This pre-main amplifier employs a non-feedback power amplifier and features a high-quality power transformer. The front panel and switches are in relatively good condition despite their age. However, the input selector switch has some contact issues, occasionally resulting in output from only the left channel. Adjusting the switch slightly can restore contact and sound. If this concerns you, please clean the switch (see photo 6). This appears to be a common issue, as several articles can be found online (search keyword: a-927 selector switch).
I have confirmed audio output from CD, tuner, and line inputs, as well as speakers and headphones. Apart from the selector switch, there are no issues with the volume controls or other noise. While other functions appear to be working, please note that a thorough check has not been performed.