Synths, anything special with multiples of 8?

Subconsciously (or consciously) that has no effect on the engineers - there are 12 semitones in an octave and that's the figure we design to - we don't design a synth with 8-notes in an octave.

 

2, 4, 8, 16, 32, 64, 128 etc. is binary, which fits will with digtial circuitry, and it also a binary progression, (double, then double, then double again ad infinitum). Even in analogue circuitry things happen in powers of two - if you make a VCO you can make a dual VCO, if you add another dual VCO into a system you get 4 VCOs, etc. If you have 4 VCOs then you can distrubute those over a binary division of voices, patches of keyboard bank. Those divisions will also be a binary division.

 

If you can multiply up the complexity of a circuit by simply doubling the number of fuctional blocks then they can be divided just as easily. So if you have a bank of many circuits it is more flexible to make them divisible by powers of two therefore more natural to make them in powers of two.

 

128 is far more natural than 150 - if you think about all the factors of 150 (2, 3, 5, 6, 10, 15, 25, 30, 50, 75) they are not all factors of each other whereas factors of 128 (2, 4, 8, 16, 32, 64) all are factors of each other.

 

 

 

 

http://en.wikipedia.org/wiki/Yamaha_GX-1 

"Binary" numbers come from the fact that, most synthesizers are actually specialized computers, having CPU and memory. and number of patches is limited by memory available. Memory units have size measured in power of 2 (256, 512, 1024, etc) . So , if there is a chip capable of 256, why use only 170? 

Apart from the ease of programming, a lot of modern synths use multiples of 128 so they can fit a General MIDI bank in. So a lot of synths have 256, 384, 512, etc. patches.

Patch number is stored in memory cell, if the cell is 8 bit, max possible number of patches is 256

or 128, if 7-bit  used

I guess this is why old General Midi standard allowed only 128 patches . It was  invented in the time, where most chips used in synthesizers was 8 bit 

even in the 8-bit era, it was possible to overcome this limitation. for example, have 2 separate cells for storing bank number and patch number , having 256*256 possible combinations 

Yeah you are right. But I think the GX-1 was really expensive and also not many were made, so not many artists used it on their recordings? Not sure about the Polymoog but I don't recall it being listed on many albums. I've seen the Prophet 5 and the Oberheims listed on a lot of albums. I think they were much more affordable and more reliable than the Polymoog and the GX-1.