The stereo system is connected to the Zynthian V5. I usually have it running 24/7 and it allows me to turn on the S88 Mk2 Keyboard anytime and start playing.
I also installed librespot on the Zynthian, so I can use it as a Spotify Connect device and listen to music on demand using my phone.
I have Android TV running on a RPi4 (works quite well) hooked up to a projector.
For watching movies or playing games (using Moonlight/Artemis) I found a great solution to get the audio from the Android TV to the Zynthian: scrcpy. The newer versions allow you to easily stream audio only using wireless adb. Works really great and is low latency enough for movies/games (~30ms buffer is fine with my setup).
Here’s the problem tho. I updated the Zynthian to Oram today (had it on a super old release before) and now I can’t hear neither librespot nor scrcpy.
Did something change recently-ish that changed how programs access the mixer/audio outputs?
That probably also means that my Zynthian DOOM port also doesn’t play audio anymore…
While I’m at it, here are the installation steps i took for librespot & scrcpy on the Zynthian. YMMV.
Bridge alsa and jack (so programs can output audio)
apt install libasound2-plugins
nano ~/.asoundrc
Paste:
pcm.rawjack {
type jack
playback_ports {
0 system:playback_1
1 system:playback_2
}
capture_ports {
0 system:capture_1
1 system:capture_2
}
}
pcm.jack {
type plug
slave { pcm "rawjack" }
hint {
description "JACK Audio Connection Kit"
}
}
pcm.!default {
type plug
slave { pcm "rawjack" }
}
This bridges alsa (what the programs use) and jack (what zynthian uses) so that any program can output audio to the zynthian.
Note that this bypasses Zynthian’s mixer, which is desirable in this case.
Install scrcpy
Scrcpy allows us to stream Android TV audio to the Zynthian with low latency.
That is an unreservedly amazing room arrangement @Kosro!
I’m curious about a couple of questions:
Are you using a ceiling-mounted projector? Do you get a decent pixel resolution and image brightness on the wall?
How do you handle the uncompromising line-level output of a musical instrument (Zynthian), on the signal chain of a stereo system with amplifier and passive speakers? Since these appliances are designed for the carefully profiled and limited spectrum of recorded audio signals, it is notoriously tricky to employ them with instrument-grade direct audio. Typical dangers are for the speakers’ cones and the final amplification stages, depending on nominal peak wattage and impedance.
It’s a ceiling-mounted ViewSonic PX747-4K, but it’s incredibly loud when the pixel shift is enabled, so we just use it in 1080p. Then it’s completely inaudible over low volume music/movies.
1080p is totally adequate for our purposes, and the RPi4 would die five times if I so much as think about running Android TV in 4K ^^
(a good heatsink alumunium case is key even at 1080p)
It’s quite bright at 3500 ANSI Lumen, but I still lower the blinds a bit when the sun is out.
No problems with the audio levels so far. The volume ranges seem to fit together quite nicely (Zynthian Instruments, Spotify Connect, Android TV scrcpy audio, builtin Amp bluetooth).
I’m using a ridiculously tiny amp, but it get’s the job done. Supposedly does up to 150W per channel, the speakers are rated up to 200W.
I believe this tiny amp would blow up first, before anything serious happens to the speakers.
The amp is set to ~10% at most, much higher would shatter our neighbours windows.
I have it plugged into the headphone output, which had it’s output level lowered a bit in the Zynthian settings.
Thanks for the details on your HDMI projector model, and the AliExpress link of the basic and inexpensive, but apparently functional, stereo amplifier.
For the little it costs, it really surprises me that you didn’t notice any obvious harmonic distortions, when you passed through it the beefy audio output of the Zynth’s synthesiser engines, controlled by your nice S88. It obviously feels more predictable that the multimedia audio streaming is comfortably handled by your setup. Good to know .
In the past, many years ago when I couldn’t afford proper active speakers, I managed to fry twice the final stages of general-purpose stereo amplis, and once almost physically dismantle a couple of beloved and venerable Bose passive boxes. That’s why I was curious, about your overall signal management of untamed synth output on a normal stereo equipment.
I checked out the datasheet for the power amp & it gives surprisingly low THD (<0.1%) up to 80W. That would have been super hifi class when I was a kid!
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