Just built wireless MIDI into my AX Synth

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Arjan
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Joined: 16:30, 29 December 2003
Location: Netherlands
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Just built wireless MIDI into my AX Synth

Post by Arjan »

DISCLAIMER: DO NOT ATTEMPT THIS MODIFICATION IF YOU DON'T KNOW WHAT YOU'RE DOING. IT IS POSSIBLE TO DAMAGE YOUR AX SYNTH AND YOU WILL CERTAINLY VOID YOUR WARRANTY. IF YOU DO THIS YOU DO IT AT YOUR OWN RISK ENTIRELY. NO GUARANTEES ARE GIVEN THAT THE MODIFICATION DESCRIBED BELOW IS SAFE TO DO OR THAT IT WILL NOT HARM YOUR AX SYNTH, EVEN IF YOU PERFORM THE MODIFICATION EXACTLY AS DESCRIBED.

Hi everybody,

I just finished a fun little project: I built a CME WIDI-X8 wireless MIDI sender/transmitter into my AX Synth.

Being a keyboard guy I'm not used to walk around on stage, especially not with some cords trailing behind me. I also didn't like having to deal with the CME as a bodypack, the MIDI OUT on the AX Synth is located in an inconvenient location imho. So after noticing how much empty space there is inside the AX Synth when I first opened it to install some straplocks I decided to check if it would be possible to build my WIDI-X8 unit into the AX Synth.

As it turns out that is relatively easy to do. THE WIDI-X8 is perfect for this mod because the MIDI, USB and power sockets are on a separate PCB that connects to it's 'main' PCB through a simple connector which can be conveniently used to connect the AX power and MIDI output to the Widi-X8 PCB.

Like I said there is plenty of space inside the AX SYnth and I was able to find out where to tap from the +5V power that the AX Synth generated for some of its digital circuitry. The best place for that is probably C177. That's on the same PCB that also has the MIDI sockets.

Originally I had hoped to be able to use a neat little trick to allow the regular MIDI IN/OUT ports to continue to be used with no side effects whatsoever if for some reason there's a problem with the wireless reception. Basically I wanted to make some special MIDI plugs that would simply loop back pins 1 & 3 to pins 4 & 5 respectively and connect pins 4 & 5 internally to the WIDI-X8 MIDI ports. However Roland managed to find a MIDI chassis part that has litereally no metal whatsoever in the holes for pin 4 & 5. So much for that brilliant idea.

In the end I decided to just hardware the AX MIDI ports to the Widi-X8 MIDI ports with the idea that if I can't go wireless I'll just play those songs from behind my keyboards. If you really want a backup you could abuse the ATT switch to switch the connection between the AX MIDI OUT and the Widi X8 IN so you could still use the AX Synth's regular MIDI OUT in a pinch.

Actually it might be possible that the AX Synth MIDI OUT can drive both the internal Widi-X8 and the external MIDI OUT but that's not according to MIDI specs. It might work but I haven't tried it yet.

Another bonus is that since the WIDI-X8 is now powered off of the AX Synth's batteries I only have one set of batteries to worry about and I can see their charge level (the WIDI-X8 has no charge level indicators). NOTE: I HAVE SIMPLY ASSUMED THAT THE CIRCUITRY AND COMPONENT IN THE AX SYNTH ARE CAPABLE OF HANDLING THE ADDITIONAL POWER DRAWN OF THE WIDI-X8. THIS MAY OR MAY NOT BE TRUE.

Without further ado here are some pictures:
Overview of the AX Synth after the modification. Widi-X8 PCB is on the far left where the straplock is.
Overview of the AX Synth after the modification. Widi-X8 PCB is on the far left where the straplock is.
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This is where I take the +5V to power the Widi-X8 from the AX Synth's batteries (or wall wart)
This is where I take the +5V to power the Widi-X8 from the AX Synth's batteries (or wall wart)
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MIDI OUT/IN must be taken from the bottom side of the PCB, luckily there's plenty of room to accomodate the cable.
MIDI OUT/IN must be taken from the bottom side of the PCB, luckily there's plenty of room to accomodate the cable.
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This is where I put the Widi-X8 PCB, secured with a tie-wrap
This is where I put the Widi-X8 PCB, secured with a tie-wrap
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So now I'm the lucky owner of an AX Synth with completely built-in wireless MIDI :-) I have the Widi-X8 set to 'Auto' so that it will scan for the frequency of my other unit. Seems to work quite well so far.
captaincowhouse
Posts: 21
Joined: 19:30, 8 December 2010
Location: Brighton, UK

Re: Just built wireless MIDI into my AX Synth

Post by captaincowhouse »

Did you get hold of a service manual then?

That's a really good mod, how's it working out for you? Certainly has got me thinking about doing the same with my audio wireless unit...
Arjan
Posts: 892
Joined: 16:30, 29 December 2003
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Re: Just built wireless MIDI into my AX Synth

Post by Arjan »

captaincowhouse wrote:Did you get hold of a service manual then?
;-)
captaincowhouse wrote:That's a really good mod, how's it working out for you?
Tomorrow is going to be the first time I will be testing it (during our normally weekly rehearsal) since I did the mod. If any problems turn up I'll be sure to report here. I'll also test if the regular MIDI output can still be used. If not it may be wise to use the ATT switch to disconnect the built-in wireless transmitter in case of interference so I can fall back on a cable.
captaincowhouse wrote:Certainly has got me thinking about doing the same with my audio wireless unit...
Should be quite doable if it's small enough to fit and if it doesn't draw too much power. My own ad hoc rule of thumb which I used for my WIDI-X8 is that if it will run for several hours on two AA rechargeables it can't be much of a problem for the AX synth to supply it with power since it lasts only several hours on 8 AA rechargeables itself.

That said if I wanted to do wireless audio I'd probably get one of those transmitters that looks like a large jack plug without a separate bodypack and not bother about building it in. Or perhaps I would :-)

One extra word of caution: I actually slightly scratched some of the black keys of my AX by having the top panel of the AX lyying upon the keyboard: there are sharp metal thingies in there. So when you do this make sure to put a towel or someting on your keyboard to prevent this. I'll see if I can get them shiny again with something like Displex and if not I may order a few replacement keys from Roland.

Incidentally, did you read my final response to your question about the ATT switch?
captaincowhouse
Posts: 21
Joined: 19:30, 8 December 2010
Location: Brighton, UK

Re: Just built wireless MIDI into my AX Synth

Post by captaincowhouse »

I did, thanks. I've got some spare time next week, so i'm going to have a look then. What does the manual say about it? Or is that classified info? I did a gig last night sitting down, and not being able to see the volume knob was a quite a hassle so I am looking to do this mod soon.

Yeh it's the brace audio wireless unit. It only takes 3v so that won't be a problem. Although i've been thinking about getting a different one. Been doing some gigs down on the beach (of which I need to post some videos!) and the wireless range is significantly reduced outside for some reason. I've emailed Brace about it, hoping for a reply soon.

When you've given you're setup a proper test, can you report back on battery consumption. I'm usually getting 2 2hr functions out of my batteries. Hopefully i'll still be able to taking the power for the wireless aswell!
Arjan
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Joined: 16:30, 29 December 2003
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Re: Just built wireless MIDI into my AX Synth

Post by Arjan »

captaincowhouse wrote:When you've given you're setup a proper test, can you report back on battery consumption. I'm usually getting 2 2hr functions out of my batteries. Hopefully i'll still be able to taking the power for the wireless aswell!
Although I wouldn't call a single rehearsal a proper test I can tell you so far it's working out just fine. When I switched on the AX Synth charge level meter showed 80%. After the 4 hours rehearsal it had dropped to 71%.

Keep in mind that I don't play this thing continuously, I only intend to use it for a few songs so much of the time the AX was in low-power mode. The wireless MIDI does not go into low power mode so it was using power all the time. Don't know if it consumes significanly more power when it's actually transmitting notes but it has to transmit a carrier and keep-alive signal anyway (the units have a MIDI panic all notes-off if they lose communication). The manual of the WIDI-X8 states that a set of batteries (2x AA) will last about 20 ours. I assume they are referring to regular batteries, not rechargeables.

All together it appears that this will not significanly reduce the battery time of my AX Synth. A _big_ bonus is that the AX Synth charge level indicator also aplies to the WIDI-X8 which itself does not have a charge indicator.

I also tried if I could still use the regular MIDI output with a long MIDI cable and that seemed to work fine too, even though the WIDI-X8 was connected in parallel so the output from the AX MIDI OUT was effectively split with a simple Y connection. Good to know that I can fall back on using cable if my wireless ever fails me during a gig. Just need to remember to pack a long MIDI cable.

So far I'd say it's a big success.
Lenny
Posts: 98
Joined: 18:48, 1 September 2004
Location: The Live Music Capital of the World

Re: Just built wireless MIDI into my AX Synth

Post by Lenny »

This is certainly the most useful mod for a synth I have seen. Thanks for posting the great photos and details!
fixxxer113
Posts: 23
Joined: 22:45, 1 November 2008
Location: Athens, Greece

Re: Just built wireless MIDI into my AX Synth

Post by fixxxer113 »

Hey Arjan, great work on that mod! Thanks for attempting this, testing it and sharing your results!
I just finished the same mod on my AX after reading your post.

I went for a different solution for switching the wireless MIDI on and off. I didn't want to sacrifice any functionality, so instead of using the ATT switch, I just installed an extra one. I removed one of the cable holders, widened the hole a bit and fit a switch there. It is wired so it will open and close the connection between the X8 MIDI pins and the AX MIDI pins.
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This switch can handle 4 wires and already barely fits over the motherboard (there are a couple of capacitors in the way). If there is a smaller one that can handle 6 wires, you could probably wire the power supply to the X8 on the same switch so when you disable the WIDI, you also don't have the X8 drain your batteries even a little.
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Again, thanks a lot for this great idea! One of the things this allows me to do now, is combine the AX with my Fantom X6 not only as a MIDI controller, but also using its audio output through the Fantom. I can now have only one cable on stage, the audio one, and be able to use some crazy layering :)
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