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Monthly Archives: November 2014
VD-1221 Replacement Substitute Diodes
We’re lucky that these days you don’t need to stock very many diodes in the parts drawers for refurbishing most vintage gear – pretty much everything except for the main power supply rectifiers can usually be replaced with some combination … Continue reading
Posted in Audio, DIY, Electronics, Vintage
Tagged 1n4148, amplifier, bias, diode, diode substitute, series, Sony, substitute, TA-4650, TA-5650, TA-8650, varactor, varactor diode, VD-1212, VD-1220, vd-1221, VD-1222, vd1221, VFET
8 Comments
Vintage Schematic Mistakes
Every once in a while, you run into places where a drafting tech made some mistakes on the schematics. This one was a Philco 42-360 radio, which has the wrong tube called out in the tube line-up vs. the schematic. The … Continue reading
Posted in Commentary, Electronics, Vintage
Tagged drafting, error, mistake, schematic
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Harman/Kardon Control Amplifier A-401 Restoration
This little Harman/Kardon Control Amplifier, model A-401, just came through the shop for a full overhaul. It was in a pretty sorry state to begin with – one channel distorted, one barely gasping for air, and a world of scratchy … Continue reading
Posted in Audio, Electronics, Hi-Fi, Projects, Stereo, Vintage
Tagged a-401, amp, amplifier, circuit boards, control amplifier, harman/kardon, hi-fi, photos, pictures, rebuild, restoration, stereo, stereo pictures, vintage stereo
4 Comments
Sony TA-4650 VFET Stereo Amplifier Inspection and Upgrade
This Sony TA-4650 was shipped to me from Canada for a shop visit on its way to its ultimate owner in California, who just bought it on eBay. He had it sent to my shop for an inspection and a … Continue reading
Posted in Audio, Electronics, Hi-Fi, Vintage
Tagged 2SK60, amplifier, integrated amplifier, Sony, stereo, TA-4650, VFET, vfet amplifier
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EICO Stereophonic Integrated Amplifier HF-81 Repair
From the late ’50s, I had this nice example of an EICO HF-81 amplifier come through my shop. These are nice little stereo amplifiers with a built-in phono pre-amp and RIAA equalization and feature about 14W of power output per … Continue reading
Boes 901 Series IV Active Equalizer #241792 Refurbishment
Bose® 901 Series IV Active Equalizers are getting up there in years now, too, so more and more are coming up for repair. This one came in with a flickering power supply in need of an overhaul. Series IV was … Continue reading
Posted in Audio, Bose, Hi-Fi, Projects, Stereo, Vintage
Tagged 901 active equalizer, active equalizer repair, Bose, bose repair, equalizer repair
1 Comment
Boxed Kit Amps’ Gobo Stereo Amplifier Build and Review
If you’re a subscriber to Nuts and Volts Magazine, check out my article in the December 2014 issue where I build, test and review the Boxed Kit Amps Gobo Stereo Amplifier, a great little desktop reference amp for any skill … Continue reading →