Wednesday, December 13, 2017

Roland PB-300 Schematic



Here are some scans from the Roland PB-300 service manual. It was released in '83 as a
companion to their HP-400 digital piano. It stands as Roland's final, fully-analog drum machine.

First, a runthrough of the presets:




Higher resolution and additional images on imgur here.




An AVR replacement CPU offering MIDI triggers



11 comments:

  1. The Boss DR-110 is an analogue voiced drum machine which was released in 1984. I believe the Dr-110 was the last analogue drum machine by Boss/Roland Corp.

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    1. The DR-110's digital noise source keeps it from being fully analog.

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  2. Did you try adding trigger ins for the PB300?

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    1. I didn't add voltage triggers, but I did replace the CPU and include MIDI triggers.
      Here's a picture: https://i.imgur.com/9X9oU5h.jpg

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    2. what cpu replacement is that? I just got a PB300 and am investigating what can be changed.

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    3. The chip is an AVR microcontroller. The board and code are something custom I made. I can make you one.
      It's a bit hard to remove the original without damaging the board though. The traces are particularly fragile.

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    4. Amazing. Let me know how best to reach you to discuss this. I'm really intrigued by what's possible. I finally switched the notification on here so I can get back to you sooner. Safe and happy holidays!

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  3. This comment has been removed by the author.

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  4. Hey sorry I missed this! I just saw your response. I would love one of these CPUs. I'll reach out now. Thank you for offering!

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    1. Hi Aldergrove.
      I found the schematic for the CPU adapter. I've added it to my Github:
      https://github.com/Skidlz/PB-300-CPU

      I can't find the code I wrote for it though. I only got as far as implementing the MIDI triggers. There was no pattern support.

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    2. Cool thanks! Having a look. I messaged you on Soundcloud if you want to discuss this in more detail. I have ton of questions! Thank for doing this.

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