Fostex PC-100USB VOLUME CONTROLLER, 2014, made in China

Link: fostexinternationa | Owner's Manual [PDF]

Model PC-100USB is a high grade version of PC-1(W) that converts USB digital audio signal to analog signal to feed to powered monitor speakers such as PM0.4n, PM0.5n etc. for high quality reproduction of computer audio . The volume for the left and right monitors can be controlled simultaneously at your handy position. It also offers a headphone out (stereo mini) for head-phone monitoring.

MacOS Catalina 10.15.7 работает без ... Помнится что Catalina только под 64 bit... пляшем дальше. "Сударь", позвольте следующий гаджет в студию...

Думается нам что самое главное запрятано в следующих 5ти строках:
- Built-in 16bit DA converter from digital (USB) to analog (RCA Pin)
- Quality volume control knob
- Headphone out (stereo mini)
- Rugged metal chassis construction
- Rubber legs on the bottom for secure placement

Specifications
[USB] connector
Connector type: RCA jack
Sampling frequency (Hz) / Bit rate: 32k, 44.1k, 48k / 16bit

[OUTPUT (L,R)] connectors
Connector type: RCA jack
Nominal output level: 6dBv
Applicable load impedance: 10k ohm

[PHONES] connector
Connector type: 3.5mm stereo mini jack
Maximum output power: 5mW + 5mW (32 ohm load, THD < 0.5%)
Applicable load impedance: 32 ohm or more

General
Power requirement: USB bus power (5V, 500mA)
Max Power Consumption: 2.5W
Dimensions: 66 (W) x 44 (H) x 70 (D) mm
Weight: Approx. 190g
Supplied accessories: USB2.0 cable (Type A male to Type B male) x 1, RCA – RCA cable x 2