Sound difference between 6581 and 8580?

westerling · Post by **westerling** » 28/10/2005 - 18:47

When I rediscovered sid-songs listening with Sidplay for Windows I thought: Hell this sounds good!!! This was some five years ago. Since then I have begun to collect C64Ã‚Â´s and C128Ã‚Â´s. And they sound extremely good.

I have one old C64 and two C128Ã‚Â´s (They all have the 6581-chip) Now I wonder how the new version of C64 (with the 8580-chip) sounds like. (I had one as a kid but I canÃ‚Â´t really remember). Of course IÃ‚Â´ll get one of those "new" ones one of these days, but in the meantime I hope someone can describe the sound difference in words.

trace · Post by **trace** » 28/10/2005 - 19:54

I _think_ it was the filter that was changed, some of my tunes sounded wierd with the new one ;/

Tonka · Post by **Tonka** » 28/10/2005 - 20:41

The main differences to my ears are that the filter is more open on SIDS (kinda squelchier), there is less background noise from the RF modulator and the oscillators sound a lot cleaner.

Put it this way, if I wanted to record a SID that didn't use a filter, I would use a C64C for it's cleaner sound.

Oh yes, and the digi's are too quiet on on the C64C (or is that too loud? Damn, I'm getting old - can't remember)...

Tonka

Chris Abbott · Post by **Chris Abbott** » 28/10/2005 - 21:52

Tonka wrote:The main differences to my ears are that the filter is more open on SIDS (kinda squelchier), there is less background noise from the RF modulator and the oscillators sound a lot cleaner.

Put it this way, if I wanted to record a SID that didn't use a filter, I would use a C64C for it's cleaner sound.

Oh yes, and the digi's are too quiet on on the C64C (or is that too loud? Damn, I'm getting old - can't remember)...

Tonka

Heh. Too quiet on the C64C, since the click bug was reduced in magnitude.

Waz · Post by **Waz** » 29/10/2005 - 5:25

Tonka wrote: Put it this way, if I wanted to record a SID that didn't use a filter, I would use a C64C for it's cleaner sound.

I've recorded stuff from a real old breadbin, and it's actually sounded fine. Mind you, I didn't use the RF modulator output to avoid some of that dreaded screen buzz.

Don't forget also that the first batch of C64Cs (like mine) actually have a 6581 R4 in - it was later models that then had the 8580 in them - and that's when people started to notice the quiet digi sounds..

Tonka · Post by **Tonka** » 30/10/2005 - 8:14

Waz wrote:
Tonka wrote: Put it this way, if I wanted to record a SID that didn't use a filter, I would use a C64C for it's cleaner sound.
I've recorded stuff from a real old breadbin, and it's actually sounded fine. Mind you, I didn't use the RF modulator output to avoid some of that dreaded screen buzz.

Don't forget also that the first batch of C64Cs (like mine) actually have a 6581 R4 in - it was later models that then had the 8580 in them - and that's when people started to notice the quiet digi sounds..

Yeah, I got me one of those babies (Ã‚Â£4.00 from a car boot)!!! They don't suffer from the dreaded SID buzz either, but I didn't want to confuse the post by going into Sid revisions!

What do you mean when you say you don't use the RF modulator output? You mean the lead that goes directly into the TV? Either way, I've found buzz going from either output. Do you know a way of turning the RF mod off?

Tonka

Waz · Post by **Waz** » 30/10/2005 - 9:07

Tonka wrote: What do you mean when you say you don't use the RF modulator output? You mean the lead that goes directly into the TV? Either way, I've found buzz going from either output. Do you know a way of turning the RF mod off?

Well, as I'm only interesting in recording stuff from an original SID chip, I don't need the screen display. Not least when using the trusty AR cart, after switching the 64 on I can just do F7, F1, enter to load and run the first file off the disk.

The lead I have is basically a DIN to audio lead, and one of the connectors carries the mono signal. This is then connected to a lead which goes into the line in on my soundcard. I then of course record the line in input (making sure I mute all stuff like microphone of course) and it sounds pretty clear.

Mind you, I also use PSID64 to make runnable C64 .prgs from the SID file. If you do psid64 -b <SID filaneme> the program runs with a black screen, and $d011 switched so that the screen is off. That helps a fair bit too.

Put it this way, some of my SID recordings have been used on the C64 Takeaway podcast, so they can't be that bad!

Tonka · Post by **Tonka** » 30/10/2005 - 9:37

Waz wrote:Mind you, I also use PSID64 to make runnable C64 .prgs from the SID file. If you do psid64 -b <SID filaneme> the program runs with a black screen, and $d011 switched so that the screen is off. That helps a fair bit too.

Yep - that's the method I use with, a first batch C64C + a selection of about 10 different SID chips (depends on which song I am recording to compensate for the damn filter variations)!

Haven't tried it with an original breadbox, but I just assumed that the dreaded buzz would still be there due to the RF MOD interference, regardless of whether the screen is blanked or not...

Thanks for the info - I will have to experiment further...

Tonka