Bozak Cma 10 2dl Manual

The CMA-10-2 and 10-2DL mixer was designed at Bozak for sale to discotheques. Bozak didn't cease production of DJ mixers until some years after the death of Rudy Bozak. Buzzy Beck (a former engineer) and Paul Hammarlund carried on the work for a time. Bozak Model CMA-10-2DL Owner's Manual Professionally made reproduction of BOZAK Model CMA-10-2DL Stereo Mixer Preamplifier Installation & Operation.

Was pretty excited to come across this mixer at an auction recently, especially given the good condition this old box was in. Since there doesn’t seem to be much information on the internet regarding these units (although there is a fair bit on the more famous DJ mixer, the Bozak CMA 10-2DL) I figured I would post some info and photos of the unit I have. Bozak CMA 10-2 stereo mixer. 10 channels of transformer isolated mic pres. Each of the 10 channels can either be mono or stereo (mono is pin 3 hot, stereo is left channel pin 3 and right channel pin 2). Each channel has only an XLR input, gain control, mono/stereo switch and a pan switch (for hard left, hard right or center). From here the signal goes straight to 2 x unbalanced stereo tape outs (pre EQ and pre master gain) on ¼” connections (looking at photos on the internet, these also were sometimes RCA connections).

There are also 2 x XLR (unbalanced) master outputs which are post the high/low shelving EQ and post L and R master gain control. Reading up on some history of Bozak mixers, the first models were the CMA 6-1 and CMA 10-1 which were mono 6 and 10 channel ‘orchestral’ mixers developed in the 50’s.

The CMA10-2 came after these but before the famous DJ mixer, the CMA 10-2DL which first came about in the early 70’s. Based on this, I would have a guess that this mixer was made sometime in the late 60’s. Unfortunately, the mixer didn’t come with any documentation in the way of manuals or brochures. Interesting to know if anyone else has come across these mixers?

Thanks Sweetbeats. Tracked a song with my band last night on it. Python pdf for beginners. The rotary knobs on each channel appear to work like a volume fader rather than controlling the preamp gain.

From what I can tell the preamp gain is fixed, which is fine for most microphones but using a high sensitivity condenser like a Rode NT1 (as I found out when recording medium-loud vocals) would distort on moderately loud sources and turning the rotary knob to minimal doesn't change the level of distortion. There is a -10dB pad switch for each channel just above the mic input connector which helps control this but I have to use an external pad for some loud sources to control the level of distortion - though I wouldn't say it's an unpleasant distortion but important to be able to tame it when needed. Overall the pre's sound real good, definitely has a sort of hi-fi 60's sound (reminded me of something like Bob Dylan's Blonde on Blonde).

Glyn John's mic setup on the drum kit (stereo SDC overheads and an EV RE320 on the kick) and instantly a great, natural sound. DI bass guitar had a very smooth and round bottom end. The plan is to use the Bozak for tracking AND mixing, if all goes well, would probably sell the mixer I was using previously in this setup, the Yamaha RM804. Reached out to some folks about your Bozak. A couple comments from some in-the-know good people: “Great Sound Reinforcement mixer from the early 70s. WARNING: PIN THREE HOT, pin two may not be connected on unbalanced line inputs.

I don't think it can hold a candle to the audio performance of a modern Mackie or Yamaha mixer, but it's a tank.” “These date to around 1967. The one that I was familiar with was kind of bare bones in terms of features, but really well built. It was all-discrete, and had a separate monitor output (not foldback monitor, but for the user). No aux sends, no eq on channels. Kind of a solid-state 1567a.” Check your PMs.

Yes, from what I've read the CMA/Bozak partnership started around mid-60's and they first manufactured mono mixers (CMA 6-1 and 10-1) before developing the stereo version I have. I like the comparison to the Altec 1567a, it's from the same era in terms of simple and minimal circuitry design. There is just a mic pre with 10dB pad, one pan selector and a summing amp into the stereo tape outs. There's a separate master output which goes through a high and low shelving EQ and a master gain control as well but that's it.

Only just tracked the first song of a ten or eleven song album last week and will only start mixing after tracking is completed for all songs, but I'll endeavor to put up a sample to demonstrate the sound of the Bozak when I have something ready.