Parallel SIDs vs. Multiple Cores

[natemccoy]

Hello,

I would like to know about the options I have in implementing multiple SIDs.

My ultimate goal: to use my two SID chips to get a maximum polyphony of 6 simultaneous notes.

My question is this:

Is there a way to use two SID chips in parallel by using only one core module to get the result I am looking for,

or would I have to buy a second core to achieve my goal?

Thanks in advance.

//The reason I am asking this question is because I bought another SID module thinking

//the CORE module could control two SID modules independently so I could achieve

//my goal of having a maximum polyphony of 6 simultaneous notes

[philetaylor]

Is there a way to use two SID chips in parallel by using only one core module to get the result I am looking for,

or would I have to buy a second core to achieve my goal?

Hi. As per The MIDIbox SID Walkthrough each CORE8 can control up to 2 SID modules:

Connecting a second SID module for stereo sounds

• As you can see in mbhp_8xsid_c64_psu_optimized.pdf, the second SID module is connected to the same port as the first one. Just only the MBHP_SID:J2:SO input is connected to MBHP_CORE:J14 instead, so that the core module can access the SID registers individually.

Cheers

Phil

[seppoman]

regarding the 6 voices - that is possible using the Multi or Drum engine as these sound engines are using the simpler one oscillator voices. The Lead engine doesn't provide more than one voice, it does three oscillator sounds with various stereo modulation features.

S

Edited June 11, 2010 by seppoman

[natemccoy]

philetaylor,

But in this configuration I would have both SIDs playing the SAME sound at the SAME time correct?

Or is the MIOS capable of distributing the multiple MIDI notes across both SID modules?

I would like to utilize the full 6 note polyphony if possible.

Also, it seems this option is only available for synthesizers running MIOS 2.0

I am running MIOS 1.9. I am assuming I would have to upgrade. Is this true?

Hi. As per The MIDIbox SID Walkthrough each CORE8 can control up to 2 SID modules:

Cheers

Phil

[philetaylor]

Hi.

Hopefully seppoman or somebody else will chime in here as my knowledge of internal workings of MIDIbox SID is pretty bare (practically non-existant).....

For the CORE8, MIOS 1.9g is the latest version of MIOS, I'm not sure where you got MIOS 2.0 from? There is MIOS32 which runs on a different hardware platform (STM32) but there isn't (currently) a released version of MIDIbox SID for MIO32.

Unless you mean MIDIbox SID v2? This runs on top of MIOS 1.9g but it does require a PIC18F4685 based CORE8.

Cheers

Phil

[TK.]

But in this configuration I would have both SIDs playing the SAME sound at the SAME time correct?

No, as Seppoman already mentioned, you can control each voice separately in Multi and Drum mode.

Did you already read the user manual where such details are described?

interesting pages that answer your questions:

-> http://www.ucapps.de/midibox_sid_manual_hw.html

-> http://www.ucapps.de/midibox_sid_manual_m.html

-> http://www.ucapps.de/midibox_sid_manual_d.html

I would like to utilize the full 6 note polyphony if possible.

E.g. with the multi engine you could assign each instrument to a different voice.

Best Regards, Thorsten.

[Janis1279]

From Wiki pages :

Can you connect multiple SIDs in parallel to one Core, to get a "unison" kind of sound?

Yes, this feature is available starting with the MIDIbox SID 2.0.

Is this next piece still relevant?

As TK says: you can connect multiple SID modules to one core module, in this case they always listen to the same control data. But the audible effect isn't really so interesting. If you are having two identical SIDs, then the volume will just be doubled (the oscillators are digital and therefore always output exactly the same waveform). This option can make sense if you want to switch between 6581 and 8580 because of the different filter characteristics. But for really interesting (especially fat) sounds, seperate cores are the best option, so that the SID parameters are modulated independent from each other. The result is much more analog-like(especially when the LFOs are in freerunning mode and the finetune/portamento/ENV parameters are slightly different).

Can we have more SIDs in one MB SID?

TK: As always I have to define such specs before beginning with the implementation. First I thought that controlling two SIDs from one control surface is sufficient for stereo effects. Then I was possibly in such a volatile temper that I decided the incredible: controlling 4 SIDs from a single PIC, which is doing the sound engine of one SID in parallel! Hard to believe that this works without affecting the realtime capabilities too much. I'm really proud that it works without trouble.

However, if you really want 8 SIDs, TK suggests: you could build two 4*SID systems… this will possibly cost you 50 EUR more, but what are 50 EUR compared to my unpayable sparetime

I'd go with that suggestion

[TK.]

Wrong - you read the MBSID V1 FAQ, and you are mixing MBSID V1 features that have been developed 6 years ago with MBSID V2 features that are the current state. Meanwhile I spent a lot of sparetime to improve *a lot of* things.

However, you are free to read the MBSID V2 manual on my webpage and to write a new Wiki page based on what you learnt, because it seems that nobody felt triggered to do this so far (probably because most people are aware about the V2 users manual)

[text macro]Thats poor community effort btw. - if you don't like this, go away and search for another project!

If you see the problem and want to help, feel welcomed to improve the wiki![text macro]

Best Regards, Thorsten.

[natemccoy]

Thank you for the information,

I will have to reread the documentation you have listed.

I also seem to be confused about the difference between v1 and v2. I thought it was a reference to the MIOS.

From the limited information i have read within the last day, i see what i will have to do now.

I will finish up adding the second core and if i still have problems i will post my questions.

Thank you.

No, as Seppoman already mentioned, you can control each voice separately in Multi and Drum mode.

Did you already read the user manual where such details are described?

interesting pages that answer your questions:

-> http://www.ucapps.de/midibox_sid_manual_hw.html

-> http://www.ucapps.de/midibox_sid_manual_m.html

-> http://www.ucapps.de/midibox_sid_manual_d.html

E.g. with the multi engine you could assign each instrument to a different voice.

Best Regards, Thorsten.