Mercury Champ 600 Manual Download Page 3

Page: 3 / 32

Fender ’

Champion “600”

•

Mercury Upgrade Kit

This project and its documentation is the result of technical investigations made by the engineering staff of

Mercury Magnetics

. The disclosure of the information herein may pertain to proprietary rights and

the furnishing of these documents does not constitute an expresed or implied license to use such materials.

SOLDERING NOTE

: Your amp is assembled using

RoHS

compliant, lead-free solder. Working with lead-free solder is different than

standard solder. Generally a hotter iron is necessary. For more information we recommend doing a web-earch for “lead-

free soldering techniques.”

CAPACITOR DISCHARGE WARNING

: Safe discharging of

filter

capacitors matters. It is essential for your safety and

to prevent damage to the amp’s circuitry, that large or high voltage capacitors be fully discharged before measurements

are made, soldering is attempted, or the circuitry is touched in any way. For information on how to do this, web-search

“capacitor discharging.” Also see the appendix for additional information.

CAPACITOR POLARITY

: Note that many capacitors have positive and negative polarity, and are stamped accordingly.

Be sure that their polarity is correct when soldering to a PCB.

BRAIDING, TWISTING AND COILING LEADS

: Do not braid, twist or coil the power transformer’s B+ lead wire. Check

our reference illustrations and photos to see which leads are twisted together. Typically only the filament leads of the

power transformer. Other positioning of leads may be necessary to minimize amp noise. Follow are diagrams and

instructs for optimal performance.

TRIMMING TRANSFORMER LEADS

: To minimize noise, measure and trim the solderable lead lengths of the trans-

formers and

Mini-Choke

™

. Route all wires cleaning around the tubes, chassis,

etc

CLIPPING

. UNSOLDERING PCB COMPONENTS

: To make this

Upgrade

it will be necessary to remove several

components from the Main PCB of the amp. Due to quality issues with modern off-shore PCB manufacturing, it can

be difficult to unsolder an item without creating other problems, the most typical of which is an eyelet detaching from

the PCB. Therefore we’ve indicated which components should be clipped vs. unsoldered. To unsolder heat your iron

to 800ºF, then very quickly heating up one side of the existing solder connection while pulling it through on the other. If

the iron is not hot enough, or you linger too long, the eyelet will get damaged (or fall off). If this happens you’ll have to

fabricate a repair, or created a jumper to a trace. See this manual’s appendices for tips.

POWERING UP A GUITAR AMP

: After making any modifications to an amp’s circuit (e.g. this

Upgrade

) use a

Variac

along with an current meter (some have both) to slowly apply power to the amp while checking for warning signs of

circuitry errors or shorts. See the section on “Using a Variac” at the end of this manual.

LOADING OUTPUT TRANSFORMERS

: You must connect a speaker or speaker cab to your amp before powering it

up. Without a load the output transformer will blow.

MINI-CHOKE FACTOID

: A

Mercury

Mini-Choke

™

replaces a resistor and adds a disernable amount of tonal dimen-

sion to the circuit.

TRANSFORMER BREAK IN PERIOD

: As a general rule, transformers require approximately 30 hours of

playing time

to be fully broken in. Please refer to

Mercury’s

website for more information.

BE SAFE! ALWAYS USE PROTECTIVE EYEWEAR!

Table of Contents

Reference photos of stock amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Mercury Upgrade wiring schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Mercury Upgrade PCB location diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Transformers and choke specifications sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Transformer locations on the chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

How-To illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Appendices:

Using a Variac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Tips ’n Tricks – Working on PCBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

The Output Transformer Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

DANGER! Discharging those Filter Caps! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

CAUTION!

The voltages in your amplifier can be dangerous. Transformers and chokes are not user servicable parts. Installation of

these components should always be performed by an experienced technician. The simple ability to use a soldering iron is not enough

to qualify a “do-it-yourself person.” Those who are inexperienced in working with electronic circuits should never attempt to service their

amplifiers. Household line currents can be deadly!! Transformers, chokes and large filter capacitors can store dangerous charges for

several days, or longer, after the amplifier has been unplugged. Never touch the terminals of these components without being certain

of their charge status. Risk of shock and damage to equipment may result from mishandling and/or improper use of these components.

Please use common sense and always think safety first. After all, great tone is most enjoyed when you are alive to hear it.

Recommended tools for this project

• Good quality solder iron (capable of temps at > 800ºF)

• Electronics grade solder

• Solder sucker and/or wick