Find:
About Me
Blogs
- Antique Radio Blog
- Arcane Radio Trivia
- Audio Tweak
- Audioklassiks
- BuildLounge
- Classic Receivers
- Coffman Labs Blog
- Confessions of a Part-Time Audiophile
- EEVBlog
- Engineering Radio
- Glowbugs Times
- Glowbugs Web
- Guitar Fool
- Hack a Day
- HeavyDIY
- High on Solder
- Ilektronx
- MicroSyl
- Nick's Radio Corner
- Old Stock Audio
- Pragmaddux
- Radio Stuff
- Radio Time Traveller
- Richard Sears, Vintage Electronics
- Seventies Stereo
- The Paleotechnologist
- The Signal Path
- Tube Addict
- TubeSound
Friends
Resources
- 6V6
- Active Equalizer
- AM
- amateur radio
- amplifier
- Antique
- antique radio
- audiophile
- Bose
- Bose 901
- capacitor
- capacitor replacement
- converter
- cost engineering
- Craigslist
- eBay
- eico
- electronics
- Equalizer
- fried electronics
- GE
- General Electric
- grunow
- grunow 586
- grunow 589
- grunow chassis 5-U
- grunow radio restoration
- ham radio
- hf
- hf converter
- hi-fi
- HP
- kenwood
- Klipsch
- KN0CK
- LCD
- LF-116
- old radio
- oscilloscope
- philco
- photos
- power supply
- project
- projects
- radio
- radio retailing
- rca
- receiver
- repair
- replacement
- restoration
- RTLSDR
- SDR#
- Series 1
- shortwave
- soldering
- Sony
- Speakers
- speaker spotter
- stereo
- stromberg-carlson
- teledial
- test equipment
- tube
- Tube Amp
- tube radio
- tweeter
- up-converter
- Upconverter
- vacuum tube
- vintage
- vintage ad
- vintage radio
- Westinghouse
- zenith
Categories
February 2026 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Meta
Tag Archives: Bose
Bose® Active Equalizer Test Platform
This project is going to take a while since I’m slammed in the shop, but I’m in the process of converting a Bose® 901 Series I Active Equalizer to a test platform. With sockets for the transistors, and clip connections … Continue reading
Posted in Audio, Bose, DIY, Electronics, Stereo, Test Equipment
Tagged Bose, conversion, Equalizer, sockets, test platform, transistor
3 Comments
The Speaker Spotter – March 3rd, 2016
Some interesting stuff on Craigslist in this week’s The Speaker Spotter, a curated selection of Seattle’s local speakers for sale online. As always, Retrovoltage is not affiliated with any of these sellers and you should click through the link to the … Continue reading
Posted in Audio, Collections, Speakers, Stereo
Tagged Bose, carver, dali, ess, jbl, kef, phase research, tannoy, the speaker spotter, totem acoustic
Leave a comment
Bose® 402E Active Equalizer #102853 Repaired
The first Bose® 402E Active Equalizer, for the Panaray speaker system, just came through the shop. It’s a small speaker array system, designed around similar drivers in the 901, and uses an Active Equalizer for the same effect. They’re designed … Continue reading
Posted in Audio, Bose, Electronics, Projects
Tagged 402, 402e, Active Equalizer, audio precision, Bose, bose 402e, curve, frequency response, panaray
7 Comments
The Speaker Spotter – Speakers of Craigslist: June 3rd, 2015
It’s back – the Speakers of Craigslist, a periodic round-up of what’s interesting on my local Craigslist these days. Sorry for the hiatus, putting these together is a bit of work! As always, I am not affiliated with any of … Continue reading
Posted in Audio, Collections, Commentary, Speakers, Vintage
Tagged Bose, cornwall, Craigslist, cs-88, Electro-Voice, eminence, EV, heresy, Klipsch, knight, lewis erath, lwe, pioneer, Speakers
Leave a comment
Bose® 901 Series VI Active Equalizer #199732 Repaired
A first for my shop, I recently worked on a Bose® 901 Series VI Active Equalizer! These are considerably newer than the Series I-IV that typically come through the shop, although they’re still getting to be 25+ years old at … Continue reading
Posted in Audio, Bose, Electronics, Projects, Vintage
Tagged Active Equalizer, Bose, Bose 901, capacitor, capacitor replacement, vintage
Leave a comment
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
The Speaker Spotter – Speakers of Craigslist – April 18th, 2014
There’s always something interesting for sale on Craigslist, especially in Seattle. Do click the titles to see the original postings with more photos and additional information if you’re interested – otherwise, enjoy the virtual window shopping! Rain City Audio is not … Continue reading
Posted in Audio, Collections, Photos, Speakers, Stereo, Vintage
Tagged 7000A, A25, altec, altec lansing, Avid, Avid 100, Bose, Bose 601, Dahlquist, Dahlquist M-905, DDS1, Dynaco, Dynaco A25, exponential, Fisher, hi-fi, Horn, Klangbox, M-905, multicell, Nova-6, Radio Shack, RB66, Realistic, Realistic Nova-6, Seeburg, Seeburg Discotheque, series III, speaker spotter, Speakers, stereo, Technics, Technics 7000A, Telefunken, Telefunken RB66, tweeter, vintage, VOTT, woofer
2 Comments
The Speaker Spotter – Speakers of Craigslist – April 11th, 2014
There’s always something interesting for sale on Craigslist, especially in Seattle. Do click the titles to see the original postings with more photos and additional information if you’re interested – otherwise, enjoy the virtual window shopping! Rain City Audio is not … Continue reading
Posted in Audio, Collections, Hi-Fi, Speakers
Tagged 501, Bose, Bose 501, Dahlquist, Dahlquist DQ-10, dome, DQ-10, EMIT, EMIT-k, Horn, Infinity, Infinity Modulus, Infinity Reference, Infinity RS 5000, Legacy Audio, Legacy Audio Signature, Mach One, Modulus, multicell, pioneer, Pioneer CS, polycell, Radio Shack, Realistic, Realistic Mach One, Reference, RS, RS 5000, speaker spotter, speakerlab, Speakerlab 7, Speakers, tweeter, woofer
Leave a comment
The Speaker Spotter – Speakers of Craigslist – March 14th, 2014
There’s always something interesting for sale on Craigslist, especially in Seattle. Here’s a selection of especially notable vintage speakers and other audio products for sale on the local Craigslist. I’m not affiliated with any of these sales, but if you’re interested, you … Continue reading
Posted in Audio, Collections, Photos, Speakers, Stereo, Vintage
Tagged 12W, 15W, Active Equalizer, Akai, altec, altec lansing, Bose, Bose 901, cornwall, Craigslist, Duchess, E-V, Electro-Voice, Electrovoice, Equalizer, EV, heresy, heresy II, KG4, Klipsch, Regency, S-1117, Sansui, series I, series II, series IV, Series V, SKO, SP-100, SP-12, SP12, speaker, speaker spotter, speakerlab, Speakers, speakers of craigslist, SW 177, T25, T25A, T35, The Duchess, Voice of the Theater, Voice of the Theatre, W-35, WD-35, Wharfedale
2 Comments
What do we have here?
I was reading about how to build a capacitor checker from the December 1959 issue of Popular Electronics and stumbled across something that looked very familiar. I know that shape. Nearly identical to a Bose® 901 Series I/II cabinet, and even … Continue reading →