Dynaco ST-70 Audiophile Boards

Posted on February 23rd, 2008 by Simon.
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We now have Dynaco Stereo 70 Audiophile grade circuit boards available. The base model with Solen FAST caps is available immediately, others are special order. Here’s the list:

Solen: $100 (get a discount if you buy from our eBay Store)
Kimber: $140
Hovland .1 with Solen .047: $150
Multicap RTX: $165
Hovland .1 with Allesandro .047: $205
Cardas Golden Ratio: $220

Jensen aluminum paper in oil: $250
Allesandro foil in oil: $280
Jensen copper paper in oil: $310
Mundorf Silver/Oil: $325
SoniCap Platinum: $360
Mundorf Silver/Gold: $400

This is an exact replacement for the original Dynaco® PC-3 board, fabricated from 0.062″ FR4 material with plated-through holes with pads and solder mask on both sides pre-assembled with a complete set of audiophile grade components using silver-bearing solder. If you are serious about getting the absolute best sound from your Dynaco Stereo 70, either this board or our board kit is a must. It uses the 7199 circuit from the original, not an unknown “new improved” circuit. Its mounting holes and numbering are identical to the original Dynaco PC-3, allowing easy replacement. It is easy to install using the instructions in the Dynaco Stereo 70 manual (not included).

All the components on this board are of the highest quality brought to you at a reasonable price. I had to shop several vendors to find the quietest resistors at the best prices. All components have been carefully chosen to support the high voltages found on the ST-70 board. Most of the resistors are Vishay/Dale metal film resistors, which are the most generally respected resistors in the industry, used in many high-end tube amplifiers such as Cary, etc. A few of the resistors are even quieter resistors from PRP. As a nod to maintaining the warm vintage sound of your Stereo 70, the feedback resistors are NOS vintage Allen Bradley carbon composite resistors. Most of the resistors have 1% tolerances; those that do not have been hand matched to within 1%. The base coupling capacitors are Solen FAST caps, which are superior to Orange Drops both in sound and ease of installation. The board also includes high quality silver mica capacitors and high-quality gold-pin ceramic tube sockets. Also included are two Vishay/Dale resistors to replace the signal-to-ground resistors on the RCA inputs.