Note: I originally posted this on 25ms.org, a blog that started my journey into the world of audio and JackTrip. I’m reposting it here in case it may be useful to others.
I finally dusted off and some hardware today that I’ve been wanting to test out for a few months…
Pisound (100€) is a very high quality audio HAT for Raspberry Pi made by a Lithuanian company named Blokas. Most notably, it features 192kHz 24-bit Stereo input and output driven by Burr-Brown Op-Amps, ADC and DAC chips. It also has solid 1/4 jacks for stereo Input and Output, coupled with smooth physical dials to control their volume levels. The sound quality is excellent and the latency is one of the lowest I’ve seen, on par with HiFiBerry’s boards.
The Audiobox 96 ($100) is a highly regarded external USB device made by an American company named Presonus. It features two XLR-1/4″ input jacks similar to Focusrite’s Scarlett 2i2 ($160), but sells at a fraction of the cost. This is a great option if you have a microphone that needs 48V power, or want to plug in a second instrument to play while singing.
I used jack_delay -E with a loopback cable to run latency tests for these devices. The results are below, with the HiFiBerry ADC DAC+ Pro results added for comparisons.
| Device | Hz | FPP | Latency |
|---|---|---|---|
| Audiobox USB 96 | 48k | 128 | 339 frames (7.0ms) |
| Audiobox USB 96 | 48k | 256 | 501 frames (10.4ms) |
| Audiobox USB 96 | 96k | 128 | 309 frames (3.2ms) |
| Audiobox USB 96 | 96k | 256 | 633 frames (6.6ms) |
| Pisound | 48k | 128 | 44.247 frames (0.9ms) |
| Pisound | 48k | 256 | 44.267 frames (0.9ms) |
| Pisound | 96k | 128 | 46.340 frames (0.5ms) |
| Pisound | 96k | 256 | 46.363 frames (0.5ms) |
| HiFiBerry DAC+ ADC Pro | 48k | 128 | 51.100 frames (1.0ms) |
| HiFiBerry DAC+ ADC Pro | 48k | 256 | 50.416 frames (1.0ms) |
| HiFiBerry DAC+ ADC Pro | 96k | 128 | 50.393 frames (0.5ms) |
| HiFiBerry DAC+ ADC Pro | 96k | 256 | 50.459 frames (0.5ms) |