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Discussion Starter #1
So I, along with the help of a much more knowledgeable friend, are embarking on a Fender Champ build that's made up of a mojotone build kit, and a chassis plus transformers I got for free from a pal.
Started off by populating the board with the components. Everything in the kit was pretty on point, except there were one or two resistor values that were wrong. Luckily my pal had some more laying around!
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After we got good contacts we set it aside and started in on the chassis. Ended up having to widen some pre-existing holes with a drill press, and making a couple new ones for the sake of the layout, which is still pretty hectic. I didn't take a great picture of this chassis, but it has seen war and has the extra holes to prove it!
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The project came to a sudden standstill when we realized that the PT, although being meant for a Champ, does not have the secondary 5v wires to go to the 5Y3 rectifier tube (far right), just the 6.3v going to the 6V6 (center). So as it stands right now we are thinking of maybe throwing in a 6X4 rectifier and seeing how that goes, but that means drilling a new hole, probably above the 5Y3 and space is already very limited.. Anybody ever run into this problem and have a possible tried and tested solution that involves me getting to keep that octal socket and run at 6.3v?

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This is where we ended the night. Given the fact that it's a small chassis and everything is so tightly packed we decided to go the not-so-pretty route and run all the wires from here on in across the top of the board. The few that need to be ran from point to point on the backside still are. Probably going to mount the OT on the bottom portion of the chassis because it won't be in the way of how I want to mount it as a combo. Also, my red secondary wires from the PT were cut too short to make it to the (now obsolete) rectifier socket, and that's why you see them going from red to black on that little strip. It won't be the prettiest thing, and it still has a ways to go, but I am excited to keep at it and troubleshoot this main issue currently. Even though progress quickly came to a screeching halt, I am very happy and excited to finally be getting into amp building and can't wait to grow and learn from these set backs.
 

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Nice little fixture for holding the board you've got there!!
It's a little late now, but you could have just gone solid state rectification and not had a rectifier tube at all. Good luck with your first build :)
 

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It's hard to believe that so few components can sound soooooooooo good! Keep us updated please (with sound clips when it's finished!).
 

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I would be looking for a bridge rectifier. 5Y3 has a directly heated cathode so will elevate your 6.3vac to whatever your B+ is.
If you've had a stout PC power supply go south, you might find an adequately rated rectifier there in the junk pile.
 

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How about adding a little 5V aux. transformer for the rectifier heater? Never looked for one but I'd think they are small and cheap. (bridge rectifier mentioned above is also a simple solution)

Please turn that big blue cap around. It's a bomb waiting to go off installed backwards like that. :D
 

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You need to change tubes layout, it will save you time trouble shooting your project after. Preamp tube should be at far right. Easiest way, just close the hole with square piece of metal and redrill a new one for 12ax7 socket.What is high voltage of your power transformer ?
You might go with two diodes full rectifier instead of the rectifier tube. It wouldn't change the sound of the amp at all.
And JB gave you best advice, change the orientation of big filter cap first !
 

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Discussion Starter #9
Please turn that big blue cap around.
Goddamn, thank you big time JB!! I'd like to say I would have caught that before soldering it in place, but I'm surely glad you came into this here post and point that out just in case!!

I decided on doing a diode rectifier to rectify the situation and move forward, as it seems like the easiest solution that still yields for good tone. Basically the same rectifier style in newer champs and Epi Valve Jr's.
Maybe even try out this style that my friend linked me to... seems interesting!!

• Make a solid state rectifier - Tube amps: build, repair, modify
 

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Discussion Starter #10
Little update. So I decided to do some more wiring and I got about as far as I'll go on my own I think, leaving the wire work involving the transformers & rectifier. I'll wait until next weekend when my pal and I can get back together and work on it. Trying to make the wiring decently clean.
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Noob question, but if you look at the layout and see the type of speaker jack they've provided, what's the way of wiring it with the more common mono speaker jack as opposed to that one?

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Here's how I'm thinking of mounting the output transformer to the chassis, an idea I got from my Matamp combo, and the way I'm going to mount it on the combo enclosure won't have it in the way of anything.
 
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