What is this thing?

The Lounge Other Gear
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I’ve found this rather cheap piece of gear last year in a thrift store. Since then I wasn’t able to figure out what it is or how it works. Given that I want to ask if some of you may have a suggestion or an idea of what it might be…
To give some clarification
Backside

  • Fuse
  • On/Off switch
  • 2x 5Pin-Din Ports (Midi?)
  • 3.5 mm trs Port

Frontside

  • 16x cruchy faders
  • 6.3mm trs Port
  • 1x rotary switch
  • 1x Potentiometer
  • 2x 2-pole switches
  • 2x 3-pole switches

Inside/IC’s
PCB connected to the 16 faders

  • 2x HEF4015BP
  • 1x CD4011BPC
  • 1x CD4024BE
  • 1x Z/8035
    PCB connected to the rotary switch
  • 1x HCF4046BE
  • 1x SFC2747EC
  • 1x CD4013BE
    PCB in between
  • 1x HCF4046BE

Given that I’ve been told that most of the IC’s are logic ones, I would guess that it might be a 16-step step-sequencer? maybe an EQ?
I wasn’t able to receive or send any midi data, same with audio into or out of the trs ports besides the crackle of the faders. I’ve checked the internals which seem to be about fine (from my amateur perspective). At least electricity reaches each PCB.

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You have quite the sense of adventure – the price would have had to be close to zero for me to take a leap on a mystery box like that! That being said, I would say your idea that it’s a sequencer is probably pretty close.

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It actually was, 7 bucks was worth the adventure I guess! Could’ve gotten half of a cable for that price though ^^

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this might be helpful to other budding sleuths… CC @darenager

dual edge-triggered 4-bit static shift register (serial-to-parallel converter)

CMOS gate

7-Bit Ripple-Carry

?

Phase locked loop

voltage regulator

Flip Flops Dual CMOS

PLL/Frequency Synthesis Circuit, CMOS

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Almost certainly a analog step sequencer, definitely not an eq.

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Also probably din sync rather than midi, as dinsync can be made using logic ICs, midi requires a microprocessor and optoisolator.

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That’s the Octatrack MK3. Great find.

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Interesting! So the 3.5 trs is most probably for CV but what about the 6.3 mm on top? Would one use these ports for CV as well?

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Looks like a pretty nice DIY build, I reckon the rotary switch selects stages, the toggles probably for direction and other playback related stuff.

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Probably CV and Gate - are the trs jacks using 2 or 3 poles?

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I agree. Sequencer of some kind. It may have some onboard division as well. The 4046 PLL chip has a built-in VCO, so this could be the clock source.

Interesting that it also has the shift registers. This could be used for several things. Gate outputs, pseudo-random gates, maybe digital noise if this is some kind of percussion thing also.

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Maybe one of the toggles is for internal/external clock, the easiest way to test would be check the voltage on the jacks using a meter and have a fiddle with the controls.

Yeah could be some kind of noisemaker with integrated sequencer too.

Whatever way you look at it a nice little bargain in parts alone.

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2 poles on each trs

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If I remeber correctly (sadly I’m not sitting in front of the unit) one or two of the switches were directly connected to the DIN ports

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Could be something from a workshop too, like Rob Hordijk’s Blippoo or Benjolin workshops. (or just plain DIY of course)

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Does it work?

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Almost certainly a dinsync input then, the switch probably turn it to internal clock or dinsync in.

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Could be a choice between DIN sync and internal clock then. If those are for sync, and not some custom purpose.

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Looks like it runs from mains voltage, the blue box is a transformer from 220v to +12v and -12v.

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Light management?