Hawkeye

Hi there, apart from a very few solder joints on the backside (sidback1), which do look like "rain drops", not like "eiffel towers" :) i can´t see anything right now - you might want to resolder those and see if it fixes the engine1 output section problem... My other guess would be, that the power supply is at its limits which would explain the low voltage across the board sometimes - can you exchange it? Many old C64-PSUs are overloaded by the power draw of a fully populated MB6582... I´d also recommend to buy or build your own powersupply, to avoid frying those expensive sids, when the old c64 psu goes into berzerk mode :) I hope there will be additional feedback, not only from me :) Many greets, Peter

Ok, no problem, there seems to be a power supply problem mixed with some problems on the output circuitry... Unblurred, well-lighted high-def photos of the area above sids 1+2 (front and backside) will hopefully help to solve the mystery. Any other ideas from other MB6582 builders are highly welcome! What makes me wonder a lot is how can there be 3V on SID1 Pin 28, when all the others have 12V - the circuit is quite simple there, so sth. strange is going on ;-) Many greets, Peter

Very nice! Do you like the 8x8 TPD so far? Many greets, Peter

Have you checked, that the jumper above pin28 of the first sid is set to 12V (not 9V)?

Hi there, the board looks great - i´d recommend to add MIDI OUT4 and MIDI IN4 for more general purpose usage - a BLM can be connected e.g. with an external cable harness that connects to both ports... Also, methinks MIDI Thru is not necessary, as you can do all sorts of routing from within the SEQ router... Many greets, Peter

Very nice! And cool lyrics, kinda mad-max style :) Many greets, Peter

Interesting! Before continuing, lets make sure the voltages are spot on, while the MB6582 is powered up... Use a digital multimeter in the 0-20volts range and measure SIDs 1+2 from Engine1 from PIN 14 (ground, lower left) to Pins 25 and Pins 28 respectively - the voltages should be around +5V and around +9V or +12V depending on your SID type... If these check out ok... can you pull one of the SIDs (ofc while powered off) on the first engine and see if sounds still appear on both sides? It might not be the output circuit, but some problem on the control circuit for those sids, and that they sometimes/somehow get the same commands from the core (thus the "fake stereo") along with other problems that lead to the symptoms like osc glitches you described... If there is mono output on the engine1 6.3mm output jack after this test, please grab a good hi-res camera and take a few shots of SID engine 1 core (front side and back side), that would be around the rightmost PIC chip and post them here. If there is stereo output on the engine1 6.3mm output jack after this test, please do the same and take a few pictures of the output section (front side and back side), that would be around the sids 1+2 and the section above it and post them here. Many greets! Peter

Hi Simon, I do agree and would also guess, that the SID has a problem! Would be glad to hear about your findings after you´ve installed the new one! Many greets, Peter

Hi Adam, first of all - congratulations on finishing that MB6582! No worries, the problem will be found ;-) Regarding SID numbering: the rightmost SID (when viewing the baseboard from top) is the first sid, the second-right is the second sid, these two are controlled by SID Engine 1. (Which is active by default when starting the MB6582). Which physical output jack are you testing? The mix output, that adds all outs together (3.5mm jack) or the leftmost (as viewed from the back) 6.3mm SID Engine 1 out? The possible problems are: a) Output circuitry on one channel on SID engine 1 has some problems b) A SID on SID engine 1 is damaged (broken filter or osc) They can be narrowed down by doing these tests: Swap the rightmost two SID chips with each other and see if the problem "wanders" to the other channel? This test is good for testing oscillators and especially filters (which are reported broken quite often). Swap in other SID-pairs from another engine, e.g. swap SIDs 3 and 4 from the right with SIDs 1 and 2? This test is good for testing a complete engine output circuit (left and right channel) with "known good" SIDs. For testing, please use an "init" patch, which uses the "Lead" sound generation model, with no filters turned on at first. Then test the three OSCs by detuning them against each other. Then activate a LP filter on all three OSCs and do a cutoff frequency sweep (all controls in the left-lower section of the MB6582 CS). Many greets and best of luck.. Peter

Nice work! Am going for an el-cheapo portable second SEQ, that would benefit from such an enclosure - please keep us up to date, if everything fits :-D Many greets, Peter

Interesting! If it was a problem for the old core, it is likely still a problem for the new one and a specialized led driver ic is recommendable - as the processing power has risen, but not by magnitudes.... What I don´t understand is, why are 10khz update rates necessary to achieve "flicker-free" 3 bit pwm brightness? Say, a human eye regards illuminated->non-illuminated pattern changes with a 100hz refresh rate as flicker-free... The darkest illumination pattern for 3 bit brightness would be: on off off off off off off off -> cycle Then, all eight steps should happen within a 1/100th second timeframe to be perceived as flicker-free. So, the individual pulse pattern steps should cycle at 800hz, not with 10khz? Without further inspection, I guess this should be possible even on an old Core8... But me iz probably missing a key point somewhere, maybe someone can enlighten us... :-) Many greets, Peter

If it is high enough, it won´t be noticed by the human eye, but certain camcorders/webcams can be affected by it, when both pwm and cam run at fixed "frame" rates, it creates interference, kind of a "moiré effect" over time, hard to explain :)

Probably the best way to test would be with another C64 or another 6581 SID chip and swapping chips... Most failed SID chips have broken filters, i´ve not yet heard that that the master output volume control breaks, but of course, it could be possible, especially if you are sure that the output circuit components work fine... From the 6581 Datasheet: Audio Out (Pin 27) -This open-source buffer is the final audio output of SID, comprised of the three SID voices, the Filter and any external input. The output level is set by the output Volume control and reaches a maximum of approximately 3 volts p-p at a 6 volt DC level. A source resistor from AUDIO OUT to ground is required for proper operation. The recommended resistance is 1 KOhm for a standard output impedance. As the output of SID rides at a 6 volt DC level, it should be AC-coupled to any audio amplifier with an electrolytic capacitor in the 1-10uF range. Best of luck! Peter

A few personal thoughts regarding that blog entry that you linked... MIDIbox is more than fine as it is right now... I don´t even think the build-10 sell-10 rule is necessary... The MIDIbox users have been critizised by people stealing TKs concepts and hard labour as a bunch of elitists, that do not open up :-)... Tell you what, in my not-so-humble opinion, that is a great thing! There are more than enough commercial music gear vendors out there, that are very glad to sell their products to these people... MIDIbox demonstrates, what great things can be achieved with well-documented, but license-restricted open hardware - it is in many ways superior to closed-box approaches, because once you understand the guts, you can modify hardware or code to your hearts desire... Finally, I can´t stand individuals, who employ whatever available methods to try to make a profit off other peoples´ hard work, that has been donated to the public in only the best-possible intention: free music hardware for everyone... Many greets, Peter

Small idea, not really important, but might be nice for melodic people :-). The euclidean pattern generator works very nicely to create interesting beat patterns... It would be great, if there would be a new record option, that is neither "live", nor "step + x", but "pretriggered step", meaning it will record the next note on the next already gated/lit step, keeping the previous step length intact ("overdubbing the notes of an existing track")... This way, you could enter a melody (with no particular beat in mind) and let the sequencer populate the steps that were previously chosen to be gated... I often use "step + 2" or "step +4" to enter a "noodle", but this results in very uninteresting rhythms... Instead of using the euclidean pattern generator for gate pre-selection, one could also pre-record the rhythm in "live" record mode, e.g by just hitting the c-3 key with the correct beat in mind and later record the melody on top using this new recording mode. Or one could "re-write" a melody track that already has the correct rhythm. The idea stems from my inability to simultaneously play somewhat interesting notes and keep the desired rhythm pattern :-) Many greets and thanks for evaluating this! TK., if you like the idea, i´d like to give it a try, haz been far too long since I´ve seen the SEQ sources :-) Bye, Peter

Welcome to MIDIbox ! You´ll find a lot of very skilled and helpful people around here, it may be one of the best music diy electronics communities in the world :-) Also Technobreath´s advice is a very recommendable approach: start small, and then expand, the MIDIbox hardware platform is very modular, so you could start with a minimal control surface, at first just a few encoders and tactile switches, see if it works and then you can add more :-). Many greets, Peter

This one: The SEQV4L is great, but a (portable) full SEQV4 is definitely more powerful... Many greets and thanks again to all people invovled in the SEQV4 project, it rocks! :) Peter

I think they do gladly accept minor quantity sales, as long as it does not disrupt their business process... I would do that, as a business owner, at least... But ilmenators argument is also valid, if all the people interested in this year´s bulk now flood them with orders, they may rethink their distribution policy. What is probably needed is someone based in Germany with enough time on hands (i haven´t) and enough credability to do the bulk order. Many greets, Peter

Available at SmashTVs shop only - he also helped in the creation of the MB6582 PCB and does great parts kits - highly recommended to buy a complete kit for a fun build without sourcing trouble :) Many greets, Peter

yes, if you want to debug modern microcontroller logic 20mhz is too low :) but as you said, totally sufficient for audio stuff and all kinds of old-school circuits :)