Razmo Posted May 16, 2006 Report Share Posted May 16, 2006 Hi everyone! :)I finaly had my MB SID finished, and are now playin' around with making some patches for it. One of the things i HATE about the SID (both 8580, 6581 & 6582A) is that bloody envelope bug (know it gives it that SID SOUND, but... i HATE it nonetheless ;D). I find that all patches I make end up having ADSR settings of 0,0,15,0 which is one of the only settings that does not give you that sloppy attack feeling on the sounds... that bugs me! ::)...So I thought; What if an "artificial" amp envelope was developed?... One that takes the final output and amps it by software?... of course this would require some additional hardware (that i'd be happe to include just to get better amp control! ;D)... but then I also thought: The C64 was capable of playing 8-bit samples using the volume register... could this perhaps be done in software?... what about VERY rapid dithering of the volume register? ... possible?... Thorsten?Well... I know that the 6581 has noisy vol register ´switching, so that's possibly out of the question... but what about the 8580? I recall having routed an envelope to the volume register on an 8580 in my own old C64 SID synth project with great success (with fast decays! otherwise steppings was clearly audible!) believe the best result would be the make a dedicated DCA of some kind, but is that possible with the MB SID?One of the cool things either a software dithering mechanism or a hardware DCA would give us, would be to make really snappy percussive sounds (especially with the Curve feature, that I came up with once 8) ), and also, the noisy oscillators of the 6581 SIDs would be eliminated by this trick.Regards, Jess D. Skov-NielsenDenmark. Quote Link to comment Share on other sites More sharing options...
Wisefire Posted May 16, 2006 Report Share Posted May 16, 2006 you could use a VCA, and use an aout or aout_LC(i think) for controlling..its about the same for people who get anoyed about the filter..a simple VCF, and you're trucking! Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 16, 2006 Author Report Share Posted May 16, 2006 OK!... and this AOut is specificly for the MB SID? ... The point was, that the envelope should be directly controllable from within a SID Patch, otherwise it would be worthless when sharing patches with others i think...People are anoyed by the SID filter!? :o ... well, is the filter not the sole reason for people wanting to get nostalgic with the SID!? ??? ... I know that the 6581 filter is quirky, but is that not the nice thing about it?... well... guess it's not up to me to decide, but for me, routing the SID sound around it's internal filter for processing through another seems well... funny :D... you could say the same about an extra amp envelope created the way I suggest of course... guess it's basically the same, but for me, what makes the SID sound different from the rest is the filter... hmmm...In any circumstance, if any of my idears are to circumstancial, then at least the option of routing an envelope to the volume register would be nice... for fast snappy basslines, this works pretty nice even though the vol register has only 16 positions.Regards, Jess D. Skov-Nielsen. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 16, 2006 Author Report Share Posted May 16, 2006 And now that we are talking about the SID 6581 filter... I fiddled about with the filter on the 6581 one time ago, and found that the problem with it is that the register value for fully open filter, and fully closed filter varies from chip to chip... maybe on one chip the fully open filter is at 0, and on others another value... with this in mind, it should be possible to better the function of "defect" chips by making a callibration routine... a routine that makes you (by ear) listen for the max closed/open filter settings, and then note down these values.... these values could then be used in the filter routines for scaling in between these too values... usually, the values above/below these two points in the full filter cut-off range are "dead ranges" with no apparent change in sound... at least that is what I've noticed... this would require some significant changes to the filter engine of MB SID, but should pose no real compatibility issues i think... as long as the callibration is selectable in the patch itself.Regards, Jess D. Skov-Nielsen Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 16, 2006 Report Share Posted May 16, 2006 Heya Razmo,First post and you're that far in! You should join the board and share your experiences! Maybe there are others who would like a Danish MB-SID tutorial :)You might like to search the forum and wiki for MBFX. There have been fairly active discussions about this recently.That's an interesting observation about the values passed to the filter, I wonder, if the minimum value is offset, is tha maximum value offset also, or is it scaled? Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 16, 2006 Author Report Share Posted May 16, 2006 Hi Stryd! ;D ...Well... In fact I was making my own SID synth when Thorsten notified me of the MB SID, and asked me if it was necessary to invent the wheel twice ;D ... and honestly: NO! it was not, so I took on and suggested the Curve parameter since it allows rather snappy bass patches. I've now (finally) build my own MB SID (into the hood of a departed Control Synthesis Deep Bass Nine analog synth, using some of it's interrials), and thus I divin' in this forum rather sharply ;) ... I'll be here from now on to give my idears ond such... I've got quite an amount of synthesizers in my studio, so I know quite a bit about synthesizers in general, and maybe I can help out on stuff... also know quite a bit about the SID ;) ... and I know how to code the 18f452 PIC also as this was also the chosen MCU for my own synth back then... I'll have a look at that MBFX thing.... sounds interesting already :)and about the filter scaling: I tested it thorougly, and found that it's SCALED between those min/max values... or at least it sounds very much like it. of course there are still differences between very early revisions and the later ones, but the worst problem is the filter not opening and closing correctly between revisions. If the cutoff-values used was just scaled between these min/max values, the result would be much more equal and useable between different 6581 revisions, and still (important in my opinion) still be a little different from each other... That is the charm of the SID 6581... 8580 all sound the same (which is also a good thing). The "working range" of the cutoff is not just offset... the "working range" can be different so that one chip works between say; 127 and 10.000 while another works between 234 and 9.000 (these are just fictive numbers... real numbers may be different). so it's not just an offset. 6582A by the way, is nothing more than a 8580 with a different number on it... I've testet it against the 8580 and can hear no sound differences.Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 16, 2006 Report Share Posted May 16, 2006 Hi Jess,welcome aboard, I'm very glad to hear from you after so long time! Just two weeks ago I highlighted again the importance of the curve parameter (with an explicit hint of the originator of this algorithm -> http://www.ucapps.de/howto_sid_bassline.html) :-)Current situation: MBSID V1 will only get minor changes in future due to various reasons, e.g. code and patch memory allocation. But with MBSID V2 all concepts will be overworked (see MBSID Wishlist posting, which you've already discovered - more about this topic there) - which means: than more ideas are discussed now, than better the chance to get this into the next major redesign.So, you are joining this forum just in time! :)My thoughts on your proposals: yes, a dedicated envelope with analog output would be the best solution for MBSID V2. Currently it would only be possible to introduce a new "sound engine option" (4 bits are still free) in order to enable a path from a selected envelope (e.g. ENV2) to the volume register, or to an analog output (-> MBHP_AOUT_LC module). Modulation of the volume register could already be tried out with a small number of lines. I will try it this evening just to get a feeling about the benefit and post the required code here. Note that the resolution is 4 and not 8 bit, however, we will see..But as you already mentioned, an external VCA would be the best solution - especially if it has a log characteristic (to match with the dB damping and to decrease the required resolution). Here you can find a schematic for this concept http://www.midibox.org/users/kd/kd_fmsid.pdf but nobody tried it out so far.To the filter calibration: so far I understand your suggestion, this would only require a linear scaling routine, and not a table (which would consume too much memory). Thanks to the hardware multiplier, it shouldn't consume so much execution cycles (see math_mul16_16.inc), I will give it a try, but would need the help from some people who own different SIDsBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 16, 2006 Report Share Posted May 16, 2006 I just have integrated the new sound engine option "E2V" (ENV2 to Volume) - works better than expected!I will try the filter calibration now (I noticed that I already did something similar for the 8580, but with a static scaling), and release a new built in ca. 1 hour :)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 16, 2006 Author Report Share Posted May 16, 2006 Hi Thorsten! :)Yes! I noticed my name while browsing the pages ;D 8)... I can understand the reasons for the few enhancements we will see for the MBSID... one being the upcomming V2 :P... in fact I'd also rather see work on a new thing, than the old one... I believe in progress and backward compatibility, but backward compatibility should NEVER interfere with new inovations! ... my point of view! 8)Definitely seems that I'm arriving at the right time here!... and I'm full of idears ;D ... I'll keep them comming! ... and I'll gladly be of as much help as i can, so if you want anything of me... just write me! ;) ... I'm not the biggest of hardware magician, and probably not even as adept in PIC programming as you, but my knowledge of different synthesizers and their strengths and weaknesses are my force, and I've seen quite a few in my time! (tell me if you're currious of which... it's a loooong list ! ;D)I know that the volume issue I wanted has to be fixed in hardware to be fully realised... and I could easily route the output into one of my synths to trigger their amp envelope on it, but the point is to make it part of the patch in the MB SID, and this is only possible with the first suggestion... I'm just tired of not being able to have a little release on a patch without the attack of the sound getting irregularly muffled! ... I want PAAAOUOOUW!!! when i do those leads! ;D a thing that the SID does VERY VERY well in combination with it's oscillator phase reset function!Another thing that I'd like to see, is the ability to tune the filter cutoff in semitone steps!... just like the frequency! ... when the filter is tracked like this, and the frequency cutoff and pitch lies in the same spot, then the resonance will do wonders!! (think aciiiid!), and the effect will follow with the keys! ... very ellementary dear watson! ;DOne thing I like about you Thorsten, is your dedication! :) ... I give idears today, and you are trying them out before the night is over! ... oh dear how i wish other manufacturers had that spirit! :D ... Yes, I tried the volume routing from an envelope myself once, and it's astonnishing how good it sounds compared to the low number of bits... just do not try it with a 6581... it will "click" horribly if I recall right :-\ (another reason to choose 8580!)The filter scaling would make many SIDs much more useable I think... in fact I've heard revision 1 and 2 SIDs that I find VERY fat sounding... only drawback is the dead ranges in the filter values making it hard to sculpt bass sounds just right.. and sharing the patch makes it horribly "mutated" on other chips.Now... I only just started messing about with the MBSID within the last days, so all of these issues and ideas are my first notes about the engine... I'll keep you posted as I get new adears. :)Anyways; DAMNED GOOD ENINGE!... really really good synth, and even if no changes would be made, I'd still rate it VERY high!... it had to be good, cause I sacrificed a Deep Bass 9 synth for this work of art you did! ;)Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 16, 2006 Report Share Posted May 16, 2006 Hi Jess,short info (I'm hacking the new features into the firmware in parallel ;-)Another thing that I'd like to see, is the ability to tune the filter cutoff in semitone steps!... just like the frequency! ... when the filter is tracked like this, and the frequency cutoff and pitch lies in the same spot, then the resonance will do wonders!! (think aciiiid!), and the effect will follow with the keys! ... very ellementary dear watson!-> CC#116 (Filter Key Tracking) :)One thing I like about you Thorsten, is your dedication! Smiley ... I give idears today, and you are trying them out before the night is over! ... oh dear how i wish other manufacturers had that spirit!Thanks! :) I not always have the time for trying things out immediately... however, in difference to others you are making feasible suggestions and don't demand for unsolvable things (or putting requests like "Synth A and B has this, why not MIDIbox SID?")The filter scaling would make many SIDs much more useable I think... in fact I've heard revision 1 and 2 SIDs that I find VERY fat sounding... only drawback is the dead ranges in the filter values making it hard to sculpt bass sounds just right.. and sharing the patch makes it horribly "mutated" on other chips.Yes! Btw.: my current implementation requires static values defined in main.asm, you need to upload a new firmware built in order to try out the changes - it would be too difficult (as fast solution) to allow a calibration via SysEx or control surface. But I could consider this for MBSID V2 (I see the need)Best Regards, Thorsten.P.S.: just uploaded the change - it works. I'm writing the changelog now ;-) Quote Link to comment Share on other sites More sharing options...
TK. Posted May 16, 2006 Report Share Posted May 16, 2006 Alright, so the first release candidate can be downloaded from here:http://www.ucapps.de/mios/midibox_sid_v1_7303b_rc1.zipThe ENV2->Volume modulation path has to be enabled with the 4th flag of the sound engine option. This can be made from JSynthLib, from the control surface (SEO menu) or via CC (CC#111 = 0x08)For filter calibration you have to select the appr. type in .asm (e.g. in main.asm or setup_*.asm) ;; select the filter type here: ;; 0: if a 6581 is controlled from the core ;; 1: if a 8580 is controlled from the core ;; 2: 6581 + freely definable scaling (define MIN and MAX value below) ;; 3: 8580 + freely definable scaling (define MIN and MAX value below)#define DEFAULT_FILTER_TYPE 1 ;; only relevant if DEFAULT_FILTER_TYPE is 2 or 3, values between 0 and 2047 are allowed#define DEFAULT_FILTER_CALI_MIN 20#define DEFAULT_FILTER_CALI_MAX 500 ;; set this if you want to switch between two different Min/Max values ;; (works only with DEFAULT_FILTER_TYPE 2 or 3)#define DEFAULT_FILTER_CALI_SWITCH 0 ;; and define the used pin here (default: pin RC.3)#define DEFAULT_FILTER_CALI_SWITCH_TRIS TRISC#define DEFAULT_FILTER_CALI_SWITCH_PORT PORTC#define DEFAULT_FILTER_CALI_SWITCH_PIN 3 ;; define the second set of Min/Max values here (0..2047)#define DEFAULT_FILTER_CALI_MIN2 0#define DEFAULT_FILTER_CALI_MAX2 2047[/code]Sidenote: the difference between 0/1 and 2/3 is, that the 8580 selection delinearizes the control curve of the filter by mapping the value through the frequency table - this was also a suggestion made by Jess some months ago...Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 16, 2006 Author Report Share Posted May 16, 2006 Hi Thorsten!Unfortunately I cannot test the 6581 code, since I've build a 8580 version, and caps + regulator has been soldered onto the board (don't want to unsolder). I'll have to test this later on.The ENV2 -> volume register feature I have testet though. It works well if programmed correctly I feel... on some patches you can hear faint clicks and stepping, but considdering this, if you program carefully, you can make some patches that are unique, so I think it's worth keeping. The idear could be improved though to minimize some of the faint clicks:When a key is released, the SIDs oscillator envelopes cut out emmidiately because of their release settings of 0, making a DRASTIC envelope volume change from max to min.We need a bit of ENV2 release time on the volume register, but this is impossible due to the SIDs oscillator envelope settings which MUST be 0,0,15,0 for things to work.The solution is that when this new ENV2->Volume feature is ON, there is no need to trigger the gate bits more than once! ... The gate bits just need to be set and the volume register set to zero when this routing is switched on... then everytime a new note is triggered, you just trigger the ENV2 again automatically and with it the "fake AMP envelope"... this will also allow the routing of ENV2 to work with it's release setting, which would not normally be possible because of the gate bits...Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 16, 2006 Report Share Posted May 16, 2006 Hi Jess,I like this idea, and fortunately a change is very easy: open sid_sw.inc, search for "SIDSW_Note_GateClrReq" and replace: bcf INDF2, 0 ; SID_Vx_CTRL.0 is the gate bit[/code] by: [code] btfss SID_SE_OPTION, SE_OPTION_ENV2VOL, BANKED ; (don't clear gate bit if ENV2VOL option enabled) bcf INDF2, 0 ; SID_Vx_CTRL.0 is the gate bit(don't be confused about the operation on the test flag below this line, this will only taken into account if oscillator phase synchronisation is enabled)It works very well.Wouldn't it make sense to provide this modification as a seperate option? Because the oscillator outputs cannot only be damped by using the volume register, but also by using the lowpass filter (which has a higher resolution)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 17, 2006 Author Report Share Posted May 17, 2006 Hi Thorsten.It should absolutely be an option to turn this on or off, you are absolutely right on this one :)You wrote something about not worrying about the test flag, and that it would only be taken into account using the phase sync option. Are you triggering the gate bits if phase sync is on to reset the phases? ... If I recall right, it is not nessesary to toggle the gate bits to reset the phase using the test flag ... is it? In fact, I hope not because the resetting of the phases is important also when routing the ENV2 to the volume register.Also I've been thinking about something; in your code, when you trigger the gate bits, and reset the phases, how fast are your routine at doing this on all three oscillators? ... If I did the code, I would make sure that the three oscillators would perform the triggering with THE LEAST AMOUNT OF TIME in between the three oscillators... in fact I would do the triggering on all oscillators at once with just ONE write to the SID flags to make all oscillators set off at exactly the same time... the reason for this is, that if the oscillators are phase synced, and all play the same waveform and pitch, then the closer the triggerings is to each other, the more gain you will get from the oscillators... in essence it's like mixing the same waveform with itself three times... doing this will increase volume by approx. 3db for every oscillator playing this way...The nice thing about this is, that it will GREATLY overdrive the filter doing this, making squelchy acid basslines easier to create.Regards, Jess. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 17, 2006 Author Report Share Posted May 17, 2006 Hi Thorsten...I was thinking about something... I would like to ask you something about the MB SID that I made myself:As I told you, I cannibalized a Control Synthesis Deep Bass Nine analog synth and made it's housing the home of the MB SID. I did this because the housing is a one unit high rack thing, and that's exactly what I want, and it has the necessary holes drilled already, and the TRS plugs was easily unsoldered and reused... also the power switch has been reused... and it's internal powersuply also, since this gives me no wallwart suply, 8)and now the question:The power supply that is within the housing is split into two coils (I believe that is the name), one with two lines running from it, and the other with three lines. The first one I measured, and it shows to deliver 10 volts AC... so I connected these lines to the core module for the 5 volt DC supply (the rectifier deals with the AC->DC I remember). The second one had markings saying that one cord is +17 volts, the other -17 volts and the last one 0 volts (also AC). I use the +17 volts and the 0 volts lines, and have connected these to the SID modules 12volt input (I know that using the two -+17volts give more than 35 volts, so I'm not connecting those together ... don't worry! ;D).Everything works flawlessly, and I get a very clean and crisp sound from this setup... I'm just wondering, if I'm doing this right... don't want to put any pressure on the boards. The regulator of the 5volt gets hot, but not overly much, and I assume that doing 10->5 volts is no big deal?The 9 volt regulator does not get warm at all, or if it does it's not very much at all!... this puzzles me, since it is doing 17v -> 9v!!!... how can that be? not that it's a bad thing it does not get hot, but I just wonder...Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 17, 2006 Report Share Posted May 17, 2006 Hi Jess,the new build can now be found here: http://www.ucapps.de/mios/midibox_sid_v1_7303b_rc2.zipThe "gate stays active" flag is the fith bit of the sound engine optionI also redefined the filter type switch - now it allows to switch between all 4 types (6580/8580 with or without calibration) - hope that all 16 possible combinations (type 1=0..3, type 2=0..3) are working ;-)The reason why I wrote "don't be confused about the test flag" is, that actually this isn't really the test flag you know from the SID - it is a "sync request" instead and utilized within sid_sr.inc (the SID register access handler). There is the place where all SID registers are written as fast as possible (as the serial interface allows). It is ensured, that all three oscillators are synced within less than 20 uS, this delay is acceptable I guess - let's assume some bass tones are played around 200 Hz. (is this still bass? anyhow...) 200 Hz have a period time of 5 mS, and 20 uS are just only 0.4% of this period. I think that this small offset is ok :)sid_sr.inc also ensures, that the synchronisation is done *after* all other SID registers have been updated.Yes, the amplitude is much louder, this especially brings one of my (older) 6580 chips into a nice distortion when filter is active at the same time :)But I think that it makes sense that I check this synchronisation again on the scope (or sampler), it's long time ago I integrated it, and I only tested it by ears, and not visually.To the transformer of your cannibalized rack: I think it will also work flawlessly in future, so long no big consumer - like a backlit LCD - is connected to the core.The voltage regulators transform the unused wattage (U*I) into heat. Than higher the voltage difference between the input and output voltage and/or than higher the current, than higher the heat problems.The 8580 draws ca. 25..50 mA in the 9V domain, the voltage difference is in your case ca. 15V-9V = 6V (15V because of the voltage drop over the rectifier), makes ca. 150..300 mW - so, no issue :)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 18, 2006 Report Share Posted May 18, 2006 I just had a play with this ENV2->Vol option and it's fantastic! Now I can do things that were just too hard or impossible to do by modulating the volume register with the wavetable. Now you can modulate ENV2 depth (or just sustain) using a wavetable... and the effects are so cool...Here's something similar to the Trancegate patch (in Wavetable Sounds Tutorial #2) to use ENV2 depth instead of filter cutoff.Enable ENV2->Vol option.Assign track 1 of the Wavetable to CC#79 (ENV2 Depth).Set ENV2 Depth to 32, Atk 13, Dec 0, Sus 127, Rel 65.Adjust the Wavetable Rate to 94 and enter following sequence:STEP CMD #100 Play +2001 Play -2002 Play +2003 Play -2004 Play +2005 Play +0006 Play +0007 Play -2008 Goto 00[/code]Now you can tweak the filter for your own purposes, and get fading in and out, since you can now use attack and release phases.Unfortunately, the combination of leaving the gate on and poly mode doesn't work well... if you play three notes, and then just one, you'll hear two of the notes previously played. P.S. I hope for MB-SID v2, it's possible to just add the volume register as a modulation target, so any envelope or LFO can modulate it. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 18, 2006 Author Report Share Posted May 18, 2006 Hi again Thorsten :)I'm about to check out the new build right now! ... And about the time between gating the oscillators; I think it is very good already... I ONLY wrote you about it, to make sure that you would optimize this delay to be as good as at all possible because the less delay; the greater distortion ;D ... and we like that!... don't we!? ;D ... but I think you are right... with this small delay you mention, it's not bound to be a big problem... in theory it should be possible to trigger all three gate bits from just three writes to the SID control registers should it not? ... of course , as I can see you have a delay value on all oscillator envelopes, and with this delay taken into account, surely you can not be triggering the three oscillators in just three consecutive writes to the control registers eh? ... well... don't worry too much about this... it's working well, just wanted you to go for optimum optimization within limits of this 8)Now that you mention the old 6581... there is some significant difference in the design I've noticed with respect to filter input from the oscillators with respect to the 8580... if all oscillators are on and 8580 is cranked all the way up (full volume and syncronised phases), and then routed through the filter, it will distort wildly, but if you then turn down the volume register, you will notice that the distortion disappears!... this gives a great effect when routing the ENV2 into the volume register since it starts out really saturated, but gradually become smooth in the release tail of the sound... makes bass patches rather ok! ... with the 6581 I once noticed, that turning down the volume like this had no effect on the distortion!?!?... I'm almost confident I noticed this many months ago on my own system... I wonder why this is so... to me this hints at the fact, that the volume knob is "located" AFTER the filter section on 6581, and BEFORE the filter section on the 8580!!!this is pure speculation though... don't hang me up on it! ;D but if true, then a drawn block diagram of the synth architecture will be different between 6581 and 8580. (actually I've got an 6582A SID here also... to me it sounds like a 8580 SID, but I'm going to dive in further, and test it someday, to see if any major differences is present).My cannibalized rack will NOT include either pots, buttons or LCD at any time... I rarely use the front panels of my synths and prefer to remote control them, so therefore I'm running the absolute minimum of the MBSID... I'm strongly thinking about making a full featured version of your next V2, with full 8 SID modules in it... hope it will deal with that! :D .. my major concern with my rack here was, that I was unsure about the "0volts" line... well, I measured the lines to 17volts, so I thought it might work, and to be honest... IT DID! ... in fact I'm rather proud because, I had absolutely zero problems making this synth... all was working from first try... lucky me 8)I've got ONE hardware question more though: I'd like to have two LEDs on my synth... one for "POWER ON" and one more for "MIDI ACTIVITY"... now; the power LED is no problem since that's just a resistor and a 5v source, but what about the MIDI gate LED? ... any idears on this one without having to build a dout module or something?Regards, Jess. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 18, 2006 Author Report Share Posted May 18, 2006 Hi Thorsten!I'm testing your new build now... and occationally while playing, some of the oscillators drop out, and then later drop in again... I'm wondering why this is, but maybe you have a few places in your code where the gate bits are still cleared that you've missed? ;)Otherwise it works rather ok... of course it's not the perfect way to get the envelope bug fixed, and still a hardware sulution would be better, but it opens up a lot of new potential in patch creation, and anyways; SID is about lo-fi sounds and nostalgica, so this feature just put a little extra on top... in fact the curve parameters work really nice on the volume register as well... nice and punchy sound... just try a patch with all oscillators set to SAW... now detune two SAWs by +10/-10 and transpose the last SAW down by 1 octave. now crank the curve of ENV2 all the way left and set the decay to 127 and the sustain to 18. no filter used and no phase sync used, but it's still fat, punchy and nice! this sound was not possible without this feature :)Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 18, 2006 Report Share Posted May 18, 2006 Wilba: thank you for this nice idea! I will try your patch this evening, and propably extend the wavetable tutorial, because this possibility shouldn't get lost in the deep grounds of this forum :)Jess: yes, the oscillators can be synched with a single write into each control register. But I'm doing two writes - one to trigger the reset (test bit set), another one to set the gate bit. The advantage is, that the envelope won't start before the oscillators have been synched, this avoids unintented "crackles"Your speculation about the volume sounds interesting. I will also do some tests with different SIDs in order to find out, if I can notice the same (I like such tests ;-)Btw.: have you ever checked some different caps on pin 1/2 and 3/4? I never had the endurance for finding out the best fitting values :-/MIDI LED: if a DOUT shift register would be connected to the core, you could assign a Rx and Tx LED to the outputs by changing the DEFAULT_MIDI_RX_LED and DEFAULT_MIDI_TX_LED assignments in main.asmAlternatively, you could also trigger a free pin of the PIC instead, just modify the appr. code in midi_rxtx.inc :)Oscillator drop outs: it could be that this problem is related to the "unsynched register write issue" - more details about this can be found here:http://www.midibox.org/forum/index.php?topic=5748.0I built a special clock synchronisation routine into the firmware, but it only works if the SID is clocked directly from the PIC, and not from a 1 MHz oscillator.So: could you please try if the problem disappears with a direct clock connection?Your patch: just great!I see, these two changes open a completely new field for sounds - Jess, when will you release your first preset Bank? :)I just have noticed that I forgot to disable the DEFAULT_FILTER_TYPE_SWITCH in main.asm, therefore: if somebody has uploaded the main.hex file, the filter settings for a 6581 will be propably selected.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 18, 2006 Author Report Share Posted May 18, 2006 Hi Thorsten :)Yes, I've tried a few other types of caps, but I found no other that does the job better... in fact it sounded horrible when I tried it...Hmm... I gave it great thoughts if I should use the oscillator crystal, or the PIC itself... and of course I chose the crystal ::) ... I'm of to solder a bit again I think :-\ ... but what the heck...He he!... my first preset bank? ;D ... well... When it's done I guess. I'm playing around with the engine at the moment, and as I do patches I find good, I save them, and I've done about 3 now, so I WILL get there... in time... And You will be recieving it as soon as I'm through... also, I'm about to order 8 pieces of 24LC256 to fill up... it'll take some time though, but my intention is to fill it up totaly 8).One thing I'd like to do is to make at least ONE bank with recreation of some of the most famous patches from the C64 era (hubbard, daglish, david, daglish etc.)... they should be as close as possible, but when you then move the mod wheel, two extra oscillators should step in and make the patch FAT LIKE HELL!... that would be a cool thing to have when remixing for the RKO scene ;) ... you know... start out cheesy C64 style, and then KAPOW!... rock'in'an'a'rollin'! ;DThank you for the hardware info btw. :)Regards, Jess. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 18, 2006 Report Share Posted May 18, 2006 One thing I'd like to do is to make at least ONE bank with recreation of some of the most famous patches from the C64 era (hubbard, daglish, david, daglish etc.)... they should be as close as possible, but when you then move the mod wheel, two extra oscillators should step in and make the patch FAT LIKE HELL!... that would be a cool thing to have when remixing for the RKO scene ;) ... you know... start out cheesy C64 style, and then KAPOW!... rock'in'an'a'rollin'! ;DYeah!!! :)Btw for those who don't know RKO: check out http://remix.kwed.org, search for "Razmo" and download at least the Terra Cresta Remix - it's one of my favourite remixes, not at least because of the spectacular sounds :)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 19, 2006 Report Share Posted May 19, 2006 Nice! All SID?I'm curious, are all those weird robotic kinda noises at the beginning synthesised or samples? Quote Link to comment Share on other sites More sharing options...
Razmo Posted May 19, 2006 Author Report Share Posted May 19, 2006 Hi Stryd...No... there is no SID sound at all in this remix... all done with synthesizers. The robotic noises are samples. Actually I thinl that it would be cool to have real SID sounds in a remix, which is one of the main reasons I did this MB SID hardware :) The thought of doing a whole remix with just SID has crosed my mind lots of times, and it's certainly possible to do it so that people would not believe it's the real SID ;DRegards, Jess. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.