Decisions Decisions..Which SID?

MIDIbox SID
1

Hey guys, I need some advice today.

I got myself an old (very old, 1983, same age as me!) C64 a while back to steal it’s SID, but I decided to use it with the Prophet64 cart instead. However, having had it running today now I’ve been home to get my datasette etc, It appears there’s a few things wrong with it, (ie, datasette won’t work with it, some RAM is not recognised).

So, I did get it to play the loading screen on my rick dangerous cart (best game EVER) with the accompanying tune so I could compare it to my newer 1990 8580 C64. As it turns out, the bass is much fatter and more grimy on the old 6581. It’s probably more distorted, but it just sounds more exciting. THis put me in a bit of a quandry since I can’t use this unit with the Prophet64 cart.

I’d originally planned to make a 6581+8580 dual MBSid, but then changed to a dual 8580. My reasoning is that with two 8580’s I can get 6-note polyphony. Other than that, I don’t think the 2x8580 has any advantage. (If Slorrin’s reading this, i’ll still get both 8580’s either way, one can go in my SID2SID/prophet64 unit.)

Can anyone help me out with some ideas and samples as to which direction I should go? Maybe I should build a 2x8580 AND a 6581, but I suspect that’s overkill?!

Oh, I should mention i’m a big fan of old monosynths like the SH09, SH-101 etc, does that have any bearing on my choice of SID??

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Hi Jaicen!  :slight_smile:

Well… to start a debate on what SID is the best would be like judging wich is better; Apple or Orange! … both are fruits, but have a different taste!

I can give some explanation of the differencies though (soundwise):

6581 (R2-R4AR):

The 6581 Rx have many bugs wich the 8580 does not. The most notable soundwise is the filter which has strange working frequency ranges making every 6581 sound a little different. Also, the 6581’s resonance is more like distorted feedback. Also, the 6581 has an error that make the chip noisy when everything should be quiet. Also, the mixed waveforms does not work correctly.

8580 (R5):

The 8580 R5 has some of the bugs correctet; the noisy running oscillators that should be quiet when the envelope release has finished has been fixed, and the filter’s resonance now works as it “should”. The AND’ing of the waveforms (mixing) also perform correctly. All in all, the 8580 has everything fixed to how it SHOULD have been, all from the beginning! (exept for that DARN envelope bug! grrrr!)

Conclusion:

Well… what is then best?.. I’m certainly building one of each. If you want nostalgica, and distorted rumbling creamy bass, I’d take the 6581. If I want piercing resonance I’d go for the 8580.

The good thing about the 8580 is that they sound identical, so if you decide to share patches and want them to sound the same at everyone elses MBSID, then the 8580 would be the best choice.

To me, it seems that having just one of them makes me miss the other. As to the 6 voice polyphony I don’t really think that is worth much, since two SID’s give you only 2 filters, so if you are to play 6voices polyphonically, you’d have to omit the use of the filters.

It’s a tough job… but if I could only choose 2, I’d go for one of each  :wink:

In fact, I’ve been playing alot with the idear of connecting an 8580 to the ext. input of a 6581… this way I could use the better 8580 for the oscillators, but get the creamy filter of the 6581. In fact you could also connect two 8580’s like this, and get a cool 24db/octave filter instead of the 12db/octave! … or or how would an 6581 routed through an 8580’s resonant filter sound? … AAAAARGH! you see what I mean!? it’s impossible to live without each!.. they should be “meltet together” those two SIDs!!!  ;D

Hope this helps a bit…

Regards, Jess.

3

The other advantage of having 2x 8580 will be cool stereo effects, which will become easier in MBSID v2 (when both SIDs are controlled from one Core) but is still possible now with the current MBSID v1, you just need two different patches. Since 8580 consistently sound the same, they’re a better choice for doing stereo effects. Also, TK has mentioned that the 303 sound only works well for the 8580 filter.

My totally biased option is to prefer two 8580… as I’ve had the worst luck with 6581 (busted filters on all I have salvaged) not to mention a dislike of the noise. I suppose if I actually had a working 6581 complete with a quirky, unique filter, then I might have a different opinion and appreciate it (and say things like “best of both worlds”)… but right now I’m enjoying having four 8580 SIDs all sounding the same.

If you are interested in buying two (or more) 8580 chips I will be selling a bunch soon, fully tested, really cheap. Stay tuned.

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If you are interested in buying two (or more) 8580 chips I will be selling a bunch soon, fully tested, really cheap. Stay tuned.

I’d like to buy it least 2 8580 chips. or maybe 4. tell me the price!

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My 8580 sale is here:

http://www.midibox.org/forum/index.php?topic=6949.msg44789

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Hi again Wilba!  :slight_smile:

Well… if the choice was to only have one SID, I’d certainly also choose the 8580, no doubt on that! … But the 6581 DOES have a very grungy-smooth sound to it, if you can manage to find a “working” piece! … With “working” I mean, that the filter range works so that lowest and highest cutoff freq. is between 0 and 127…

Finding such a chip is to keep searching… I actually just resoldered my MBSID just to etst my 6581 SIDs today, and believe me, don’t count on revision numbers as a sign of BEST SOUND! I testet all chips, on both R2, R3, R4, R4AR… even the two R3’s was way appart in quality! … My R4AR was good, but not the best! … actually, the best chip I’ve got (6581) is an 84 R2!!! … in fact I have only TWO SIDs that have “working” filters! the R2, and one R3.

I have to say, that the 8580 is much more versatile then the 6581, and if you ask me, overall it’s just plain better, but if you want distorted grungy gritty dirty bass sounds, the 6581 will rock your world!

Just take a listen:  :wink:

http://media.putfile.com/6581_R2_DEMO

Regards, Jess D. Skov-Nielsen