PlanetZ forums - scopeusers.com

Does Xite-1 and the cards provide MIDI power?

I consider buying a thru box and a merger, both of which needs MIDI power.

What do you call MIDI Power ?
There is no Power over MIDI but some MIDI Solution boxes are using the MIDI flow to get their power supply from what I understood.

HUROLURA wrote:What do you call MIDI Power ?
There is no Power over MIDI but some MIDI Solution boxes are using the MIDI flow to get their power supply from what I understood.

By MIDI standard MIDI-Out ports provide +5V power to a receiver´s MIDI Input.
Only a small amount of current can be supplied and the receiving unit must support that.
I have such a setup w/ my Yamaha KX76 and a EES Velocity Transformer unit which is MIDI powered by the KX76.
In the EES, which was/is prepared for that purpose, there had to be a bridge soldered according to the manual and in the KX76 a by standard MIDIsignal unused PIN of the MIDI out port is used.
You need a MIDI cable using more than 3 wires/PINs.
Most MIDI cables only use 3 wires/PINs of the 5-PIN DIN MIDI connector.

Bud

From the MMA site I cannot see any 5 pin MIDI cables specified:

http://www.midi.org/techspecs/electrispec.php

There is a +5V on in 4 of MIDI out or Thru but it is used to supply the next device MIDI in opto input, not intented to be used as a power supply.

Using the NC pin for power supply seem to be more or less manufacturer specific (you sometimes also find 7 Pin "MIDI" connector with power supply available on the 2 extra pins)

Yep, no power over midi by any standard. And I can second the fact that midi solutions (and some other companies) make some low power stuff that feeds off the data TX signal, and uses the ground, without any modifications or special needs. I've used a Midi Solutions 1-input to 4-output thru device for distributing midi clock, and that wasn't an issue (no power needed), but I know that's about the limit of capability. If you mention specifically the midi merger you would like to use, just post it and we can give our definitive opinion.

HUROLURA wrote:From the MMA site I cannot see any 5 pin MIDI cables specified:

I don´t need a specification for a cable.
When I tell you I power my EES M3 Velocity Transformer w/ a 5-PIN DIN MIDI cable from my Yahama KX76, you can believe me it works and it does since I owned the KX88, then the KX76 and the EES (I own 2).

I wasn´t aware of the option until I buyed the EES and there it was in the manual w/ the intention making the walwart obsolete.
I think they use the +5V line from MIDI Out and because MIDI In has different pinout, there´s the prepared and optional solder bridge for on their circuit board.

http://www.interfacebus.com/PC_MIDI_Pinout.html

So, I assume, also Midisolutions MIDI boxes use that too and have a bridge somewhere between pins on MIDI In socket or on the circuit board.

Bud

My TattleTail shows the XITE-1D is outputting power until Scope starts up. When Scope starts, the output stops.

Bud Weiser wrote:

HUROLURA wrote:From the MMA site I cannot see any 5 pin MIDI cables specified:

I don´t need a specification for a cable.
When I tell you I power my EES M3 Velocity Transformer w/ a 5-PIN DIN MIDI cable from my Yahama KX76, you can believe me it works and it does since I owned the KX88, then the KX76 and the EES (I own 2).

I wasn´t aware of the option until I buyed the EES and there it was in the manual w/ the intention making the walwart obsolete.
I think they use the +5V line from MIDI Out and because MIDI In has different pinout, there´s the prepared and optional solder bridge for on their circuit board.

http://www.interfacebus.com/PC_MIDI_Pinout.html

So, I assume, also Midisolutions MIDI boxes use that too and have a bridge somewhere between pins on MIDI In socket or on the circuit board.

Bud

The MIDI Solutions boxes don't have the solder bridge option. Most of their devices don't even have a wall-wart option It's power by MIDI only.

That's a nice feature of the EES, so if you did use a wallwart (and no solder bridge), it wouldn't fight with the power supply of the midi device connected to it's input (which causes noise).


Just more info: The "5V supply" of the MIDI cable is fed through a 220 ohm resistor, which means about ~23mA of current is available. MIDI specifies 5mA required for the optoisolator on the receiver, so a device has about 18mA to make use of. Since the schematic of the MIDI interface is set in the standard, it's rare that a device deviates from this, and provides more power than 22mA. The usual way around it is to use a 7-pin cable as mentioned (I once had an old ART MultiVerb that did this to power it's external footpedal controller).

jksuperstar wrote:If you mention specifically the midi merger you would like to use, just post it and we can give our definitive opinion.

I am thinking of going from Xite to this -> http://www.midisolutions.com/prodqth.htm, and from this -> http://www.midisolutions.com/prodqmr.htm back to the Xite.

i've used that stuff with PCI cards and it was a-ok.
if all else fails, the controller should provide power....

jksuperstar wrote:
The MIDI Solutions boxes don't have the solder bridge option.

I know, I own 2 of the 2>1 mergers.

jksuperstar wrote: Most of their devices don't even have a wall-wart option

I know too (see above)

jksuperstar wrote: It's power by MIDI only.

No, it´s not,- it´s powered by 5V+ current.
MIDI is just only the shortform for "Musical Instrument Digital Interface".
Now power anything w/ term ...

Read the Midisolutions FAQ,- link is in my reply to Dante.

jksuperstar wrote: That's a nice feature of the EES, so if you did use a wallwart (and no solder bridge), it wouldn't fight with the power supply of the midi device connected to it's input (which causes noise).

Correct !

jksuperstar wrote: Just more info: The "5V supply" of the MIDI cable is fed through a 220 ohm resistor, which means about ~23mA of current is available. MIDI specifies 5mA required for the optoisolator on the receiver, so a device has about 18mA to make use of. Since the schematic of the MIDI interface is set in the standard, it's rare that a device deviates from this, and provides more power than 22mA. The usual way around it is to use a 7-pin cable as mentioned (I once had an old ART MultiVerb that did this to power it's external footpedal controller).

The info is correct, but that´s the theory and it real world it might differ,- you´ll read in Midisolutions FAQ.

My Yamaha KX5 is modified to work w/ a long cable connected to a custom made PSU and MIDI buffer and we used 7-PIN XLR connectors to realize that.

Bud

dante wrote:My TattleTail shows the XITE-1D is outputting power until Scope starts up. When Scope starts, the output stops.

What´s a Tattle Tail and what exactly do you see there ?
Sorry for asking, but I really don´t know that term and cannot imagine what it is.
I wondered about that already in the other thread where we discussed MIDI data appearing on Jimmy´s XITE MIDI-Out before a project is loaded at all.

Now, when there is data at XITE MIDI-In and it is "MIDI echo"-ed to the MIDI Out as long there´s no project loaded, what is echoed is data, not current.

In hardware and at MIDI-Out (and MIDI-Thru too b.t.w.), there´s 5V+ always at PIN #4, that´s current.
At MIDI-In / PIN #4, it says only + !

Now, when you have an external device which works w/ a walwart, eventualy optional to buy, but is prepared to work w/ 5V+ from MIDI Out too, the soldering bridge offers the option to make it work w/ BOTH alternately (or this or the other), because the 5V+ from MIDI replaces the walwart´s current when the walwart isn´t plugged in and vice versa.
That´s how the EES M3 Velocity Transformer works when connected to a MIDI transmitting device´s MIDI Out.

The Midisolutions boxes (I have 2 mergers 2>1) all work w/ that power,- and also w/ stock MIDI cables.

That wouldn´t work when there´s only power when data flows (MIDI signal is present),- power would be interupted when stream of MIDI data is interupted,- which is the case always when you don´t press keys or don´t tweak controllers.

My KX76 is another story.
As a stock device, my KXes didn´t deliver constant 5V+ on PIN#4, but we made it work which was done in about a minute once it was open.
In fact Yamaha ignored MIDI standard in many cases just from the beginning and already w/ the 1st DX7.

All I can say is,- I myself in my setup, I need a 5-Pin DIN MIDI cable, all pins wired.
I´m unsure the setup uses all 5 wires, maybe it uses 4, but it doesn´t work w/ a standard 3-wire MIDI cable like it (not always) does w/ the Midisolutions boxes.

Also Midisolutions Products won´t work w/ some MIDI devices,- read the FAQ explaining issues w/ MIDI cables and devices not delivering power at MIDI-Out and according to MIDI spec (!!!):

http://www.midisolutions.com/faqs.htm scroll down to:
"Why does the MIDI indicator LED not light up even though the keyboard connected to the MIDI Solutions product is turned on?"

5V+ at Pin #4 is MIDI standard.
But it is up to the manufacturer to decide for his "MIDI receiving" product what it does w/ it.
It´s also a shame MIDI cables on the market can be crappy wired, are working for standard MIDI signal nonetheless, but not w/ the constant 5V+ line.

When it comes to SCOPE PCI card or XITE,- it might be different w/ both.

Now the question is if it is only data not running once a project is loaded and no connection made to hardware MIDI destination, or if your Tattle Tail (whatever that is) displays current.

Bud

Bud Weiser wrote:

dante wrote:My TattleTail shows the XITE-1D is outputting power until Scope starts up. When Scope starts, the output stops.

What´s a Tattle Tail and what exactly do you see there ? Sorry for asking, but I really don´t know that term and cannot imagine what it is. I wondered about that already in the other thread where we discussed MIDI data appearing on Jimmy´s XITE MIDI-Out before a project is loaded at all.
Bud

Its just a midi activity led. Just a midi plug with an LED on the end instead of cable. The LED glows RED constantly if XITE-1D is on but Scope not loaded.

When a project loaded and you play on keyboard, the LED just flickers as you play or move mod wheel etc. Then shows nothing when you stop playing.

dante wrote: The LED glows RED constantly if XITE-1D is on but Scope not loaded.

Thx for info,- that behaviour is interesting compared to the behaviour below.
Because it glows constantly, that cannot be MIDI active sensing, what I assumed in 1st place.

dante wrote: When a project loaded and you play on keyboard, the LED just flickers as you play or move mod wheel etc. Then shows nothing when you stop playing.

For me, that behaviour indicates it is designed for monitoring MIDI activity, not current,- and SCOPE/XITE behaviour is correct when project is loaded.
But it can be, Tattle Tail monitors any other output @MIDI-Out as well.

Now I´m curious if Midisolutions merger works w/ project loaded (or in general) and what kind of data Kurz PC361 MIDI monitor reports before project is loaded.

Bud

Bud Weiser wrote:For me, that behaviour indicates it is designed for monitoring MIDI activity, not current,- and SCOPE/XITE behaviour is correct when project is loaded.
But it can be, Tattle Tail monitors any other output @MIDI-Out as well.

Yes - except MIDI activity, at the end of the day, IS current

So there is a voltage coming from XITE-1D MIDI OUT when XITE is powered on and Scope isn't loaded. And its not active sensing, as I've seen active sensing and it is more of a flicker than constant glow bright red.

dante wrote: Yes - except MIDI activity, at the end of the day, IS current

No question it is !

dante wrote: So there is a voltage coming from XITE-1D MIDI OUT when XITE is powered on and Scope isn't loaded.

Yes, but when project isn´t loaded it´s constant reported by Tattle Tail and w/ project loaded it seems it´s not.
I doubt it´s not because opto couplers on the reiceiving side need the current.
Means,- when project is loaded, Tattle Tail monitors data only and ignores constant current,- because it flickers only when you press keys or tweak controllers.
I think that is how these tools work and I also think, because that was the question of OP,- XITE provides power to small MIDI tools not requireing much current.

I´ll test soon and confirm if it really does.

I´m busy w/ taxes and read PlanetZ in between on my office machine since 3 days ...
Next week all over I hope.

Bud

Thanks for all your answers