Welcome to Dave’s Store. contact dave buttonHere 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 boards will be introduced over the course of 2013, as quickly as production, and the time required for those involved in the transition process can make it happen. These are bare boards, that will require your assembly to complete, with parts you order from a BOM that is provided for each board. General assembly and installation instructions will also be provided for each board, with all three of these documents available for download when a board becomes available.

Also coming are two new universal boards that will allow the installation of EFB operation in virtually all of the popular vintage amplifier/receivers, whether they were originally designed with fixed or cathode bias. These boards will accommodate triode, pentode, or UltraLinear operation, with the board applicable for existing cathode bias operation also providing the capability of individual bias adjustment for each tube or channel. EFB operation will virtually always result in lower distortion and longer tube life, and for many applications, increased power output as well. 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 allowing the continued production of exact copies of his boards as used in his AR Dynaco restoration products, the use of his detailed BOM and instructions for assembly and installation, and for his selfless and unwavering efforts to make the transition to production under D. Gillespie Designs possible. 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. Finally, AudioKarma member Jon Yeager (BuzzK) has also provided significant guidance in this effort as well. Without the efforts of these people, the availability of these products would not be possible.

 

PC-10A Output Board Set PC-10A top-bot low
 
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 completepc10_a scaled 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.
  red order button2 low
! 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

 

efb top-bot low
efb assembled low

 

SCA-35 EFB Power Supply Board

Perhaps the most significant upgrade available for the SCA-35
Our new power supply / capacitor board with EFB™ converts your SCA-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.

Download the Assembly Manual (0.3MB)red order button2 low

Download the Installation Manual (3MB)

 Only $28.95 

*EFB™ is a trademark of D. Gillespie Designs.

 

sca_restored scBoards for the Dynaco SCA-35 Integrated Amplifier

  • FR4 Fiberglass Construction
  • Plated Through Holes
  • Solder Mask
  • Top and Bottom Silkscreens
Daves store banner2 low

_

 

ST35_restored scBoards for the Dynaco ST-35 Power Amplifier

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

 

ST35_efb scST-35 EFB Power Supply Board

Perhaps the most significant upgrade available for the ST-35
Our new power supply / capacitor board with EFB™ST35-EFB top-bot low 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 Chartred order button2 low

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.

Download the ST35-EFB Assembly Manual (0.3MB)

Download the ST35-EFB Installation Manual (4MB)

 

pc13 scPC-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)

PC-13 top-bot low

 

Set of two: only $29.95

red order button2 low

 

 

PC-11B top-bot low
pc11b sc

PC-11 Preamp Board

Perfect for restoring your SCA-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-11 Assembly/Installation Manual (0.2MB)

Only $25.95

red order button2 low

Only $28.95