ACML Posted September 14, 2014 Share Posted September 14, 2014 There are some Atari 400 svideo/composite upgrades out there, some DYI and low_budget has a nice board. The problem I'm seeing is that they all connect PIN 37 of the POKEY for sound output, but forget there is a cassette audio that can be tapped off R160. I have a question: How would you combine both POKEY and Cassette audio to one RCA jack? Should I put a capacitor on both outputs before I combine them? If so, what value? Quote Link to comment Share on other sites More sharing options...
BillC Posted September 15, 2014 Share Posted September 15, 2014 One issue is the 400 adds a subcarrier to the audio signal, I am including a schematic with the different portions of the circuit highlighted. If you're not going to use the RF output you could disable this subcarrier by removing R162. R164 could be used for the combined SIO/POKEY audio. Disconnecting R164 would also isolate the combined audio from the video signal if not using the RF output. Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.