Contact us to discuss details, payment / ordering options and pricing.
UPDATE: No ST-35 transformers available until August or September
Photos are only representative of the unit to demonstrate the general build characteristics.
Chassis is available in a machined finish nickel plate (non-reflective) or a mirror polished stainless steel chassis is optional for $25.00 extra. The amplifier seen in the video (see link below) has the polished chassis as does the other ST-35 (with bias control) I have listed on this site.
includes brand new matched tubes (upgraded tubes available per request) unit pictured has an upgraded vintage tube set installed
- This amp is all new, it's plug & play, needs nothing
- New chassis and cover
- New power and output transformers
- New circuit boards and ceramic tube sockets
- New EL84 output tubes
- NOS/New 7247 preamp tubes
- Upgraded to Cornell Dubilier (CDE) 940 Series Capacitors
- Upgraded to Yageo, KOA Speer Carbon Film resistors and also TE Connectivity, PRP and Takman 1% audio grade metal film resistors
- Upgraded chassis feet, 6A power switch, C-354 choke
The Dynakit Stereo 35 by Dynaco is widely regarded as the pinnacle of Dynaco tube amps for its exceptional sound quality. Don't be fooled by the simple old school look and utilitarian design. The circuit is pure genius, representing simplicity and innovation that made David Hafler into an audio legend. The Stereo 35 produces amazing sound quality. This all new amplifier is meticulously hand built with upgraded components and quality tubes, the sound is simply stunning.
Whether you're in to vinyl, reel to reel or more modern formats of music, this is your amp. The "Baby Dynaco" is aso a very compact amplifier measuring only 4.5" tall x 5.5" deep x 13" long. It weighs just 16 lbs. You won't beat the sound or quality of this amp in this price range. If you would like more detailed information please keep reading:
This classic amp is all new, designed and built to almost the exact specifications as it would have been when purchased new over 50 years ago but with much higher quality parts. A few features were added to improve performance, reliability and functionality. Although the original Stereo 35 never used a choke, it was proven that the noise floor of the amp could be lowered even further by its use so a Dynakit C-354 shielded choke is installed, an excellent upgrade. This amp is dead quiet, no hiss, no hum, the music is all you hear. These amps never included a power switch and the chassis sat nearly flat down on the surface wherever it was placed. A small 6 amp toggle switch is added on the back side of the chassis to provide power on and off. Four 1/2" tall rubber feet are installed for better isolation, better chassis cooling and ventilation. An inrush current limiter is incorporated to soften the power on process. The power transformer is mounted on isolation bushings. The new chassis is heavy duty (non-magnetic) type 304 mirror finished stainless steel with durable black epoxy silkscreen lettering. The cage/cover is included.
This amplifier is equipped with a Dynakit PA-774 power transformer and the matching pair of Dynakit Z-565 output transformers. These are the heart and soul of the amplifier. These are exceptional quality current production transformers that meet or exceed the performance of the originals and they are made in the USA. The Z-565 output transformers use M-6 grain oriented laminations and they are interleaved wound just like the originals. With these new Z-565 transformers, this ST-35 will now accommodate a pair of either 4 or 8 ohm speakers making it much more compatible for use with more modern speakers than the 8 and 16 ohm design of the original Z565 transformers. The new PA-774 power transformer is wound for today's real world 120v + line voltage as opposed to the originals which were wound for the 112-117v of the 1950's. A huge and convenient improvement which allows this amp to operate directly from a standard outlet without the need of a voltage reducing device. Another big improvement is the fact that the PA-774 incorporates Class "B" insulation and wiring which is better designed to handle significantly higher operating temperatures. Based on findings from a tear down and close inspection of some number of original production Dynaco PA-774 power transformers, it was concluded that all of these old units were of a Class A design with a maximum operating temperature of only 221 degrees Fahrenheit. The new production PA-774 units are designated as "B" classification, a NEMA Class 150 C design having a maximum operating temperature of 302 degrees Fahrenheit. Operating close to or beyond a transformers temperature rating will eventually result in a premature failure of the unit. The bottom line is the new production Dynakit power transformers are designed to handle measurably higher operating temperatures than the original Dynaco power transformers resulting in near zero failures and greater long life durability.
There is always a "buzz" over cloth lead transformers, folks there is no magic in those cloth lead wires whatsoever. The magic is that the older cloth lead versions of some transformers are often in fact of better quality than their new production replacements. This is certainly NOT the case with these transformers which incorporate the latest design advancements in metals, insulation, resins and construction resulting in even quieter and cooler operation while providing increased performance. This Stereo 35 amplifier uses cathode bias, just like the original design so there is no manual bias adjustment. This amp also has solid state diode rectification as did the original design.
The circuit boards are Dynakit PC-13 boards, made in the USA. These new heavy duty boards are faithful to the original circuit design, layout and color, made to military specs with superior modern methods and materials of the highest quality. The boards are populated with high precision carbon film and metal film resistors and excellent quality audio grade capacitors. The 7247 tubes are dual triodes, each 7247 tube contains two dissimilar triodes. This tube is especially suited for applications requiring a high voltage amplifier and a cathodyne type phase inverter like the ST-35 amplifier. The dual triode driver circuit is one of the secret weapons this amp uses to generate such exceptional sound. Four JJ 6BQ5/EL84 output tubes were purchased new specifically for this amp, platinum matched by plate current on an Amplitrex tester. The premium NOS Cinch sockets provide excellent heat shielding for the circuit board and grip the tube pins tightly for positive contact.
The assortment of carefully selected capacitors sound superb, as you would expect. The imaging, depth and detailed sonic range of this amp are just incredible. Original capacitance values were kept, however the voltage ratings were increased for higher reliability. The 60/40/20/100 multi section filter capacitor is new, also from Dynakit and made in the USA. Precision film resistors ensure the circuit is dead quiet, strong and operating correctly. The carbon film resistors and film capacitors, solid state rectification with the twin triode driver tubes give this amp its great ability to resolve complex musical passages in superb detail while keeping all the magic and warmth you want.
This amp is for the true audiophile. Here's what renowned VTA tube amp guru Bob Latino had to say a while back about the Dynakit Stereo 35: "Many feel, and I concur, that this little amp, within its power range, is probably the best sounding all stock power amp that Dynaco ever put out. Only 17.5 watts per channel but, even unmodified, a very clean sounding 17.5 watts. EL84 output tubes, an all triode driver system and a solid state rectifier gave this little amp excellent frequency extension and very low distortion figures." My feeling is that if Bob Latino says that, and many others agree with him, that you will be convinced as well.
This is the original 1963 release from the Dyna Company regarding their new Stereo 35 amplifier:
The Dynakit Stereo 35 is a dual power amplifier of deceptively simple appearance and circuitry. Behind its seemingly conventional design is an extremely sophisticated circuit configuration representing the most recent advances in power amplifier engineering and construction. This high degree of technical refinement, combined with the conservative use of premium-grade components, has resulted in a typical Dynakit design offering superb performance at low cost.
Each of the two channels in the Stereo 35 is rated as a 17.5 watt amplifier. Although not evident from this simple rating, the power stated is available on a continuous basis at any frequency from 20 to 20,000 cycles per second.
A music power rating would make the Stereo 35 a 45-watt amplifier, although even this rating would not disclose that full power is available at low distortion throughout the audio spectrum. Nor would such a rating indicate that the Stereo 35, even when driven to power output levels beyond its rating, is able to handle these overloads gracefully, with minimum detriment to the sound. As a result, the Stereo 35 can, if necessary, duplicate the sound intensity of amplifiers with much higher power ratings when called upon to do so.
The heart of the Stereo 35 is the special Dynaco Z-565 output transformer, a patented design tailored specifically to this circuit. The transformer is free of resonances, has extended frequency response (from 6 to over 60,000 cycles), and is wound by special techniques on a carefully designed core to insure low distortion over a wide frequency spectrum. Transformers of this calibre have never previously been used in low-cost equipment of moderate power rating.