Champion 600 Upgrades

New mod. Sheffield 12 " cab for $100.

 

An L-Pad is only $5 so I'd like to try it as long as it doesn't hurt the amp. I don't want to play it cranked at night, I just need it to be a little quieter. With my Strat, mine breaks up with the volume at about 4 after all the mods so I don't need it to be too much quieter.

 

G'day fellow Fender fans from Funtasia,
Here's what my amp looks like now. The knob on the left is the modified 1meg pot that replaced the R19 lift switch. The Mercury Mag OT is back in action, moved away from the PT and at a 45 degree angle. I also replaced the heater wires and routed them away from the pcb. I haven't put it through it's paces yet. Thats about it, for now at least. Not sure if I'll do any more mods, she's pretty complete. Not sure if I'm too keen on the Holy Grail though after all :neutral:, I might try some other method there later on down the track.
Cheers,
Andrew.

 

A little rundown of my upgrades:

- Negative feedback resistor connected to on-off switch (Always lifted, small but nice effect)

- R19 connented to on-off switch (I prefer stock, but it's lifted when I'm in the mood. Large effect and nice to have if you don't use gain pedals)

- Changed the speaker to a 6" Jensen (Better tone, less farty)

- Changed both tubes to new ones from TAD (Noticable effect on tone)

- Changed caps to orange drops, same values (Maybe some effect, or just placebo...)

- Changed the OT to a OT10SE from musicalpowersupplies.com and added a impedance selector switch. This gives me the possibility to run 4, 8 or 16 ohm speakers. OT was much beefier, seems more reliable and had to be rotated 90 degrees to fit.

- Got a custom-made color-matching 12" extension cabinet from Mark at http://afcustomcabinets.weebly.com/ Properly jointed wood and removable back panels for sound versatility. I will fit a Celestion G12H in this MF'er this weekend. 100dB sensitivity will make this amp loud! Can't wait to test it out!!!

- I've also got a selection of NOS 12ax7's and 5751's to test out when I've loaded the cab.

- I've also built a mini pedalboard with the "essentials", to be covered in same tolex as amp. I'm using a Hall of Fame reverb, a Polytune Mini tuner, a Mooer Pure Boost, a Mooer Green Mile and a Crazy Horse Fuzz. Loads of different gain tones and some room to round off the tone.

- I've also built an 8 ohm L-pad into a Hammond pedal housing. It does the job, maybe I'll get use for it when I install the new speaker, but with pedals and stock size speaker it's not needed.



The amp has now got a much better tone and a lot of versatility. With a 12", the tone is much better, and I guess it will work fine in a band setting if you're not relying on a superclean sound. For small trips where you need to pack light, the internal speaker will do the job for practicing and low-volume jamming.

 

Some pics!

 

More pics of the cab, custom made by Mark.

Lovely!

 

Pretty cool Magnus.
I've actually been toying with the idea of building a cab to fit 4 x 6" Weber AlNiCo Sigs and wiring them in series & parallel to keep it at 4ohms.
Not sure yet, as that is 4 x 15watt speakers. I need to do some serious research. I don't want to cook my amp.

Andrew.

 

As long as the speakers have a total load of 4ohm, you'll be fine! It is also quite simple to change the output transformer, which gives you more versatility in speaker setups.

4x15=60w will maybe result in less character from the speakers, as they're not breaking up. And they might give you a more nasal, boxy sound than 1x12" or 2x10"? 1x12" 15w Celestion Blue might be a better option? Or two 10" 8 ohms wired for 4 ohm? Just hypotheses, as I've never tried the setups....

 

Some info on parallel vs series and impedance: http://www.bustedgear.com/faq_Speaker_wiring.htm

I would say the Champion 600 requires a 4 ohm load with the stock OT. I've tried with 16 ohm load, and several components were destroyed after 10 minutes. Never tried with 8 ohm, but I wouldn't take the risk.

 

Now that is the sort of thing that would stop me from my next move (above in red). That makes a lot of sense.

I've already changed the OT for a Mercury Magnetics & installed a choke( the full monty from FARGEN ) and all the other odds & ends.
I might email Josh Helmberger at WEBER and see what else they can come up with regarding 4 x 6" spkrs ( with lower wattage), I'm not ready to give in just yet. Lucky I got a good job !

Andrew.

PS: I don't need to do these things as my C600 can put it's dukes up now, it's the hobby thing. Keeps the mind active and all.

 

It's not working again. I took out C10 so it wouldn't be too distorted and buzzy with my Les Paul and now it doesn't make a sound. I didn't touch anything else.

 

Wire type (and more...)

Hi you all Champ modders
I have a Champ since a few month, perfectly happy with it stock, but reading this forum, you gave me the curiousity of modding it a bit, just for the fun.

I'm going to :
-change the grill cloth and the tubes (Tung Sol 6V6, NOS 12AX7). No need to bias the amp that's right?
-put a switch to select between the stock R19 value (15k) and 47k to have more mids
-increase R7 value (22k) to open the sound and make it more dynamic
-make the "alnicomagnet AA764 mods" (standby, hum reduction, orange caps in the tonestack)
-change C10 with a 2,2uF cap, to keep it clean even after 6/7
-change R11 with a 1.8k to run it less hot (I've read it won't affect the tone, and preserve the power tube) not sure about this one
-perhaps a speaker upgrade too with a Weber 6" alnico or ceramic (late breakup, i like it clean) don't really know which one to choose, if someone has something to say about it, I'll be glad to read it.

So, I think I'm ready, read everything I could about the subject, but I have just one question left :
Which type/size of wire do you use for the connections between R19 and the switch?
I see 0,14mm2 ; 0,2mm2 ; 0,5mm2 ; 1mm2 (which are I think respectively 26, 24, 20, 17 AWG) surface sections in the shop here in France where I'm going to buy the parts.
Thanks in advance for your answers
Gilles

 

Hi muadgil and welcome from this side of the great pond .

Lot's of great vids on YouTube on this subject .


i've just changed the stock speaker to a Jensen and put other ( JJ ) tubes in .

 

G'day Muadgil,
For the wire size, it won't matter much but the rule that I use is "make sure the wire is the same diameter as the lead on R19 or thicker".
The same principal as used for replacing a fuse, etc.

Andrew

 

Thanks guys for the help.
My order is done now, waiting for the parts to make this great lil'amp even more likeable
Finally I went for 20 AWG stranded which seems to be an average value that fits with everything.
I'll wait before the speaker swap, see if the results off the electronical mods are enough (I don't feel that the stock speaker sounds that horrible)

 

Its not a twin but its not a toy I plugged into a 10"EV an actually used it
at practice sounded great also plugged into a 212 loaded with eminence
Texas heat. I put a ts in front an it worked great. Not as portable so I didn't
Solve your problem but it can get loud and sound good at lower volumes
Its a great little amp in my opinion

 

Hi everybody,

Here is my modified champ 600 : weber alnico speaker, JJ tubes, OD capacitors, some switches and a L-pad attenuator.



All feedback appreciated, and i'll be happy to aswer questions regarding my mods. now i need to improve my playing !

 

nasdak very cool. So did you make that attenuation setup?

 

Thanks,
As i could not find a 4 ohms Lpad i used a 8 ohms 100w stereo, wired in // so it makes a 4 ohms load.
Really easy !
You don't need a bypass switch because it's totaly transparent a 100%

 

Here is a demo of my C600 (pictured in post #923 above). 1st time I've played for a while.

http://youtu.be/8bCUE1xx1dw