H9 modification for MIDI power

[nickrose]

Some product, for example, those from MIDI Solutions, rely on power being supplied by the connected MIDI Output socket.

H9’s before Serial 16329 did not supply this power, but a simple modification can be made to remedy this.

Instructions are attached (ignore first page) – soldering is required, but it should only take 5 minutes for a skilled person.

This only applies to H9 – ‘Factors do not have this issue.

 

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[javiceres]

I had no idea about this
I just assumed MiDi power was a no no
Thanks a lot for all this useful info!!

[camn]

Would it be practical to send power out the unused pins of the MIDI ~INPUT~?

Cuz I could get behind self-powered MIDI controllers.

 

[nickrose]

Alas, the H9 does not have enough spare power to do this. It would also be pretty non-standard.

Some products, including our Eclipse, send out power on pins 6 and 7 of a 7 pin DIN, but the H9 only has 5 pin DINs. Further, the voltage and polarity of this power is unspecified, and it would need a special cable.

You could hard-wire your H9 and make as special cable….

 

[camn]

fine. Ill use standard wiring 🙁

 

wouldn’t that be elegant though?

[camn]

Also why do people need a 7-pin cable to include back-voltage… When a MIDI input only needs 3/5 leads?

WHO DESIGNED THIS STANDARD AND WHERE CAN I FIND THEM

[luedmo]

hi Nick
I clicked all over your post but cannot find the instructions
How do we find these please?
Thanks
:L

[nickrose]

I fear these were lost during the Web Site changeover. Sorry. I’ve asked our Web people to look into it.

I’ve attached the core file that tells you how to modify your H9 (this involves taking the unit apart and soldering a wire to the bottom of the main board, so modest technical skill is needed). Ignore the first page. Note that this is only needed for H9 before 16329.

I’ll re-attach the original file when we find it.

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[luedmo]

Hello Nick
Thanks for that
So it’s page 2 we look at – which is the main board? I guess the bottom board. If so, then it looks like all the ports have to be dealt with first. Any tips welcome there before I get in a skilled pal to do this (with 22 awg wire).
Best
:L

[nickrose]

The main board is the bottom board. The only modification required is one wire at the MIDI connector.

It’s an easy mod – you need to be “skilled” with a screwdriver to take the unit apart, then able to make two solder joints.

The skill warning is to say you need some idea of what you are doing. Almost any wire will work – the 22 awg specification is for our manufacturing people.

 

[luedmo]

Thanks Nick,

yep, I saw the screws for the main board 🙂 but…
~ do we have to unscrew the jack ports as well? It looks like we have to…
~ also, can we clarify which direction the power goes and from which socket?

Your first post text says:
> Some product, for example, those from MIDI Solutions, rely on power being supplied by the connected MIDI Output socket.

I have an M-Audio MIDI sport 2×2 MIDIMAN feeding MIDI into an H9. User “Camn” seemed to want something like that too.  Please correct me if I am barking up the wrong tree, but MIDI controllers (that need power) tend to feed into an H9 therefore the power should come out of the MIDI Input socket, rather than the MIDI Ouput, no?

Best

:L

[nickrose]

The “MIDI power” comes from the MIDI out jack. Note that this is a very modest amount of power, and is only usable by units especially designed for it (such as MIDI Solutions). It is not suitable to be used as a general power source, and as a result is not supported on the MIDI IN jack and would not suit Mr. Camn’s purposes.

Sorry.

 

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