Barton simple dual quantizer.
http://synthcube.com/cart/index.php?route=product/product&path=73&product_id=170
Requires some mechanical skill to assemble, separate power to each board (2 boards).
The main disadvantage of this module is that it can't be adjusted. My module has scale about 0.98v/Octave and it is not OK for me. It needs just one more TL072 and two multi-turn trimpots. At least as the option.
The PCB layout is far from being perfect. It is impossible to use DIP-sockets with MCU. I had to solder it right to the board. There was some missing components in the kit. The PCB design requires too much wires. but this tiny circuit might be made on a single one-sided board with maximum possible amount of PCB-mounted components. The pots in my package had too long shafts pushing pot caps to extra-height about 7mm above the surface of the panel. This is sole module in my rack having such problem.
The circuit, logic and design are OK with exception of missing adjustment possibility.
By the way, you can share power between two parts of this module. There is corresponing holes in the PCB, named +12v, GND, -12v, +5v. So, there is no actual need to use both LM7805. One of these can handle enough power to feed entire 5v bus of the 6u case.
P. S. Panel design could be much more useful having any legend
I was able to get the MCU socketed it required using a non dust shielded alpha pot instead of the one provided.
While the v/octave may not be perfect it is much better than my MFOS quantizer, plus there are many different modes/scales supported, and the range is better than the MFOS one.
The V/octave is set internal to the MCU which contains both DAC and ADC. Potentially the MCU could be recoded.
For what it does and compared to what else is available I'm quite happy with mine.
Interesting note on the Barton website concerning this module:
"1.It's out of tune!Check your +5V supply. If you're running on less than 5V your quantizer's notes will seem flat, if it's higher they will seem sharp. If you're using an adjustable +5V supply, then adjust it until you're in tune. If you're using a 7805 on board regulator, swap it out for a different one. I buy the cheapest 7805s I can find and I've never gotten one so out of spec that it bothered my ears, you're probably going to get a good one. You can also use the 7805 to LM317 adaptor PCB to make a tiny adjustable +5V supply."
