More details, from Singxer's Taobao:
Large balanced output power:
16Ω 10000mW
32Ω 5500mW
68Ω 3100mW
120Ω 2000mW
600Ω 380mW
Single-ended power: the corresponding balanced output power divided by four.
SA-1's Class A model:
Balanced 16 ohm load: below 500mw;
Balanced 32 ohm load: below 1000mw;
Balanced load of 68 ohms: below 3000mw;
Balance the load above 68 ohms: almost all power is Class A;
SA-1 headphone amplifier gains:
1. Single-ended input, single-ended output: low gain is 0db, high gain is 11db;
2. Single-ended input, balanced output: low gain is 6db, high gain is 17db;
3. Balanced input, single-ended output: low gain is -6db, high gain is 5db;
4. Balanced input, balanced output: low gain is 0db, high gain is 11db;
LOW-Z is low-impedance mode, HI-Z is high-impedance mode:
Low-impedance output impedance is 1.4 ohms (balanced) and 0.7 ohms (single-ended);
High-impedance output impedance is 11.4 ohms (balanced) and 10.7 ohms (single-ended);
At the front stage output, the single-ended impedance is 22.5 ohms, and the balanced impedance is 45 ohms.
Usage suggestions and precautions:
1. Based on the SA-1 is an amp with a fully balanced design concept, it has made the greatest optimization for total balance. Therefore, the recommended way to use it is: balanced input and balanced output, followed by single-ended input and balanced output.
2. If you need to use single-ended, it is recommended to use single-ended input; it is not recommended to use balanced input, single-ended output.
3. For high-sensitive headphones such as earplugs, high gain mode is not recommended.