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Old 04-13-2013, 01:14 PM
vinyl_junkie vinyl_junkie is offline
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Join Date: May 2005
Location: South East Kent, UK
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Here is some info on C/M Labs and their involvement with Bozak.

I copy and paste this bit.. Wayne talks about Bozak and C/M Labs

"I read with interest the review on Rudy Bozak’s Concert Grands in the October 2005 issue. I had no idea that so many audiophiles where still tracking some of the vintage equipment – I had left the business sometime in the later part of the ‘60s. The only reason I came across this forum was because it was time for me to find a home for my own two Concert Grands which were given to me by Rudy in the mid 60’s (I am not aware of the magnet change later, but these must be alincos). And naturally, my pair would have been the first to have been bi-amp’d – but I still have the original crossovers, if someone would want to put it back the way it came. After that, Rudy finally offered bi-amp versions for sale.

I was co-founder and president of C/M Laboratories, Inc., (a contraction of the names Chou and Morris) and I had invented, and eventually patented, an output power transistor circuit that was impervious (for the most part – nothing is perfect) to short circuits and other transients (mostly from the bass of music – and if you like Bozaks, you were sure to pass a lot of heavy bass just to feel it in your body). Technically, power transistors were susceptible to a phenomenon known as “secondary breakdown”. Later RCA pirated the circuit and marketed it in a hybrid chip. And HH Scott, published a paper about how his amplifiers would not blow up (describing my invention without giving me credit or my permission to do so, either). Since I was very enthusiastic about sound reproduction, this circuit found its way into our first power amplifier, the 35D, which produced conservatively 50 watts rms/channel, with very low distortion, for its day. In developing the amplifier, I sought Rudy’s help – borrowing loudspeakers from him, as well as exchanging amplifiers for speakers when we went to shows and exhibits. Rudy and I became good friends. Through the four or five years that I was president, I had designed many amplifiers, pre-amplifiers, as well as combined units both for the consumer market as well as for the professional sound reinforcement and recording studio monitor market. I should add, that while Rudy designed the front panel of the CMA-10-2DL, and specified all the features he wanted in it, it was I who designed all the electronics for it, and it was C/M Labs who built it for him, hence the designation CMA. But he did supply the panels and the punched out chassis, as we specified it.

Though Rudy’s speakers were known mostly by the audiophiles in the consumer market, by the time I got to know him, most of his speaker designs had not changed – only, more or less, cosmetically. Most of the joint effort that we spent our time on was in promoting his commercial line of column speakers as well as helping him get started in the amplification end of things. We did joint projects – his speakers, along with our rack mounted amplifiers and pre-amp/mixers, at Lewison Stadium, West Point, SUNY, the New York Philharmonic trailer in Sheep Meadow at Central Park, various benefits with Benny Goodman, and so forth. It was the experience of a lifetime I will never forget. Although Rudy Bozak could be tough in business, he was a kind, gentle, and generous man. I will forever miss him.

I am still thinking of finding a home for my Concert Grands. So if anyone wants a pair, or knows of someone who wants them, please let me know. The first home I had for them sat them in a room 30 x 40 with a 12 foot high plaster ceiling. It is true – that they need the space for one to be able to appreciate their voice. They are currently being driven by my 35D for the mid and upper end, and a 911 (100 watts/channel) for the woofers, using a C/M Labs switch adjustable electronic crossover (of which very few were made – bi amping was not too popular, or well known, at the time). Still, after 40 years, I haven’t found a system I like better. Stood the test of time. But of course, my hearing isn’t what it used to be. Still, I get that great concert hall sound from the Concert Grands, never favoring one instrument over another, or making anything sound exaggerated or unnatural. The bass is tight, as it was too boomy and sloppy being driven by the usual tube amp. But it is not a matter of whether driven by tubes or transistors, as most non-technical people would try to romanticize the reasons, but rather by design of what is practical when using tubes or transistors. It just is easier to design an amplifier having output impedances where they are naturally there to begin with. Damping factor is the primary reason why transistors have that edge on controlling the loudspeaker, circuit-wise. Years ago I presented a paper on the importance of damping factor, and how it affects sound quality. Rudy and I proved that to ourselves through the many listening tests we made together. That was an exciting time for us. Eventually, he used our amplifiers exclusively for his own personal use and demonstrations, setting his McIntosh? amplifiers in storage. Today, everyone realizes that using heavy speaker cable will improve audible definition over using thin hookup wire. You cannot fake physics.

As a final note, C/M Laboratories, Inc. went the way of most everything – it was sold off to other investors who carried the line for a few years after the acquisition. We enjoyed a reputation up with Marantz and McIntosh?, but the Japanese imports were hot after US business. They had better finished panels, better control feel, all around better styling. The only thing that they didn’t have at the time, was the ability to reproduce audio at the highest level. But they were close, and catching up. At the same time, I was concentrating on developing a new FM tuner – I was warned that it would probably break us. And it did. But what a tuner. We had 25 orders from a show at $1095 (retail) a pop – FM tuner only, no preamp, no power amp. But it was the first consumer programmable digital readout (Nixie tubes) tuner, that did not require tuning (a crystal controlled synthesizer – unheard of in a consumer product, in those days), all solid state circuitry, linear phase bandpass filters, and a new all solid state linear detector (no discriminator to add harmonic distortion) – all specs (capture ratio, stereo separation, distortion, selectivity, 3rd order intercept, etc.) to exceed anything else on the market then including the famed Marantz 10b, the target to beat. The prototype/breadboard had been tested by a couple of reviewers, so we knew we were on the right track. Unfortunately, we couldn’t fit it all in a reasonably sized box (of all things), and production delays of all sorts kept delivery from coming to fruition. It was the closing bell to C/M Labs as we knew it. Thanks for listening."
--The future scares me, any chance of a lift back to the past any one?--
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