sidetrack

i figured perhaps that might be a problem. Speaking of which i noticed something strange happen with a couple of pots that I think might be problematic. With the power on I turned the pot all the open and a bright light and puff of smoke came out, something definitely ignited when the flange turned all the way around. That isnt normal as far as I know. I guess I could order some more pots, or go find some new ones.

OK.....I had to take a break for a few months as this was killing my brain. I worked on it for so many hours straight to get it ready for shows I had, but in the end I couldn't fix the issue. Now I'm back at it, with renewed interest. So I have basically decided to start with one pot and continually add pots until I find the problems and can then fix them. I believe I have a little more insight as to the symptoms of my problem. Basically i got to about 5 pots in when the problem arose, noise issues when there should be none. I checked and double checked everything... open connections are all sent to ground, every pot is correctly hooked up, solder points are solid... I even replaced many of the wires. Now I noticed something by accident that seems to rectify the issues I have, when i pull on certain wires that are part of my ground loop between pots, the noise goes away completely. That is if i just use my finger to pull the wire upwards and put stress on the two connections. Can anyone explain to me what could cause this??? or if anyone has heard of this? If I go through this simple circuit of 8 pots I notice that wiggling certain ground wires causes noise to happen, all the connections are well soldered... I just dont understand what this means. Thanks for the help in advance. R.

yea you are definitely correct. looks like ill have to get into that today. I'll post back if i correct the problem.

my problem must have something to do with the way that I'm hooking up the second ainx4, because I decided to continue building my second box the other day and got it up and running with no issues... using my previous approach to wiring the Vd and Vs to the pots. Should the grounds on the two boards be kept separate or should they be combined?

Looking at the diagram for star like wiring, I'm not really understanding what is happening here. Or how it is different from what I'm currently doing. It looks to me like the diagram tells you to chain all the Vd to one rail and all the Vs to one rail. Currently, with my wiring, each 4051 output uses its own Vd ito power the 8 pots hooked up to it. Then All the ground pins are chained together and directed to one Vs on one of the ainx4's. Maybe you can help me understand the diagram a bit more here.

Hi all, So I'm building my second and third midiboxes here, I thought I had a full understanding on how to wire up the pots to avoid midi noise/jittering, but apparently I was wrong. The way that I have hooked up all the grounds is that I have chained each pot's ground connection together then clamped it to the ground on one of the boards (not in a loop, its just one pot the next). I have also clamped the unused outputs to ground, them being the last 4 on my second ainx4. I did this on a previous midibox64 and had no issues, mind you it only had one ainx4. So I have been doing some trouble shooting trying to figure out what is wrong and I'm getting some weird things. When i disconnect the first ainx4 and clamp its outputs to ground I get a stable second ainx4 without any noise (although I did get noise once, but it went away..found that strange). So this leads me to believe there is something wrong with the first ainx4, but after switching it out with one that I know works, I get the same issue (so maybe it's safe to say the issue is not with the board itself). Now after checking, rechecking all the solder points and ground connections I cannot for the life of me figure out what is wrong. Additionally I had tested that board before hand (only a couple of the outputs, but it worked just fine). Another odd thing that is occurring is that when i wiggle any of the ground connections between the pots I can see values being sent out like crazy (more so than just the normal noise), not sure if that is relevant. Anyways, can you guys please give me suggestions on how to fix this. I need ways to test the grounds, the actual board itself etc. Or maybe someone can just tell me the one thing that I need to hear to fix this :)

well! i just looked at the solico list that is above. And the rep that I have been calling is no longer listed! No wonder I'm not getting anywhere.

ugh.. i have been waiting for 3 months over here in canada. I keep getting "we're looking for them, it should only be 2 more weeks" getting frustrated. I'll try target electronics, the canarep guys cant do anything for me.

great info thanks, theres a distributor in my neighbourhood!!!

hmmm I have a vic20, i wonder what kind of chip it has in there? I haven't thought to harvest anything from it.. maybe i will take a peek inside to see what it has.

holy! i probably should have googled that.. haha. I'll go grip some! thanks a lot.

Perfect! thanks wilba. Would it perhaps be possible to hot glue instead of jb weld?? I don't believe I have access to any welding equipment. That really helps me out! Since I'm not designing any pcbs I will have to use protoboard, or veroboard. SWEET! By the way, wilba, your work is sooo amazing.

i figured it would involve using spacers and holes in the panel. I will most certainly check out wilba's post, pictures is really what i need.

Hi, Let me start this off by saying that some of you may deem this a straightforward question that doesn't need asking. Nevertheless I would very much like to hear of the different methods people use. My question is regarding the mounting of pcbs, protoboard, and other non panelmount items to a panel. What methods do you use? Say if you are using faders, how would you go about attaching them so they are sturdy and solid underneath the panel?? Or other pcbs for that matter? So far in my experience I have been only using panel mount parts, so I have not come across this problem, but in my new design I will have to use non panel mount buttons and faders.. so some guidance or examples would help me out. Thanks for any help. S

How did I not think of this.. hahaha, good point, I will go get a 25k to make sure that this is ok and then I will order some! Thanks for the link I will check it out, and I had thought that it might be tough to get matching knobs. But I've found a few different ones around, it would probably be best to oder both from the same location. thanks.

yea i did some searching for resistance values on pots, but I neglected to search for anything on dual concentric pots. I think that the solution would be to get my hands on one of these pots and test it, however.. they are at the very least $10 a pop and it seems pointless to order one when I actually need 10 (plus they are coming from the US, and I will get ruined on custom charges). I'll do some searching, but I would appreciate anyone else's input, perhaps someone has gone down this road. I've never tried opening up a pot so I'm not sure how difficult that is to do, I think I will leave switching the element until I'm out of options (if a 25k introduces too much noise). thanks.

Hi, So I have a quick question here, I am really trying hard to source some dual concentric (stacked) pots. It would seem that the only ones available are from guitar parts stores, I have found a bunch that I can order (maybe someone knows a good place to get some for N.america) however they range in resistance values quite a bit. I was wondering if someone could clearly let me know what the allowed range of resistance values for pots connected to the AIN module. I know that 10k linear is what we are supposed to be using, I just want to know what else we could use. It seems like the smallest I can find is 25k... Is this a feasible idea?? I would like to use it for a sweepable eq setup (i.e. freq/gain), I suppose if this doesn't work I could just use two 10 k pots.. Thanks in advance! S

so inspirational.. i want to go home and build build build!

lolll Well thanks a lot! I switched out the regulator and it works fine again! Hoorraay. But yea I did some research on the the power supply section and I have a much better understanding now. That brand must look pretty sweet! I have a perfect circle branded into my arm from a vaporizer bowl that shot out of the heating mechanism directly onto my forearm, the chicks dig it... lol. As I am sure they will dig yours. Did yours hurt like all hell? man I was in some serious pain for a whole day or two. Thanks guys. now back to making music.

thats sick man. That kind of soldering looks amazing!.

I don't think it's the cap, I did a resistance test of it out of the circuit and it was showing readings as high as 39 mega ohms, but it would shoot up very fast and say O.L often so that makes me think it is functioning correctly. The rectifier appeared to have two pins around 9v, and the voltage regulator is definitely not outputting 5v, it receives the correct voltage but doesn't output correctly. Therefore I am going down to the store soon to replace these two components. Then we shall see if it functions!. Thanks for the help you guys, I will be back with results.

thanks a lot! I will try all the things you have mentioned.

So in using this link http://www.ucapps.de/howtodebug/mbhp_core_extract_measuring_vdd.gif I have found that I'm no longer getting +5v at any location. It seems to be all over the place, I have seen .2v a few times. Would this possibly be due to the voltage regulator being damaged? If so how do I check that it is doing its job correctly. At the input to the system (J1) I am receiving the voltage that my wall adapter is giving out (10.17 v). I can follow it a little ways into the rest of the system but I'm just not sure what the values should be at every step of the way. I am going to remove the cap to test its capacitance.

anyone have any good links on how to test these particular components?

no doubt man, i guess i just figured otherwise. But I'll give the choice from now on. I have another show coming up soon at Lotus (vancouver) so I will post a new mix for that one, and of course a notice for anyone that would like to go.