Replacing BeatBuddy Mini DIN Socket with TRS Midi

great thanks a lot. But my BB is still on warranty that’s why I wanted to make my PS / 2 and 2 x TRS (RC-5 side).
I put my first cable attempt that I have to redo.
Do I have to buy a BB midi cable?
knowing that I already have all the connections to solder.

Please refer to this connection…

hey there what a genius idea, this would be so helpful if you had
a step by step video guide on BB mods as i would be so scared to even open mine up lol & wouldn’t know where to even begin? asking from all the way from nz…

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I was happy to read the report above about the conversion of the midi socket. I also want to rebuild my bb because I have more and more midi failures because the plug slips out. Singular Sound should have responded much earlier! However I still have a question: does the old midi socket still work after the conversion or will it be shut down? If so, can I still keep it working?

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hi @897 your existing midi socket will still work as normal after this modification.
we are just running parallel connections from the required pins.

Thank you for your information!

do I have to make a connection between ground midi-in and midi-out?

You will want ground, but you could pull ground from elsewhere. Doubt the different ground points will matter in this application. YMMV.

The MIDI specification requires ground to be connected only on the transmitter end. You should not connect pin 2 between the MIDI IN and OUT sockets. The specification actually says “Do not connect any pins of the MIDI IN jack directly to ground.” Note that this includes the cable shield.

There is a technical addendum to the MIDI specification which allows for optional grounding via a capacitor. This can improve EMI/EMC performance and RF grounding. Usually such a solution would also include matching ferrite beads to effectively build a LCR filter circuit with the desired characteristics.

tl;dr: Do NOT connect MIDI IN to ground.

thanks for the detailed information


I am sending my thanks to @Nepali_brother and @XBeat for this article.

Thru the process I discovered that one of my MIDI breakout cables was simply bad on the OUT side. I had purchased another breakout cable from Singular Sound(by way of Sweetwater) and still had some trouble when trying to use the MIDI OUT. Very intermittent even with the new cable. I have accomplished the mod and it works. I purchased the mini TRS jacks and they ground the sleeve to the chassis and that means that MIDI IN has a ground too. It seems to work and since my rig is rather simple I am going to go for it even tho i broke a rule by grounding MIDI IN. @peteru Can you describe the risk to my MIDI connections after I broke this rule?


The only problem that can arise is a audible hum in the audio provoked by a ground loop. If you don’t have it, no problem at all.

One more update for the community…
I have successfully modified my second Beat Buddy with the technique outlined in this post and comments.
I ended up using some 3.5 mm TRS jacks that ground the sleeve to the chassis. At first I was concerned since this grounds both the IN and the OUT side. (see my exchange above with @XBeat.)
I did some testing with a multi meter and the standard MIDI Breakout cable from Singular Sound and found that the wire from pin 1 of the mini-DIN connector was not necessary because that is the shield and is electrically equivalent to the “pin 1 to sleeve” wire.
Thanks again, @XBeat and @Nepali_brother!


Thanks @XBeat
since my MIDI is a Blue Tooth interface I am golden. If there were more wires in my rig it might be a thing.


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@AlvinK glad I could help. Lets rock!

I am glad you found the post and uploads helpful.