DragonMaster

There are multiple ways to get more or less what is needed. I already started a topic about this a year ago : http://www.midibox.org/forum/index.php?topic=7813.0

Well, my idea was to make four 4-channel OPL3 sets (or 8x 2-channel) connected through MIDI in the same box. I asked TK a while ago and he said it was not possible to link cores or use multiple OPL3s per core, unfortunately.

::)

Both : http://www.middleatlantic.com/rackac/chassis/chassis.htm#2

I'm more a flexibility maniac than anything else, and I'm a little cheap at the same time. Buying OPL3 sets is cheaper than filters, and if I have lots of polyphony I can output multiple times the same sound with slight detuning and delays to get something interesting without filters. A single OPL3 is quite limited, and one bare synth sound without filter is quite boring IMO. So, I put myself on the list for one set, and if I get Wilba's card at the same time, I'll have the 3 missing DACs I need. I still have no PCB though ;) , I got a few problems lately that made it impossible to work on any projects I wanted to : -Laser printer broke as I was going to print my first PCB layout, still haven't got to fix it, dead $30 part. >:( -35 hours/week at school + 15 hours commuting since August :-\ -No $$$ :'( I'll try to get my old laserjet IIP working during the winter...

http://www.mouser.com/ $20 Shipping about $15 for something of that dimension IIRC.

It's not Paia, but Middle Atlantic Products seems to make stuff that isn't too expensive.

In fact, I have 4-5 cards, but wanted 16 channels ;D Yep, considering you need two cards...

Would it be possible to get YAC512s alone as well?

Sorry to post in an old topic, but just to specify about displays: LCDs are the most reliable, just make sure you get one with a *LED* backlight. Older and some new LCDs are backlit by EL foil connected to a DC -> AC 120V 400Hz inverter. It's dangerous, noisy and produces interference. Also, EL foil gets darker with time, that's not a great solution, considering that the backlight will fail and you'll be stuck with a dark screen unless you decide to fix it. LCDs can have an OLED-kind effect by removing the polarized film on the top and putting some new one in place(Google or ask for more details). It will invert the colors. The background will be black and characters will be lit. VFDs are an other option, much better looking than LCD, but suffer from degradation. However, recent and good quality models don't seem to suffer from much problems. I haven't done tons of research, but Noritake seems to be one of the biggest guys out there(if not the only one), their VFDs are pretty good from my experience (I guess they filed tons of patents...) They make LCD drop-in replacements, and it looks like they have great support for custom projects and tech support. I'm not affiliated with them, but their products look cool and well built.

Well, with a wiimote you surely can use the nunchuck with one of the existing Wii remote mouse drivers. I know you can use RM-X Automation with the Wii remote itself at least.

Hi, if you're connecting a computer with your midiboxes why don't you use it as your touchpad -> MIDI controller?

http://devlincomponents.co.uk/switch5.html ;D 31-LED LEDring encoders I don't know their price directly from the manufacturer, all I know is that Farnell (no. PLA1810-1) won't stock them anymore, has 13 units in stock and they cost :-X £40.

Hi, software or hardware could solve your problem. You will need to invert the signal and connect the common side to positive rather than negative.

PSU filtering is the capacitors around the voltage regulator to remove the voltage ripple when converting AC to DC. Rectifiers aren't perfect, and capacitors are needed to make DC constant. The thing with batteries is that they output ripple-free power, so no filtering is needed. A switching power supply converts DC to high-frequency AC and then converts everything back to DC. It creates noise in the power supplies lines, and it could be heard at the audio output if you don't use good filtering. Since your 9V-powered equipment probably has regulators in it(regulators remove a good part of the ripple), you would just have to put an electrolytic capacitor between the equipment connected and the SMPS PSU, it should be enough. This switching PSU you linked to is probably a good option to keep a longer battery life, even if you have a few caps to add, which isn't really a problem anyways. Just make sure you don't exceed two amps usage with it, it's the max current for 9V. It's not much more expensive than building a switching regulator. I've never built switching regulators as they need inductors, possibly one of the hardest to find component(in the required values).

Hi, lead acid batteries are much more than car batteries, they can be a few inches large to >200lbs monsters : http://batterymart.com/c-sealed-lead-acid-batteries.html http://batterymart.com/c-gel-cell-batteries.html http://batterymart.com/c-deep-cycle-marine-batteries.html (They don't ship to Australia, it's just a reference) I'm not sure, but they're surely the cheapest per Ah. Chargers are like anything else, there are cheap ones which just charge(a power adapter with a rectifier), and there are triple-stage pulse chargers with LCD screens, etc... To specify, it's not that simple, the regulator could start overheating with 12v maybe. Note that a 2x20 will consume a few mAs more if not nothing more at all compared to a 2x16 LCD though. Remember calculators work without problem using incredibly small solar panels. I think that both sizes even use the same controller, so there's nothing to lose with a 2x20 unless it's much more expensive or if you already have a 2x16 LCD. For a battery meter, I thought about it, and I think that an analog needle meter would be a better solution, you'd be able to keep an eye on voltage that way. I saw some circuits a few times, but I'm looking right now and can't seem to find one. As nebula said, a good part of the equipment could run off from 12v directly. If there's one that consumes much current, then a 7809 would not be a good idea. There are 3A versions of the 7809, just make sure you use an heatsink with those, because linear regulator have about 40% efficiency. You could start dealing with switching regulators, but they need quite good PSU filtering. You can pretty much forget power supply filter caps with batteries, but with a switching regulator, you lose that advantage. You didn't mention any amplifiers to get the sound out of that equipment, what are you going to use? As for the battery size, it really depends of the total power usage the lot will have. A 250Ah battery is not necessary, it would make a great 200lbs weight though, or make miter saw busking possible ;D

Hi, your battery will probably be on the edge of being drained out every times you'll finish using it, and considering batteries degrade with time, it's probably not the greatest solution. They claim 8 hours @ 200mA, I think you'll have to build the circuit first, measure how much current it takes and then buy a battery based on this. You can be sure to find the proper battery, as they're available in about every voltages and Ah possible, you just need to be sure of what you need. The National LM2941 voltage regulator should suit your needs as an LDO regulator, the only thing is that it's variable so you have to do (simple) maths to get the proper resistor values. Dropout voltage on this one is 0.5V. If you need someone to get the circuit done for you there's no problem. http://www.national.com/mpf/LM/LM2941.html I don't think that there are low dropout exact replacements for a 780x that can handle 1A as well. The LM2941 is the closest I've personally found to replace an LM317(variable version of 780x) Even if you use National's regulator chart, it's the simplest solution. (I think there are some fixed voltage LDO regulators, but they're of the switching type, so we would have to start playing with inductors there.) To save power, you could use efficient LEDs if you need some, and use low power version of certain parts(PIC, opamps) Just wondering like that, what will be the power source of your other equipment? Is it possible to get power from a larger battery or something? I see TK replied as I was writing. You should add a low battery indicator to prevent errors like that.

I was mostly wondering how much effect separate crystals would have on the sound, but it looks like it's not that different from what have been said. Using 1 xtal could also save 50¢ on the BoM, but that's not really useful...

Well, I was effectively talking about connecting the same XTAL to all the PICs to synchronize them all (LFOs, etc.) Oh, it's not that bad finally, I thought about this when I saw four different XTALs on the PCB, and at the same time knowing that doing digital recording with multiple soundcards that are not synced was causing timing differences after some time. Connecting them all on the same crystal can be done easily IIRC, the XTAL output pin of the PIC is simply a voltage source, so connecting the crystal to Vcc and connecting it to a buffer sending the signal to the PIC XTAL inputs should work.

Hi again Wilba, I thought I would ask a question in the forums rather than by e-mail this time. Is there any reason why the cores don't use the same crystal? It would have the advantage of syncing all the cores together, to make up for the timing differences crystals can have. It is easy to apply, and it just needs a buffer. Or, have you decided to use different crystals to make the SID pairs sound different from each others, to make it more "analog" sounding?

>:( I pay duties and 14% taxes EVERY SINGLE TIMES I use government postal systems(USPS, Canada Post, Royal Mail), UPS or FedEx. Last time, they even charged $13 for duties rather than the usual $5 (Though that package came from UK). Or if you're going with Canada Post, they're going to charge you taxes for what they think the content is worth if they happen to open it. (I once paid taxes for a $300 value when I bought a $120 broken laptop) It sucks, but they're not the worst guys out there(UPS and FedEx charge even more).

If they get out of sync as well, your HDDs can be good, and you can lose your data because of the mobo or something like that. Should not be a problem if the chipset can lock the PCI bus, etc. Recent computers shouldn't cause any problems, lots of motherboards are designed for overclocking.

Just one little more thing, a Core 2 Duo might be interesting with the 30% and up price cuts Intel just announced.

OK, if you want a cheap but good machine, it's quite easy, you just don't need to get a $500 video card, highly overclockable RAM and a motherboard that supports 3 video cards. It's not a gaming machine, so it's almost impossible to make it expensive. If you want any extra safety features(Mirrored HDDs), it will cost something. First, the CPU : Intel Core 2 Duo or AMD Athlon 64 X2. Leave the BS arguments Intel and AMD guys give. There isn't one that is crap and the other is good. A new AMD X2 and Core2Duo passed enough revisions to be stable. What makes a system unstable is standard RAM and/or a cheap motherboard. Get an Intel or an AMD(Socket AM2), it's as you want. Performance users tend to prefer the Core 2 Duo because it's easier to overclock and the architecture is newer/more performant than the X2, but they don't trust the stock Intel heatsink and compound. Get a dual core, or a quad core(Expensive tho) it will keep latency low if a background program decides to do something. If you live in the US, buy from ZipZoomFly or NewEgg. About everyone here forgot about the PSU, it's one of the most crirical components. Get a good Enermax, Corsair or Cooler Master. They pretty much have the same features. There are a few Enermax PSUs that provide maniac power filtering, which is preferable. For a motherboard, watch before buying, EVERY companies have lemons(It's often the chipset's fault), but some make more reliable stuff. Look for DFI Expert, DFI-ACP, Asus, and cheaper but decent stuff like MSI, Foxconn and Gigabyte. RAM : OCZ, Corsair, Mushkin, Crucial are great. Try to find RAM with low latency, and at least DDR2-667. Especially if running an AMD, since the memory controller is on the CPU rather than the motherboard, it's affected a lot more by the RAM size. You will probably run WinXP 32-bit, so get 2GB of RAM. XP 32-bit can't take 4GB, and 2GB is now the RAM size standard. RAM will be one of the most expensive part of your computer. HDD : Get Seagate 320GB or + SATA2 Perpendicular-heads drives. They perform very well and perpendicular recording stores the data more safely. You can get multiple drives and run them in parallel, or mirrored, some options are safe, some not. Putting drives in parallel is faster, but you have more than twice the chances to lose your data. Mirrored, if one drive fails, there's still a backup. Both at the same time, well it's faster AND safe. Video card: To prevent your comptuer from slowing down, don't get a motherboard with intergrated video, it's stealing the main RAM. If you just want to run 2D and maybe watch or encode video, an AMD/ATi X1650Pro will work great. Sound card: There's onboard sound in EVERY computers now, it's crap. You should look for M-Audio and a couple other good companies, you might want to take a look at a Gadget Labs external box, these are pretty good apparently, but the company doesn't exist anymore. There are XP drivers, but note it will NOT work in Vista. Get an external card. Case: You might want a silent one, there's Silverstone, Antec, CoolerMaster, Thermaltake, etc. you might want to look at. Antec has pretty cheap and silent stuff, the Sonata series. It comes with a low-end but decent PSU. Optical drives : LiteON, NEC, LG. About dual boot, you need either : two HDDs, or to resize your current partitions and leave space for the new system. Progs may get screwed with two same-OS installs tho. This is pretty vague I know, if you need more details let us know.

Found this PDF at Yamaha's site, simple explanation of FM, it could be added to the links in the midibox FM description page. http://www.yamahasynth.com/download/sw1000xg/FMINFO.pdf