NJM8065 (labelled 8065 902F JRC) by Japan Radio Company. High-gain, wide bandwidth, dual operational amplifier. Data sheet.

The NJM8065 combines many of the features of the NJM4558 as well as providing the capability of wider bandwidth (10MHz typ.), and higher slew rate (4V/μs typ.) make the NJM8065 ideal for active filters, data and telecommunications, and many instrumentation applications. (From the data sheet)

BAR 43S STM. Small signal Schottky diode.

There are several resistors in the circuit: 188: 1.8 GΩ, 018: 100 MΩ, 102: 1 kΩ, 010: 1 Ω.

4K switch soldering points.

The PCB was not properly cleaned of flux residues after soldering. High quality products are usually very clean.

The 4K Legacy circuit is boosts higher frequencies and adds harmonic distortion to the sound. This analog effect can work well in live broadcasts with darker microphones such as the Shure SM7B. On the other hand, the 4K circuitry seems to introduce more noise into the signal. I recommend leaving it off for high quality recordings.