Uploaded September 2019 | Updated September 2026, 1 week ago
In this video, I give a tour and demonstration of my 1979 Sanyo M9990 boombox.
I forgot to mention I had the repair guy perform the Aux In mod detailed here:
boomboxery.com/forum/index.php/topic/19813-m9990-line-in-soooo-easy
However, it actually messes with recording to tape. It makes a whooping noise. Perhaps some kind of feedback loop. So either I keep the mod or snip the wires and get my recording function back. I decided I want to keep it as factory intended. I have a Sony CFS-66 boombox that has a proper Line In Aux function. Boombox of this time intended the line in only to be used for recording. That's the only time you will hear what's coming in from the RCA jack. I can fake a recording by pausing, but that just runs the motor unnecessarily, so no thanks.
In this video, I give a tour and demonstration of my 1979 Sanyo M9990 boombox.
I forgot to mention I had the repair guy perform the Aux In mod detailed here:
boomboxery.com/forum/index.php/topic/19813-m9990-line-in-soooo-easy
However, it actually messes with recording to tape. It makes a whooping noise. Perhaps some kind of feedback loop. So either I keep the mod or snip the wires and get my recording function back. I decided I want to keep it as factory intended. I have a Sony CFS-66 boombox that has a proper Line In Aux function. Boombox of this time intended the line in only to be used for recording. That's the only time you will hear what's coming in from the RCA jack. I can fake a recording by pausing, but that just runs the motor unnecessarily, so no thanks.
