Diy Top Octave Generator. It wouldnt be cost-effective to mass produce a string synth like that though. When you drop the top section down only the back part of the recessed area of the board is covered leaving the control pedals exposed and easily accessible.
Top Octave from www.sdiy.org
CD4024 CMOS divider ICs are then used to divide down the 12 tones. The 74LS93 is an updown module 16 binary counter which divides top octave frequencies to produce remaining lower octaves. TOS - Top Octave Synthesizer or TOG - generator I dont know if this has been mentioned before somewhere - but now that we dont need top octave synthesizers any more they have become extremely easy to make.
The TOS SelectDivider board produces a square wave output consisting of tones 1 through 85 C1 through C8 and is driven by the hard-to-find MO82B1 Top Octave Synthesizer IC.
The inherent capacitance of the input terminal is about 5 pF. Chips are cascaded to provide additional octaves. The top layer houses the additional pedals mostly stompboxes in this case and folds back revealing the utility area with a power supply and compressor. Built-in clocks for 4MHz pin 3 and 1Mhz pin 4 are provided for testing and applications where no.
