SMA wrote on 2022-04-07, 15:30:

I think, better is using the SilLabs SI8910 insulated amplifier… and we need additional Nyquist filter in case of infinite spectrum of the Delta function.

SilLabs SI8920 used.

I draw some schemes using KiCAD 6.0.2... https://www.kicad.org/

Any comments are welcome. The PCB Layout is not designed at this moment. Please check availability and pricing in your country for used components before I start design the textolite.

Please comment what class (trace width / spacing) are availible for your production.
I want trace in two layers.

SMA wrote on 2022-04-07, 15:30:

Please check availability and pricing in your country for used components before I start design the textolite.

I am sorry — I was asked the question, but not upload any BOM (Bill Of Materials).

New schematic arrived. I hope this is final schematic revision and future updates are PCB only.

Changelog:

rev-03
PSU replaced by isolated module — now all power brings from OLD PC 3,5" floppy connector.
Some comments and graphs are added.

rev-02 (unpublished)
Double check all math and correct mistakes.

rev-01
Initial release.

I've been known to capture it by routing through a sound card like a SoundBlaster and using the mixer to mix it with the signal. I also have made my own simple mono cables too for PC's without.

Sometimes to try and reproduce/make it sound more authentic I use a guitar effects processor with just a little bit of reverb and a slight E.Q. to make it sound like a PC in a room rather than some kind of home-made monosynth project.

creepingnet wrote on 2022-04-12, 02:21:

I've been known to capture it by routing through a sound card like a SoundBlaster and using the mixer to mix it with the signal.

It is, probably, excellent solution. Not only SB supports record from PC Speaker. Some other sound cards also have, at least, function to play PC Speaker to line out.

SMA wrote on 2022-04-12, 00:57:

New schematic arrived. I hope this is final schematic revision and future updates are PCB only.

Final revision probably...

Changelog:

rev-04
PCB design finished (bottom layer are optional — should be workable with front copper only).
PCB design compatible with "Laser-HotIron" prototyping method.
Schematic diagrams for Cables added.

rev-03
PSU replaced by isolated module — now all power brings from OLD PC 3,5" floppy connector.
Some comments and graphs are added.

rev-02 (unpublished)
Double check all math and correct mistakes.

rev-01
Initial release.

SMA wrote on 2022-05-22, 19:18:

Final revision probably...

Major remarks for Rev.04:

1. USB cable for PowerBank only! Not for wall charger. Not for PC USB port.
2. Output is not compatible with phantom power.
3. Originally designed for powering from Old PC floppy connector (from signal source, not from recorder).

Thank you very much! 🙂👍