OrganGrinder

this i agree with,, as murphy said "a $3000 picture tube with save a 1/2 cent fuse by blowing first"

hi all after fixing the original problem for this topic, i have come across a few more. when testing the board with p18, i found the voltage at mclr was around half the 12.5 volts it was supposed to be. i worked over what i did wrong, and guess what? it seemed just like the original voltage problem i had before, so i turned the bc337 around and it worked perfectly from then on. but that wasn't the end of by problems... turns out that i had swapped the yellow and red leds, that shouldn't have been too much concern, but they didn't work when testing Vcc and Vpp, turns out i had placed then in backwards, which i have fixed now. after all that, the board tests correctly and i have programmed all my pics with no problems (after slowing the io transfer a little). now i am waiting to recieve the pcbs i have ordered from smashtv and hopefully not make these mistakes again. being a newb is hard work, fixing the mistakes you should have not done in the first place (especially after trying to avoid these specific mistake). cya OrganGrinder

hi again looks like i did have the lm317 on backwards afterall. now the initial test for the pic burner works (i can get 15 volts if i wanted). I have it set to 12.5 +/- 0.02 volts, so i think i am in business for now. just realised i forgot to attach the printer port to the board, but thats another story for anyone who hasn't guessed already, this is my very first electronics project (i do not count the stuff i did in highschool nearly 20yrs ago, didn't even use solder then) well i got this done by the DIY code, i did it myself. a few more mistakes like this and i will be an expert. see ya all OrganGrinder

hi again i have replaced the 2k trimpot with a 5k, and also have bypassed the bridge rectifier (i am using a pair of 9v batteries). the results - now j2 reads 10 volts, still short of the 12.5 i need. i have also played around with disconnecting d1 and/or r1 but either does not have any effect. i don't think i connected the regulator backwards (switched input and adjuster/ground) but then i don't know what the results of that would be if i did. btw i connected the 5v resulator correctly - it outputs 5v as expected. just for your info, i can turn j2 down to around 0.5 volts and the power led turns off when j2 is around 5 volts (but that was expected considering the schematic). any advice would greatly be appreciated. OrganGrinder

hi i have completed making a pic burner on a stripboard following the schematics on the page. the only deviation was that i replaced the 2.2k trimport with a 2k trimpot (2.2k was not immediately available) now when i am testing (before placing the chips) i get a maximum voltage across j2 of 9.5 volts. could this be because of the trimpot i used, if so i assume i would need to go to a 5k trimpot, is this ok? if something else may cause the problem, can i have some suggestions. btw, the 5v sections are working fine, same with the power led and i am running off 2 9v batteries. thanks OrganGrinder

hi DrBunsen i disagree with your conclusion before condeming software sequencers you should consider what you are comparing. Firstly the hardware sequencer is a dedicated piece of hardware designed for the specific task you are testing. The hardware sequencer would not require a fast range of peripherals such as com ports, video, keyboard/mouse, hard disk controllers, usb etc. and if any of these are provided they are on a secondary system so as not to interfere with the hardware sequencer. A PC (or mac or any other) is a generic computing machine where the provision of millisecond precision i/o was not a primary design specification. in reality the pc's i/o is shared between many systems including com ports, video, keyboard/mouse, hard disk controllers, usb etc... so in the end, your comparision is like comparing who comes first in a race between a ferarii and a mac truck. the ferarii may be faster but you cannot carry what a mac can. similarly, a hardware sequencer is limited in what you can do with it, if is not in the design and final product, it will not do it (expansion modules only enhance the system so far). on the other hand a software sequencer (especially if you can modify the source code) can be customised to do virtually anything you can concieve. looking at your results, you should be amazed that a pc can achieve the results it did and still do everything else as well. when comparing win98 and win2000 did you use the same pc to midi interface? also what other hardware was the win2000 machine using in addition to what the win98 machine had? add also the fact that win2000 is much more sophisticated (complex) to win98. in conclusion, the better of the two will depend on what you want. the hardware for a dedicated solution with limited expansion but very good precision. the software for customisation, versitility and good percision (it had a variance of 1-2ms). please don't take the above personally, i just believe that your conclusions didn't take all the factors into acount. OrganGrinder ps. it might be interesting to see how a real time operating system which is dedicated for use with sequencers would compare.

I have the service manual to the organ, a Gulbransen 600 series. Just because I don't have experience or much knowledge of electronics dosn't mean I can't read a curcuit diagram. I have an IT degree majoring in Software Engineering and can read UML (very similar to circuit diagrams). It's just the electroncs side that my knowledge is lacking. Anyway back to the organ. The keyswitches are directly powered from the power supply at 15V DC, the tone signal is not added until after the signal passes through the gate matrix (the next curcuit in line). My thought was to include the lines to Din and Dout (isolated from each other with a diode) and connected to the keyswitch curcuit boards, I believe there is some curcuitry on the keyswitch boards in case of feedback from the gatematrix so connecting through the wires is probably not a good idea (not to mention difficult as they are bundled together). If I had access to a scanner, It would be easy enough to give a diagram of the workings and where I was thinking of connecting the lines to Din and Dout. Anyway the planned locations were near the keyswitches before too much additional circuitry got involved. The idea for Din was that when a key is pressed, the current passing through the keyswitch would also go to Din (with appropriate voltage reduction) and continue without problems. With Dout, the idea is first in software a check to see if the key if already pressed is made, if no Din signal then provide the Dout signal. The Dout signal would be amplified (preferrably with the same power source as the keyswitch pcb) and sent through the pcb at an appropriate location where it wouldn't also activate Din but still activate the rest of the board as if the keyswitch was pressed. From what I can work out, this is the only place I could include Din and Dout without interfering with the rest of the organ (as jimhenry has warned about) and still maintain the functionality I am after. I will have to check again, but I think the stops use a conditioned signal so directly connecting Dout to them would probably cause trouble with the workings. I haven't mentioned the peddle board yet. The peddleboard is run by a 2in/13out diode matrix and should be easy enough to handle in software if I can't find a hardware solution for it. ie check the in lines to determine which note is played by the respective out lines. Organ Grinder

I don't want to go off topic into areas of why I am preserving the original workings of the organ or if using samples is better or anything else like that. But I will discuss my motives for this and although I would appreciate constructive comments, I am not interested in a debate. Anyway... The organ that I am midifying was my late great uncles and is currently in near perfect condition for a pre 1980 organ. Only part of one octive on the lower manual dosen't work right and it is not the contacts but elsewhere, and I am getting that fixed soon. Anyway I was planning on donating this organ to the chuch which I attend, being that I am the only organist and the current organ is woefully inadiquate. What I thought is that if I installed midi in and out to the organ, it would provide a level of future proofing the system. It would provide several advantages: 1. If through age the internals of the organ break down, it is still usable with an external module. 2. If I move elsewhere, the organ can still be used with a sequencer of some kind (probably a laptop). 3. The organ sound can be supplimented with sound modules or the roland piano which is already at the church. I have already considered a radical midification (replacement instead of supplimenting), but have rejected the proposal for several reasons: 1. Replacing the innards with not only sound modules but also the other equipment such as amplifiers and speakers would make the endeavour very expensive and beyond my means. 2. I can't see that it is likely that I could duplicate the stops, traps, toys and effects that already exist on the organ. If I change the functions of any tabs or buttons, I would also have to change the labels or panels on the organ to maintain the turnkey approach of the organ console, and being that I am inept at any kind of woodwork, I don't think that is a good idea. Now I do have a Wurlitzer 950 which seems to be on its way out (many things aren't working right or at all and it is only getting worse) and that would be a good condidate to radically midify, but a working system which only needs a small fix seems to me like throwing the bady out with the bath water. I hope this my motives clear OrganGrinder

Hi This is my first post, so I hope it is in the right place. I am a newbie with electronics, done some minor stuff in highschool >20yrs ago but generally don't know much. I am trying to midify an old organ of mine while preserving the orginal organ. The organ currently uses 15V, 17V and 20V for keys, pedals and stops respectively. I also understand the DIN and DOUT modules from SmashTV work on a maximun of around 5V. So my questions are: 1) for DIN, how do I limit the voltage from the organ so I don't fry the core/DIN. 2) for DOUT, how do I increase the output voltages to the requirements of the organ circuitry. Thanks in advance OrganGrinder