Stromberg-Carlson ASR-433 (c. 1959)
The Stromberg-Carlson ASR-433 is a stereo integrated tube amplifier from the late 1950s, sold as the Stereo "24" Control Amplifier. Stromberg-Carlson was a pioneer in American communications, telephony especially, but only a relatively quiet presence in hi-fi. A French vintage-audio reference describes the ASR-433 as a tube integrated amp very well known on the other side of the Atlantic.
Stromberg-Carlson's advertising in High Fidelity (December 1959, p.130) described the ASR-433 as a dual-channel control amplifier delivering 12 watts per channel. The company touted the output as notably clean and balanced. Two channels at 12 watts make 24 watts of total stereo power, hence the "24" in the name. An item in High Fidelity (June 1959, p.105) noted that the amp used silicon rectifiers in a voltage-doubling power supply. That choice reduced the size and cost of the power transformer.
Beyond the magazine record, information is thin. The one firm technical detail to survive in collector circles is that the output stage runs push-pull EL84s, which fits the rated 12 W/channel. The usual 60-year-old-tube-gear caveat applies: owners report these amps typically need their capacitors replaced before being trusted again. The few collectors who have handled one say Stromberg-Carlson built high-quality stuff.
What's reasonably well established:
- Stereo integrated tube amplifier
- 12 W per channel (24 W stereo)
- Push-pull EL84 output tubes
- Silicon-rectifier voltage-doubling power supply
- On sale by 1959, when it was reviewed in High Fidelity
Production years, original price, dimensions, and detailed circuit documentation don't appear in the surviving record we have. If you own one, the basics above — plus a careful recap — are probably the whole story worth knowing.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Stromberg-Carlson AM-666 (1955)
- Stromberg-Carlson ASR-120 (1968)
- Stromberg-Carlson ASR-444 (1968)
- Marantz 2226 (1974-1976)
- Marantz 2226B (1979-1980)
- Marantz 2235 (1974-1977)
- Marantz 2238B (1978-1980)
- Marantz 2250B (1978-1980)
- Marantz 2252 (1974-1977)
- Marantz 2252B (1978-1980)