Tuesday, December 10, 2013

1981 Fender Champ, line out mod

Today we have an '81 Champ, great little amplifier. It came to me to have a simple line out mod installed. There are a couple ways to do this, one which requires drilling a hole in the back of the amp, the other you can simply use input #2 as the output. We opted for this because these lil' amps are valuable now. If you have the option to do a mod so it's completely reversable than I say do it that way.

First the parts needed.

1 2.2K ohm 1/2 watt resistor
1 220-270 ohm 1/2 watt resistor
A piece of shielded cable
Some silicone glue or whatever fastening method works for you.

First here's a photo of the input jack:

What we'll do is remove the yellow wire coming off input jack #2 then seperate the 2 jacks from one another.

Next locate the speaker output jack:

You will then solder the 2.2k ohm resistor to the hot coupled with the 220-270 ohm resistor to ground.
You will notice that I'm using 2 470 ohm resitors in parallel to make one resistor that is approximately 235 ohms. Under normal circumstances I would of course use the proper part but that part is stuck in a snowstorm somewhere between Texas and here! Customer needs this tomorrow so sometimes you just need to make it work!

Next take a piece of shielded cable and connect the center to the 2 resistors. On the other end of the cable connect the shield to ground on the #2 jack and the center to the tip.

You are done. Give the amp a good socket and pot cleaning and button it up!

This is a great little mod that I personally use with my Magnatone Varsity amp. I've  since given up overdrive pedals cause there is no comparison to the real thing! I plug into the Magnatone and out of there I can go directly into whatever big amp the house has. Pure, HUGE, tube tone! Try it!

And of course, before you do any of this, please bleed the filter caps. They can contain lethal voltage even with the amp unplugged. If you don't feel comfortable doing this take your amp to a tech who knows what they are doing!

Peace, JB

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