Welcome to Dave’s Store. Here you will find all the boards you need to restore your small Dynaco amplifiers, and upgrade them with new power supply boards, which include the popular EFB modification that provides greater power output, lower distortion, and extended tube life.

These immensely popular boards are sold as bare, unpopulated boards, requiring your assembly to complete, with parts you order from a BOM page that is provided for each board. Separate Assembly and Installation instructions are provided by way of free downloads as required for each board, with the BOM page located in each Assembly manual. The power supply boards include the EFB™ modification, which has been proven the world over to produce more power, lower distortion, longer tube life, and promote cooler operation. EFB is a trademark of D. Gillespie Designs.

The ordering process is strictly low tech, with the savings passed on to you. When you order, I will respond with a PayPal invoice by email. Once that is remitted, boards will be promptly mailed out in envelope mailers. 

I am deeply grateful to George Ronnenkamp of Pacific Audio Regenesis, for providing the design of his boards as originally installed in his AR Dynaco restoration products, the use of his detailed BOM pages and manuals for assembly and installation, and for his willingness to promote the continued production of his boards by D. Gillespie Designs. I would also express my gratitude to Steve Lafferty, proprietor of the Tronola website, for his generosity in extending a portion of his site for my use, his superb skills in posting and publishing all the material in Dave’s Lab and Dave’s Store, and his unwavering dedication to making the entire Tronola site second to none. Without the efforts of these people, the availability of these products would not be possible.

 

Boards for the Dynaco SCA-35 Integrated Amplifier

• FR4 Fiberglass Construction
• Plated Through Holes
• Solder Mask
• Top and Bottom Silkscreens

 

Boards for the Dynaco ST-35 Power Amplifier

• FR4 Fiberglass Construction
• Plated Through Holes
• Solder Mask
• Top and Bottom Silkscreens

 

ST-35 EFB Power Supply Board

Perhaps the most significant upgrade available for the ST-35
Our new power supply / capacitor board with EFB™ converts your ST-35 from cathode bias to a new and innovative “Enhanced Fixed Bias” mode.

Benefits of EFB™ include:

• Increased output power (both channels driven)
• Lower distortion
• Lower bias current for extended tube life

View Performance Comparison Chart

Much more than just a replacement for the original twist-lock cans, our capacitor EFB™ board also replaces all the resistors and rectifier diodes associated with the
power supply. Significantly larger overall capacitance and 105 degree rated
components are specified that far exceed the originals in quality and reliability.

The boards now being supplied are second generation boards, with additional
circuits included that provide enhanced protection for the regulator under all modes
of operation. They also significantly reduce its operating temperature, to maximize
the life of the device.

Download the ST35-EFB Assembly Manual (0.3MB)

Download the ST35-EFB Installation Manual (4MB)

 

PC-13 Output Board Set

Perfect for restoring your ST-35 while maintaining the stock circuit configuration.
The original Dynaco component mounting hole spacing and eyelet placement is retained for easy drop-in replacement.

Download the PC-13 Assembly Manual (0.2MB)

Download the PC-13 Installation Guide (0.3MB)

 

Set of two: only $29.95

 

 

Only $29.95

 

PC-10A Output Board Set
 
The D. Gillespie Designs PC-10A replaces the obsolete, increasingly hard to find, and expensive 7199 driver tube with either a 6GH8A or 6U8A. Either of these tubes is relatively low cost and readily available. Note that this is not just a tube swap. Additional components have been added to prevent stability issues that can occur when these tubes are simply used with adapter sockets in the original PC-10  board.

The PC-10A retains the original PC-10 eyelet locations for complete compatibility during installation. In fact, with the
exception of a few added components, the layout is virtually
the same as the PC-10.
 
For those who doubt the ability of the 6GH8A or 6U8A tubes to compete with the 7199, please take the time to read page 3 of the July 1990 Audio Basics Newsletter by Audio by Van Alstine. 6U8A tubes were also used by famous makers, like H.H. Scott, for exactly the same purpose (phase splitter) as they are in our PC-10A. They DO work well.
 
! Note: The PC-10A is NOT compatible with the 7199 tube.

Download the PC-10A Assembly Manual (0.2MB)

Download the PC-10A Installation Guide (0.7MB)

Set of two: only $29.95

 

The boards now being supplied are second generation
boards, with additional circuits included that provide
enhanced protection for the regulator under all modes of
operation. They also significantly reduce its operating
temperature, to maximize the life of the device.

_