12 Jan
2012
12 Jan
'12
8:43 p.m.
On Jan 12, 2012, at 3:01 PM, Dave McGuire wrote:
It's not a downgrade per se; they actually improved it from a technical standpoint, in
the same way that transistor amps improve upon tube amps from a technical standpoint (both
from a consistency and a distortion point of view). The problem is that sometimes the
distortion sounds better. :-)
The 8580 certainly sounded more consistent from chip to chip; it has a much
"cleaner" sound. Some games actually had knobs to twiddle because the filter
blocks in the old 6581s could vary so much that the music would sound kinda wrong. It
also didn't distort quite as much and the filters were much more resonant due to the
higher gain of the HMOS II process over the older NMOS process.
Check out the different samples in the site I linked; the 6581 versions sound
distinctively more "dirty", which could be a good or a bad thing depending on
your point of view (and depending on what music you're trying to play through it).
There's a pretty spiffy interview with Bob Yannes (designer of the chip, later founder
of Ensoniq) here: http://sid.kubarth.com/articles/interview_bob_yannes.html
And lots of cool die shots of various revisions here: http://oms.wmhost.com/misc/
And hopefully some time in the future, a visual interactive simulation here:
http://visual6502.org/images/pages/Commodore_8580_SID.html
- Dave
Major
difference is with the SID chip - the new SIDs aren't as good as the
older ones (sound-wise). The PC board is also mostly all surface mount and
with a reduced chip count. Apart from that, largely the same as the old
breadboxes.
Ahh, gotcha. Thank you for the info.
I wonder why they downgraded the SID chip. Cost reasons?