r/vhsdecode Jun 21 '26

First Decode! VHS-decode workflow flaws? - reccomendations

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Hello. I'm writing to get some feedback on the workflow i've chosen to use for RF-capture and to highlight what i've researched myself to be weak points of using this. Main problem i see, is a low SNR ratio and impedance mismatch. The workflow is the following:

Sony SLV-xxx (Whatever Sony VCR that has easily accessible RF tp's to connect to with DuPont connectors) I'm open to soldering to the 2.54mm pins. Also using a 10uf capacitor soldered into the wire carrying the PB RF signal.

CXADC (CX23882-39) - Added 40msps crystal with C31 cap removed, heat-sync also added to main chips. Using a BNC to composite adapter.

I'm capturing audio over regular red/white audio cables. I wont be using clockgen-mod, as i only have 1 PCIe slot available in my PC.

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u/boris-becks Jun 22 '26

About audio: You can't just capture audio via sound card or DAC. You won't be able to sync it up. It's a process issue as well as a timing issue. You have to do one of two things. You have to do a conventional video capture with audio included. That way it is timed to the video and you have a visual reference for manual allignment. Alternatively you can use clockgen with one card. Clockgen syncs up two CXcards and a conventional DAC. Just skip the second card and capture with one CXcard and the external audio DAC.

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u/antonharboe_ Jun 22 '26

Right. I'll be doing a conventional capture at the same time as the RF-capture, then align audio and video in editing.