sign of the dreaded "digititis" so prevalent in modern classical recordings, leading him to proclaim that the Colossus "could justifiably be included in any contemporary listing of the seven wonders of the audio world."
My appetite whetted, I listened to one of these recordings, Stephen Kates playing Rachmaninov's Cello Sonata in G Minor, accompanied by Carolyn Pope Kobler on a Bösendorfer piano (Bainbridge BCD6272), one of my favorite pieces of chamber music. JGH had declared that this was the most natural-sounding CD recording of a cello that he'd heard. I have to agree that the tonality of both instruments is very natural, although the acoustic surrounding the instruments is very close and dry. In my opinion, a less closed-in, more reverberant recording venue, one sounding less like a small, modern, heavily draped hall, would have been more sympathetic to the music. That, however, is a matter of taste, and not germane to this followup report.
Something I found much more disturbing was the fact that the music was accompanied by often quite severe distortion at climaxes, sounding just as if an amplifier had been clipped. Instances from the first movement are at 0m 44s, 0m 55s (left channel only), 7m 20s and 7m 24s (right channel only), 7m 50s, 8m 34s, 8m 41s and 12m 12s. To ensure that this was not due to the playback system being driven into overload, the disc was auditioned on three systems, at a variety of levels, the final listening being done via a pair of Stax Lambda Pro headphones. Checking the recorded level against a 0dBFS reference indicated that the distortion appeared to be due, not to the recorded waveform "banging its head" against the maximum possible digital encoding level on the CD, but against a level 1.27dB below the maximum (fig.1). A maximum-level sinewave was reproduced by the same CD players without clipping.
Fig.1 Rachmaninoff Cello Sonata, example of digital clipping from the first movement. Note the waveform's flat tops and bottoms at a voltage equivalent to –1.27dBFS.
The 1981 copyright date on the CD jacket and the ADD SPARS code imply that the Colossus digital processor had just been used as a transfer medium for the mastering of an original analog recording (footnote 1). In view, therefore, of what I can only term an obvious error on the part either of the engineer who made the digital copy of the original analog tapes or of the engineer who prepared the CD master, Stereophile's recommendation for this recording must be withdrawn, as natural as the recorded sound may be.—John Atkinson
Footnote 1: Bainbridge says that the SPARS code is, in fact, incorrect; the original recording was digital. Engineer Leo Kulka confirms that it was made with a highly modified Sony PCM1 PCM processor. Regarding the "clipping," the disc is being remastered, Mobile Fidelity Productions of Nevada's Manufacturer's Comment elsewhere in this issue giving the facts of the matter.—John Atkinson
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Manufacturer's Comment: Colossus Recordings
Editor: Upon receiving the critique by John Atkinson, a laboratory examination of the specific compact disc in question was made by Lou Dorren. Lou's comments are as follows:
1) The original PCM-1 digital master is clean, with no distortion as described by JA.
2) When the PCM-1 to Colossus transfer was made, the digital medium was truly exercised with regard to program level.
3) This push of the medium may cause the kinds of distortions referred to by JA. The levels on this disc were recorded within 8 bits [LSBs] (hexadecimal notation FFF4) of the maximum level for a 16-bit system (hexadecimal notation FFFF). Any offset error in the D-to-A converter or the sample-and-hold system of the CD players that exceeds the 8-bit margin (hexadecimal notation 0008) will cause the distortion described, due to nonsymmetrical playback of the reconstructed audio signal.
4) The assumption made during mastering was that CD player manufacturers were adhering to the EIAJ standard. Apparently some are not following the standard to the full 16-bit dynamic range of the system.
5) This disc in its current configuration will certainly verify the offset accuracy of one's own CD player. We have one player in the lab now that will not play this CD at all.
6) As a consequence, a new master transfer will have been prepared on April 4, 1988, in which the level was reduced by 3dB (hexadecimal notation F800). This translates to a 2048-bit margin (hexadecimal notation 0800) instead of an 8-bit margin. Any owner of this CD who would like to trade it for a remastered version may do so at no charge. However, one should consider the retention of the disc as a test medium for one's own edification, being certain to mark this particular disc for identification.—Brad Miller, Lou Dorren, Mobile Fidelity Productions of Nevada
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John Atkinson Comments
Manufacturer's Comment
That is all for now,
Lou Dorren
