In 2002 I was on the market for a good quality analog monitor controller to use with Steinberg Nuendo which I would use for my audio projects.
At the time there was Coleman Audio, but passive design brings it's own set of problems with cable capacitance, limited functions (no mono summing) etc.
Then there werere surround controllers, but they all used DCA's, VCA's, digital volume control IC's (Crystal CS3310 being popular) and other similar devices I tried to avoid.
That's led to the design of mc02.
Addendum 2008
I made 7 controllers and 6 of them are in use in mixing and post studios.
In the meantime the mc06, surround analog monitor controller is under testing.
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How good can be a design with just standard components, but with optimal PCB design?
Only standard audio IC's are used,like 5534/32 and Motorola 33078, together with SMD resistors and SMD small capacitors. All SMD devices are mounted on the bottom layer, they are almost soldered to IC's pins, thus avoiding long feedback paths which can and do affect audio quality.
Additionaly, ground paths returns on PCB's are kept separate for power and audio, for inputs and outputs, and a high quality external discrete power supply with electrostatically shielded power transformer is used (no 7815 or LM317 here).The importance of a clean and stable power feed for audio cannot be overstressed. |
All switching is performed by relays and monitor pot is Alps RK40.
Noothing beats the RK40 with matching tollerance between channels within 1 dB at -60 dB.
Unfortunately, they are not made anymore. I found them on German Ebay.
Alll outputs are single ended. Without transformer there is no such thing as a perfect balanced output driver.
I decided to use "impedance balanced" outputs, which are in fact single ended, but with noise canceling performance of a balanced circuit. Having 6dB less level on the output is not a problem because most amps need just a few volts for maximum output. |
