Champ 600 Upgrade Kit Installation
Although we no longer stock the Champion 600 Upgrade Kit, we have left these instructions up for those who might find them useful in modifying their Champ 600.
These upgrades improve the tone of the factory design of the Fender® Champion 600 Reissue amplifier; they do not change the circuitry from stock. We are simply using higher quality, better sounding components of the same value to improve the tone and feel of the amplifier.
It is recommended that these modifications be performed when you are at your best and able to take your time. You may wish to download a pdf version of the Champ 600 schematic.
Disclaimer: Specialty Guitars, LLC is in no way liable for damage caused to yourself or your amplifier in installing this kit. We recommend that you review the proper discharging of filter capacitors before beginning work on your amp. if you do not feel confident to install this kit, including taking the necessary safety precautions, we strongly recommend that you take your amplifier to a qualified amplifier technician.
Step By Step Instructions
Remove back panel. Unplug the speaker cable from the chassis and gently remove both tubes from their sockets. The metal shield must be removed from the preamp tube by turning slightly counterclockwise and pulling down. Pull down on each tube while working it in a gentle circular motion. Remove the four screws holding the chassis to the cabinet (two on the back and two on the sides) and slide the chassis out of the cabinet. Sliding the chassis out can be difficult as it can be a tight fit, so take your time and work gently.
The tone and coupling capacitors to be replaced are C1, C9, C8 and C2.
Remove all of these caps by gently desoldering from the top of the board. Remove excess solder from the through-holes using a solder sucker and/or solder wick, or whatever means you prefer. Once the old capacitors are removed, take the twisted pair of green wires that go over the top and very gently pull back behind the J20 ribbon connector.
Start by installing the 250pF silver mica capacitor (C1). Trim the leads to approximately 3/8". Install as shown in photo and carefully solder from top side of board. After the solder cools, bend slightly at an angle toward R8.
Next, prefab the leads of the 3 caps in the orientation as shown in the photos. It is imperative that C8 (.1 mF)
and C9 (.05mF) be lifted off the board somewhat. Their leads will have to be bent underneath the bodies of the
Be sure to "dry fit" the components before beginning to solder.
Cut four 3/4" lengths of the white spaghetti insulation included with your kit and install on the leads of the .05mF and the .1mF caps. C2 (.02mF) may sit on the board, but it is recommended to put a dab of silicone under it to keep it from vibrating. You may also install white spaghetti insulation on its leads, but it is not necessary.
Now, install and solder C2.
Next, install and solder C9, paying attention to the lead orientation with regard to the board mounting screw
Finally, install and solder C8 as shown in the photo. Once soldered, the components can be moved slightly to adjust them into optimal position. It is recommended to put a dab of silicone between C9 and C8 and between C8 and C2.
Now, gently move the twisted pair of green wires back into place over C8 and C9. Some repositioning of the caps may be required. It is again recommended to put a dab of silicone on the twisted wires where they touch the top of C8.
If you have purchased a kit that includes the Weber upgrade speaker, with the chassis still removed from the cabinet,
gently remove and unplug the factory speaker as shown in the photo. Carefully install the Weber speaker in the same
orientation as the original. Install the screws, turning a little at each time on each one. Do not overtighten!
Now fasten the speaker cable connectors to the Weber speaker, matching red to red and black to plain.
Finally, install the JJ 12AX7 preamp tube and replace the metal preamp tube shield. Install the JJ 6V6 and slide the chassis back into the cabinet, being careful not to bend or damage the tubes. Reinstall the side screws first, making sure not to tighten all the way. With the chassis in proper position, install the two faceplate screws, then tighten the side screws until secure. Reconnect the speaker cable, and screw on the back panel.
One thing that this amplifier invariably needs is power tube bias adjustment. The Champion 600 Reissues that we have seen have had the 6V6 power tube biased for too much power dissipation. The correct power dissipation for a 6V6 is considered to be between 12W and 14W (12W for vintage 6V6s and up to 14W for some of the newer 6V6s). The Champion 600s that we have seen were biased for between 15.5W and 16.5W. This is simply too high and does not sound optimal. We have found that the installation of a 200 Ohm to 240 Ohm 2W resistor in series with the factory installed 470 Ohm resister in R10 will achieve approximately 12W to 13W power dissipation.
There is much more that can be done should you wish to take it further. This amplifier, like all single ended amplifiers, would greatly benefit from hum reduction achieved through a DC filament supply. You will find that there are countless threads on countless message boards dealing with modifications to the Fender® Champion 600 reissue and if you wish to carry things further we suggest that you search out some of these threads.