On 2020-05-27 12:39 p.m., Russell Reiter via talk wrote:
I also had a weird experience when I used a line adapter to plug a guitar into the line in and play out the speakers. After I defined the loopback device for pulse audio I'm not sure what it was but, when I adjusted the potentiometers on the guitar for base, treble and volume, I seemed to be able to tune in an audio broadcast channel and got that signal out the speakers. I know it was a broadcast, I heard it clearly, it was a one sided conversation, but in a language I don't know.
The guitar has big coils: the circuit has high impedances, and in the case of a connection to a regular audio line input, it's not optimally terminated. And bingo, an impromptu radio receiver. We used to hear a HAM radio operator key up transmission through our subwoofer. You could see his antenna rising up over the houses a block over.
Thanks for that explanation. You read about weird edge case RF stuff like
On Wed, May 27, 2020 at 12:56 PM El Fontanero via talk <talk@gtalug.org> wrote: that but unless you actually experience it for yourself, it can be hard to sort out the source of the issue.
So my thought was to get an audio breakout to usb via the Thunderspy port, but that would defeat the purpose of using the Realtek codec features of the board. What I really need is a good quality junction between the guitar phono I/O and the computers stereo line-in.
Guitar in to a mic preamp is not as exciting but is fairly clean. From there you can go to line level with impunity.
I had a look around for non usb direct input hw. The ones with the 3.5mm output are a couple of hundred bucks. The direct phono jack adapter and cable I used with 3.5mm connections at both ends cost about ten all total. The sound is clean enough, but the mechanical connection causes a lot of static. The fittings don't match to high enough tolerances and the cord jiggles the connection too much when I play it. Reminds me of when I was ten and built a crystal radio. I was disappointed that I could only tune in one station, 1050 CHUM AM, the closest one to my house. Looks like I accidentally anachronistically recreated CFRB (Canada's First Rogers Battery) using a two thousand dollar Linux solid state home computer system, a forty dollar electric guitar and cheap ebay audio fittings and cables, although I'm pretty sure that wasn't CFRB I was tuning in. https://torontoist.com/2012/12/toronto-invents-the-batteryless-radio/
Linux, Linux, Linux. There. :-)
Cheers, Mike
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- Russell