lylehaze

Mike makes a good point MOST of the display is numeric, but the 2 letter "day of week" may not make the transition to seven segment very well.. If you can figure out how you want it to look in 7 seg, then OK, all patterns are possible for the PIC to drive. Have Fun, LyleHaze

You have a scope, so you can see things that most people can't. Let's use it. The crappy graphics I drew before are back.. This time with "follow the bouncing trace" diagnostics. Test conditions: GM5 interface is connected to PC, with software ready to dump sysex on request. PC software is set to display incoming SysEx if it ever gets here. MIDI cable under test is connected from GM5 MIDI OUT to GM5 MIDI IN. Scope is powered up, grounded to GM5 ground, and set to see 5VDC trace. MIDI OUT MIDI CABLE MIDI IN opto +5Volts---/\/\/\/\/-----<<------------------------->>-----/\/\/\/\/----|>|-----\ | PIC OUT-----------------/\/\/\/\/-----<<------------------------->>-------------------------/ Now figure this, the 5 volts will be divided across three resistors and an LED inside the opto, so IF the current loop is complete, we'll see about 1.5 volts drop across each of those four devices. Since the loop starts at +5 volts, we'll see that only when the PIC output is LOW, completing the current loop. So without getting into the GM5 traces, let's see what we can scope off the backs of the MIDI jacks.. While at "rest" (not sending), BOTH of the MIDI OUT leads will probably read near 5 volts. Now look at each one while MIDI is sending. Good readings, showing a complete current loop: The one closest to the (PIC,GM5,Buffer) Out should be showing a square wave from +5 volts to about +1.5 volts. The other MIDI OUT pin should be a square wave between +5 volts and about +3.5 volts. Bad Readings, showing an "open loop": One pin will be square wave from +5 volts to near 0 volts, the other could be anything, probably always +5 volts The difference between those two is whether the loop is complete, so current can flow when the PIC output is LOW. Notice the MIDI cable is "straight through", so looking at the 2 pins on the back of the MIDI IN jack should give the same results as above. Because MIDI is a "current loop", ANY break in that loop will stop it from working. If you are testing a MIDI connection between two different devices, the scope should be connected to the ground of the MIDI OUT device, since it drives the link. That's why the MIDI IN circuit needs an optocoupler. One other detail: The MIDIBox, and a lot of other MIDI IN circuits have a "back diode" across the optocoupler LED, that allows current to flow backwards if needed. (not shown in my cheap graphics, see the core schematics) If everything I described checks OK, but it still doesn't work, you may be have the wires crossed in your MIDI cable or any of the MIDI jacks. If the previous tests check OK, move the scope ground to the MIDI IN device, and look at the Output of the optocoupler(6n138 Pin 6). Always High is the "at rest" state, it should pull low pulses as MIDI messages come in. I hope this all made sense. The "current loop" will divide the voltage as it passes through each resistive component of the circuit, but only if current is flowing. If there is an "open" in the circuit, you get +5 or 0 volts and no current through the optocoupler. I said the drop per resistor would be about 1.5 volts. That's a rough guess, so if you want more accurate estimates, subtract the forward voltage of the opto LED from VCC, and divide the rest by three. _IF_ you can "float"(separate) the ground on either your scope or your MIDI gear, (DON'T do this if you don't know exactly what that means) you can connect the ground lead of your scope to the 6n138 pin 3, and the scope probe to the 6n138 pin 2. You should see a positive square wave of about 1.3 to 1.7 volts when MIDI is coming in. If this is correct, you have tested everything you can right up to a working LED inside the opto of the MIDI IN circuit. Maybe it makes better sense now, maybe I've just confused everyone. If I get feedback that I've flown too wild, I'll gladly delete this post. Good Luck, LyleHaze

You'll need to modify the program.. The LCD works by sending ASCII codes that describe which character to display (Google "ASCII Chart") The LED digits work by lighting up to seven segments for each character. (Google "7 segment") You'll need to build the drivers electronics, probably multiplexed. You'll need to convert ASCII to 7 segment (Google "PIC table lookups, RETLW") Modify the code to convert the ASCII values to 7 segment data, and drive each digit with the results. Done! Have Fun, LyleHaze

OK, I can answer a few questions, but as always, I could be wrong. On the bright side, if I AM wrong, there will be someone here to correct me in short order. I'll try to be more detailed than I need to be, since it makes everything clearer, and because others may be reading this too. The difference between voltage and current: the Output from the PIC switches between +5 volts and zero volts. It is capable of sourcing (5 volts) or sinking (zero volts) about 25 ma per pin. In the case of the MIDI output, the signal goes through a 220 ohm resistor, then directly to the MIDI OUT jack. The return comes off the MIDI OUT jack, through another 220 ohm resistor, and then to +5 volts... OK, I have drawn a simple .bmp to help me explain, but I can't figure how to upload it here.. Here's the current path for a MIDI communication. We start with +5 volts from the sending (MIDI OUT) port, through a 220 ohm resistor, and off to the MIDI OUT jack. The MIDI cable carries this to the MIDI IN jack, where we go through another 220 ohm resistor,then through the LED inside the optocoupler. The current path then goes back to the MIDI IN Jack, through the MIDI cable, back to the MIDI OUT Jack of the sender, through one more 220 ohm resistor, and to the PIC (or GM5 chip) that's sending the data. MIDI OUT MIDI CABLE MIDI IN opto +5Volts---/\/\/\/\/-----<<------------------------->>-----/\/\/\/\/----|>|-----\ | PIC OUT-----------------/\/\/\/\/-----<<------------------------->>-------------------------/ The point I was trying to make.. you can use a scope to see lots of activity at the PIC output, or anywhere along the bottom wire, but unless the complete circuit, including the +5 pullup on the "other side" of the MIDI OUT jack is in place, the opto will not pass the current needed to light it up. Another point, if the wires are swapped, the LED in the opto will never "light up", so it won't work. And this leads well into my other point.. You have what appears to be a working GM5. So IF it has normal DIN sockets for in and out, you can make a couple MIDI cables and test each one by just plugging IN to OUT. To answer your question: yes, midi can go full speed in both directions at once. After doing a loopback test on each of your MIDI cables, you can be SURE that: The GM5 is working, The GM5 drivers are working, the MIDI cables are tested OK, your MIDI OX and/or MIOS Studio are correct, and all your shit is good. Once you have that, you are MUCH closer to figuring out how your MIDIBox is really doing. Anything less than that, and you're just making your troubleshooting more difficult than it needs to be. Hope it helps. If I got anything wrong, have me kicked and banned. ;-) LyleHaze

Hello, Sorry for your difficult day. I will offer a few things to try, but I am not as smart as the others that helped you already, so if I say "A" and they say "B", you can bet on "B" for sure. ;-) Sometimes a different approach might help, so here goes.. As best I can tell from your mad ranting, you have been able to see MIDI from MidiBox to GM5, but not much from GM5 to MIDIBox. Good news, you're halfway there. (I'm trying to be positive!) I'm going to start with the loopback problem, 'cause if you haven't got control of your MIDI interface, you're not going very far. You say that you can see pulses with your scope, but it's not working. Maybe I can help with this observation: A scope looks at voltage, but MIDI works with current. If that doesn't ring a bell, I'll try it another way: Your scope is referenced to ground, but the input optocoupler is referenced to the other MIDI conductor, usually a resistor to +5 volts, I think. If the "other side" of that circuit isn't there, it will act just like what you are describing. All voltage and no current will bust your chops every time. (I can almost hear the forehead slap and the low groan) I have one other suggestion, but it's a guess, I could be completely wrong.. Wire your MIDI Jacks completely and use real MIDI cables in between them. Don't cut corners with a bit of wire hacked between where the MIDI jacks are supposed to connect. There is no problem making your own MIDI cables, but make them right, and make good,clean soldered connections. Don't go cheap on how things are connected, that's just asking for extra headaches. If you have a cable that works "most of the time", either fix it or destroy it. Flaky cables are just not worth it. I hope this helps, good luck. LyleHaze One other thing.. You might want to start by uploading a file for a completed project, such as "midimon" or something, before trying out something you put together yourself.. Just to reduce the number of possible sources of trouble.

I had not considered using polyfuses as the pulse circuit. I would guess that they are not durable enough for that many blow/repair cycles. But extra points for thinking outside the box! I would suggest that IF you try this with MIOS, that you write this application to work through MIOS, and you avoid rewriting any part of MIOS itself. This offers you: The ability to work in a higher level language like C instead of ASM, and it makes it possible to easily port your app to newer MIOS versions later. Let MIOS provide the well tested framework, and you just add the application specific stuff you need: Incoming NOTE ON will turn on an output, and the velocity is stored somewhere.. periodic timer decrements the stored velocity by some preset amount.. when the velocity is decremented to zero or less, the output is turned off. That's a simple framework to start with anyway. since the max velocity is 127, you can juggle the decrement value and the timer interval to determine the maximum allowable ON period. Later refinements might include ignoring additional NOTE ONs of any note that is already ON, and ignoring new NOTE ON messages until a note has been OFF for some preset "release time" MIOS handles all the startup, bootloading, MIDI management, and lots of ugly stuff for you, all you need to do is add the "fun stuff" described above. Have Fun, LyleHaze

I find the hardware / software discussion very interesting.. Yes, either CAN fail, but they don't have the same failure modes at all. Once code is "stable" it can be tested thoroughly, and it's behavior should be as predictable as that testing was thorough. As long as the definition of "code" is the complete package, MIOS, application, and settings, and the testing includes all variations of MIDI input, valid and invalid. I'd LOVE to say that tested code never fails, but I have had bit errors in the program storage of PIC chips.. Does that count as software error or hardware error? But the code will always be subject to the hardware it is running on. No matter how well the code is written, a power failure, loose connection, or blown fuse can always bring the software down. A great mind in a frail body will soon perish. Getting back to the discussion at hand, I suggest the following considerations: A stuck output may burn a solenoid, but it will not put life or limb in peril, so there is no need for "extraordinary" safety measures. Another reason to avoid explicit hardware timers for each output are that they would complicate the option of letting note velocity control pulse duration. I think a reasonable protection level could be reached with slow-blow fuses, either at the power supply or maybe for each separate solenoid if you want overkill. Another option could be polyfuses, as they are self resetting. This has the advantage of reducing service visits, but can give a bad reputation for intermittent reliability if nobody fixes the root cause of the overcurrent problem. As technology becomes more accessible, better ways become available if we want take it that far. A simple current monitor reading back to an analog input would allow the PIC to monitor current usage while operating, and then establish a "baseline" of current consumption while it operates. Now we can be smart enough to know when one (or all) the outputs are drawing more current than they used to. It sounds "over the top", but it's neither difficult nor expensive to do. Just a good challenge to teach our machines to do self-diagnosis. Any abnormal readings could be transmitted by SysEx messages that describe the variance. Finally, from a failure analysis perspective it's important to consider, a bad solenoid can destroy the driver transistor, and a shorted driver transistor can overheat and destroy a solenoid. I'm not the only tech here who has a background in pinball machine repair. Fun to think about, I hope I didn't get too far off-topic. Have Fun, LyleHaze

There are two sources for kits that I know of. SmashTV runs a webshop at http://www.avishowtech.com/mbhp/ Mike has a shop at http://www.mikes-elektronikseite.de/shop_englisch/index.htm There are also (sometimes) "bulk orders" arranged by individual members as a favor to the community. Most of the kits here are the circuit boards and parts only, so building the boards is only the first part of the adventure. Then you need all the buttons/sliders/encoders/LEDs for whatever you are building. Finally, you get to design and build your own enclosure to hold it all together. In the case of MBSeq, there is a "complete board package" that will really speed the project along, but that will depend on whether you can get in on the bulk order, Yes, by the time you complete a successful build, you will know how every part on it works, and you'll learn about basic electronics and some programming, too. How long it takes is a guess at best, but it's a good idea to take your time. Finally, the answer to the questions you didn't ask: If you are looking for the shortest path to a complete, finished product, MIDIBox is probably not a good choice. Likewise, if you want the cheapest possible solution, this is not it. What MIDIBox projects are best for are people who want to make something special with their own hands. TO get involved in every step of the design, construction, and programming of a unique, one of a kind MIDI device. People who are willing to take the road less traveled, to work a little harder to get a finished project that they can take special pride in. What will it take to complete? There is a lot to learn. there is also a HUGE amount of information here to help you along. The very first thing you'll need is a willingness to at least try and figure things out. There are a lot of people here who can help, but they'll only be willing to help if you have at least tried to figure it out yourself first. Too many people come around expecting answers without doing the "homework" first. WE are a VERY helpful community, but your project will begin and end with "Do It Yourself". I hope this has answered some of your questions. I have deliberately made my answer as generic as possible. That's so I can cut and paste this answer the next time somebody asks the same question. Read the recent posts in the Seq forums. Look at the MidiBox of the week posts to see some beautiful casework. Go to the Wiki and read as much as you can about everything you can. By the time you have completed that, you'll know if this is a project you want to try. If you're not willing to read that much, then this is definitely not your cup of tea. As always, I'm not the "expert". If any part of my answer is wrong, I hope someone will jump right in and correct me. Have Fun, LyleHaze [edit] Ooo, lucky you. Looks like there has been a bulk order for the control surface. That should make your wiring task a lot easier, IF the bulk order is still open. Start reading from here http://www.midibox.org/forum/index.php/topic,11802.msg102412.html#msg102412

That depends on what part of the world you live in. Two popular choices in the us are digikey.com and mouser.com The search term is 6n138 The package is DIP Have Fun, LyleHaze

The bargraph display option.. It's not that important, as the dB display is more accurate and it works with all display types. But if you are looking for a display that will support the bargraph option also, I have found the following at electronicsgoldmine.com: 2X20 Vacuum Fluorescent display. for about $25. It is almost identical to the display I'm using, and includes the vertical bars from 0x10 to 0x18 It's a Noritake Itron, part number CU20029ECPB-W1J I like VFD displays, but they do use a bit more power than the LCD types. Have Fun, LyleHaze

I have some experience with the UM-1 interfaces. Since we might be dealing with a driver problem, remember there are TWO different drivers you can use. The interface has an "Advanced Driver" switch on the side. When it is ON, you'll use the drivers supplied with the interface, when it is OFF, you will use the standard OS drivers for class- compatible interfaces. Please note that the interface identifies itself as soon as it's connected, so if you want to change the switch setting, you should probably unplug the USB cable first. I had the pleasure of writing the "class compatible" drivers for another OS. Once the drivers are right, the UM-1 will work correctly with the "Advanced Driver" switch off. Have Fun, LyleHaze

Adding a 4 band EQ is easy enough, but the changes to the board would make it a "full mixer" only, so we would lose the ability to use that board as a stereo line mixer, as the EQ would be for a mono channel only. That would make it less flexible, so not as good for the hobbyist bunch. How far can it go? Way too far to be affordable. If I was to design without care for cost, I'd have a channel strip with: PGA2500 front end, including balanced / phantom power options PGA4311 for 4 channel EQ PGA4311 for 4 effects sends PGA4311 for main and monitor stereo feeds. VU metering of all levels (input, post-EQ, and each output) available in the DATA STREAM (no local LEDS) local processor for control, networked by MIDI messages over CANBUS. Funny enough, I'd want to keep the same channel board size, as it's still getting packed into a cabinet without much (or any) local controls. Can you imagine designing a control surface for a monster like that? But, it's not really a great idea when you get too expensive. It would be over $75 per channel strip just for the big chips. by the time it all got added up, nobody could afford the damn thing. Also, at SOME point, it's a better idea to go digital. But what I like about the way it is now is that the audio is all analog. Since that's a big part of what makes this special from other mixing boards, I'd hate to lose that. SO we are back to where we are now. I made it as flexible as possible, and I get to wait and see how many different directions it goes in. The rest is all just dreaming. :-) LyleHaze

I REALLY hope you are wrong. I went to great lengths to separate the digital and analog circuitry, and even mapped out four separate ground circuits when I designed the circuit boards, all to reduce noise to the lowest possible levels! OK, so I know that's not the noise you meant. I'm just trying to be funny here. I'm really proud of the work, it has taken a few years to get it just the way I want it. I am a bit scared of how many different directions it might go in. At first I thought Orkspalter was a bit crazy about using it for guitar effects, but now I see a way to do some really neat stuff with that. I'm even thinking of making a guitar effects hub myself, even though I sold my guitar two months ago. I was asked about using it in a church, just because the presets are so easy to use. That's not a bad idea, even for animatronics shows like Chuck-E-Cheese, or theme parks. It makes audio control as easy as adding a MIDI port, and it's smaller than a board with motorized faders. And I'm still wondering when "Home Automation" will take off. I expected that to be big business twenty years ago, and I'm still waiting. This would be a great start on the audio part of that. I think the biggest problem right now is that the software only goes up to 16 channels. That's really easy to get around, but I'm sticking with 16 because that's how many channels MIDI has. To do anything different would be moving away from the "standard". As it is now, you can plug a stock BCR or BCF deck into it and it just works. Same for whatever software mixing boards you might have. Hey, maybe it'll get popular enough that someone will offer me a job! now THAT would be cool. And I'm still adding "stuff" to it. I have an MP3 player and USB file access (see MBStor), I am adding a remote control receiver to it now, just because I'm lazy. The remote will connect to the mixer by a regular MIDI jack. I'm kicking around the idea of supporting VU meters, even though that will mean adding a bit of hardware. Once the VU meters are working, maybe a volume correction option (slow compression) for television channels that blast commercials... That would be all software. Maybe tone controls too. That would add an extra 4311 for each channel board, but you'd get a 4 band EQ for that channel. Yeah, the ideas keep coming. I'll shut up now.. Thanks for the interest! The future is getting closer every day.. LyleHaze

Madox: Yeah, that might create a problem. Kris: Thanks.. the numbers help to give a clearer picture. There is little doubt that the Microverb runs on DC internally, but the question now is whether it is running a single supply or bipolar (positive and negative) supply inside. Single Supply: Even if it only needs a positive voltage to operate, many manufacturers include a bridge rectifier and capacitor at the power input jack, as _some_ protection from getting the wrong power pack plugged in. SO if you plug in a DC plug with the leads swapped, or even an AC plug, it all gets rectified into the proper polarity. This is "responsible design". Now, once that is done, the manufacturer is free to supply AC power supplies, which may be a bit cheaper than DC supplies, if both are transformer based. (With the newer switching supplies, DC would be cheaper, but may not be more desirable for audio stuff) Bipolar supply: If the device needs positive and negative voltages, an AC input would be the easiest way to get it. If you were to plug a DC supply in to this type, you would get only a single voltage, and if you got any sound at all, it would be distorted. What to do now: I did a quick web search, there are many MicroVerb types. (original, 2,3,4..) Which do you have? If I could find schematics or a service manual for your microverb, I might be able to tell you more, but without that I'm just guessing. The amount of power your device uses is a pretty light load. Looking into a DC to AC inverter might be a cheap solution. These commonly let you use small electronics while in your car. All of the ones I could quote are 120Volts AC, your area would have something different. With that you could just use the power supply you have already for 9 volts AC. Finally, if it were me, I would TRY connecting 12 volts DC directly to the Microverb, just to see if it works. but I cannot be responsible if it does bad things. Maybe someone else here has better advice to offer... Good Luck, LyleHaze

Very nice.. I guessed that the meter code wouldn't work on most displays.. But the dB code from Pilo should work with everything. It should be possible to define the special characters for the meter in software, but I got busy working on other parts of the project. Lately I've been busy moving. Most of the furniture is already gone, and there is nothing at all left in my office. Now the audio rack with MBMixer and Amp are sitting in the living room along with a pair of 12" stage monitors, and are connected to the television. My wife is getting spoiled by the "Big Sound" we have for movies now. I may never get my stuff back for my office! That also explains why I'm working on a remote control receiver with MIDI out, so I can adjust the volume without getting up from my chair. Thanks for posting the pictures. Once the boards are available I hope we'll get a few more builders interested. LyleHaze

There are many ways, depending on what you are really doing, and how much current you need.. The more information you give, the better your answers will be. Since you gave very little information, I'll offer a few ideas off the top of my head: You can: Buy an automotive power inverter, which will convert 12volts (actually closer to 14.5) into 120 AC, then use a wallwart power supply to get whatever you want. You can: Build a 555 timer in astable mode to get a 12 volt square wave, then feed that into a transformer to step it up by about 50% to 9 volts AC. Depending on the requirements of the transformer, you might need to amplify the output of the 555 somewhat. You can: get a transformer that will step down 12VAC to 9VAC, and connect the primary directly to the 12 volt DC battery, then switch the leads real fast 50 or 60 times a second. Use off the shelf DC to DC convertes to create + and - 10 volt supplies, then use bipolar transistors and a function generator to create the desired output. What did you have in mind? :-) LyleHaze

An "off the shelf" option might be to use an Edirol UM-550 or UM-880 MIDI interface. Like the GM5x5x5, they offer USB to MIDI, and either 5 or 8 inputs and outputs. In addition, they offer MIDI signal routing with or without a connected PC. I think building your own would be more fun, but hey, if you want a "quick and easy" those will work. I have an 880 here, and it works well. But they have been discontinued, so may not be easy to find. Have Fun, LyleHaze

Nice project.. looks great. My question: Where did you get the knob? I have a single encoder that needs a knob just like that one, instead of the basic bright-aluminum one it has now. (or is that aluminium?) Thanks, LyleHaze

I can offer a few thoughts, but I do not have a completed project to show off.. I have begun a similar project, but it's just one of about five open projects I have going on, so there's no telling when or if I'll finish it. As I began the project, there were a few tradeoffs to consider.. The math for converting period to frequency, then frequency to note number, requires some higher math functions. I usually try to avoid this kind of stuff, but it leads to the first tradeoff: If you just want to find the closest note, you can use a lookup table to avoid the math.. that's the easy option. You can also shift the period left and right for octave changes.. so all that is good, as long as you don't need to also calculate the "pitch bend" values to cover the differences. Next possible simplification: If you're only watching for the period of the incoming audio, you don't even need to use an analog input. A simple comparator will output a digital signal that you can use to calculate the period of the incoming audio wave. You can also use A/D conversions and just watch the most significant bit. I would suggest basing your math on the FULL wave, not just a half-wave, to eliminate any errors from offset bias. Finally, your choice of platform. I'm guessing that any of the suggestions made will work, some better than others. Of course you will find people here are biased towards using MIOS and the MIDIBox. [EDIT] I know nothing of the picaxe, but there seems to be a lot of BS in the chat forums. ;-) Starting off with just using a lookup table to determine the closest note would be a great start. How far you go from there is up to desire and determination. Have Fun, LyleHaze

Glad it helped, but I'll pass on the expression of gratitude. Not all my answers are useful, but at least I get a few right every now and then. Have Fun, LyleHaze

I also see they have MIDI IN and MIDI OUT reversed in the example hookup picture. :-) LyleHaze

If only 1 and 14 are marked, there are two ways you might interpret it. Could be: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 or 1 3 5 7 9 11 13 2 4 6 8 10 12 14 Notice that both have 1 and 14 in the same place. I need to find my PDF file for my display. This page offers some comments on it. http://www.geocities.com/p9019/lcd.html Have Fun, LyleHaze

Just guessing.. I see the datasheet does NOT specify how the first 14 pins are numbered. Are the pin numbers printed on the Circuit board? I can't find the datasheet for my own right now, but there is a drawing of the pin numbers. Good Luck, LyleHaze

MOST M-Audio stuff will work, but only after you change a setting. The way they ship, the MIDI ports connect to the device itself, but if you change a setting, it will pass the MIDI connections to the IN and OUT ports on the back of the gear. From the manual: When installed, the Axiom appears as a simple MIDI device with two input ports and one output port. You should select the first listed Axiom input port as the MIDI input device in your software. Once this is set, your software should be able to receive notes and controller data from the Axiom. If you have connected external MIDI gear like a drum machine or another keyboard to your Axiom’s MIDI IN port, this gear can be interfaced to the computer by selecting the second listed Axiom input port. This way, your Axiom is acting as a MIDI to USB interface. It is also possible to stream data from your computer to external MIDI gear connected to the MIDI OUT port of your Axiom— effectively a USB to MIDI interface. To do this, you should select the Axiom output device in your software. Note that some other steps are necessary to make this work that will be fully explained later in this manual. \ Later in the manual.. MIDI Out from USB can be used to switch the source of the MIDI data seen at the MIDI Out port of your Axiom. On initial power up, MIDI Out from USB mode is off. This means that as you play your Axiom, MIDI data will be sent to the MIDI Out port. If you turn MIDI Out From USB mode on, playing your Axiom will no longer send data to the MIDI Out port. The data is instead streamed from the computer. So, as long as you have selected your Axiom as the active output port in your computer’s sequencer, this is the data that will be sent the MIDI Out port. For example, if you want to control a sound module from your Axiom, you should ensure MIDI Out from USB remains off. If you want the sound module to play data streamed from your computer however, then you should turn MIDI Out from USB on and ensure that the output port for your Axiom is selected as the computer’s MIDI output device (this is done in your computer software). To control MIDI out from USB mode: 49- and 61-note versions: < Press Data 2 and Data 3 together to change the MIDI Out setting to MIDI Out from USB. < You will see a MIDI plug symbol appear on the LCD display. < To turn MIDI Out from USB mode back off, press the same button combination again. When you do this, the MIDI plug symbol disappears. 25-note version: < Press the Advanced button. < Press the MIDI Out key to activate MIDI Out from USB. < You will see a MIDI plug symbol appear on the LCD display. < To turn MIDI Out from USB mode back off, repeat these steps. When you do this, the MIDI plug symbol disappears. All this is straight from your owners manual. If you look there you'll also see some pictures that I didn't post. Have Fun, LyleHaze

OK, looks like a sweet bit of classic gear. I looked over the service manual you provided. The transformer has a "tap" (alternate connection) to select between 100 Volts and 117 volts, making THAT change would be as easy as moving a wire. But if you want higher voltages, you would need to replace the transformer and four fuses. The 220/240 volt transformer is listed as part 022-067AD. As you mentioned before, finding one of these will probably be close to impossible. If you want to find your own replacement transformer, I can see that it needs three separate secondary windings. the prints do NOT tell what the voltage and current of each secondary are, so you'll have to fire it up and take measurements from the one you have now. The chances of finding a transformer "off the shelf" that will match all three secondaries is pretty bad. You will most likely be looking at a custom transformer. I don't know how much that will cost, but I'm betting it's a deal breaker. Changing out the entire power supply is a non-starter as well. It looks like there's a lot of "other stuff" wrapped into the power supply circuit. The "Echo Cancel Footswitch", "Repeat Rate", "VU MEter" and more are part of the power supply circuit. It's looking like an extra transformer is your first choice, and buying another one that is already 220 is your other choice. Have Fun, LyleHaze