AndrewMartens
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Posts posted by AndrewMartens
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Assuming that down the road you plan to provide PCBs for people, one option would be to have the 28- and 40-pin layouts side-by-side (ie; one row of 28 pins, one of 40, space, one of 28, one of 40) so that the user could simply solder in a socket for whichever size they had - without needing to built their own adapter board, or using point-to-point "dead bug" wiring. The downside is that (assuming you have a 28-pin device), you're paying for 40 useless holes per board.
Looking at the datasheet, the footprint difference between the AY-3-8910 and -8912 is somewhat compatible, though not perfect. This approach might work with only a few jumpers required on a single-sided board.
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mrcam,
It does indeed look interesting, but the site and documentation needs translation for us monolingual types. The Data sheet for the YM2149 shows it to be pin compatible with the AY3-8910/12. It may do the same thing.
This is correct. Several years ago I picked up a bunch of old audio ICs from VintageFunWorld (now closed), including this assortment of chips (plus a SID and a few POKEYs). At the time I was looking at the YM2149 / AY-3-8910/12, and they are all essentially the same thing. You'll need to make a 40PDIP to 28PDIP adapter board if you want to use the YM2149 / AY-3-8910 in a board designed for the AY-3-8912, though.
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Great work!
I must say, I'm so impressed with everyone pulling together all of these MIDIbox user projects for all the classic chip synths. I had acquired some AY-3-8912s and POKEYs several years ago, but never had the time to do anything interesting with them. Kudos, and I look forward to seeing the final project! :D
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The rat can make some pretty sweet sounds, that's for sure. The circuit is also very simple and runs happily off of +9V. Built it on a breadboard, worked great; moved it to a stripboard, and it still worked great ;D I was definitely tempted to build it into my SID, but it will most likely end up as a piece of outboard gear once I package it up.
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I looked at building the Wasp filter a while back, since IIRC it runs off of +9V happily. Alas, mine never worked properly, whether due to a cheap breadboard or cheap capacitors, I'm not entirely sure.
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I've had issues with 7912s as well. IIRC the problems I was experiencing were with ST's 79xx regulators. From a bit of Googling, I believe it had something due to them locking up (?) when there was no current draw on the output. Supposedly it could be fixed by adding a resistor to ensure a constant current draw during power-on, but that didn't seem to resolve the issue that I was having, either. Recently I picked up some 7912s from two other sources... and both of those sent me ST units as well. ARGH.
I think I'm going to be reduced to using a MAX660 or an SI7661, etc. as a voltage inverter for my bipolar supplies.
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Fantastic! Now, I just have to figure out what box to put one into! I foresee a MIDImerger with an 8x output driver in my future ;D
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this was about the timeframe when PC-s were 200 mhz and the Sharc 21065 was new.
I remember those times. Creamware had launched Scope, and with a whole lot of Sharcs on board it was an amazing (and amazingly expensive) product. It was a shame Pulsar only came out later, as I had already exhausted my computer budget by then, and never had a chance to play with their products.
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Awwwwwwesome! I just acquired a Juno-6 a while back and haven't used it as much as I would like simply due to not being able to sync the arp on it. Now I have something I can fit into the extra space inside my 1U rack SID project :-)
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Just taking a quick look at the circuit, I noticed one problem... in the middle of the schematic, R42 (20k) should be connected between pin 8 and -9VDC. Pin 9 should also have a 20k resistor R43 connected to -9VDC. On your PCB layout, I believe these correspond to E$14 and E$15, except that you have them connected to +9VDC instead.
This might cause it to be maxing the resonance value, hence why all it does is oscillate. Fingers crossed!
[uPDATE]:
On a slightly longer glance, you seem to have V+ connected to pin 6, and V- connected to pin 11. From the schematic, V+ should be on pin 11, and according to the LM13700 datasheet, V- should be on pin 6.
... aaaaaaaand all that really means is that on your PCB layout, the + and - labels are reversed. But assuming that you hooked it up with red = V+, then you at least have connected it correctly.
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That's a nice, easy-looking layout there. Should even be pretty simple to put on a veroboard. Bipolar power supply, I assume?
Regarding ceramic vs. styroflex caps, of course the conventional wisdom is to use better caps in filters, but... meh, you don't really *need* to. Sometimes it's easier to just use whatever you have on hand. ;)
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E.g., what I don't like on your proposal is, that a 4x16 LED matrix is not sufficient. Just think about all the possible setups. There is a 8 track drum sequencer, which controls 16 instruments. Accordingly, the LED matrix should consist of 16x16 LEDs - but are the increased frontpanel costs really reasonable?
This project isn't really on my radar, but I thought of one possible alternative to keeping panel sizes down: bi-colour LEDs. One instrument on a shared 'track' of LEDs would be green, the other red. It wouldn't help with DOUT or wiring complexity, but would keep the panel a bit smaller.
And to give you more insight into my secret plans ( ;-) ): one of the next things I want to evaluate is MIDI-over-IP, since it's natively supported by MacOSX, and not only useful for sending MIDI control data, but also to handle the OSC protocol (useful for windows users as well, e.g. Reaktor supports OSC). So, the control extension could provide an ethernet option as well. And this would make it to a real universal solution, which is worth the DIY effort.
Awesome idea! Just promise me that you'll find some good (free) Windows drivers for MIDI-over-IP :-) Are you thinking of the ENC28J60, or of one of the PICs that has a built-in MAC for Ethernet (which iirc there is one or more out by now)? I remember looking at the ENC28J60 a while back for a different project, and one issue I had with it is that essentially the PIC is a slave of the 'J60 when it comes to accepting packets on the SPI bus. There are a number of nice features, though - the 'J60 has a lot of capabilities for pattern-matching and filtering in the packet, which should make it a lot easier to reduce the amount of traffic that the PIC has to deal with.
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I've always been a fan of threaded rails, myself...
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Looks like my board is fine after all. I'm just a NOOB!!! And had my power plugged into the wrong pins on the core module. This was causing my PIC to only get 3.0 volts instead of 5.0. :-[
I'm sure that we've all misapplied power at one time or another. I managed to swap Vcc and Ground to my LCD!
One more question....How hot does the SID chip get while in operation? Mine seems to get pretty warm to the touch.IIRC my 6581 gets warm, but not too hot to touch. If you're concerned (and your SID isn't going to be moving around much), you could always attach a heatsink to the top of the chip with a bit of thermal paste. I had more heat issues from dropping 12VDC into my 7805 at 250mA, though - that one got the heatsink.
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If you haven't done perfboarding before, I would suggest buying a cheap breadboard and start with that. Then you can place the components (start with the IC and the electrolytic caps, leave some room), and then connecting pins together with the resistors, ceramic caps, and any necessary jumper wire. That will help you determine how and where to place the components together - and also to make sure that your proposed layout will work. Then condense it as much as possible, if you are trying to save space. I personally like to draw it out on a piece of graph paper - solid lines for components on the top, dotted lines for connections underneath. Alternately one can use various software to do this.
For actually building the perfboard, I typically start with soldering in the IC socket, and then adding the resistors. If you have 2x the necessary components, then you can leave your breadboarded version intact and use it for reference when debugging. A lot of times you can just bend over the component legs of resistors and caps on the underside to use instead of jumper wire. If you take a look at the top two images from my MB SID build, you can see how this tends to work: http://www.midibox.org/forum/index.php?topic=7521.msg53808#msg53808
It's a bit of an arcane art, and one that I don't pretend to be an expert at. Normally if there is a reasonably priced kit available (that I can actually get shipped to me for a reasonable price), I will take that over bothering to acquire components separately and perfboard.
Hope this helped...
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Yeah, I actually built my Canakit with the recommended transformer... and...
Well, the +12V worked fine. -12V? Nope, nothing. Build an identical circuit with some larger caps and a fresh 7912... still nothing on the -12V. The transformer seems to be sending an appropriate voltage, but it's just not working right for me. Tried a different rectification scheme, and that didn't do the trick either. I experimented quite a bit and never managed to get it working.
Then I got laid off, went on vacation, found a new job, and have been busy working on things around the house since then. My "AC power supply test board" is still sitting on the shelf. On the plus side, if I ever get it working, I have a very nice switch with a built-in LED that will look snazzy on a 1U FM box :-)
Let me know when yours is working!
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Interesting... iirc the DS-8 and (Korg) 707 were mostly compatible, I wonder if it uses the same chip as well? Time to crack open my 707, it needs cleaning anyways...
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If you're running linux on there, you could always get tektrakker (aka ttrk). It's a pretty simple console-mode pattern sequencer for linux. I made a custom version of it (basically to change the scrolling mode) and it ran fine on a P120 laptop with 32 MB RAM. I can't remember which version of linux I put on there - it was probably debian, and I think this was back in 2002 or so.
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Try holding your fingers above (not touching) various components, including the voltage regulator. Be careful, as the voltage regulator can easily get hot enough to burn you. It's probably that, and if you slap a heatsink on it with a bit of thermal paste (I just used some spare Arctic Silver from working on my PC), it will help matters.
Another method is to buy a can of that spray-coolant stuff, spraying the board, and then turning it on. Watch to see which component thaws first, and that's probably your culprit.
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It's just SID + feedback.
It works with a 6582 or 8580, but not with a 6581
*cries*
Oh well, I'll just add an external filter and an AOUT_LC like I was originally planning, then.
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Note to self: when I build my SID V2 into a rack, I need to use the feedback patching with a knob on the front... man that sounds GOOD, TK!
How many SIDs do you have going there? And is that a delay or just a really big reverb?
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There must be some vendors that you can order from in canada. Can´t belive.....
I order from Digikey all the time up to Canada, and never have to deal with any shipping/cross-border hassles. I think there's about a $7.95 flat shipping charge on any order over $32, and that's about it. So just order a whole bunch of crap so that it's a smaller percentage of your order.
That said, their selection is somewhat more limited than Mouser...
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I can see how something like this could be useful. A very minimal CS (a la SID) that could conceivably be used for patch editing (for a masochist), but more useful for just calling up patches; several buttons, an encoder, and a 2x20 LCD. One could cram this into a 1U rack with perhaps a few other front panel controls for other $COOL_STUFF in the same rack.
Looking through the code and config for MIDIbox FM, it looks like it should be possible, even if would be very annoying to edit patches with. And as TK mentioned, the main page that displays the patch/ensemble information would be truncated - this might require a bit of additional custom work from the user to ensure that the most relevant info is displayed in the first 20 chars.
I'm embarking upon this kind of adventure myself, and will be sure to post some notes about my successes (and failures)...
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smash's encoders are good quality... You might want to check your soldering, and maybe try another one, perhaps you overheated it or something...
Good to know, I have the same issue with the encoder on my SID. Hasn't really bugged me that much, since I do my editing from JSynthLib, and about the only thing I use the encoder for is patch selection.
Nice 1U SID rack! Once I finish my MBFM (and SID V2 is officially released), I'm going to transplant my SID into a rack as well.
How deep is that case? It looks to be about 12" or so.
A full-blown newb on the way to a POKEY synth
in MIDIbox User Projects
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I think I might have a spare (ie, I have two total) in the batch I ordered a few years back. Let me take a look for it. Whereabouts would I be shipping to?