• skylark

    a few questions from a circuit board noob… your MKS-80 has a 110VAC PSU… is that Japan spec? (i thought they were 100VAC)… so then USA spec is 117VAC?
    (i inadvertently skipped my step-down transformer and plugged a Japan-spec Sony turntable straight into 117VAC… 20 years later i found my error, when i moved to another home)

    you said the MKS-80 “requires a +10V precision reference voltage for the VCO/DAC”… i’m confused… since the MKS-80 is VCO/VCF/VCA why/where does a DAC come in?

    please post your progress… interested to follow… thanks!

    July 05, 2019
    • amsynths

      Hi, it is an 100-117VAC transformer. The +10V reference voltage is used by the VCO’s and not the DAC. Rob

      July 06, 2019
    • Pete Brown

      skylark: DACs are used in polysynths to supply the voltage to the VCOs. They’re also used in some modern mono synths for the same purpose.

      In a poly, you can’t use use the keyboard as a voltage divider and feed that right into the VCO. Instead, you have to scan the keyboard and then use the DAC to supply the voltage. To support MIDI, you have to do the same.

      March 25, 2020
  • It is an honour to have inspired this interesting project. Funnily enough, a guy in Norway is doing same for D50 D550. He approached me and I helped him, reviewed his layout and circuit. I will put a link and pictures to it on my site when he’s ready. There is usually a fair bit to think about. For me, it’s a shame I used someone else’s converters in the design, but it is easiest and cheapest way for low volume.

    I’d be happy to do same for you too and link to your site when you complete it.

    July 28, 2019
  • Radar Caves

    Wow, Just wow. as an owner of MKS-70 and MKS-80, i keep a close look out for modern day mods and upgrades. Vecoven and Guy W, have both added so much to the MKS-70, and I was always in hope someone would step up to the technical challenge of the MKS-80 and help future proof it.. nice work, i look forward to seeing this PSU design completed.

    September 19, 2019
  • Kevin de Vries

    Nice work, I am also looking for a solution to replace my mks-80 rev 5 110 volt power supply to 220 volt.
    If all works and you want to order the pcb’s I am very interested to join.

    Friendly greetings,


    September 22, 2019
  • Pete Brown

    I’m curious to know if you took this any further. Were you able to find a good solution to the tolerance concerns? Any working prototypes?

    March 25, 2020
    • amsynths

      I have started to lay out a PCB but my Behringer work has taken priority over the last few months, but this will stop soon and the power supply project will be restarted. Thanks for the interest… Rob

      March 26, 2020
  • the pieces of design you have taken from my site have been published by you without permission, not without proper referral to my site.

    principal is, we as small operators should help each other rather than take liberties.

    please remove them

    February 07, 2023
    • amsynths

      Hi Guy,
      Good to hear from you. Rather surprised at your comment, as back in 2019 you posted a positive comment,see above.
      Very happy to add some links to your site from the content, if you grant permission.
      There was no intention of taking any liberties, just quoting your talented designs.
      I have no ambition to create a commercial power supply for the MKS70/80 as its been done already.

      February 07, 2023

Leave a comment

Copyright AMSynths 2022