For my non-technical readers: a phono preamp is a device which does two basic things: 1) it equalizes the program…
Download a three-page article from Electronics World "Hi Fi Annual & Audio Handbook 1960" which details the construction of a…
Alright! So earlier this week I described the successful completion of the RCA OP-6/BA-2 microphone preamp. Check out this previous…
The vacuum-tube powered program EQ that I described in this previous post is nearly complete. This thing has sat on…
(image source) The RCA OP-6 'Portable Amplifier' is one of a handful of truly visually-iconic vintage mic preamps. The OP-6…
Circuit for a simple bass/treble parametric equalizer that uses no inductors. Could be a useful piece. Not sure if 250k/500k…
Some more interesting bits from AUDIO magazine c 1955: plans and schematics for a radio station mixing console. Very little…
In a previous post, we looked at the Altec 436 vari-mu tube compressor. I built one of these a few…
The Craftsmen C-500 power amplifier Today we have some hi-fi amplifiers from the mid 1950s to look at. Many of…
Today we'll look at some of the more interesting audio-circuit plans and schematics from the first two years of Audio…