In 1992 I was on the market for a new mixing desk. But I was a bit dissapointed when I saw what I could afford: an average midrange desk, with a number of average microphone preamps I didn't need, and with an equaly unimpressive EQ section which sounded best when in bypass. For the money available I could also get a patchbay with plastic jacks, TL074 all over the place and perhaps CMOS switches instead of relays or fets. So I decided to built one.
It was not an easy decision. Today I'd rather buy a top brand second hand desk, but in 1992 there was no second hand market as it is now where you can buy a used SSL for 50k.
Alpha is an all input desk, as simple as it gets. All channels are identical and there are no mic preamps built in, and at any time there is only one signal inside a channel. There are 3 stereo and 6 mono aux sends, 4 band EQ/ two full parametric sections, hi/lo filters, 24 busses and 48 input channels. Each channel has an hi resolution DIN standard peak meter with an separate multipoint overload detector, which monitors signal on 4 different locations inside the channel. An 864 point patch bay is integrated into the desk. The operation is extremely simple. We rely on independent producers and engineers who need to be familiar with the desk in a couple of hours.
The desk is logicaly divided into left (monitor) and right (source) side, each 24 channels. Each side can be central status controlled, like switching between line and buss sources, channel and EQ on/off, insert reset etc. Solo system is also separated for each side, to allow full monitor solo without disturbing sources. When mixing, both sides can be linked.
Each 12 channel section has it's own power supply and can be switched on/off also during operation without danger for speakers, due to a softstart power system. All interfacing is balanced, including internal bussing, and relay switching is used for main signal paths.
Master section has 9 stereo returns with stereo width control, and 10 stereo monitor sources can be selected independently each for control room, studio and external (lounge client speakers). Master section is logicaly controlled and can be reset. Each aux feed from channels can be selected globaly pre or post fader, and an additional post mute position is available, so that channels can be soloed, muted or automated without disturbing headphone feeds. The automation system is Optifile Tetra.
|
