Arturia Rev LX-24 V-1.0.0.3771-AUDIOWAREZ

quote by Dr. David Griesinger's bioBut by then I had made my own microcomputer, so I had the skills. The first digital reverberation device I made used 12 bits, and had hand-wired memories.

The architecture eventually became the Lexicon 224. This was before there were any digital reverberators were on the market. My first algorithms were promising but not good enough. At a chance meeting Barry Blesser (the designer of the EMT 250 reverberator, which soon hit the market at $30,000, told me about the Schroeder paper. I found it at the MIT library. Harvard did not have it. It was helpful, but I did not like the sound of either the EMT or the Schroeder algorithms. They were all too plate-like.So I made several of my own.

The next prototype was in a pretty blue box, with some commercial Z80 computer cards along with my hand-wired audio CPU, memory, and IO. I loaded the operating system (CPM) from cassettes, and the reverb programs also. The IO was 14 bit implemented with 12 bit A/D and a 2 bit syllabic floating point. The digital system sounded VERY good – better than most, and probably any, commercial digital systems at the time. I used this unit with success on my own recordings and demonstrated it to the president and vice president of Lexicon. They immediately hired me.

We added a remote to adjust parameters, and it became the Lexicon 224. The software was in two assembly languages – Z80 assembler, and an assembly language I devised for the audio CPU. I wrote a primitive higher language compiler for reverberation. You had to know all of them to program the unit. We demonstrated the unit at several trade shows, which generated enormous interest.

The device had several VERY important design features. First – it was a stereo in, stereo out processor. I was enough of a physicist to know that any static impulse response has a sound color. If you mix all your channels to mono and send them through any reverberant system – including a room – the result will have a tone color. In real rooms every instrument has a different reverberation – and many of them move a bit while playing. There is no color when you hear them all together. Using a stereo send and avoiding panning the reverb outputs mitigates the color to some extent. So you need at least two independent inputs and reverb systems and at least two outputs.

The other feature was internal time variance. This also mitigates color, but must be done very carefully. Barry’s EMT also used time variance, but he did it differently. Time variance of one kind or another is an essential feature of Lexicon reverbs.