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Dynaco ST-70 Stereo Vacuum Tube Amplifier Factory WiredDynaco ST-70 Stereo Vacuum Tube Amplifier in excellent overall conditionRare Factory WiredFully tested recently and working very well. This amp comes from my own collection. I have owned this amp for many decades.Note: this item is roughly 65 years old. It would be advisable to replace the coupling and multi-section can capacitors. The bias circuit has been rebuilt and the EL34 tubes are new and perfectly matched.Power output: 35 watts/channel, 80 watts peak each channelFrequency response: 10 Hz - 40 kHzShipping weight: 16 kg (tubes shipped separately)117 VACMade in U.S.A.NOTE: Please be sure to write us about the shipping cost before making a purchase. Since September 2025, the shipping costs change almost weekly, that we can't keep up with them.
At US$895, this sits below the typical used market for the ST70, but not by a huge margin: your database anchor puts the median at US$974, with the 25th percentile at US$934 and the 75th at US$1,013. That makes this a modest bargain rather than a steal, and a sensible buy if the amp is genuinely complete and presentable.
The ST70 is well regarded for its classic Dynaco sound, strong community support, and easy parts/upgrades path, which keeps these desirable even decades on. At this price, the main value is in condition: a clean, unmolested unit with a known service history or original iron is the sweet spot, while a tired example can eat up the savings fast.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Dynaco emerged in 1955 from Philadelphia, Pennsylvania, when hi-fi pioneer David Hafler partnered with engineer Ed Laurent to form the Dyna Company. Hafler brought expertise from his earlier Acrosound venture, which produced high-quality output transformers starting in 1950. The duo targeted the burgeoning hi-fi market with affordable, DIY-friendly kits, launching the Mk II 50-watt tube amplifier shortly after incorporation and relocating to a former chocolate factory for expanded operations.
The brand specialized in tube amplifiers that defined its legacy, including the iconic Stereo 70—over 350,000 units sold—alongside models like the Mk III. Dynaco expanded into FM tuners such as the FM-1, bookshelf speakers like the A-25, solid-state amps, and innovative systems like the Dynaquad for simulated four-channel sound. Late-1970s efforts included the Phase III speakers, though the company shifted toward kits and components emphasizing value and performance.
Dynaco holds a revered position as the era's top-selling tube amp maker, beloved by budget-conscious audiophiles for reliable, high-value hi-fi. Liquidated in 1980 after Hafler's sale to a toy firm, its vintage gear remains a collector's staple, with later revivals by Panor Corporation producing replicas for tube enthusiasts seeking that classic warmth and build-it-yourself appeal.
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