Doug @douggg.bsky.social · 11/12/2024Here is the basic audio flow diagram. The CD, tuner, and tape go through a pre-amp mounted on the tape board. Anything we’re plugging into this already has a built-in amplifier, so we don’t need to utilize this one. 100
Doug @douggg.bsky.social · 11/12/2024After the pre-amp, the signal goes to main board #1. Thanks to the internet we have an extensive service manual with the full schematic for the boombox. On the main board the signal goes through a PT2257 volume control chip. Our phone/mp3 player/laptop already has volume controls, so we can skip it. 100
Doug @douggg.bsky.social · 11/12/2024The power board contains the main power amp, a BA5417 chip. We want to tap in upstream of this, since it provides the power needed to drive the speakers. The connector on the cable from the main to the power board is the most convenient place to add some wires, so we’ll connect our cable here. 110
