Champ 600 Point-to Point Rewire! The first One?

[Mandopicker]

Well...here it is!

I decided to make it like Tweed Champ (5F1) Sounds great, but now the speaker is weak link.

I'll wait for Weber's 6"Alnico.





Slightly less than street for amp, $100 bucks and parts hanging around and its a one of a kind!

[Marc]

nice work!

Is the second pot to tweak the bias?

Marc

[Mandopicker]

Extra Pot in Champ 600

Yes, it is a 200 ohm pot for bias adjustment.

[JJGross]

Very nice!
When I saw the title of the post, I was wondering if you'd done what Fender did on he originals : have everything hard wired together and floating in the air just waiting for something to short out. ;D

Looks great, very clean.

Cheers!

[Mandopicker]

Like a 50's tweed with a tiny speaker.

Thanks for the Kudos...

Given the weak nature of the early models, as well as the point your brought up, I though just wiring it up based on a 50's tweed.

Recently reverse engineered the PC board and found that it is more like a 60's-70's Champ without the tone controls, I will probably try that schematic in there at some point to be more accurate.

At this point just having fun with the experiment. In its current form, it leaves a lot of room to customize. Next step is the output transformer to allow for 6L6, 4 and 8 ohm speaker outputs. Should be way more versitile.

Regards,

David

[HTH]

very nice job, no chance of squeezing an 8" speaker in there?

suppose you could always put a 1x12 under it with a G12H-30, that'd get things cooking.

[axpro]

I just ordered the supplies to do a similar mod last night! Seeing as it was a blackface/silverface type circuit, and i liked the sound (and i already have a tweed champ i love) i decided to go with a blackface circuit. vol, treble and bass. and i ordered a 6" ceramic from weber (Don't want to wait for the alnico!) Once i get the parts i'll wire it up and add a photo.

[Mandopicker]

BF/SF rewire instead.

Yes, I actually decided to make it a bit more simple as I already had a 73 Champ.

Go for it...Can't wait to see the photos.

Have fun...

[khelstrom]

Rectifier

Is that a 5Y3 rectifier I see in the picture? Also what is that I see to the right of the 6V6?

[Mandopicker]

Rectifier

Yes, it is a 5Y3.

Depending upon your perspective, I believe you are referring to the output transformer. (Stock Chinese version) Since the photo was taken, the OT has been upgraded to a proper Champ output transformer to match the (required) new Power Trans. (needed 6.3v fil wires for tube rect.).

You could avoid changing both by leaving the SS rectifier in the circuit.

Sounds perfect!

Thanks for the interest.

[khelstrom]

OT

Thanks' Where did you get the OT, Mercury? Dose it make a huge audible difference? I have a vintage 6" alnico speaker I'd like to use but it's 8 ohms. Ive read some places that I could get away with the miss match but I would ultimately would like to get the popper OT.

[Mandopicker]

OT

The output transformer I got from CE Distribution.

I also just wanted to be able to bolt the new OT in place. It fits the spacing of the orignal perfectly. Made the swap out a snap! It is much stronger and less "Farty" sounding.

For this experiment, I wanted to keep it 4 ohm, but I am intending to try a multi-tapped OT (4--8-16 ohm.) Try Weber or there is a number of Hammonds that are useful. Doing that, you can wire the amp up for both 4 ohm and 8 ohm. I think that is the real ticket for vesitility. (Though I plug my 600 into my Deluxe and boy is it cool. Makes a great head...and with an 8ohm out...unbelievable!

That said, I really liked the idea of keeping it with a 6" speaker, as I already have at least one of each size in other amps. I do like the tone, and larger size speakers can't really recreate the sound.

FYI
* After my experiment, my buddy decided to use a weber alnico 6 x 9 full range that is just killer. Fits well. He also used the Hammond 125E OT so that he could run a 6L6 and it really rocks. The OT is huge though, so be prepared to move stuff.

Making it pseudo P to P wiring makes all these experiments possible, so have fun!

[Howlin' Mad Mac]

Wow! That looks real sharp there. Could you share your schematic with the changes/mods you've added. I like the idea of an adjustable bias although I'm not quite sure how to incorporate it into my design (I'll be posting some pics soon.) I've also noticed what appears to be a silver mica cap hard wired to your volume pot (guessing it's a 250pf or 500pf cap) & thinking that might be something I'd want to try. The original sound of the Champion 600 was ok but I thought very ho-hum. I'm still working all the bugs out of my build but I must say the tone is an improvement but I still feel mine could use a bit more tweaking... You know the old saying: If it ain't broke... TWEAK IT! LOL

[CSPRINGER]

Beautiful small amp work !

When / If my Peavey 5 watter starts to have issues this is the king of build I would like to do. Please provide extensive narrative on the sound impact with each mod....

These tiny tube amps are fantastic.

http://music-electronics-forum.com/t14880/#post121189

[macpgh]

speaker

I would suggest that you put in a 1/4 jack female & then wire the stock speaker to the amp chassis with a 1/4 male. That way you'd be able to run a different speaker cabinet & use the unit as a head.

On the pittsburgh craigslist, there is a listing for a guy that has a blackfaced vibro champ that he has set up in a blond head cabinet & piggy backed on a 2-10 blond cabinet. Its a nice inovation, but his item is a bit way over priced.
I have my combo set up as mentioned above with the jack for the speaker out & run it on other cabinets besides the stock 8 incher. Mine was a silver faced champ somebody gave me. His mom got it at a yard sale for $5 a few years back.
On mine I cut the fixed baffle out but left enough material around the sides so I could have battens to screw down a floating baffle for remounting the stock speaker.
Years ago while cleaning out an old guys house that was a friend of the family. He had a wood shop in his basement & he gave me all his tools as he was bound for the old folks high rise at the time. He played guitar, and he gave me his guitar & amp. SO while cleaning out the basement up on a shelf above his work bench was a wooden box looking thing with a wooden handle on top......looked all home made. I figured it was one of his old projects & basically didn't think much of it as we were cleaning out & couldn't take everything out of the shop.......some stuff had to be thrown away. Well I looked at the wooden box briefly & saw that it had a speaker in it & a chassis...stenciled on the chrome was fender. It was an old model 26 with a 10 inch speaker, and I tossed it in the trash as I had no clue what it was at the time & neither did anybody there.

The guy that gave me the champ had a buddy give him an old amp he found in the trash on garbage day. He was driving down the street & noticed a wooden box sitting on the curb so he stopped & grabbed it. So they were playing with it & it had this gnarly sound to it but they had no clue what it was as the chrome chassis lost all the marking on it & it had no covering on it & no back panel. I didn't know what it was at the time either, but later found it was a early 50's fender delux & the first to go with 9 pin pre-amps. I was hoping to liberate it before they trashed it, but no such luck this time. They blew the speaker & gave it to somebody else.