Back to Vinyl

Vinyl LPs are making a comeback. While reading some of the recent stories about the return of phonograph records, I was reminded that one of the last products that I designed at Harrison Systems was a phono preamplifier targeted at the broadcast station market.

Here’s the schematic diagram for an updated version. The original used 5534A op amps. This one uses the newer OP275. Click on the diagram to embiggen it.RIAAIf enough people are interested, I’ll layout a pc board and make it available for sale.

9 thoughts on “Back to Vinyl


  1. Back in the day, in my experience, Vinyl had better sound quality than any other recording device except for Reel to Reel at slow speed, at least in the seventies.

    I’ve recently acquired a Technics semi-auto turntable…found it at the dump…and it still sounds almost as good as my CD’s.


  2. I guess I shouldn’t be so succinct in my comment/question but should explain why I am asking. I have worked in broadcast for 28 years and always used BNC’s for video and XLR (canon) for balanced audio and RCA for unbalanced. Your BNC jacks caught my attention.


    • BNC connectors lock; RCA connectors don’t. Other broadcast phono preamps typically used terminal blocks. The version with a balanced output used XLRs for the outputs.

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