seppoman

That´s possible. did you change to 9V? did you measure the current going into the box? too hot to touch is not necessarily bad - I think the 7805 will work even at 80-90 degrees C. too hot to touch is already 50 degrees. But to be safe you can always use bigger heat sinks. If your case is out of metal, you could use wires between PCB and 7805 and mount it to the case. About the "higher voltage helps" again: the usual 7805s start working correctly at about 6.8V (DC!). If it doesn´t work with 7.5V, this can only mean a) thermal shutdown or b) the input voltage isn´t smoothed enough, so the 7.5V drops too much below 6.8V with each half wave. You can test this by measuring between 7.5V and ground (under load at the regulator) and using AC mode of the multimeter. that´ll show you only the ripple. If it´s more than a few hundred millivolts, b) is the reason. In this case a higher voltage does help but is only the second-best solution. Better is to use a larger capacitor to keep the input voltage stable. If you already have 2200 uF, try a 4700 uF or several parallel 2200uF caps. When using more than 500 mA, the bigger cap and heatsink solution is definitely preferrable - with a linear regulator, you always want to keep the dissipated heat within reasonable levels. Seppoman

Hi Wilba, once I also had a C64 PSU with "wrong" 5V pin - all PSUs I´ve seen were european 220V versions, so this is not the distinguishing factor. Seppoman

Does the SEQ also reboot when not in Arpeggiator mode? If not, it´s a software issue. If yes, it might be PSU-related. You could measure the current going into the box. But as long as you don´t push the backlight pot to the max, the 1A of the PSU can´t be the problem - a normal 7805 can take max. 1A anyway, so just make sure the box consumes less. But the heatsink suggestion should be the right way. The regulators have internal thermal protection and the output voltage drops when they get too hot. So keeping them at a temperature that you still can touch them for a few seconds is a good idea. But this is easier when staying at 7.5V - even if raising the voltage could help in some rare cases, the 7.5V can´t be the cause of the problem! Seppoman

Hi, about the colors: at least on my monitor I like ACs colors better. The other suggestion is too aggressive in my eyes. And I´d keep the text background neutral. Seppoman

Good news, everyone :)

Just upload the normal MBSID application. This should replace the Testtone app (as long as the upload is successful). Seppoman

Huh? why? Are 6 answers of potential buyers not enough or is it illegitimate to ask about the price? Seppoman

depending on the price I´d be interested. Seppoman

it has pros and cons. The new solution needs one more PIC pin. Software compatibility doesn´t really change as long there are dedicated (non DOUT chain) gate outs. Only using regular DOUT gates - might be a nice solution, only it introduces some slight jitter of about 1 ms. but removing the 595 is definitely a good idea. It would´ve been possible to invert the clock polarity for the 595 to make it compatible, but putting DAC and Gate on the same chain was not the best idea from the start. The problem is: even if you only want to update one CV or gate, both must be sent. In combination with the stupid 16 bit check of the DAC (which is not clearly worded in the datasheet), this produces a lot of unnecessary performance load. So Nebula, I think I´ll do my changes on the PCB and then sleep a few times over it before calling the work done, so I´d say within the next 2 weeks. Availability to order them somewhere might take longer, can´t say anything definite about that yet. Seppoman

Hi, In this thread http://www.midibox.org/forum/index.php?topic=7777.msg70420#msg70420 there was some discussion about the quality and precision of AOUTs. I´ll answer here: I´m not sure how much more testing I can do with my limited equipment - what I can tell you for now: the output signal is clean and stable, and a connected VCF works like a charm. I don´t have any analog VCOs for testing (and actually for my personal use, I´m also not at all interested in VCOs), so when time comes, someone owning some VCOs and an "old" AOUT should do a comparison between AOUT and AOUT_NG to find out if in real world any of this datasheet stuff does matter. Doing exact measurements of stuff like precision in LSBs is nearly impossible without VERY expensive equipment - both my multimeter and my oscilloscope have a measuring error that probably is higher than 1-2 LSB. What I can and and am going to measure is that probably the deviation/INL is not as bad as 6LSB suggests, because this is like the number that could be reached under most negative coincidences, e.g. bad luck getting a DAC that was just good enough not to be discarded from production, and then this DAC is used in an environment with fast and extreme temperature changes. It´s 6 LSB max and +2/-1 typical. I already tried things like saw/square waves with an amplitude of only a few dozen mVs. They look quite clean and stable. I´d say the precision is at least better than a lot of the commercial CV gear that even often uses 8 bit DACs (!!!). So probably I made too much fuss about these specs anyway. Now I made some people afraid that the quality might not be sufficient for their needs. THIS IS GENERALLY NOT TRUE :) While the old AOUT DACs have slightly better specs, 99.9% of all Midiboxers won´t notice any difference in their application with the NG´s precision. For VCFs, VCAs, drum VCOs etc, the performance is perfect. Even for synth VCOs, as long as nobody has reported the opposite from actual tests, I claim that the precision is good enough for really good results. So, FEAR NO MORE ;) Taking price, availability, features (onboard bipolar option etc) into account, only very special situations will bias the decision enough to make one choose the old AOUT over the NG. Seppoman

Hi guys, this thread is Ooold and was about the MAX525 Aout, so I´d rather not do a full detailed discussion of the pros and cons of different Aouts here. I´ll write an answer in the New AOUT thread. I´m not sure how much more testing I can do with my limited equipment though. Seppoman

Hi Dr :) there are a lot of nice discrete filters out there - The samples on the MFOS page surely sound cool. But both adding external multimode features or building discrete filters doesn´t match with the goals of the usual Midiboxer, like e.g. me ;) I personally never was interested in building modular synths - too much time, work, money, no interest in messing around with patch cords. If I wanted to build absolutely the best and most flexible filter in the world, I´d hang around not here but on Synth-DIY etc. The reason for me to be interested in the 2044 is: I just want to have a nice sounding analog filter that is easy to build, easy to calibrate, has a low parts count and complexity and therefore does use up little space, time and money. At the moment, I´m hoping to get two channels of 2044 filters on a PCB sized about 8x6 cms. The extention board from your first link looks like double that size for only one extention of one filter, i.e. we´d be talking about 4 or 5 times the total board space. That reason alone would kill the whole concept of using an integrated low parts count VCF for me. Please don´t feel offended - your comment and both your links are definitely interesting for all the modular guys out there - just I don´t see the application in usual Midibox projects. Seppoman :)

Hi, Gavin: I don´t know about differences between 13600/13700 and I don´t have 13600s so I can´t try it out. But I think I´ve read about the 13700 in most cases being a good replacement for 13600 cirquits. So when the board is finished, you could just try it. If it doesn´t work as good, just buy a 13700 for 50 cents or play around with the surrounding resistor values. NLX: stryd is right, if you want to save filter settings and have envelopes controlling everything, you need an AOUT. The fonik board has CV ins, too. main difference is that you´ll have exponential Q CV response with it, i.e. for fixed Q values in a patch, you need to use other values (finer control over low Q settings, worse with higher Q). For Q envelopes/LFOs, the behaviour will be quite different. My board won´t be having extra connectors for manual pot control, so everything´s controlled via the MBSID app. Adding them would be no big problem, but when you can´t save the settings with the patch, I don´t see much use for them anyway. Seppoman

More update: As far as I can tell with my cheap 80ies Goldstar oscilloscope, there´s no digital bleed through, no overshoot/zipper noise, and an overall very clean output :) Only hard transitions (jump Max->Min) on a channel make the other ones slightly blip with a short 1 mV "spike". But according to the datasheet, this is normal. 1mV even after V/Oct amplification, so this won´t be noticeable at all! I´m very happy with the results ;D Seppoman

Hi, the next one asking for pre-built boxes - don´t any of you ever read the forum or FAQs before posting? from yesterday: http://www.midibox.org/forum/index.php?topic=9648.0 Anyway, welcome to the forum. You´re gonna have to solder yourself, but a C or D in soldering is absolutely sufficient ;) Kits are available from SmashTV: http://www.avishowtech.com/mbhp/buy.html If a simple box is sufficient for you, then just order one Core kit (with 4685) and depending if you want mono or stereo, one or two SID kits. one 24LC512 doesn´t hurt for saving patches. Except for the SIDs themselves and a bit of wires/connectors, this is everything you need just to have the sound. A LCD, one DIN and some buttons would be necessary if you want to edit the sounds directly on the box. Seppoman

I know that problem well enough ;) where´s that damn screwdriver again :))

Hi, here´s another link to the Fonik board: http://www.modular.fonik.de/Page27.html I also took some inspiration from it. The schematic is not very far away from the reference design in the SSM datasheet. The Fonik board is definitely nice for modular synths and completey manual control. One thing all (except one) schematics I found are missing is a linearization for the resonance CV. The datasheet suggests a neg log pot, and Fonik simulates this by the resistor in parallel to the pot. So for manual control this probably works fine. Only for CV control, like with the MBSID/MBFM, the problem is that the response is still exponential. This means that in the lower quarter of the CV range, not much happens. Then it starts to have more and more influence and after about midway the thing goes off like a rocket. The only implementation I found that deals with this issue is this one: http://www.emulatorarchive.com/assets/PDF/SSM2033%20SSM2044%20Circuits.pdf Here, a 3080 is used for linearization. As the 3080 is obsolete by now (still widely available, but nevertheless), I used a LM13700 instead and played with the values until it worked well. For MB applications, this is quite a benefit! I don´t want to diss the Fonik board at all, but from my board you´ll get two channels on a similar PCB size (left out all the pot and additional CV stuff) and a (kind of) linear response of Q. Also, some values are adjusted for +/-12V instead of +/-15V supply. So it´ll be more suitable for Midiboxing (while being less suitable for modular stuff because of the missing direct control). Seppoman

Hi, short update: Today I hacked a small test program into an Atmel, mainly to put out a few voltages, square and saw waves - so no real Midibox test ;). Still have to do some more in depth tests like measuring small voltage differences, looking with the scope for zipper noise (or hopefully the absence of it ;)) etc. but at least I found out that the board seems to be working as intended. I also already connected my SSM2044 test board to it and can hear the filter sweeps from the saw wave, so everything looks promising :) Seppoman

If you want to take a shot on a 2164 board, just do it :) As I said, I probably won´t have time for this anyway in the next few months, so any activities are welcome :) In a 2U case, space won´t be the problem. Just use two "floors" of PCBs, e.g. put all analog stuff on the bottom of the case, buy some really long screws and spacers and cover everything with the Wilba PCB :) Seppoman P.S. virtual beer is ok ;)

For this, midio128 is not the right application. It is used for reading and outputting logic signals like switches, keyboards, driving relays, leds etc. You are already completely in the MIDI domain, having both drums outputting MIDI and light controller accepting midi. Did you try to receive and send midi via DIN/DOUTs? This won´t work. What you want is the MIDI Filter/Processor - with this you can make a little program that interprets received MIDI and sends one or more events depending on the input. Seppoman

Hi Gavo, you mixed up the numbers a bit :) NLX wanted a AOUT+SSM2044 board. The first thing I´m doing right now is a double 2044 board and then some time (definitely more than 2-3 months!) a 2164 board. And as I said, I don´t think I would do a combined board of any type - this just makes the number of necessary boards higher. With single modules, you can combine stuff more flexibly. For example, I also want to add some 2044s to my MBFM, so I don´t need 2164s there and it would be annoying if I had only two 2044s together with an AOUT on one board. Modularity is one of the main concepts of Midibox, and while I really appreciate the availability of Wilba´s board (and have ordered one myself), I think that doing all-in-one boards for every possible configuration just doesn´t make sense for the community. The Wilba board is something different because it provides a good and integrated way to have everything for a full normal MBSID on one board. But stretching this to all combinations of nice filters, nice VCAs and every combination of this would be too specialized IMHO. Thanks a lot for you comments about the filter sounds, really interesting! Seppoman

Hey Sasha, no offense taken, but: Just that a Prophet 5 is expensive doesn´t mean its owner is a rich bastard - this Prophet example came from a co-student of mine who just bought a slightly broken one for 1700 Euros and asked me to check it. He doesn´t earn much money and makes his own music all day and night. He saved his ass off for it. And you´re partly right about the SIDs, but: millions of C64s existed, and even the ones not having been trashed by now must be hundredthousands. A Prophet 5 was an expensive beast back then and probably was built a few thousand times, remaining functioning units perhaps a few hundred. And so are the necessary spare parts. CEM and SSM were nowhere near as big as CGS/MOS were. I think the big number of 2044s comes from SSM having missed the end of the analog era. They must´ve had produced like 10,000 of it and shortly after nobody wanted to buy them anymore. As I said, this was not a "don´t do it, you evil !$%&$"!$§!", my point was just: Only use really rare parts when you know and value the difference to the alternative. If you just love the CEM3320 sound and this is exactly what you want, then go for it. If you just want to have any great-sounding analog filter from good old times, then do the Synth Lovers a favour and choose the SSM. Even while there are probably several great machines collecting dust in some rich-ass basement, most people spending money on these machines do appreciate the difference to a Nord Lead :) Seppoman

NLX: don´t think so - 1. it wouldn´t all fit into the 80x100mm of Eagle light and I don´t want to redraw everything in crap like Kikad... 2. It´s not bad to keep things a bit modular. 3. This would be not instead of the normal AOUT or the normal (non-existant) SSM board, but in addition. So already three boards to maintain, document etc. After all, it´s only 4 CVs and power to connect between the two. Seppoman

Hi, the 3320 is a classic and good filter, as is the 3372. Can´t say much about the sonic differences as I didn´t hear them yet. If you can source enough CEMs, a design around them would be surely rewarding, as it would with any other classic analog filter. My main reason to post is that at the moment there´s a lot of CEM hype in this forum some people who repair vintage gear won´t be happy about. These ICs are mostly really rare, and a lot of vintage 70ies/80ies analog synths could be saved instead of building a 8x MBSID with CEMs. This is not to stop you personally from doing this, just when there are a lot of people doing projects with multiple filters, it starts to influence the market/availability of these ICs and at some point it could get impossible to save the real classic gems like e.g. the Prophet 5. Midibox has become big enough that it can cause serious problems. If even a quarter of the Wilba PCB guys would want to have analog filters and all wanted CEMs, this would draw 200 ICs from the market - the price would go through the roof and availability drop to zero. You already mentioned the alternative: SSM2044. Seemingly there´s a lot of old new stock available. If you check IC databases, you can find that there are asian companies which have thousands on stock. I recently got 10 pieces on eBay from hongkongsuperseller for 75$/55 Euros incl. shipping. I´ve already built a prototype and it surely does sound fat, warm, analog, really cool. Right now I´m designing a PCB for pairs of these. As I said, I don´t want to discourage you - if a certain CEM is your dream filter, just do it :) - only if you just want to have *some* analog filter, think about the SSM. Apart from the moral, it´s also way cheaper and easily available. These are the reasons why I´m doing this PCB right now (plus I want this PCB too ;) ), and I´ll publish it when it´s ready :) Sorry to distract your topic, Sasha ::) Seppoman P.S. a SSM2164 VCA board is also in the queue, but I didn´t start yet, so don´t hold your breath ;)

Congrats Sasha, nice one :) Would look cool together with my disk drive :) http://www.midibox.org/forum/index.php?topic=4873.0 Seppoman