New Product Announcements

I'm pleased to announce the first in a series of exciting new products for Dynaco owners.

First is our Stereo-70 Upgrade System on Board (SoB)  - a complete amplifier on pc board. Everything (driver, bias supply, quad cap, filters) is included. Find out more here.

Next is the first in a series of modules for SCA-35 owners. Our first product is a Capacitor System Module - it completely replaces & upgrades all of the system power supply capacitors and adds two channels of output stage cathode capacitors. Rectification and filter resistors are there too - a complete power new supply. Plus- since all signal path caps are bypassed with high quality polypros, you will see dramatic audible improvement. Read more here.

And now for something any tube amp owner can really appreciate - our Amplifier Bias Control (BCS) System Module. This small clever pc module monitors and controls the bias setting in every one of your output tubes - independently. No more worrying about setting the bias or if it has shifted either too high (tube failure) or too low (high distortion). No more need to use costly matched output tubes. You can find all about it here.

Dynaco designers never expected their products to still be in service after 50 years. Although the transformers are virtually ageless, the other components are not. Therefore it is very common for stock units to require service. To improve the reliability (and performance), it is a good idea to upgrade several critical components at the same time. Here at CAE we have repaired and restored hundreds of Dynaco amps, preamps, and tuners. With this dept of Dynaco knowledge & experience, we have prepared a comprehensive collection of information and products - everything you need to repair, rebuild, upgrade, or extensively modify your Dynaco tube preamp or power amplifier. Please feel free to download full copies of the original owner's manuals and our comprehensive troubleshooting guides. They have been written using the same diagnostics procedure we use and will guide you step by step to the source of the problem. You are welcome to e-mail us with a description of the problem and we will respond with suggestions that specifically address your problem. Alternatively if you prefer, you may send your amplifier to our lab where we will professionally repair, restore, upgrade or perform our extensive modifications per your specific instructions. You can learn more here.

Once you have located the defect, we can provide you with an exact replacement or audiophile premium direct substitute parts. We now offer drop in modules to replace the original (and highly unreliable) "Quad" electrolytic capacitor with a composite that increases the voltage rating and capacitance, includes the bias supply, and optionally allows you to use solid state rectification should you choose - in effect, an entirely new power supply. If you would like to make small but highly effective modifications and dramatically increase reliability, consider our latest Stereo-70, Mark-3 and Mark-4 SoB (system on board) modules - the entire amplifier on a single pcb.  These all inclusive modules dramatically simplify wiring, guarantee correct power & signal path grounding and insure performance targets. Our designs employ simple and highly linear topology and deliver outstanding sonic gains for a very small investment. And of course for those wanting to extract the ultimate performance, we continue to offer our premium modification package that includes the highly regarded Constant Current Differential Amplifier driver module and our HiSpeed LowZ regulated power supply modules for the ST-70 and MK-3 - also available in the SoB package.

Whatever path you choose, all of our solutions are optimized for the specific Dynaco frame and provide the most articulate and realistic audible performance while insuring the highest reliability. They are specifically designed to "drop-in" to the existing chassis and hole patterns - there are no strange appendages or dangling parts. Installation is easy - in just a few hours you will have revitalized your amp or preamp to a level of performance and reliability equaling (and bettering) the finest commercial amps available. And you will have the satisfaction of having completed it yourself.

As always, I encourage you to contact us with your questions, comments, and suggestions. e-mail  inquires will always be quicker and help me keep track of our discussion and if needed, we can schedule a mutually agreeable time to schedule a phone conversation.  If you're ready to order, e-mail your name, address, and phone number and the part numbers of the items you need. Or you may mail our order form. You can review our full PriceSheet or additional ordering details.

A complete power amplifier system on a single PC Board that in concert with your existing Stereo-70 chassis, transformers, and choke provides a completely new amplifier. Included on board are:

• High Voltage Supply - Rectifier & Filter Caps

• Bias Supply - Rectifier, Caps, Pots

• Independent Current Legs for All Output Tubes

• Cascode-SLPI Driver Stage (Same as our Upgrade Module)

• Optional DC Balance Control

• Optional AC Balance Control

Our SoB Module installs completely inside of your Stereo-70 and includes a complete power amplifier using our Upgrade driver circuit and our Quad Cap module plus lots of other enhancements all on one PC Board. Really easy to install - just make connections to the output tubes, power transformer, input connector and choke. With all of the wiring on board it's really easy to install plus you can be guaranteed peak performance year after year. Get the details here.

·        Blank Board (P/N PWB-S7-SoB-U) @ $165

·        Blank Board w/ parts (P/N KIT-S7-SoB-U) @ $260 (w/o Tubes)

·        Assembled & Tested Board (P/N ASM-S7-SoB-U) @ $325 (w/o Tubes)

Recommended Options

·        Hi-Rel Ceramic Output Tube Sockets, Set of 4 (P/N S7-SKT-80-4) @ $24/ set

·        Teflon Rewire Kit (4X 10ft Red, Black, Wht, Grn) (P/N TWK) @ $24/ set

·        Polypropylene Capacitor Option (OPT-PPC-3U) = Add $21

·        Premium Dual RCA Input Assembly (Gold ) - (P/N D-RCA-G) = Add $28

·        DC Bal Adjust Option (P/N OPT-S7-SoB-U-DCB) = Add $12

Useful Options

·        Driver Tube Option - (P/N OPT-V-3) = Add $48

·        Hi-Rel Ceramic 9Pin Miniature Tube Sockets - (P/N OPT-9PC-3) = Add $21/set

·        Output Tube Quad Set - (P/N OPT-VO-4) = Add $100

·        AC Balance Option (P/N OPT-S7-SoB-U-ACB) = Add $12

·        Replacement Power Switch - (P/N SLSW-2P) = Add $7

·        Replacement Fuse Holder - (P/N S7-FH) = Add $8

Stereo 70 Driver Board (7199 Board) Replacement Modules 

B. Upgrade Module - (shown installed on the photo to the left) All triode fully direct coupled design (cascode amplifier with split load phase splitter) that preserves the musical midrange of the stock ST-70 while significantly improving its bass tightness and high frequency extension over the stock board and dramatically increasing both stability and reliability. Accepts 6922, 6DJ8, 7308, 6FQ7/6CG7, and 6N1P. Simple to install – less than 60 minutes. More details here.

·        Blank Board (P/N PWB-3U) @ $67

·        Blank Board w/ parts (P/N KIT-3U) @ $110

·        Assembled & Tested Board (P/N ASM-3U) @ $140

Recommended Options

·        Tube Option - 3 Premium 6922 Dual Triodes (P/N OPT-V-3) = Add $48

·        Polypropylene Capacitor Option (OPT-PPC-3U) = Add $21

Useful Options

·        DC Bal Adjust Option (P/N OPT-DCB-3U) = Add $12

·        AC Balance Option (P/N OPT-ACB-3U) = Add $12

C. Premium Modification Module – Proprietary all triode cascode differential amplifier (CCDA) w/ current source that transforms your Stereo 70 into a world class high resolution wonderfully musical tube amp. It delivers the ultimate audible performance. Includes an on board high speed / low impedance servo regulator to completely isolate circuit from the output stage current loading. As a stand alone driver stage it has no peer. It can be used alone but excels when combined with our S7P Stereo 70 Power Supply / Regulation Module to turbo-charge the output section of your ST-70.  Delivered with all premium components including polypro caps. Accepts 6922, 6DJ8, 7308, 6FQ7/6CG7, and 6N1P. Simple to install – less than two hours.

·        Blank Board (P/N PWB-3A) @ $67

·        Blank Board w/ parts (P/N KIT-3A) @ $295

·        Assembled & Tested Board (P/N ASM-3A) @ $300

Recommended Options

·        Tube Option (P/N OPT-V4) = Add $64

·        Quad Capacitor Module (See Below)

QUAD Capacitor Replacement Modules

Custom designed printed circuit board modules that replace the original Dynaco "Quad" electrolytic capacitor. Each version contains a composite of high quality capacitors to provide both higher voltage (to increase reliability) and greater capacitance (to improve performance) compared to the original.  Rectification provisions for either solid state (diodes) or the original vacuum tube rectifier are included  - your choice simply re-route two wires. These modules also include a complete bias supply including rectifier, filter caps, and associated resistors. There are two versions that are available - top chassis mount and below chassis mount (to preserve the original appearance of your St-70) install easily and quickly without requiring any additional drilling or cutting.

A. QUAD Cap Module - Top of Chassis Version

·        Blank Board (P/N PWB-S7U) @ $29

·        Blank Board w/ Parts (P/N KIT-S7U) @ $65

·        Assembled & Tested Board (P/N ASM-S7U) @ $98

B. QUAD Cap Module - Below Chassis Version

·        Blank Board (P/N PWB-S7U-B) @ $29

·        Blank Board w/ Parts (P/N KIT-S7U-B) @ $65

·        Assembled & Tested Board (P/N ASM-S7U-B) @ $98

Stereo 70 Restoration Packages (as described in our Restoration Manual)

A complete package of everything you will need as specified in our Restoration Manual to completely rebuild and restore your Stereo70 dramatically improving its reliability and performance. The following items are included:

Hi-Rel Ceramic Output Tube Socket set (4)

Teflon Wire Kit

Driver Board Replacement Module

Quad Cap Module (** indicates part number for below chassis version)

RCA Input Connector

New Output Tube Cathode Bias Resistors (10 Ohms)

We offer three levels ranging from a genuine restoration (completely original circuit), upgrade version (utilizing our ASM-3U all triode upgrade module), and premium version (using our unique CCDA premium driver module ASM-3A). Download (free) our Stereo 70 Restoration Manual for full details. Note ** indicates part number for below chassis quad cap version.

A. Restoration w/ Original (7199 Circuit) Driver Module (ASM-3R)

·        Blank Driver Board w/Parts (P/N KIT-3R-R) @ $263

·        Blank Driver Board w/Parts (P/N KIT-3R-R-B **) @ $263

·        Assembled & Tested Modules (P/N ASM-3R-R) @ $325

·        Assembled & Tested Modules (P/N ASM-3R-R-B **) @ $325

Recommended Options

·       Output Tube Quad Set - (P/N OPT-VO-4) = Add $100

·        Polypropylene Capacitor Option (OPT-PPC-3U) = Add $21

Useful Options

·       Replacement Line Cord - (P/N OPT-LNC) = Add $8

·       Replacement Power Switch - (P/N SLSW-2P) = Add $7

·       Replacement Fuse Holder - (P/N S7-FH) = Add $8

·       Premium Dual RCA Input Assembly (Gold )- (P/N D-RCA-G) = Add $28

B. Restoration w/ Upgrade Circuit Driver Module (ASM-3U)

·        Blank Driver Board w/Parts (P/N KIT-3U-R) @ $242

·        Blank Driver Board w/Parts (P/N KIT-3U-R-B **) @ $242

·        Assembled & Tested Modules (P/N ASM-3U-R) @ $307

·        Assembled & Tested Modules (P/N ASM-3U-R-B **) @ $307

Recommended Options

·       Driver Tube Option - (P/N OPT-V-3) = Add $48

·       Output Tube Quad Set - (P/N OPT-VO-4) = Add $100

·        Polypropylene Capacitor Option (OPT-PPC-3U) = Add $21

Useful Options

·        DC Bal Adjust Option (P/N OPT-DCB-3U) = Add $12

·        AC Balance Option (P/N OPT-ACB-3U) = Add $12

·       Replacement Line Cord - (P/N OPT-LNC) = Add $8

·       Replacement Power Switch - (P/N SLSW-2P) = Add $7

·       Replacement Fuse Holder - (P/N S7-FH) = Add $8

·       Premium Dual RCA Input Assembly (Gold )- (P/N D-RCA-G) = Add $28

C. Restoration w/ Premium (CCDA) Driver Circuit Module (ASM-3A)

·        Blank Board w/Parts (P/N KIT-3A-R) @ $427

·        Blank Board w/Parts (P/N KIT-3A-R-B **) @ $427

·        Assembled & Tested Modules (P/N ASM-3A-R) @ $520

·        Assembled & Tested Modules (P/N ASM-3A-R-B **) @ $520

Highly Recommended Options

·       Driver Tube Option - (P/N OPT-V-4) = Add $64

·       Output Tube Quad Set - (P/N OPT-VO-4) = Add $100

·       S7P Kit Power Supply Regulation Module (P/N KIT-S7P) = Add $288

·       S7P Assembled Power Supply Regulation Module (P/N ASM-S7P) = Add $350

Useful Options

·       Replacement Line Cord - (P/N OPT-LNC) = Add $8

·       Replacement Power Switch - (P/N SLSW-2P) = Add $7

·       Replacement Fuse Holder - (P/N S7-FH) = Add $8

·       Premium Dual RCA Input Assembly (Gold )- (P/N D-RCA-G) = Add $28

Miscellaneous Stereo 70 Replacement Parts & Kits

Bias Repair Kit – Replacement Diode, Capacitors, & Resistors (Note - included with our S7U or S7U-B module)

·        Bias Repair Kit - (P/N ST7-B) @ $22

·        Expanded (Expands Bias Range) Bias Upgrade Repair Kit - (P/N ST7-BE) @ $22

Stereo 70 Replacement Hardware Items - Reliability enhancers for your ST-70

·        Hi-Rel Ceramic Output Tube Sockets, Set of 4 (P/N S7-SKT-80-4) @ $24/ set

·        Teflon Rewire Kit (4X 10ft Red, Black, Wht, Grn) (P/N TWK) @ $24/ set

·        Dual RCA Input Connector (P/N D-RCA) @ $6/ ea

·        New - Premium Dual RCA Input Assembly (Gold )- (P/N D-RCA-G) = $28/ea

·        Fuse Holder (P/N S7-FH) @ $8/ ea

·        Replacement Line Cord - (P/N OPT-LNC) = Add $8

·        Slide Switch, DPDT for Power or Stereo-Mono (P/N SLSW-2P) @ $7/ ea

Driver Board (6AN8 Board) Replacement Modules 

A. Upgrade Module - The same all triode all direct coupled cascode / split-load phase inverter design as used in the Stereo 70 but mono and packaged to drop into your Mark 2/3. Simple to install – less than 60 minutes.

·        Blank Board (P/N PWB-1U) @ $80/ pair

·        Blank Board w/ parts  (P/N KIT-1U) @ $122/ pair

·        Assembled & Tested Board  (P/N ASM-1U) @ $150/ pair

Recommended Options

·        Tube Option - 4 Premium 6922 Dual Triodes (P/N OPT-V-4) = Add $64

·        Polypropylene Capacitor Option (P/N OPT-PPC-1U) = Add $27/ pair

Useful Options

·        DC Bal Adjust Option (P/N OPT-DCB-1U) = Add $24/ pair

·        AC Balance Option (P/N OPT-ACB-1U) = Add $24/ pair

B. Premium Modification Module – Same CCDA design used in the Stereo 70 but mono and packaged to drop into your Mark 2/3. This is the same driver stage used in our  Full Premium MK-3 modification package and our MQ-100 monoblocks. Simple to install – less than 2 hours.

·        Blank Board (P/N PWB-1A) @ $80/ pair

·        Blank Board w/Parts (P/N KIT-1A) @ $395/ pair

·        Assembled & Tested Board (P/N ASM-1A) @ $470/ pair

Recommended Options

 ·        Tube Option - 4 Premium 6922 Dual Triodes (P/N OPT-V-4) = Add $64

QUAD Capacitor Replacement Modules

Same design as in the Stereo 70 but packaged to fit into your Mark 2/3. Installation is simple and quick requiring no additional drilling or cutting. Below chassis mount (to preserve the original appearance of your MK-3) installs easily and quickly without requiring any additional drilling or cutting.

QUAD Cap Module - Below Chassis Version

·        Blank Board (P/N PWB-S7U-B-M3) @ $58 / pair

·        Blank Board w/ Parts (P/N KIT-S7U-B-M3) @ $130 / pair

·        Assembled & Tested Board (P/N ASM-S7U-B-M3) @ $196 / pair

Miscellaneous Dynaco Mark 2/3 Replacement Parts & Kits

Bias Repair Kit – Replacement Diode, Capacitors, & Resistors (prices are for single amps)

·        Bias Repair Kit Without Potentiometer - (P/N M3-B) @ $14/ea

Mark 2/3 Replacement Hardware Items - Reliability enhancers for your Mark 2/3

·        Hi-Rel Ceramic Output Tube Sockets, Set of 4 (P/N SKT-80-4) @ $24/ set

·        Teflon Rewire Kit (4X 10ft Red, Black, Wht, Grn) (P/N TWK) @ $24/ set

·        Hi-Rel Gold RCA Input Connector, Red & Black (P/N M3-RCA) @ $24/ pair

·        Fuse Holder (P/N M3-FH) @ $16/ pair

·        Replacement Line Cord - (P/N OPT-LNC) = @ $8 / ea

·        Slide Switch, DPDT for Power (P/N SLSW-2P) @ $7/ ea

Driver Board Replacement Module 

A. Upgrade Module - The same all triode Upgrade design as used in the Mark 3 packaged to drop into your Mark 4. Simple to install – less than 60 minutes.

·        Blank Board (P/N PWB-4U) @ $80/ pair

·        Blank Board w/ parts (P/N KIT-4U) @ $122/ pair

·        Assembled & Tested Board (P/N ASM-4U) @ $150/ pair

Recommended Options

·        Tube Option - 4 Premium 6922 Dual Triodes (P/N OPT-V-4) = Add $64

·        Polypropylene Capacitor Option (OPT-PPC-4U) = Add $27/ pair

Useful Options

·        DC Bal Adjust Option (OPT-DCB-4U) = Add $24/ pair

·        AC Balance Option (OPT-ACB-4U) = Add $24/ pair

·        Polypropylene Capacitor Option (OPT-PPC-4U) = Add $27/ pair

QUAD Capacitor Replacement Module - Same design as in the Mark 3 packaged to fit into your Mark 4. Installation is simple and quick requiring no additional drilling or cutting.

·        Blank Board (P/N PWB-M4U) @ $50/ pair

·        Blank Board w/ Parts (P/N KIT-M4U) @ $127/ pair

·        Assembled & Tested Board (P/N ASM-M4U) @ $185 / pair

Miscellaneous Dynaco Mark 4 Replacement Parts & Kits

Bias Repair Kit – Replacement Diode, Capacitors, & Resistors (prices are for single amps)

·        Bias Repair Kit Without Potentiometer - (P/N M4-B) @ $14/ea

Mark 4 Replacement Hardware Items - Reliability enhancers for your Mark 2/3

·        Hi-Rel Ceramic Output Tube Sockets, Set of 4 (P/N SKT-80-4) @ $24/ set

·        Teflon Rewire Kit (4X 10ft Red, Black, Wht, Grn) (P/N TWK) @ $24/ set

·        Hi-Rel Gold RCA Input Connector, Red & Black (P/N M3-RCA) @ $24/ pair

·        Fuse Holder (P/N M3-FH) @ $16/ pair

·        Replacement Line Cord - (P/N OPT-LNC) = @ $8 / ea

·        Slide Switch, DPDT for Power (P/N SLSW-2P) @ $7/ ea

Power Supply Supplement Module - Resolves the weakest part of your PAS - its power supply. It totally eliminates all hum. The 7A module contains a high speed low "Z" HV regulator and a complete high current regulated filament supply (with transformer). Bass impact is dramatically improved & dynamic contrasts are extended across the entire frequency spectrum.

·        Blank Board (P/N PWB-7A) @ $67

·        Blank Board w/ parts (P/N KIT-7A) @ $205

·        Assembled & Tested Board (P/N ASM-7A) @ $245

Basic Line Stage (PC-5) Module Upgrade - Dramatically improves every aspect of the line stage - the heart of your preamp. An audiophile's line stage that will transform your PAS into a world class preamp. Removes veiling and extends imaging while retaining the musicality of the original. Lowers output impedance (finally) so that any power amplifier (or crossover) can safely be driven. A "drop in" board replacement for the original Dynaco PC-5 that's a snap to install.

·        Blank Board (P/N PWB-5AH) @ $67

·        Blank Board w/ parts (P/N KIT-5AH) @ $200

·        Assembled & Tested Board (P/N ASM-5AH) @ $250

Recommended Option

·        Driver Tube Option (P/N OPT-5H-V1) = Add $16

Basic Phono Stage (PC-6) Module Upgrade - A high resolution replacement for the original Dynaco PC-6 phono PC board that incorporates high transconducance low noise triodes with a perfectly executed RIAA topology that thrills vinyl enthusiasts.

·        Blank Board (P/N PWB-6A) @ $67

·        Blank Board w/ parts (P/N KIT-6A) @ $200

·        Assembled & Tested Board (P/N ASM-6A) @ $250

Recommended Option

·        Tube Option (P/N OPT-V-2) = Add $32

PAS 2/3 Replacement Hardware Items - Common PAS 2/3 Ailments

Recommended Items for Replacement

·        Teflon Rewire Kit (4X 10ft Red, Black, Wht, Grn) (P/N TWK) @ $40/set

·        Stereo Volume Control Replacement - (P/N PAS-VC) @ $18/ea

Useful Options

·        Selector Switch Replacement Kit (Switch, Wire, and RIAA Cap) (P/N SSW-PAS) @ $38/ea

·        Selector Switch Only (P/N RSW-2P) @ $18/ea

·        Dual RCA Input / Output Connector Kit (One per Preamp), Nickel (P/N P3-RCA-N) - $40/ea

·        Dual RCA Input / Output Connector Kit (One per Preamp), Gold (P/N P3-RCA-G) - $60/ea

·        Replacement Power Transformer (P/N P3-XFMR) @ TBD

·        Anodized Aluminum Replacement Faceplate & Knob Set (P/N P3-FP) @ TBD