Jump to content

Champ Project Question


unclej

Recommended Posts

well, two questions actually...is there any reason why the power transformer can't be mounted with the wires pointing up, inside the chassis instead of down and coming into the chassis through a hole and grommet? i've got to cut a hole in the chassis to accomodate the "bulge" anyway so it will fit either way.

second, on the 5f1 layout i see that the blue lead on the output transformer goes to the 6v6 and the red to the 16mfd cap. i see by the schematic that either the black or the yellow goes to ground and the other to a 22k resistor but neither layout nor schematic stipulates which. if i was guessing i'd say black to ground. would i be right?

Link to comment
Share on other sites

i knew there was something i was forgetting to tell you....yes, it's the fender replacement # P-TF22905 8 watt, 3.2 ohm

Link to comment
Share on other sites

:D The reason I asked is that the Fender Champ OTs I'm used to seeing don't have a yellow wire, just red, blue, green and black! Red goes to power, blue to the 6V6 plate, black goes to the speaker jack ground lug (and ground) and the green wire goes to the speaker output jack hot lug and the 22K resistor in the feedback loop. Where did you get that transformer?

The only problem with putting the power transformer inside the chassis is heat build-up, but most people prefer it hanging out in the air so it can get sufficient circulation to keep it cool.

Link to comment
Share on other sites

i got it from ce distribution. it sounds like the yellow on mine would go to the same place that the green on yours would go. on this one the red and black are opposite each other at one end of the transformer and the blue and the yellow opposite each other on the other end. or to put it another way the black would be in the upper left, the red in the upper right, the blue on the lower right and the yellow on the lower left when you look down on it from the top.

for the power tranny i wasn't going to mount it inside the chassis but in order to mount it a hole had to be cut in the chassis to accomodate the bulge or hump in the transformer. since it could be mounted with the wires pointing either down or up i was wonder if there was any reason not to mount it so that the wires were already in the chasis.

Link to comment
Share on other sites

shouldnt' matter at all i have mounted them in multiple ways best contact the maker to be sure but i dont' see why not.

Link to comment
Share on other sites

shouldnt' matter at all i have mounted them in multiple ways best contact the maker to be sure but i dont' see why not.

thanks. i couldn't think of any logical reason not to but i haven't gotten to the point of trusting logic in electronics yet. :D

Link to comment
Share on other sites

You know about the old headphone trick, right? Install your power transformer in the chassis and temporarily tape off the secondaries and power it up, then hook up a set of headphones to the output transformer's secondary (tape off the primaries), put 'em on,and listen to the noise level. Move the OT around untill you find a spot that's both as quiet as possible and practical for your layout, mark it, and mount it.

Link to comment
Share on other sites

now see, that's why you're my hero :D i can tell you all the tricks of building decks and remodeling but i still feel like a baby when it comes to these amps.

thanks

Link to comment
Share on other sites

I got that particular trick from the guys over at AX84 - I've got reams of info in text files from taking notes on anything I'm not familiar with that comes up while I'm surfing. Maybe I'll live long enough to absorb it all and be really good at this stuff! :D

BTW, speaking of things I don't understand very well, have you seen the Tone Lizard site? he's got more info there than I could digest in a year, written in plain english, and with a dry sardonic humor that makes it easy reading.

Edited by lovekraft
Link to comment
Share on other sites

Thanks guys, I've learned more about electronics (one of my glaring weaknesses, thats what I get for being a civil engineer) From uncleJ's questions and Lovekraft's answers than I have anywhere else around. I also just spent half an hour at that site, and bookmarked it. Thanks again, someday I may even get around to trying more than just basic wiring :D

George

Link to comment
Share on other sites

Thanks guys, I've learned more about electronics (one of my glaring weaknesses, thats what I get for being a civil engineer) From uncleJ's questions and Lovekraft's answers than I have anywhere else around. I also just spent half an hour at that site, and bookmarked it. Thanks again, someday I may even get around to trying more than just basic wiring

we do it on purpose...actually i already know all this stuff and this is the way we get all the info out to the newbies... :D

thanks lk..i just added them to my favorites and will explore them thoroughly.

Link to comment
Share on other sites

Lovekraft that is the coolest thing ive heard for along time. that will come in so useful.

just to check, which of the OT secondaries would you connect the headhpones to? id guess 16 ohm but not for any intelligent reason lol.

that will come in mighty useful when i get to building my P1

Link to comment
Share on other sites

I assume you'd use the highest impedance available, but I doubt if it makes much difference. Any hum being induced would be in the whole transformer, so any impedance tap should let you hear it. It's a good question, though - I wonder which tap would be the loudest, or if the impedance of the headphones would make a difference? :D

Naw, that's way too much math!! Maybe one of you guys can figure it out empirically - I don;'t have the patience for it! :D

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...