From gstopp@fibermux.com Sat Apr 6 14:08:21 1996 6 Apr 96 17:08:19 +0500 5 Apr 96 17:28:43 +0500 From: gstopp@fibermux.com Date: Fri, 05 Apr 96 13:51:41 PDT Encoding: 43 Text Subject: More on the Moog 15 The "first-wave" counterpart to the Synthesizer 15 was the Model 10. This unit was very similar to the 15, but it is based on the older 901-series VCO's. It has one less VCA, and has the 907 Fixed Filter Bank as opposed to the slightly slimmer 907A as used on the 15. Thus one of the 911's is downstairs with the VCOs and VCA, and since the 901 is one space bigger than the 921 the Filters/Noise module is not there either (but that module wasn't around at the time the 10 was built anyway). The 901 VCO's don't have sync or linear FM. Also their frequency sweep range is limited and needs to be dialed in via the panel range switch. The 921 can be set to any range and then swept into different ranges by giving it large CV's. The 901A is the Oscillator Driver, the 901B is the VCO, and the 901 is both in one panel with a lot more knobs for individual levels on the waveform outputs. This Driver/Slave/Master concept was carried over into the 921 series. I'm pretty sure that in the 901 series the exponential converter was located in the 901A, and drives a bunch of slave 901B's, whereas the 921A is simply a CV summer that drives a bunch of 921B's (each with their own exponential converter) at -0.5 volts/octave. Been a while since I've looked at the schematics. But if you're on the lookout for a Synthesizer 15 and you run across a Model 10, it's almost the same thing except it comes with a 951 5-octave keyboard. Of course if you "run across" ANY Moog Modular you're pretty lucky - I was fortunate enough to get myself a Model 10 a few years ago, along with the Sequencer Compliment A, which is a 960 Sequencer, 961 Interface, and 962 Sequential Switch in another seperate "p"-style enclosure. There was an 8-space blank panel where another sequencer would go, but I went and converted it into a bunch of DIY modules, since panel space is a terrible thing to leave blank. I put in a row of attenuators, two full-blown Electronotes Tri/Square VCO's, two Chroma-design saw/pulse VCO's, a Multimode filter, two AR envelope generators, and two linear 3080-based VCA's. It's a pretty nasty machine. Too bad all my analog stuff is in storage until we find a new house. I'm having some serious withdrawls. I guess it helps for me to talk about it and at least my workbench is covered with projects.... - Gene gstopp@fibermux.com