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Audio input / sampler

Posted: Mon Jul 27, 2020 7:01 pm
by aToyRobot
Is it at all possible to use the audio input for the Amiga, or is there some other way to connect a sampler? It would be great fun to have a way to sample into Protracker et al.

Re: Audio input / sampler

Posted: Tue Jul 28, 2020 4:23 pm
by Lisko
The audio in on the io board isn't suitable for audio purposes and the amiga didn't had native line-in so the core should be also modified to simulate line-in over user port.. So the answer is: currently not and maybe never will

Re: Audio input / sampler

Posted: Tue Jul 28, 2020 5:12 pm
by bazza_12
or is it possible create the sample on pc/mac as a *.wav file and convert it to *.iff

Re: Audio input / sampler

Posted: Wed Jul 29, 2020 8:31 pm
by alg07
Of course it should be possible. Amiga samples are usually in file format iff/8svx.

You could use the Linux/Unix tool `sox` to convert or just google for "wav to 8svx" to find an alternative tool.

Re: Audio input / sampler

Posted: Thu Jul 30, 2020 12:44 am
by djhardrich
Here's a pretty dirty hack that works, I've tested the output files in Protracker 2.3 on Amiga and Octalyzer for the STe (if using ST, you need to run an ftpd on your ST core and ftp them in or make disk images in Hatari; looking into some sort of shared folder solution for ST) and haven't had any issues:

Connect a cheap ($5) USB sound card (generally mono in, stereo out) to MiSTer, boot.
Download the cross-compiled sox + scripts, copy sox to /usr/bin on your MiSTer and copy the scripts to your Scripts folder (use ssh/sftp to avoid removing your sd card). You may have to "chmod +x sox" from your MiSTer's Linux console before running "cp sox /usr/bin/" to make it executable/copy sox
For Amiga, make a /media/fat/games/Amiga/hdd/samples/ directory, set up Amiga file sharing in MiSTer.
Launch the scripts either from the scripts menu or the root console, follow the prompts.

Load your sample!

I'll also attach a schematic for one of the Amiga audio carts in the event that someone can implement it, it connects to a parallel port on the Amiga core (I also have a schematic for one of the ST audio sampler carts, same idea).

If you need batch sample conversion to get your libraries converted, check out AmigaPAL ( https://github.com/echolevel/AmigaPal ) as well!

Re: Audio input / sampler

Posted: Fri Jul 31, 2020 1:36 pm
by kolla
Sheesh, and all I do is record samples with my phone, save them to my cloud store, from where the MiSTer Linux side picks them up and converts them to various usable formats such as iff/8svx using sox, saving them back to the storage that is shared with the Minimig core :)

Re: Audio input / sampler

Posted: Sat Aug 01, 2020 1:24 pm
by aToyRobot
Thanks for everybody's replies/suggestions.

Converting samples and using the shared directory is certainly a workable solution. I guess what I was hoping for was a more authentic experience, along with a more accurate sound. E.g. I would expect a converted file to sound different, albeit subtly, than one sampled at the low sample rate and using real amiga hardware and an external sampler.

It's no big deal though, if and when I want to make some music on Amiga I will either use the shared directory or my Amiga 500 with Techno Sound Turbo.

Re: Audio input / sampler

Posted: Wed Aug 05, 2020 5:48 am
by kolla
You are right, I played a little with my old DSS8+ on real Amiga, and direct sampling does make a more... authentic sound :)
I even jacked it to my phone to re-record samples there, and those too sound better. Dang... shouldn't have tried it... ;)