Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier
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Evolution Series Dynaco 70 Dynakit ST-70 Enhanced Tube Amplifier

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$1,499.95
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$1,499.95
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Pre-Orders Only at this time - 3-5 weeks for delivery
"Evolution Series 70 Enhanced" Dynaco based ST-70 Tube Amplifier

Two Channels - 35 Watts Per Channel - 70 Watts of Analog Tube Powered Audio!
This amp  sounds absolutely stunning and will be a great centerpiece for your audio system or collection. 

Ready to SHIP NOW!

This amp is built on a Genuine Dynakit Mirror Polished Stainless Steel chassis. The amp comes with a brand new Dynakit Stereo 70 perforated steel cover in Satin Black and has a specially made solid aluminum matching badge. This is a really cool looking amp, you'll never see another one like it. This is a brand new build with all new parts. Photos are of the actual amplifier.

The transformers are new production by Dynakit. The huge PA060 power transformer and two A470 output transformers are wound for modern day voltages. These operate cooler, produce less distortion and will outperform vintage transformers in every category. The current production Dynakit transformers were reverse engineered from the original Dynaco designs, but using modern technologies and insulations. An increased lamination stack on this power transformer allows it to run cooler and provide better regulation. These transformers wont buzz or hum like the originals often do either. A major factor to consider here is that the original transformers were designed to operate on 117 Volts. Modern household AC current is often 125 Volts or more so the use of a "step down" or "bucking" transformer is necessary to reduce the voltage down to a safe operating level for amps having the original transformers. These are USA made transformers that meet and exceed every aspect of the originals. If there were some sort of "magic" in the use of cloth leads, Dynakit would have certainly insisted on using them again. There's simply no magic in cloth covered lead wire, period, it is inferior. In any comparison, these new transformers are better than those old originals, no offense intended. Modern advancements in materials, methods and technologies used in the production of these transformers has resulted in superb transformers that produce cleaner power, operate quieter and run cooler than the originals while providing less distortion and increased reliability.

The new A470 output transformers are also greatly improved, like the power transformer. The output transformers are interleaved/layer-wound and incorporate high quality M-6 grain oriented laminations. These also use better quality wire with better insulation, the primary is wound the same as the original A470 using the same number of turns on the same number of sections. These are made using the same patented Dynaco winding method, and made on the same core size and material type as the originals. These transformers are in one word, exceptional.

The Upgraded Premium Dynakit 80/40/30/20uF multi section capacitor is rated for 550V (600V surge) and uses four discrete (individual) caps inside the metal can style enclosure. The bias section has two 100uF 100V F&T capacitors with Takman 1% 2W 10K metal film audio grade resistors for quiet, accurate and smooth power. All of the other resistors under the chassis are heavy duty metal films for super quiet and dependable operation. 

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So, are you still thinking using 6GH8A/6U8A tubes is questionable?

View this scan of an original Dynaco Series 2 Tube Amplifier manual, these amps came direct from Dynaco with 6GH8A tubes! A great Read and full of information.

Here is a quick look at an important excerpt from that Dynaco document: "The original ST-70's single tube (7199) is out of production and unavailable. The ST70II uses, instead, the 6GH8A. Since this tube has been extensively used in high frequency applications, availability is excellent. It works exceptionally well in this application, yielding better consistency and lower distortion. (TECHNICAL NOTE: Though most tube manuals do not list a spec for the 6GH8A, extensive testing by Dynaco of large numbers of 6GH8A tubes has revealed noise floors that are, on average, lower than modern production 7199's. The 6GH8A is NOT a drop-in replacement for the 7199 tube as pinout for the two tubes is different. Do not attempt to interchange them. The printed circuit board material......................." (read more)

The rectifier is a genuine Dynaco labeled Vintage Mullard - U.K. made - this 5AR4 / GZ34 tube tests NOS, balanced and strong at 112%/112%. The rectifier socket is protected with two diodes that will prevent flashback current from entering and damaging the rectifier during the event of a sudden power on-off-on sequence.

The output tubes are a factory matched quad of 6CA7 big bottle type from Electro-Harmonix and sound wonderful and very smooth. These are an EL34 class of tube. The larger sized tubes give the amp a really nice look too. These tubes were identically matched by Ip for Gm with tests conducted using 400V at the plate, 250V for the screen and -17.52 bias. Original boxes with test data are included.

The back of the amplifier has 4 and 8 ohm banana jacks, there are no provisions for bare wire, banana plugs only. The unused 16 ohm output taps are used directly in the NFB circuit. The 16 Ohm outputs could be wired up if needed, however you would have to sacrifice either the 4 or 8 ohm output terminals. There is also a flush mount fuse holder using the standard 3AG slo-blo fuse. The amp has a 3 prong heavy duty grounded power cord.

This Evolution 70 also has a genuine Dynakit C-354 shielded design filter choke. This amp is dead quiet, zero hum and sounds just incredible. All wiring was done with 20 and 22 AWG solid core wire using Kester 60/40 rosin core solder. 

The amp has even more great features. The Stereo/Mono switch was eliminated. The RCA inputs have wider spacing to accept todays bigger and better RCA connection cables. 4 solid aluminum black and silver feet were chosen to give the amp a great stance. The power switch is a new CK part with a "sealed" type slide mechanism for long life.

The amp is warrantied for 6 months excluding the tubes.  Warranty details can be provided before you purchase and will be included.

All amps come with a 3 wire grounded power cord, be prepared to invest in a ground isolator or adapter to avoid and prevent ground loop feedback / hum if this surfaces as a problem when installed into your system. This is a very common issue where 3 wire / grounded cords are involved. The Hum-X device, when installed correctly, will eradicate the ground loop properly, while retaining the full and safe function of the ground. The Jensen Iso-Max is also highly effective between your source (preamp) and amp to eliminate hum that may be generated from the source (preamp) rather than through the power cord.