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Want to hear difference from 8580R5 to 6582A SID?


Razmo
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... if you want to, then check out these MP3's I made using the same patch playing on both 6582A and 8580R5 SID chips.

The major difference in the 6582A lies in the Bandpass and Hipass filters. The demo plays a combination of both lowpass and bandpass.

So the conclusion is, that there ARE differences between the two chips...

http://media.putfile.com/8580R5_BandPassFilter_Demo

http://media.putfile.com/6582A_BandPassFilter_Demo

Regards, Jess.

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Whilst I applaud this very clear comparison (really good line actually), i'm wondering if it's not just a case of playing 'the same' patch with the 6581, but rather the patch needs to be modified to work with the strenghts and weaknesses of the chip.

What would be interesting is if you could now tweak that 6581 to get it sounding as close as possible.

I'd also like to hear some dirty SH101 style bass lines. I think the 6581 will shine in that particular application, it just seems more aggressive.

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Hi again ...  :)

First I'd like to say, that the only effects used on the demo is a simple stereo delay... nothing else... forgot to mention that  :-[

I believe that no machines hold the 6582 at all. They are a small batch of chips that I believe was meant for the C65 that never went beyond proto-type state. They can be found in small stock on broker-sites though (if any left anymore)... I've seen them there, but have to be bought in large quantities. I would say it's not worth the trouble... It's too close to the 8580 I'd say.. only the HP/BP filter differs greatly.

I am just lucky to have one piece of the 6582A chip, and wanted to see I f there was any difference to the 8580 SID... At first glance it seemed that they were identical, but by looking more closely at the LP filter, there are a very subtle difference... hardly noticeable... but when I switched to the two other types of filters the difference became much more obvious... The sound of the 6582 is much more "thin" as can be heard on the demo. In fact I like that "reed'ish" sound it gives, and I'm going to experiment a little more with it these days.

And to the question about reproducing this sound on the 6581... just not possible... The 6581 has a very different filter, and the resonance that is almost non-present on the 6581 is used at full settings in the demos, so bad luck!... the 6581 excels at other fields  ;)

I do though have SIDs of both revision 1, 2, 3, 4, 4AR of the 6581, so I could do some tests one day, but unfortunately I've made my MBSID for 9volts 8580/6582 so It will not be right away  :-\

Here are an 8580R5 Demo I made with a few of my newly created patches... they will be available when I finish a 128 patch bank  :)

Hope you like em'... please remember that I played live, so If it's not tight enough for you... too bad!  ;D

also I've used a delay effect on top... that's all!... rest is pure SID.

http://media.putfile.com/SID-8580R5-Demo

Regards, Jess.

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Hi!

Nebula: Yes! It sounds very different from the 6581... The 6581's resonance is not really resonance but rather distorted feedback because of the fact that the 6581 was never fully developped before they took it into use (Yannes had only a couple of months to develop it)... The 8580 has corrected the filter bugs, and it was also made tunable in the same fashion as the frequency registers (which means that the register values change the cutoff in a logarithmic fashion... the 6581 was linear... wich is why the 8580 sounds thin on a C64)

The 6582A sound very much the same as the 8580... is also 9volts (not 12v as 6581), and controls the filter just like the 8580... there are subtle differencies on the lowpass filter, but the main difference is within the bandpass and hipass filters... they sound very different than both 8580 and 6581.

I'll post more comparisons between 8580 and 6582A later...

Regards, Jess.

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  • 3 weeks later...

Razmo, can you share the patch you used to compare the 8580 and 6582?

I've tried to make a patch for my 8580 to sound like your 8580, but it ends up sounding more like the 6582...  ???

I don't know whether it's different capacitors or different revisions... mine is MOS 8580R5, 2888

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Hi Wilba!

Well... unfortunately I do not have that patch anymore... it was just a tempoary patch I made for the test, but I can remember a few things:

The sound has all oscillators phase resetting on note-ons, and the filter type actually use BOTH the BP, and the LP types at the same time! that keeps the sound from getting too thin.

Also, the filter frequency was mapped to velocity

All oscillators was in use also ... hmmm.... maybe it's not so easy to recreate I don't know, but this is what I remember.

Regards, Jess.

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  • 1 month later...

If some one have a 6581 r3 or r4 or r4ar or a simple 6581 year of production '83 (very rare for me, never find), can play same patch (and same note :P), if Razmo give it to him, for comparing?

;)

i have 3 6581R4ARs and a 'normal' 6581 to go in my soon to be MBSIDx4. as soon as it's built i'll post something up here.

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