Red Knob Fender Champ 12

[vegetablejoe]

Re: Red Knob Fender Champ 12

IIRC, the Champ 12's gain was unusable. It's reverb tank consisted of a spring inside a carton box. Did ok with pedals though. Ok for home use, but I much preferred the tone and gain from the Pro Jr. and Blues Jr. I've had all three amps, but today prefer to use a Classic 30 as it doubles as a practice and gigging amp.

I also preferred a Champ 25SE for its cleans over the Champ 12. ymmv of course.

[Lake Placid Blues]

Re: Red Knob Fender Champ 12

......
Single ended 6L6 output amp (similar to the valve jr. but with a little more complicated circuit). I like the clean channel... a little gritty, not completely clean, not much headroom but not necessarily a bad thing. Great for cleanish, mildly overdriven blues.

OD channel is a little harsh for my taste. I do use it but with the gain way down. The difference in volume from one channel to the other is also apparent. I have to turn the volume on the OD channel way down if I want to switch from one to the other.

Reverb is OK i guess... don't use it much.

That's pretty much how I remember these too.

An EL34? That's interesting.

[kmcguitars]

Re: Red Knob Fender Champ 12

I downloaded the schem and have been trying to figure out the circuit to see how to simplify it and tame the OD channel some... I just can't figure out the LDR switching scheme. Also, I'd like to maybe use the second half of the second 12AX7 for something other than buffering the line ins (which I want to remove and use as bias test points).

I dunno... a lot can be done besides the torres mods (which I haven't tried) I guess... I'd just like to figue some mods on my own... any opinions?

Thanks!

I've had 3 of these amps. 1st one on loan from a friend, Loved it! Bought my own. Modded it (thanks Mr. torres) Tried to un mod it! Young & Stupid Grew disenchanted w/t it, Sold it. Recently got my grubby hands on a 3rd (unmodded) And I'm holding onto this one ! Only thing I've done to this one is hard wire a switchcraft input jack to it. Maybe when I've got the $$ it will see a New speaker & some N.O.S. Glass, AND THAT'S IT ! I did the torres mod to #2 about 20 years ago. All I remember it was a Lil' network of bypass caps & resistors that tied V1b to V2a. This DID help tame the nasty gain channel , But it also seemed to pad down some of the clean channels chime? A better non-evasive way to tame the O.D channel would be to try a lower gain tube in V2 . The knob mods ,He has you take out the 1meg gain & O.D.volume pots for 500k ! Now in theory Isn't this the same as turning the pots to 1/2 way? The knobs where less touchy, But I noticed a volume drop overall in the amp? The verb in these amps is weird by Fender's el cheapo design. You get a 2 spring internal cardboard tank without a dedicated driver? It splits off the OT,And is driven by the OT! But there is hope. If you look at the schematic you will see R 41 250k reverb trim pot . Just a Lil' tweak and the verb wakes up! But go easy! Go to far and it opens up a uncontrollable feedback loop.

[RomanMtz]

Re: Red Knob Fender Champ 12

Hey kmcguitars, why do you recommend to avoid the Torres mods? I looked into the Fender forums archives and several people recommend them... at leat the tone shaping mod (involves 2 resistos and 2 caps).

Thanks!

[kmcguitars]

Re: Red Knob Fender Champ 12

Hey kmcguitars, why do you recommend to avoid the Torres mods? I looked into the Fender forums archives and several people recommend them... at leat the tone shaping mod (involves 2 resistos and 2 caps).

Thanks!

In General) Torres loves to tell you what your getting & how great! it will sound,But never mentions what your losing. If your a modder or tinker you already know when you change value of caps & resistors etc. There is always something gained & something lost. It's a game of give and take, Sometimes you lose more than you've gained? #2) He sells you the cheapest parts available. You pay $20 for a $1.20 worth of parts ( I guess the $18.80 is for his intellectual property?) The Champ 12 gain mod did do wonders to rid the amp of the 80's Buzz tones, But to my ears it seemed to load down or darken the clean channel? IMO the bread & butter of any Fender amp is the clean channel. Fender gain channels (until recently) was a just barley usable afterthought. People bend over backwards to make these O.D. channels into something. The flimsy PCB material Fender uses make for a horrible mod platform IMO! I spent most of my 20's w/t a soldering iron inside my fender SF Twin,Bassman ,Super 60 & Princeton trying to heat up the Normal channel. Now in my 40's (And a bit wiser) It's much easier to just find the right dirt box & leave the amp alone. After 20 years of screwing w/t fender amps I've discovered the best mods are Good speakers & Good Tubes

[eggman]

Re: Red Knob Fender Champ 12

Howdy,

I think most of us can learn something from KMCGuitars!