JRock

Thanks for taking the time to write out this specific list of questions. That's what I'm looking for cause I am floundering. Unfortunately that's the best camera I can come up with immediately. I'll try to get some better photos. I think it's the lighting. I have a lamp right above my workspace. It's great for seeing what I'm working on but maybe not as much for Photography... :laugh: I apologize for my confusion about PIC > Opl3:J2 connections. I disconnected it for these readings. I had measured them against Opl3:J3 ground. I listed those voltages because with that being the Only connection the Opl3 module had to anything, the LED was still lighting. Here's the answers to your questions. 1) With everything disconnected, what voltage do you read from IC1:12(Vss) to IC1:11(Vdd) on the core module? : 5V 2) When you connect Core:J1 to OPL3:J1 only - what voltage do you read from IC1:12(Vss) to IC1:1(Vdd) on the OPL board? : I connected Core:J2 to Opl3:J1 IC1:12 to IC1:1 on the Opl3 Module and got 5V. I was hesitant to hook Core:J1 (9V) to the 5V rail without doublechecking with you. 3) Does the LED light up with just the Core:J2 > OPL:J1 connection? : Yes 4) With no wires connected anywhere - What's the resistance between the following pin pairs on the OPL module: IC3:4 and IC1:12 24M Ohm IC3:4 and IC1:1 24M Ohm IC3:11 and IC1:12 7M Ohm IC3:11 and IC1: 7.1M Ohm J3:V+ and J3:Gnd 35M Ohm J3:V- and J3:Gnd 32M Ohm J3:V+ and J3:V- 16M Ohm 3) "I haven't attached the pull-up resistor for the CAN Bus." - the diode isn't there either? : No

I have a couple more pics but I can't get anymore to load right now. When I hook Core J2 - Opl3 J1 It's 5V. When It's just the core to Opl3 J2(1-2) The voltages read like so: -.7V -.7V 3.9V 3.9V -.7V 3.9V -.7V -.7V 4.17V -.8V around 2.5V but it fluctuates +/-.1 rapidly 4.19V I have an 18F452 and I haven't attached the pull-up resistor for the CAN Bus. After I took these pics I took out the 74s and I am not gonna hook up the +/-12V till I figger out what's goin' on. Thanks guys

Sounds Cool.

Again, Thanks for all your help and your input :flowers: I got Rev.2 so all should be good. So my core works normally. It boots up and wants to play. The LCD is working fine. With the core wired to the OPL3 via J2(1) and J2(2) and the core powered on, the LCD lights cause Pin 1 (Vdd) of the YMF is getting 3V from somewhere. The +/-12V is not connected and nothing is connected to J1oPL3. I checked the YMF262M Datasheet and I can't decipher what the internal connections are. Probably pretty complicated. The only closed circuits with pin 1 of the YMF are pin 7 of the YMF (/RD) and the 5V rail for the YACs: pins 1, 3, 7 and 9, as well as the Vdd pin for the XO; and the +5V for J1oPL3. Has anybody gotten this? What voltage does your 5V rail read when J1 and J3 (OPL3) is not connected to any power?

Hi Joel. I don't have a sammich but on my MB6582 if I put a Busted SID in on of the slots the machine will try and play it like normal... It just won't play. Same with SID V2. If you want to test the SID, POWER DOWN! - Place SID2 in SID1 spot and fire it back up. edit: +1 to what JV said. +2 to what Phunk said. Do what Phunk said. You can also put different Waveforms on the left and right channels and pan them on your mixer

Thanks guys. I did get my board from Smash. What Trace needs fixing? I was pretty meticulous about the SMDz. That doesn't mean I'm infallible but they look pretty good. I'd hate to bugger up the board so that will be my last resort. Thanks for the Link Janis. Yeah, I had read that thread a couple times. That's why I thought it might be the YACs. I guess I'll try to fix this trace (as soon as I find out what it is) first, try a different XO, then see where I'm at.

Thanks guys. For your patience and your help. :flowers: Ok. The ribbon cable is the only connection between the core and the OPL3. The core is working properly. The +/-12V is not connected. I get +3V @ J1oPL3, Pin 1 on the YMF and Pins 1, 3 and 7 on both YACs. and the LED is lit. I'm not finding any bridges or connections that aren't supposed to be. That probably cause I'm not looking in the right spots.

I meant 4 and 11 of the TLO74s :blush: I mean pins 1 and 3 on the YAC and Pin 1 in the YMF read 5V. (Like it says they ought to in the schematic) Thanks.

Here's How I'm connected. All the voltages read correctly. +/-12V on Pins 4 and 8 of the 74s. If I don't have +5 from J2core connected to +5 J1oPL3 the +5 pins on the YACs and the YMF read 2.82.

That's awesome. Thanks!

Damn. I got a 20x4 with an R232. Will it work with a core 8 or MB6582? I'm guessing no. I don't know anything about this stuff

I was just pulling the redundant grounding off. I wouldn't touch the neutral from the +/-12V or the negative from the 5V. From J2(Core) to J3(OPL3) to J4-J7(OPL3); and the +5V from J2(Core) to J1(OPL3). The LED still lights when J2 to J1 is unhooked. I just assumed that was correct. I guess I'll have to doublecheck that. My ribbon cable is only about 6" (15cm?). I'm sorting through a mess of components right now but when I finish that I'll draw up a sketch, take a picture and post it up. Thanks

I have a stable Bi-Polar PSU. I pulled the transformer out of a 1000mA 12VDC wallwart and built a Voltage doubler circuit. I tested the outputs on J4 and J7. They both sound like the clip I posted. The test tone played faint and distorted when I pulled the ground off. I couldn't hear it with the ground on. What voltages are you supposed to get on pins 1 and 4 of the 74s? I'm reading around 9V on the first two and closer to 14.5V on the third one. Maybe this sheds a little more light on things?

Hi. I can't seem to get music out of my FM. It just sounds like digital noise. \MBFM Ground.mp3 This is the sound I get when Everything is hooked up the way it is in the interconnection diagram. MBFM unground.mp3 This is the sound I get when I remove 5V and Ground from J1 and J3(on the OPL3) Both of these are bootup then press some keys, then turn the modwheel. I am using the PSU to Power the core module as well. I pulled 12V and Ground over to a 9V regulator and send that to J1 of the core module. The interconnections test worked and when I got a very quiet testtone when I pulled the ground and 5V off of J1 and J3. I've heard very quiet melodic tones while I wsa trying different stuff out... What Do I need to check? I've read a bunch of posts that are mostly similar. Do you think it's the YACs or the 74s? Maybe the Crystal Oscillator? I'm stumped.

That's happened to 2 of my LCDs as well. I never could get the backlight working though. (Not positive it has one. I think it's supposed to though.) It started fine... Then slowly the lines crept in till it's just boxes now. When I switched them the new one was boxes, but I plugged it and unplugged it a few times and it cleared up. Now over time it started to get lines and then blank and I fucked with it and got boxes again. It has been stationary and I have not been plugging it in and out (or backwards). The soldering around the trimpots and PIC and headers looks fine. I've been meaning to post about this, I have just had other things I've been whining about in the meantime. I'm glad you mentioned this PingoSimon. What kind do you have Ping? I'll check on mine and get back. They can't be that sensitive. We'll get to the bottom of this.

Not if I can avoid it :ninja: They're like goddamn stereo instructions! Strike that. I like reading stereo instructions :laugh: {(That's me laughing @ my own joke) It didn't even occur to me. I didn't think it might be the regulators... I was figgering Human Error if anything. So I can continue to feel proud of myself for building this PSU :cheer: Honestly I don't even know where I got the transformer from. I think i found a stereo for free on the roadside. Should've read the manual. It has Seven leads. I managed to get +/-12V and +/-15V out of it. I thought I was gonna be able to get 5V too but after I hooked the other Johnsons up I was only getting 2.5V from the remaining leads. I don't know what the amperage is cause the fuse in my Multimeter kept blowing out when I tried to test it. I went through 4 of them. Let's see what it does under load. I rent so fire's not a huge concern That's nice Flemming! I couldn't understand why my 1N9148s kept blowing up, then I googled bi-polar PSU and saw they were supposed to be 1N4004s (or 7s) I robbed some 4002s off that stereo PCB and they seem to be working alright.

Not real sure where to post this... My PSU ended up being -12/+11.74. I took the other 2 leads out of this transformer (It has 7) and built a -15/+14.74. I used the method described in the Bi-polar PSU Wiki with the Voltage Doubler. First, Is this something to worry about? I'm guessing for a Bi-polar supply you want both sides equal. If it is, What can I do? Should I slip a resistor into the high side and bring them both down to XX.74?

Maybe you have the leads on the PSU switched around backwards. If that isn't it just switchthe leads on your multimeter around! :laugh:

Wow :huh: Very stern... Nils, Thank you for your replies. I am very grateful to you and I really appreciate it. :flowers: I'm not trying to be a pest :bug: or fill up the forums with a glut of useless junk. Every time I ask about a part I learn what it does. I search thoroughly first. But that being said... I iz Po'! :sad: Here's what happened... I spent 2 x 15 hour days on my order list. I previously destroyed my credit so I have no hope of getting a credit card. I have to use prepaid cards and it cost $5 every time I put money on the card and there's a $20 minimum. It's been raining a lot here (Like today). I'm a stone mason, so rainey mean no workey. That's good cause I have time to work on MidiBox But that's bad cause I don't get paid. I have no extra money for shipping and reloading and such. I had what I had on my card and I checked my list 3 times and the numbers worked out so I ordered. :sweat: I got components for 4 SSM2044, 2 AOUT NG, 5 Core8, 1 Opl3, 4 SIDs, 2 GM5, 1 MB6582, and assorted DIN/DOUT modules. I got as much as I could afford (to save on shipping and reloading charges). I can't print the order lists out cause I don't have a printer. I have to write everything down and check it off. It's very tedious. So all things considered I made very few mistakes, but I am only human. I know I'm gonna have to make a tidy up order but I'm seeing what I can get away with so I can build a couple complete modules in the meantime. I'm really working hard to learn how and why this stuff works. :geek: I remember in your forum post about the GM5x5x5 you said it hasn't caused any problems using a 100nF cap in place of the 1uF cap so I keep hoping the same will be true about these other modules. It hasn't though. So like I said; Thank You Nils. I'm very grateful for your guidance. :super: I apologize for any inconvenience I've caused you. Please cut this impatient MidiBox Noob a little slack. :angel: Ps. Shuriken: Ha Ha :laugh:

I'm going through my bags and sorting components and it looks like I forgot 470nF caps. Can I get away with a different value? Will it affect the tone? What will it affect?

Thanks Nils :thumbsup: Maybe I'll just socket them and throw in a 1nF until I get paid and can hit mouser up again. Or maybe I can be patient til the end of this week. I got other stuff to do... Why is it that I never had an FM synth but now all of a sudden it's "URGENT!!" that I get this finished? (Ha Ha) :tongue:

How crucial is it that I use 2.7nF caps? I am guessing that since it is not a very commonly found denomination that there is a reason to be so specific about the 2.7nF? That's what the TL074's call for? Has anybody "accidentally" used another size and to what success? Reason I'm asking is because I forgot to order them... :pinch: