Honestly, the short answer is to google model numbers and look at discussions on sites like Audiokarma. The TLDR is that most Japanese "name brands you've hear

Honestly, the short answer is to google model numbers and look at discussions on sites like Audiokarma. The TLDR is that most Japanese "name brands you've heard of" from the 1970s are pretty good. After the mid 1980s, the build quality starts to nosedive. Top-of-range models are often still impressive, but more of the BOM cost ends up on things like decoding defunct Surround Sound formats and rear-channel amplification. This often corresponds with the change from silver-alumiuum faceplates to black plastic, and the expression "Black Plastic C*p". Speakers are a lot more subjective and also more subject to material degredation-- the foam ring that attaches the speaker cones to the casing can go brittle or crack or fall apart. This can be fixed with rebuild kits for many models, but this is a situation where new kit has some benefits with improved materials science.