Raleigh audio Rakk dac mark iii extreme preamplifier User manual

RAKK dac

Ralei

h Audio

K&K Audio

RAKK dac

Mark III

Extreme

Preamplifier

Assembly Manual

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This completed Extreme Preamplifier has a silver face plate and knobs. A black faceplate and knobs is available.

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GeneralInformation

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The Extreme Preamplifier is a semi-custom kit, which means that several standard offerings are

combined to form the base, while the inputs and outputs are added as options to the base. You

can choose to have from one to six inputs, which may be a mix of balanced (XLR) and single-

ended (RCA) jacks. You can choose to have from one to three outputs, which may be a mix of

balanced (XLR) and single-ended (RCA) jacks.

While a mix of analog and digital inputs is possible, this makes the preamplifier into a different

product – the Extreme Hybrid, and thus is not covered in this manual.

This kit is relatively straightforward to build, but assumes some prior skill with a soldering iron

and some knowledge of electronic components and assembly.

Kit version

Use this manual with the Extreme Preamplifier Mark III

•Use the applicable on-line manuals for component sub-assemblies.

Required Tools and Supplies

150 to 250 Watt soldering gun

35 to 50 Watt soldering iron

Phillips (cross point) screwdriver

Volt-Ohm-Milliamp Meter

Potentiometer adjustment tool (supplied)

1/16” hex (Allen) wrench (supplied)

5/64” hex (Allen) wrench (supplied)

1.5mm. hex (Allen) wrench (supplied)

2.5mm. hex (Allen) wrench (supplied)

1/4”, 5/16”, 1/2”, 9/16” open-end wrenches

Diagonal cutting pliers

Long-nose pliers

Wire stripper

Solder

Use the soldering gun only to solder the heatsink pins.

Use the soldering iron for all other components.

Support

RAKK dac and its associated components are produced through the joint cooperation of K&K

Audio and Raleigh Audio. You may contact us with questions on constructing this kit by sending

an e-mail message to [email protected] or [email protected]

Warnings and Cautions

Warning — a high voltage power supply (200VDC) is required to make the kit operate properly.

These voltages can be lethal. If you are not familiar with safe techniques for completing the

installation of this kit with a high voltage power supply, then you should seek someone who is

qualified to help you construct this kit safely. If you wish to review safe practice, consult the

ARRL Handbook for Radio Amateurs (www.arrl.org or often at used book stores), which has a

section on high voltage safety. Although they are usually referring to 1000v+, the techniques are

still applicable. As the purchaser, you assume responsibility for safe assembly, testing, and

application of this kit.

Caution – Use only solder that is intended for electrical circuits. Do not use acid or corrosive

flux of any kind.

Caution – Any MOSFET is subject to damage by static electricity. Thus, the MOSFETs need

special care and handling especially when the relative humidity is low. Make sure to discharge

any static electrical charge from your body before handling a MOSFET. You can discharge your

body by touching a water faucet or grounded electrical appliance.

Soldering Notes

To a large extent, the success of your kit-building endeavor depends on your ability to solder

properly. Aside from experience, there are two pretty important factors in this success. The first

is the soldering equipment. I recommend using a temperature controlled soldering station,

although any good soldering iron of 40 watts or greater will do. There are many soldering

stations on the market; I have had good experience with the moderately priced Hakko Model

936. If you do have or purchase a soldering station, or even use your existing soldering iron, I

have found a chisel style tip of about 2mm-2.5mm width to be the most useful. You can use the

flat part for large solder joints and the corner for small solder joints. The second factor is the

selection of the solder you will use. The PC boards and most of the electrical components in the

kit are lead-free, as the movement in the EU has forced manufacturers to remove the lead (and

other dangerous heavy metals) from their products. Decent (notice, I didn’t write “good”) lead-

free solder exists, such as Cardas Tri-Eutectic, but it is not so easy to use unless you have some

soldering experience. Lead-free solder tends to melt in a sluggish way and the resulting solder

joints are not the customary shiny silver color, so it’s difficult to avoid “cold” solder joints

without experience. It’s up to you to decide what to use. Choose based on your experience. I

use Cardas Quad Eutectic and can recommend it without reservation; however other high quality

solders may work just as well. Take care in handling electronic solder as most of it still contains

a significant quantity of lead. Wash your hands thoroughly after construction sessions and keep

all kit materials well out of the reach of small children.

Even though there is a “component side” and solder side” to the board, your might find it more

convenient to solder the leaded components from the component side.

TableofContents

General Information ......................................................................................................................................................2

Table of Contents...........................................................................................................................................................4

Assembly Instructions ...................................................................................................................................................5

Pre-wire the PC boards and Power Transformer ...........................................................................................................6

Pre-wire the Active Output........................................................................................................................................6

Pre-wire the RAKK Input..........................................................................................................................................7

Pre-wire the Power Transformer................................................................................................................................8

Panel Preparation.........................................................................................................................................................10

Bottom Panel Preparation ........................................................................................................................................10

Back Panel Preparation............................................................................................................................................11

Side Panel Preparation.............................................................................................................................................12

Front Panel Preparation ...........................................................................................................................................12

Panel Assembly ...........................................................................................................................................................13

Bottom Panel Assembly ..........................................................................................................................................13

Back Panel Assembly ..............................................................................................................................................16

Front Panel Assembly..............................................................................................................................................22

Final Assembly and Wiring .........................................................................................................................................23

Wire the Bottom Panel to the Back Panel................................................................................................................23

Wire the Bottom Panel to the Front Panel ...............................................................................................................26

Assemble the Panels ................................................................................................................................................31

Final Adjustments........................................................................................................................................................37

Adjust the Constant Current Sources.......................................................................................................................37

Final Assembly............................................................................................................................................................38

Parts List......................................................................................................................................................................39

Circuit kits ...............................................................................................................................................................39

Extreme Kit Contents ..............................................................................................................................................39

Document version history............................................................................................................................................42

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