USB AudioStreamer on a breadboard

First attempt to make a USB Audio 1.0 soundcard with a Microchip PIC18F2550.

The scheme is basically the one found on http://www.raccoonrezcats.com/soundcard.html made by Mike Zoran, with some personal changes (nothing important anyway).

I have used trimmers instead of digital potentiometers because I'm waiting for their deliver. Despite this, the volume can still be adjusted on the Windows control panel by moving the Wave slider.

The soundcard works ok, has a low latency but the use of a 12-bits DAC and rail-to-rail 0-5V op-amps degrades the sound a lot. Without any data streamed, the USB power supply has a bad ripple (I can hear other devices sending messages), and the breadboard can only make it work worse. An external power supply with appropriate power filtering, the use of better (audio specific) op-amps, hi-end DACs and an accurate PCB design would make it sound waaay better.

As Mike wrote, his project was released ONLY as a cheap learning tool. An EXCELLENT learning tool ;-)

Category:

Science & Technology

Tags:

• usb
• audiostreamer
• audio
• streamer
• sound
• card
• soundcard
• microchip
• pic
• pic18
• pic18f2550
• firmware
• framework
• cheap
• diy

[daxweb]

Questo è un progetto che vorrei saper fare anch'io...

La pagina del progetto di riferimento non è più disponibile...

[TexZK]

@daxweb Già, sfortunatamente non sono riuscito a recuperare il materiale che avevo salvato su disco fisso :-( Non è niente di complicato comunque! Dovrebbe esserci un esempio simile allegato alle ultime versioni del framework USB di Microchip.

[aletorno]

Really good job!!! there are not a lot of people how can do this...

Usb is still hard... i use CDC and HID usb class but i dont have any example of midi class...

Thanks for post it.

[TexZK]

Eheh, I know! I'm dealing with those things because some holy people published such projects on the Web, otherwise you can't find much!

I've never programmed with HID and I don't need CDC. I'll go for HID devices when not requiring native MIDI, but I still have to learn USB-HID API (from Windows DDK, on Linux it should be easier to find something).

[tiernanmac]

Hi, i have been tryin to build a soundcard similar to yours above with a PIC, but i seem to be gettin a lot of noise which I think is due to my ADC sampling code. Do you have any tips on programming the ADC? And also did you use an external oscillator?