A4000 060 - Audio & Dune

[GadgetUK]

Hi, a couple of questions about audio on the A4000



1) Can anyone confirm - is the A4000 audio slighly different to say an A500? I notice it sounds like the filtering behaves a little differently? I guess I can compare to A500 schematics when I get time later, but I just wanted to run this past experience A4000 owners here to gauge opinion?

Everything sound related seems fixed on this A4000 I am working on, it has been recapped and I've fixed a number of issues with broken traces and missing supply rails etc. All connectivity around the op amps are as they should be in relation to all the caps and resistors etc etc. But it does sound a little different, particularly on low to mid, and high frequencies.


2) Dune - the wind noise at the start of the intro is kind of broken up and does not sound correct at all. Confirmed the same thing occurs with a good version (WHDLOAD) - the rest of the music sounds OK, but with perhaps more emphasis on certain frequencies that I dont notice so much on the A500 / A2000 etc. Is there an issue with this game and the start of the intro music, perhaps in relation to an 060 CPU? Other than that I cannot fault the sound in other games, despite it sounding different with regards to how it handles certain frequencies.

[dlfrsilver]

A4000 ? Possibly sound driver that has to patched or correctly to run on this computer.

[klx300r]

Originally Posted by dlfrsilver

A4000 ? Possibly sound driver that has to patched or correctly to run on this computer.

What's the latest sound driver ?

[dlfrsilver]

Originally Posted by klx300r

What's the latest sound driver ?

the sound driver drives the sound. Every game on amiga has one.

Dune is made for A500. the A4000 is AGA and the CPU runs way way faster.

[GadgetUK]

I notice issues with the "singing" part on Aladdin AGA too. It would be really helpful if someone else with a 4000 060 could confirm they get issues with these two games! I cannot fault the audio in other testing, but I just not 100% sure at the moment.

[AmigaHope]

Sound will seem different between A500 and A4000 because OCS-era Amigas had more aggressive low-pass filters baked into the audio channels (that is, not the "LED" low-pass filter which can be disabled, but the always-on low pass filter that you can't turn off).

Most people seem to prefer the less-aggressive filtering of later machines, and you can modify the A500 to change the secondary filter. Here's a related thread:

http://eab.abime.net/showthread.php?t=86880

Regarding timing of samples, very aggressively-timed sample loops that rely on realtime clock + DMA rates can be confused if they don't take into account the difference between the NTSC/PAL crystal. I regularly ran into problems using an A4000 with an NTSC xtal but with the jumper set to PAL on the motherboard -- something I learned the hard way you should never do because it causes all sorts of tiny timing errors that seem to come from nowhere.

[Kin Hell]

I don't want to sound harsh on Christmas Day, but one of those annoying things in life is hearing about Hardware Drivers for the Amiga.....

This is not a Bill Gates Abomination style Platform.

You install the latest software possible & that's pretty much it.

Your version of 060 Libs might be the culprit & something in the back of my mind wonders if there was a patch for Dune back in the old BBS days? - I can't be sure.

Which 060 card are you using?

[jotd]

when running under whdload, the 060 libraries aren't active.

[AmigaHope]

The 060 libraries wouldn't even be relevant for running most userland code targeted for a stock A500. They're only needed to keep the OS happy and for code that uses deprecated stuff from 020+ era. (Bootstrap excepted, where the boot ROM runs rudimentary patches to keep the OS alive until 060 library loading, which is why A3640 conversions are so finicky.)

As I mentioned before, the user's issues here seem to be more of a timing problem. (not counting the frequency response, which is just a change that happened in the low pass filters over later Amigas -- the A1200 has the same less-aggressive filtering as the A4000, and the A600 wasn't supposed to although at least some A600s seem to keep the A500 filters)

[GadgetUK]

Thanks for all the comments and suggestions guys! I've sorted it! The good news is that the issue with those 2 games was just related to a miss behaving audio circuit!!! NOT the 060 at all! It's hard to believe because almost everything I tested on it sounded normal, but those 2 games had certain parts that sounded very wrong indeed. The cause, a shorted ceramic cap - that's one reason I don't like using ceramics in place of SMD wet types.

[Solo Kazuki]

If You have A4000 with 060 why You not use Dune PC port? It have better graphic (256 colour palette) and more features.

[GadgetUK]

Originally Posted by Solo Kazuki

If You have A4000 with 060 why You not use Dune PC port? It have better graphic (256 colour palette) and more features.

Thanks but Open Dune is NOT the same as Dune! It's a version of Dune 2. The other point here is I was repairing an A4000 and testing specific games that I am familiar with - that was the purpose of using Dune (1) on this machine! Anyway, it's working 100% normally now!

[Kin Hell]

Originally Posted by GadgetUK

Thanks but Open Dune is NOT the same as Dune! It's a version of Dune 2. The other point here is I was repairing an A4000 and testing specific games that I am familiar with - that was the purpose of using Dune (1) on this machine! Anyway, it's working 100% normally now!

Wet Caps.... Yuk!

Kudos though & glad you're sorted.

Dune 2 on a fast Amiga is still awesome!

[Solo Kazuki]

Originally Posted by GadgetUK

Thanks but Open Dune is NOT the same as Dune! It's a version of Dune 2

Oops, don't know why i thought it's about Dune II.

Sadly, there's no PC version port for Amiga, but (still) game is better for PC for same reasons as Dune II.