Dynaco Pat-5 User manual

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Updatemydynaco

Dynaco PAT-5 Preamp

Power Supply (PAT5PM15)

+/-15 Volts only

ASSEMBLY MANUAL

Revision 1p08 March 27, 2021

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Table of Contents

Table of Contents ................................................................................................................ 2

Table of Figures .................................................................................................................. 3

Section 1: About This Manual ............................................................................................ 4

Who Should Attempt this Project? ................................................................................. 4

Tools you’ll need ............................................................................................................ 4

Helpful Tools .................................................................................................................. 4

Project Overview ............................................................................................................ 5

Important Safety Notes ................................................................................................... 5

About Components ......................................................................................................... 5

Recommended Solder ..................................................................................................... 5

Warranty ......................................................................................................................... 5

Section 2: Kit Building Hints .............................................................................................. 6

Section 3: Building the Power Supply ................................................................................ 7

Component Order............................................................................................................ 8

Install the diodes ............................................................................................................. 8

Install the Resistors ......................................................................................................... 8

Install the non-polar Capacitors ...................................................................................... 9

Install the Polarized Electrolytic Capacitors ................................................................... 9

Install the TO-220 Regulators and Heatsinks ................................................................. 9

Check your work ........................................................................................................... 11

Removing the Old Power Supply ..................................................................................... 11

Connect the Transformer .................................................................................................. 13

Connecting the low voltage transformer wires ......................................................... 13

Connecting the AC line-side transformer wires ........................................................ 14

Connecting AC Power to the PCB ............................................................................ 15

What if PAT5PM Is Installed? .................................................................................. 15

Take a break .............................................................................................................. 15

Testing the New Power Supply................................................................................. 16

Installing the New Power Supply ................................................................................. 17

Complete Zig-Zag Wall and back panel re-Installation ............................................ 18

Re-connect Power Supply to Preamp and Phono Sections ....................................... 18

Testing the Power Supply Line-Stage Combination ................................................. 20

Final Re-Assembly.................................................................................................... 20

Schematic ...................................................................................................................... 21

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Table of Figures

Figure 1-Assembled PAT-5 Power Supply......................................................................... 6

Figure 2-Empty the power supply components into a soup bowl ....................................... 7

Figure 3-Silk screen shows power supply component locations ........................................ 7

Figure 4-Applying thermal compound ................................................................................ 9

Figure 5-Regulator and Heat Sink mounting screws and soldering mounting posts ........ 10

Figure 6-Assembled Power Supply .................................................................................. 10

Figure 7-Remove hardware that holds power supply bracket to chassis floor ................. 11

Figure 8-Remove these 2 screws and 2 screws on the opposite side ................................ 12

Figure 9-Remove the screws and nuts that hold the zig-zag shield to back and front of

chassis ............................................................................................................................... 12

Figure 10-Original Transformer wiring ............................................................................ 13

Figure 11-Mount new PCB to shield and mounting brackets ........................................... 17

Figure 12-wiring power from back to front with jumpers ................................................ 19

Figure 13-Separate runs for power to phono stages and line stages ................................. 19

Figure 14-Schematic of Power Supply ............................................................................. 21

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Section 1: About This Manual

This manual gives the information needed to build and install the upgraded power supply

for Dynaco’s PAT-5 Preamp. This upgrade changes out the power supply PCB but keeps

the power supply transformer, with the following advantages over the original power

supply:

 Lower noise

 Lower output impedance

 More efficiency, runs cooler, promotes longer life of the electronics

Use this power supply, the PAT5PM15, if you are using Updatemydynaco line stages and

phono stages. This power supply does generate +/-15 volts, but it doesn’t generate the 42

volts required by the original PAT-5 phono preamp. If you’re keeping the original PAT-5

phono preamps, you’ll want to use the PAT5PWR supply that we make.

Important Note: this kit and the transformer are only compatible with 120 VAC power.

Who Should Attempt this Project?

You can build this kit if you can:

1. Solder (using normal rosin core solder and a soldering iron).

2. Use simple hand tools like screwdrivers, wire cutters, and pliers.

3. Read and follow directions.

It helps if you:

1. know a bit about electronics, or

2. have a friend who knows a bit about electronics

3. can get to YouTube to watch a few helpful videos about the assembly process

(none are posted as of this version of the manual).

Tools you’ll need

You’ll need the following tools:

1. Phillips screwdriver (#1 and #2), regular screw-drivers.

2. Pliers or nut drivers suitable for #4 and #6 hardware

3. needle nose pliers (helpful, but not strictly necessary)

4. pencil type soldering iron of 25 to 50 Watts (no huge honking soldering guns or

blowtorches)

5. wire cutters and strippers

6. multi-meter to measure power supply voltages and confirm resistor values

(strongly recommended)!

Helpful Tools

These tools aren’t strictly necessary but make building the kit easier.

1. magnifying glass, if you’re over 42!

2. lead bending jig to form axial component leads to the correct span for insertion in

the PCB.

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Project Overview

The project consists of the following steps:

1. Building the circuit board.

2. Removing the old power supply

3. Installing and testing the new power supply

4. Completing re-assembly of the preamp.

Important Safety Notes

By purchasing, using, or assembling this kit, you have agreed to hold Akitika LLC

harmless for any injuries you may receive in its assembly and/or use. To prevent injuries:

 Wear safety glasses when soldering or clipping wires to prevent eye injuries.

 Always unplug the power before working on the amplifier.

 Large capacitors hold lots of energy for a long time. Before you put your hands

into the amplifier:

o Pull the AC plug!

o Wait 2 full minutes for the capacitors to discharge!

 Remove jewelry and rings from your hands and wrists, or anything that might

dangle into the amplifier.

 If working one the equipment with the power on, keep one hand in your pocket,

especially if you’re near the power supply or power supply wires. This can

prevent serious shocks.

 Build with a buddy nearby. If you’ve ignored all the previous advice, they can

dial 911 or get you to the hospital.

 Read and understand the safety manuals of all the tools you use.

About Components

We reserve the right to make design/or component changes at any time without prior

notification.

Recommended Solder

The kit must be assembled with 63/37 Rosin Core solder1. The recommended diameter is

0.032 inches.

Warranty

With the exception of fuses, Akitika LLC will replace for free any parts of a correctly

assembled product that fails within one year of the date of purchase when the equipment

has been used in home stereo applications. It is the responsibility of the kit builder to

install the replacement part(s). This warranty applies to the original purchaser only. It

does not apply to units that have been physically or electrically abused, modified without

prior factory authorization, or assembled with other than 63/37 Rosin Core solder.

Akitika LLC’s liability shall in no event exceed the cost paid to Akitika LLC for the kit.

1 60/40 solder is also available, but according to Wikipedia, 63/37 solder is preferred as it is less likely to

have a “cold” solder joint.

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Section 2: Kit Building Hints

Yes, I know you want to ignore this section, and jump right into building the kit.

However, please take a minute and read the advice of this section. I’ve condensed it into

bullets so that even you guys who are in a hurry can benefit.

 Stop any time you’re feeling confused, tired, or anxious. Taking breaks at those

strategic times will keep the build enjoyable and greatly enhance your chances of

first-time success.

 A soup bowl is your friend. Before you build a board, carefully empty the parts

into a broad, flat, light colored soup bowl. That makes it easy to find the parts and

keeps them from getting lost.

 A digital ohm-meter is an easy way to make sure that you’ve picked the right

resistor. It’s a great cross-check on the resistor color code. Measure twice and

solder once!

 A lead-bending jig can make for quicker, neater assembly. It’s certainly not

necessary.

 Is something in this manual confusing? Does something look wrong? Send your

questions by email to [email protected] or dan@updatemydynaco.com. You’ll

help yourself and everyone who builds the kit.

Figure 1-Assembled PAT-5 Power Supply

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Section 3: Building the Power Supply

This section details the process of building the power supply circuit board. Begin by

carefully emptying the contents of the parts envelope into a broad soup bowl, as shown

below. In general, you’ll start with the components that lay closest to the board, working

your way towards the taller components.

Figure 2-Empty the power supply components into a soup bowl

Figure 3-Silk screen shows power supply component locations

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Component Order

You’ll notice that the component designations in the directions don’t go exactly in order.

We have grouped them so that all components with the same value appear together. This

makes assembly easier. You’ll find in the parts kit that similar parts, e.g. 8 1N4004

diodes, are typically (though not always) taped together.

Install the diodes

In general, you install axial leaded components (like the diodes) by placing the body on

the silk screen side of the board, and the leads through the indicated holes. Bend the leads

over on the back of the board to keep the components from falling out until your solder

them in place. Try to bend the leads in a direction that won’t lead to solder bridges

between traces that should remain disconnected.

We recommend the following procedure:

1. Insert all components of the same value or type

2. Bend the leads as described above.

3. Solder the leads on the back of the board.

4. Clip the leads.

Track your progress by placing a checkmark in the done column as you install each

component.

Diodes are polarized, having an anode and a cathode. When you insert the diode, match

the banded end of the diode to the banded end of its representation on the silk screen.

Diodes – watch the polarity! – bend leads to 0.4” width

Designation

Type

Rating,

Marking

, Description

Done? (



)

1N4004

400 PIV 1 Amp, 1N

4004,

rectifier diode

1N4004