Technical

Interesting Passive EQ circa 1961

Above, a 'distortionless' equalizer circuit circa 1961 as designed by one Carlos Moura.  Separate bass and treble boost functions (2…

13 years ago

Vacuum-Tube Output Stage for Shure Level Loc

Many of my regular readers will be familiar with the Shure Level-Loc.  For those unfamiliar, the basics:  the Level-Loc is…

13 years ago

Mics of ’56

Above: Belden 8411, 8422, and 8412 microphone cable.  I still use Belden 9451 for most studio hard-wiring tasks, although I…

13 years ago

AWA (Amalgamated Wireless Australasia) Broadcast Equipment

Download a 24pp pdf with schematics and technical information regarding all AWA-brand vacuum-tube broadcast audio amplifiers circa 1967: DOWNLOAD: ABCstudioEquipment…

13 years ago

Audio Transformer As Signal Processor

Sometime in the past couple of years, Tape Op ran a short piece by Allen Farmelo titled "Using Transformers to…

13 years ago

Audio Anthology: Collected Hi-Fi articles from AUDIO ENGINEERING in the 1940s

PS dot com reader Paul R. was kind enough to send us a scan of "Audio Anthology," (ed. C.G. McProud)…

13 years ago

Original EMI-modified Altec compressor on eBay: UPDATE

image source NOTE: the above unit eventually did sell on eBay for $35,000.  See below for scan... Here's something that…

13 years ago

UPDATED: So You Want A Good Cheap Ribbon Mic: Upgrading the $69.99 MXL R40

UPDATE: since this article seems to get an enormous number of pageviews, I thought I should mention that we did…

13 years ago

The Old ’76

My latest microphone preamp design is completed and sounding very cool... The Old '76. The Old '76 is a novel…

13 years ago

Stancor Amplifiers and Full Transformer Data c.1937

The Stancor '306' 6-watt PP audio amplifier Download the 1937 ('third edition') of Stancor Transformers' 'Amplimanual,' a 24pp publication which…

13 years ago