Amiga.org

Amiga computer related discussion => Amiga Desktop Audio and Video => Topic started by: minator on September 13, 2012, 09:14:13 PM

Title: VSTi for recreating the Amiga sound
Post by: minator on September 13, 2012, 09:14:13 PM
There's a VSTi that does the sound of various old computers including the Amiga.  It'll even load mods and extract the samples:

http://www.youtube.com/watch?v=sQfS5PCPxn0


BTW if you want to emulate the Amiga sound you'll want to read this:

https://bel.fi/alankila/modguide/interpolate.txt
Title: Re: VSTi for recreating the Amiga sound
Post by: paul1981 on September 13, 2012, 10:30:31 PM
Quote from: minator;708023
There's a VSTi that does the sound of various old computers including the Amiga.  It'll even load mods and extract the samples:

http://www.youtube.com/watch?v=sQfS5PCPxn0


BTW if you want to emulate the Amiga sound you'll want to read this:

https://bel.fi/alankila/modguide/interpolate.txt

Haven't read it all, but the record needs putting straight here:

"This may surprise those who believe that because Amiga's maximum sampling rate is some 28867 Hz, the maximum frequency produced by Amiga is threrefore limited to 14.5 kHz or so. However, this is merely the highest frequency that may be produced without aliasing."

This is not true. With Paula, with the ECS or AGA chipset, you can have up to 56KHz sampling rate if running in one of the double line screen modes.
Title: Re: VSTi for recreating the Amiga sound
Post by: B00tDisk on September 14, 2012, 01:19:05 AM
Wasn't there a way to actually run 14-bit sound?  Or is that what you guys are saying?
Title: Re: VSTi for recreating the Amiga sound
Post by: Digiman on September 14, 2012, 02:26:15 AM
Amiga is just a straight 28khz 8bit DAC x4 simple. You don't need to emulate it you don't need to do anything to it.

The only difference when I play my mods today on my PC is because I use a 100% digital system from mod playing application to amplifier generating the music is a lot less line noise (zero) or distortion (well it is a high grade AC3 Sony)

As for the double pal/productivity mode hack for the 32khz screen modes...well few people could use those modes on their Amiga and games or demos would run slower if used as it massively saps CPU time doesn't it? So dead end really in reality unless you want a blank screen when playing mods.

There is nothing wrong with 8bit DACs though, Bob Yannes who designed the SID chip also designed the Ensoniq Mirage 8bit sampling synthesizer and the stock machine sounds so good the band Inner City used pretty much just that one synth and a drum machine and sequencer to produce their first album in high quality.
Title: Re: VSTi for recreating the Amiga sound
Post by: KimmoK on September 14, 2012, 10:08:44 AM
Quote from: B00tDisk;708053
Wasn't there a way to actually run 14-bit sound?  Or is that what you guys are saying?


Yes. I use 14bit 56khz Audio on my A4000, no problem. All system friendly AHI aware apps run perfectly. And with 060/50 the CPU load is not noticeable. (IMO, the paula audio is better than standard AC97 on x86, less noice on the sound + my ears can not tell the difference between 14bit and 16bit)

For old games and old audio apps, only basic 22+khz works, but 14bit is possible if application supports it directly.

(for 56khz you need multisync monitor for AGA output or separate GFX card like I have ... actually I have both, but anyway.)
Title: Re: VSTi for recreating the Amiga sound
Post by: paul1981 on September 14, 2012, 10:53:43 AM
Quote from: Digiman;708059
As for the double pal/productivity mode hack for the 32khz screen modes...well few people could use those modes on their Amiga and games or demos would run slower if used as it massively saps CPU time doesn't it? So dead end really in reality unless you want a blank screen when playing mods..

I thought we were talking about sound samples, not demo productions/mods.
A standard 68000 ECS Amiga such as the A500+ can play samples at 56KHz, if in a double line mode. And the Workbench screen wouldn't disappear either.

@BOOtDisk
Yes, with the CyberSound driver you can get 14bit stereo audio from Paula, and at 56KHz if in a double line mode. So playing cd's/16bit audio sounds really good, as the samples don't have to be downsampled at all (Paula will play them at 44.1KHz), scaled down to 14bits (68020 required for CyberSound).
You can try this out yourself if you like as it's included in the Play16 package:
http://aminet.net/package/mus/play/Play16
Title: Re: VSTi for recreating the Amiga sound
Post by: bloodline on September 14, 2012, 11:05:00 AM
Quote from: minator;708023
There's a VSTi that does the sound of various old computers including the Amiga.  It'll even load mods and extract the samples:

http://www.youtube.com/watch?v=sQfS5PCPxn0


BTW if you want to emulate the Amiga sound you'll want to read this:

https://bel.fi/alankila/modguide/interpolate.txt
Fun read! I really will have to get around to building that Paula AU I keep wanting to make... :(
Title: Re: VSTi for recreating the Amiga sound
Post by: jj on September 14, 2012, 01:28:23 PM
Have to give this  a go in fruity loops
Title: Re: VSTi for recreating the Amiga sound
Post by: minator on September 15, 2012, 12:16:40 PM
Quote from: Digiman;708059
Amiga is just a straight 28khz 8bit DAC x4 simple. You don't need to emulate it you don't need to do anything to it.


Read the second link I posted.PC's play at a fixed 44KHz (or higher with a good interface) The Amiga doesn't have a fixed playback rate.  It's remarkably complicated to emulate the Amiga's sound accurately.  

Quote
As for the double pal/productivity mode hack for the 32khz screen modes...well few people could use those modes on their Amiga and games or demos would run slower if used as it massively saps CPU time doesn't it? So dead end really in reality unless you want a blank screen when playing mods.


I used to run 55KHz all the time, no effect on the graphics whatsoever.


[/QUOTE]There is nothing wrong with 8bit DACs though, Bob Yannes who designed the SID chip also designed the Ensoniq Mirage 8bit sampling synthesizer and the stock machine sounds so good the band Inner City used pretty much just that one synth and a drum machine and sequencer to produce their first album in high quality.[/QUOTE]

A lot of early samplers used 8 bit DACs and some used a playback system similar to the Amiga (e.g. Fairlight).

Things have long since moved on though, 24 bit is common now.
The only reason anyone uses 8 bit for audio now is for making things sound retro or effects like bit crushers.