t_xen

Argh! :o messed up the labels. it's the tiny things I usually end up overlooking. ::) Going to swap the +/- voltage lines and test again. ;) thnx.

yea, I was directly supplying the opamp with the batteries. Oh well, the board is no longer in the case I've created for the Midibox_CV. It's now in my 4xSID, controlling a filter board from RJW Soft. I've just etched an AOUT module since I was able to aquire 2 MAX525s and a MAX6007B shunt as free samples from Maxim IC. This would be better anyhow since I have an analog synth with 2 VCOs, 2 VCO modules, and 3 VCFs. Should be the best route since I have the beginnings of a modular synth. :) Thanks for the info, TK. :D

Well, after numerous attempts, this is currently non-operational as I have yet to get this working. :-[ if anyone would like to take a shot, here's the circuit. Here's the schematic I was working with for parts and value references.

I have questions on power consumption. I need to determine how many amps are being drawn. Things I need to know so I don't blow up my wallwart....... :o Amps on a single Core Module? Amps on a single Sid Module? Amps on a single AOUT_LC module? My wallwart is rated at delivering 1000mA and I'm about to use build a half wave rectifier to get a bipolar -/+12v thanks to info provided by Wilba. I've built a 4xSID_v1 and really want to add 4 external VCFs after hearing TKs moog demos. 8) Thnx

yea, the ceramic caps are pretty much what I have on hand. ;D anyhow, it's gonna be a bit longer before I post more info on it. just tried testing it and got no audio. only osillations from the resonance. I have a few resistors coming out to only half their rated value for some weird reason, sooooooo....... Still working on it. I'm pretty confident that this will work when I get the bugs worked out since this is a prototype. :P and yes, it is Bipolar voltage required. Operates at +/-9v, but can handle a max of -/+12v.

Thanks, Wilba. That should work for what I'm trying to accomplish. :)

I have some analog filters that need a bipolar supply. I was pondering how I can make one with the parts that I have. I built a bipolar 9v supply using 2 batteries but it's not enough for these filters. So I have a question. this is a basic draft...... could this idea work, or is it just wishful thinking? ::) thnx

??? I ran into this before with mine, but can't remember exactly what I did. :-[ the endless sysex messages (if I remember right) are upload requests. try this.... turn off the Core for 5-10 seconds. While off, turn on smart mode and "wait for upload request" in MIOS studio, select the hex file and hit start. then turn on the Core. If no success, try it again without the "wait for upload request" and hit start after rebooting the core. If that doesn't work.... turn off again for another 5-10 seconds. Turn on manual mode and "wait for upload request" and set the delay to about 50-100ms. Hit start, turn on the core. if that doesn't get it, try the same thing without the "wait for upload request" after rebooting while the core is on. I had to try it a few times myself to get mine to take the upload. just keep trying different ways and it should eventually take it. :-\

I installed a bankstick today with the same thing happening. I realized I had the SC and SD lines backwards. I swapped the 2 wires, powered up, and it detected and automatically formatted them. Perhaps in your case, swapping those lines may fix? :-\ Here's what I came up with in troubleshooting on my MB_SID bankstick module.... If Vs and Vd are backwards, the core will not power on. If SC and SD are backwards, it will not read the bankstick. If you swapped SD and SC and it still will not see them, check your wiring on the Bankstick module you've built.

Btw, if they are touching, you could try mounting them like this.... hope this helps (ugh, I noticed the solderball on the board in that pic.)

I can just barely see C1 and C2 on the SID board. Make sure the legs of those capacitors aren't touching each other or anything else.

Looks like fixing the hum was a lot simpler than that. the ground line was looping through the audio ground via the case. A wire for the power jack broke. I removed the jack from the case, resoldered and tested it by plugging it into the adapter. lo and behold, there's little hum on the thing now. I could do with less, but hey, it's sounding great!

lol! Yea, I've gotten quite a few bomb comments. ;) The case was made from an old poker chip case. I saw a guy walking around with it and asked where he bought it and told him what I wanted to use it for. he thought the idea was neat so he sold it to me for 10 bucks. :D Warland, I added the 2200uF cap from the 12v line to the common ground. still got some noise, although there is just the slightest difference. I think your right about the half wave rectification. I checked and I get about 0.9mVAC coming through it. Well, it was a cheapie Radioshack adapter. Are adapters labeled if they have full wave rectification? o0O"not a bomb, but it can sound "tha bomb!""O0o :P

That was the thought I was having. I Just wasn't sure so I kinda left that on the back burner and out of the post before trying. ;) And yes, the plugback is 12v DC. The voltage on my multimeter shows 14.6v DC supplied by the adapter. I do have the SID modules stuffed with the 7812 since I'm using four 6581 SIDs. I'll give the 2200uF a shot and see if this reduces the hum and post my findings. :)

Hi all. I've gotten my 4xSIDs working again, but am getting a huge amount of hum. I can hear the sids working but the noise has a higher decibel level than the sids. :( I know it's not the SIDs and the Sid boards since I've tested each individually and get the same 50-60hz hum. I need opinions and suggestions on how to correct this. Here's a layout of the circuit I'm using to distribute the power from a 12v wall adapter. And the board... The wall adapter is connected to J1. The adapter is rated as 12v@1a. the 5v connection on the layout is used to power J2 on the Core, and power the Vd Vs connection for j2 on the Sid. The 12v connection on the layout is connected to Vd on J1. Here's what I've tested. when I have only the SID module connected (J2 to the 5v and J1 to the 12v (don't know if this matters or helps), there is no noise. Once I connect the core, then I hear the noise. I have a slight fear of building anything that deals with creating a DIY PSU (electrocution). :P I want to use a wall adapter, but I'm open to suggestions. Here's an image of it stuffed into a case for your enjoyment. :) Cheers! t_xen

mmmm! Nice! :)

Hi all. Well, On my MBHP_Sid, I have to get this repaired. I've blown the 5v regulator, after attempting to diagnose a huge amount of hum I was getting from the sids. (likely a ground loop as they were working fine before I stuffed everything into a case). Anyhow, I built a Midibox_CV using an AOUT_LC to drive linear VCOs, but then discovered that this will not work due to accuracy of the voltage output, so......... I'm going to use the AOUT_LC I've constructed to drive a filter I've etched and built by hand. I have yet to test the filter, and figure that this would be a pretty good time to do it. The filter is based off the LM13700 chip. I have 20 of these ICs. seems like a lot, eh? Well, I only needed 5 of them for other "projekts", but could only order them in a bulk of 25, and have a bunch of spares. these things sound great in the minisynth (so I knicked the schematic of the filtersection)! I'll update this thread when I've actually finished it off. Here's an image of the filter for your enjoyment. After I have this built and working, I'll post an audio clip of it in action. Before I forget, the filter will take a CV controlled cut-off, but the downside is it is not capable for CV controlled resonance. meaning you will need an extra knob on your SID frontpanel to adjust the resonance. I'll give the details on the wiring later. ;)

Side note........... Since the AOUT_LC I constructed isn't accurate enough for diving linear VCOs, I'm going to use it in the MidiboxSID I constructed. I have a filter board I've constructed. CEM filters seem to be a little expensive and hard to come by, but the filter I created is directly off the filter from the Soundlab Mini-synth section (the analog synth I'm attempting to drive with the MBHP_CV). I'll post a PIC of the filter in the SID forum. ;D

Here are the results. After attempts at calibrating, here's what I've got. I set the calibration minimum to 0v. then I set the maximum to 7v (9v battery powered). then when I select the 1v setting and set the output, I switch to 2v and I get 1.996v. I adjust to 2v and then switch to 4v. the multimeter reads 3.996v. Looks like it's falling flat, folks. :-\ Apparently (I think I read this somewhere before) that the AOUT_LC isn't suitable for driving Linear VCOs because of the lack of accuracy, but should be fine for driving anything else that's analog. ::) I requested some samples from Maxim-IC for 2 MAX525's to attempt an AOUT, but I'm not gonna hold my breath. No images yet, I want this working before I post it. :) Here the image of the AOUT_LC I constructed. I don't have a drill to make the holes for the pins, so I just put the circuit on top and surface mounted all the parts. I used clippings from the resistors to make bridges that go over the traces. This took very steady hands. ;) I'll post an image of the AOUT in this thread after it's constructed. l8r 8)

Oh duh. :P RTFM. I changed the line "#define DEFAULT_AOUT_INTERFACE 1" to "#define DEFAULT_AOUT_INTERFACE 2". Recompiled and uploaded. Now it's behaving properly. I only get about 7.5 volts for the maximum output (prolly cuz I'm using 9v batteries), but that is fine since the linear VCO's I'm driving have an accuracy of only 5-6 octaves. Anyway it's getting late here in the Pacific NW, so I'm going to try it out on my synth tomorrow and see how it does. I'll post a pic here of the end result. thnx and good night. ;)

Hi all. :) I have constructed a MidiboxCV and need some help. Here's what I have for the power. I have the core powered by a 12v powersupply and is being ran through a 5v regulator into the Core Module. I have the CV firmware uploaded into the core and its operating normally. Since I was not able to obtain an AOUT_LC, I went ahead and etched my own board. ;D The R-2R section comes within .5% tolerance. Instead of the rated 12v bipolar supply on the AOUT_LC, I have 2 batteries rigged to give a supply of +9v/-9v and ground to power it. I seem to have a problem with calibrating the thing to drive a linear VCO. could the batteries be an issue, possibly under powering the AOUT_LC? ???

I have redesigned the layout and am about to order some of these through PCB Express. The new design is not intended for building on veroboard. Before I call the board layout done, there is a thought that is somewhat pressing.... I have the shift registers and the resistor network using the ground pin on J1 and J2. the CV outs are connected to ground on J6. Will this help reduce ripples and other weirdness? Or just not a good idea for me to do this? ??? Thanks in advance... :)

*speechless..... :o

Finally finished this thing. here are the pics. Am I happy with it? HELL YES! ;D Was this easy? HELL NO! >:( Does it work? Untested. I need to build a new PSU that gives +/- 12v (already in planning stage). Feel free to use this stuff if others have (an "issue" or if one has an "issue" with not even getting emailed back) trouble getting their hands on an AOUT_LC. Whatever. >:( I just don't want to "have" to build another but I guess I got to anyways so...... (rant, rant, rant) The resistor net is a bit tricky. The diagram at the beginning may be inaccurate so you are on your own. I'll check and update it later. When I get the new PSU built, I'll post if it works or not.

My layout was done with ExpressPCB. ;) I'm almost done the first module, I have to finish running the traces from J1 to the IC's. I didn't think about using the 20k resistors. I just went by the schematic. I don't mind the extra soldering work. All resistors I'm using are 1% metal film. Pictures to come soon! ;D