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SwinSID - a pin compatible alternative to the SID chip


TheFumigator

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  • 1 year later...

Tired of SID hunting and wondered by SwinSID samples I've decided to route dual MicroSwinSID board.

gallery_9659_127_46866.png

Layout inspired by nILS 8515 module.

I'm just take NanoSwinSID schematic and combined it with sammichSID. Am I moving the right way?

I've replaced hard-to-find crystal oscillator with 74LS04+Resonator circuit which was successfully tested with OPL3 chipset. It cheaper and using available components. Also there's pin header compatible with pin-to-pin cable, like in nILS one.

PCB is not yet tested - i need one more atmega chip + core board. But if there's volunteers i'll share it.

Edited by Schrabikus
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Couple of questions to Swinkles:

1. Can i substitute Mega88PA with 168? Which of AVR's in DIP package are good for such overclocking?

2. Will it work on lower frequencies? (just for testing purposes, i need to figure out where is proplem - MCU/Oscillator/Communication with core, and not shure that my ATmega168 supports 32 mhz. Will it run with 14.318 oscillator? And i have no scope)

At this moment I have constant high-pitched tone during startup, which sometimes dissapears after CS is loaded and sometimes not. Without core and SR's it starts when i'm touching reset pin of Atmega.

That's how it looks

gallery_9659_127_84833.png

board prototype:

med_gallery_9659_127_58272.jpg

Another question is addresed to Thorsten: You said about

Possibility to control two MBHP_SID (stuffed with original SID chips) and one Stereo-SwinSID module in parallel from a single MBHP_CORE

Is it possible with Stereo-MicroSwinSID? If so - please give me a hint ;)

Edited by Schrabikus
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Nice layout work - only 7 bridges and a very pragmatic oscillator! :-)

Is it possible with Stereo-MicroSwinSID? If so - please give me a hint ;)

Easy: you can connect the address, data and control lines (provided by the outputs of the 74HC595 shift registers) 1:1 with the SwinSID and SID inputs.

Also the two chip select lines (coming from PIC) can be shared - one CS for the left, the other CS for the right channel.

Best Regards, Thorsten.

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Thanks Torsten! As I undersdand this is not equal to dual CORE configuration and there's no way to control sids/swinsids independently?

(about oscillator: why pay $8-10 per one and wait a month when there's an 30 cents solution from waste components =)

But i've modified PCB for use with DIL14S oscillator.

post-9659-0-43481900-1337249215_thumb.pn

Edited by Schrabikus
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As I undersdand this is not equal to dual CORE configuration and there's no way to control sids/swinsids independently?

No, this is definitely not possible. ;-)

MBSID doesn't only stupidly forward MIDI events to the SIDs, it has a sound engine running in background which modulates SID parameters at high resolution and update rate for best results.

This sound engine consumes CPU time and RAM, it's tailored around the resources of a single PIC to get the max out of it.

Scalability is given by using a dedicated PIC for each pair of SIDs, and by connecting them via a CAN network (e.g. so that only a single control surface is required).

Best Regards, Thorsten.

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  • 3 weeks later...

I've made atmega8515 based SwinSidX2 but it sounds very strange. Only few default patches working ok. Most of them produces noise. I've found that when filter is enabled it distorts sound. Also if patch has non zero attack/release value - they distorted too. Swinsid extensions enabled in config. Is it normal for swinsid or there's something wrong? (same results with another TDA1543, and on lower oscillator frequencies)

Recorded some samples of it sound, they showing attack/release and filter distortions.

TK, which firmware youre using with 8515? (i tried both midibox and latest version from Swinkels site)

swinsid_bug.mp3

Edited by Schrabikus
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It seems that you are using wrong DAC chip version. Please test firmware for TDA1543A. This should help.

THANKS, Man!! This was the only thing i didn't try (DACS labeled "Philips TDA1543" without A). And it works like a charm!

med_gallery_9659_127_322538.jpg

Slightly modified Crisp's PCB

Edited by Schrabikus
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igi wrote me about oscillator tuning bug, so i've checked and confirming: by default oscillators finepitch is 12 units lower (not cents, 12/127 semitone?) so you need to set finetune to +12 for every oscillator to be in tune.

We need your help again, Swinkels! :logik:

Is it clock/oscillator or firmware related?

Crisp,(and other Swinsid users) do you have the same bug?

Edited by Schrabikus
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Yes it is related to clock source and firmware, so you need special MIDIbox firmware to get proper pitch. PAL C64 uses 0.985MHz clock, so the firmware can't work with both sources equally. Unfortunately there is no MB firmware for TDA1543A but i will try to compile it for you.

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Part      Value          Device          Package      Library  Sheet


AUDIO_OUT                PINHD-1X3       1X03         adafruit 1

C1        100n           C-EU025-024X044 C025-024X044 rcl      1

C2        100n           C-EU025-024X044 C025-024X044 rcl      1

C3        100n           C-EU025-024X044 C025-024X044 rcl      1

C4        100n           C-EU025-024X044 C025-024X044 rcl      1

C5        100uf          CPOL-EUE3.5-8   E3,5-8       rcl      1

IC1       74LS04N        74LS04N         DIL14        74xx-eu  1

IC2       MEGA88-PA        MEGA88-PA         DIL28-3      atmel    1

IC3       MEGA88-PA        MEGA88-PA         DIL28-3      atmel    1

IC4       74HC595N       74HC595N        DIL16        74xx-eu  1

IC5       74HC595N       74HC595N        DIL16        74xx-eu  1

J14                      PINHD-1X1       1X01         adafruit 1

JP1                      PINHD-2X4       2X04         pinhead  1

JP2                      PINHD-1X2       1X02         pinhead  1

JP3                      PINHD-1X2       1X02         pinhead  1

Q1        32mhz          CRYSTALHC49S    HC49/S       crystal  1

QG1       32mhz          QG5860          DIL14S       crystal  1

QG2       32mhz          XO-8            DIL08S       crystal  1

R1        1K             R-EU_0204/7     0204/7       rcl      1

R2        240K           R-EU_0204/7     0204/7       rcl      1

R3        1K             R-EU_0204/7     0204/7       rcl      1

R4        2K2            R-EU_0204/7     0204/7       rcl      1

R5        4K7            R-EU_0204/7     0204/7       rcl      1

R6        470            R-EU_0204/2V    0204V        rcl      1

R7        470            R-EU_0204/2V    0204V        rcl      1

R8        1K             R-EU_0204/7     0204/7       rcl      1

R9        240K           R-EU_0204/7     0204/7       rcl      1

R10       2K2            R-EU_0204/7     0204/7       rcl      1

R11       1K             R-EU_0204/7     0204/7       rcl      1

R12       4K7            R-EU_0204/7     0204/7       rcl      1

omit IC1,Q1,R6,R7 and one of OG, if you have oscillator.

And there will be one more revision with decoupling/filtering added.

post-9659-0-65008100-1339916028_thumb.pn

Edited by Schrabikus
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  • 1 month later...
  • 4 years later...

I recently built one of these with some 8515. Works great. Was curious why the output filter is a 1K resistor with a 1uF cap. That seems like a high pole for the high pass filter at about 160Hz. Would a 100k resistor be a better selection to set the pole at 16 Hz or is there something I am missing as a reason to set it higher?

  I am currently running with a TDA1543 if I wanted to use one of the PCM17xx does anyone know where to source the second clock from for SCKI? Also would it sound better if the opamp filter was added as on the data sheet vs the passive? It would seem the design decision was for simplicity and not having to source a differential supply.  Also saw this fun tube output idea for the TDA as the output. Not sure I want the 330v in my audio gear though but I may at least bread board it out to hear it. http://www.lampizator.eu/lampizator/REFERENCES/AH%20DAC/AHDAC.html

Also is there any opinion of the 88pa version without the DAC versus the 8515 with the dac? It can run a bit higher clock and I have read that it sounds a bit better as it is running a higher sample rate. I saw that some equipment was having issues with the output but no real details on the issue.  It can be sized down a bit more so that may be nice as my midi box is in a c64 case and space is at a premium in there.

Edited by gerald.wert
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