Two 6581 SID chip but not same version

[tob]

I got two SID-chip but will they be good in a Midibox SID stereo setup?

1x 6581R4AR 2286 s

1x 6581 4383

Edited June 5, 2011 by tob

[Hawkeye]

no problemo - make sure you do not mix different voltage types though (6581 12v vs 8580/6582 9v)

[tob]

Thanks I try it, are they any difference on these chips? (I can't find any information about it) I read here on the forum that the volume and sound can separate from different rev of the chip.

Edited June 6, 2011 by tob

[Hawkeye]

Yes, it might differ, but at least for my eight 8580s (all different revisions) i cannot hear a difference...

If the volume level is different, this should be adjustable in the mix.

If I interpret wikipedia right, you have a R3 and a R4 without any audible difference

• 6581 R3 - Will say "6581" only, "6581 R3" or "6581 CBM" on the package. Had a minor change to the protection/buffering of the input pins. Made from before 2083 until 0786 or so.
• 6581 R4 AR - Will say "6581 R4 AR" on the package. Minor adjustment to the silicon grade, no die change from R4. Produced from around 1986 (week 30) until at least the year 1990.

Best regards and have fun!

Peter

Edited June 6, 2011 by Hawkeye

[tob]

Thanks!

[Shuriken]

My 6581 R3 and R4 are very different. At least if you compare the volume level. The R3 output level is considerabely lower. And there is no difference in Voltage....both are 12V :thumbsup:

Edited June 6, 2011 by Shuriken

[Hawkeye]

http://www.joogn.de/sid.html:

The SID 6581 R3 vs. R4 myth Some ppl on the cbm newsgroups seem to experience "remarkable" differences in the production versions of the MOS SID 6581, MOS 6581R3/R4, CSG SID.

Excluding the "R5" CSG SID 8580, I have made parallel recordings with serveral SIDs of different week/years productions from different factories and revisions. Personally I can not tell a R4 from a R3, or a "R-none". At times they have output differences of about 2dB. Or different saturation and distortion, if more than one oscillator is run through the NMOS/HMOS FET filters, other than that I did/do not perceive any differences.

just try it and tell us your observations, dude :)

if they are too different, you can probably swap it with someone else here on the forum, who needs a r3 or a r4.

Edited June 6, 2011 by Hawkeye

[tob]

I give it a try, when i done with my core+2xsid modules. :laugh: