Category Archives: Audio

Ohm Acoustics Model D Speaker Refurbishment

Posted on February 21, 2014 by retrovoltage

Classic speakers are always a delight to work on, and speakers have capacitors and other parts which require service, too. Over the years those components can fail and result in poor sound and even potential speaker damage. In this case, … Continue reading →

Posted in Audio, Hi-Fi, Projects, Speakers, Stereo, Vintage | Tagged , , , , , , , , , , , , , , | 1 Comment

1962 Zenith MK2670 Classic Tube Hi-Fi Console Stereo Repaired

Posted on February 15, 2014 by retrovoltage

A version of this article appears in the October 2014 issue of Nuts and Volts magazine. I recently got to work on something a little bit different – a tube hi-fi stereo console! This particular one, a 1962 Zenith MK2670, was a very high-end … Continue reading →

Posted in Audio, Projects, Radios and Tubes, Stereo, Vintage | Tagged , , , , , , , , , , , , | 26 Comments

1977 Yamaha CR-2020 Vintage Stereo Receiver Repair

Posted on January 26, 2014 by retrovoltage

The Yamaha CR-2020 drives 120W/channel into an 8 ohm load and supports 3 pairs of speakers (but only plays 1 or 2 pairs a time), dual phono inputs supporting both moving magnet (MM) and moving coil (MC) pick-ups, tape-copy functionality … Continue reading →

Posted in Audio, Electronics, Hi-Fi, Music, Stereo, Vintage | Tagged , , , , , , , , , , , , , , | 34 Comments

Bose 901 Series I Active Equalizer #50911 Repaired

Posted on December 3, 2013 by retrovoltage

I recently had this Bose 901 Series I Active Equalizer, serial number 50911, in the shop for repair. These are a lot of fun to work on and very rewarding for the great sound they produce when they’re working properly. … Continue reading →

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