The Dynaco ST-70 Series 3 Tube Amplifier is Now (Finally!) Shipping

May 1 2018, 03:10
Previewed in 2016, and originally scheduled for Spring 2017, Dynaco (a division of Radial Engineering Ltd.) announced the ST-70 Series 3 tube amplifier is now shipping. Since acquiring the legendary Hafler and Dynaco brands in 2014, Radial Engineering has been carefully working on the Dynaco ST-70 Series 3 tube amplifier, in an effort to create a truly worthy successor of one of the most successful tube amplifiers of all time. The result is finally available! 
 

The Dynaco ST-70 builds upon the proven design philosophies of the original David Hafler-designed Stereo 70, with contemporary design techniques resulting in exceptional performance improvements that meet the requirements of modern music enthusiasts. The ST-70 provides 35 watts per channel and is switchable between both 4 and 8 Ohm outputs, with Class-A push-pull stereo topography that has long been characterized as a reliable design with exceptional audio quality.

audioXpress May 2017 included a detailed article on this historical revival project.  As stated by Dan Fraser, the Senior Design Engineer responsible for the Radial Engineering team who designed the new generation Dynaco ST-70 Series 3, all the options needed to meet the expectations that come with David Hafler’s work were considered. “Tens of thousands of original Dynaco tube amplifiers are still in use around the world. In fact, more quality music systems have included Dynaco tube preamps and power amplifiers than any other combination. The original Dynaco Stereo 70 is a true classic still regarded with awe by audio enthusiasts worldwide. This “new ST-70 Series 3” reflects the illustrious history of Dynaco’s involvement with vacuum tube designs as well as the latest advances in vacuum tube technology. We like to think of the ST-70 Series 3 as the update that David Hafler would have made if he were alive today.”
 

This latest rendition has seen a substantially overhauled power supply from the original version, employing a larger dual-primary power transformer with improved line regulation, increased filter capacitance, and a solid-state rectifier that results in a much more articulate response. The redesigned front end of the Series 3 amplifier replaces the obsolete 7199 pentode signal tubes from the original Stereo 70 with more commonly-used 12AU7 dual-triode tubes, while the output stage and EL34/6CA7 output tubes retain the same elements as the original Stereo 70. A set of front-panel recessed trimmers has been provided, allowing the bias adjustment to be fine-tuned for each output tube.

Building on the legacy of David Hafler's enormously successful Stereo 70, the new Dynaco ST-70 - MSRP: $2,999.99 USD - incorporates advancements in component quality, improvements to the electronic circuit performance, and an all new exterior design that is sure to please the most demanding music enthusiasts.  

More information on the new Dynaco ST-70 is available here: www.dynaco.com/st70
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www.radialeng.com
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