Rob Robinette's Micro Champ EF80 Power transformer EU equivalent question.

RicciAntoni_07

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Yeah, your choice is to cut the end off and do it captive by tripping back the main black housing and exposing the inner wires. With the IEC you will have to solder to the pins on the back of the IEC housing and then make sure they connect to the appropriate places. You should be able to find a generic guide on IEC wiring easily, then just think of what you solder as the equivalent from the instructions you have. Something like this.
View attachment 977807
Yeah, your choice is to cut the end off and do it captive by tripping back the main black housing and exposing the inner wires. With the IEC you will have to solder to the pins on the back of the IEC housing and then make sure they connect to the appropriate places. You should be able to find a generic guide on IEC wiring easily, then just think of what you solder as the equivalent from the instructions you have. Something like this.
View attachment 977807
Cool! I am advancing! I stripped the power chord and understood my confusion and why it wasn't more of a instruction on what to do with that--it's pretty straightforward :) I have a question about the orientation of the OT--I have read that with the non toroidal PT that you should orientate the two transformers so to reduce the hum and general performance. I am drilling holes now in my chassis and seems like with the toroidal PT that I am using, the orientation of the OT wouldn't matter as much. Is that correct? Also I read there are times when you would keep those two transformers maybe on opposite sides of the chassis. Do you have any thoughts on that?

Thanks!
 

2L man

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Toroid power transformer electromagnetic stray field is strongest straight out of center hole so when it is mounted flat it should make least interaction with OT.
 

Len058

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At least 5 cm from the edge of the OT and you'll be fine. Position it close to the powertubes and B+ to prevent long wire runs. Twist the wires to prevent hum.
 

RicciAntoni_07

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At least 5 cm from the edge of the OT and you'll be fine. Position it close to the powertubes and B+ to prevent long wire runs. Twist the wires to prevent hum.
Toroid power transformer electromagnetic stray field is strongest straight out of center hole so when it is mounted flat it should make least interaction with OT.
Thanks!! I set it up flat, and will put it away from the OT.
 

RicciAntoni_07

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Wow!!! So helpful! Critical. thank you! I will be doing this very very soon. I think because I got the wrong size chassis I will wait until later this week when it arrives. Since I am a beginner I think this smarter to have a bigger chassis, at least way more space than the one I originally bought. I really appreciate the precision of this photo--that helps a ton with explaining. We need more clear photos explaining stuff, I rarely see pics on forums.
Hello again, I unfortunately got very frustrated with this and had to give it up for a little while, while i worked on other things. I am now ready to try to build this. I am beyond confused with the power transformer portion of this build.

1. i see that my two green wires are the 6.3v.
2. i see that the two red wires that are not heat sinked together are the secondaries.
3. black=0 yellow=120v purple=230v rd=240v

I am confused about what to do next in terms of the photo. I think i got the answer for the power chord colors for europe--I have a blue, a brown, and a green/yellow. ( so i will go back through the thread and try to find that.

I'm lost what goes where to hook up the PT to the board. and which wires go to the power and connect to the power cable. I am dying to be able to do this, i just need help with a few things.

In your picture you are measuring the PT but i don't have a multimeter like yours and I don't know what i would even do with the measurements.


This is my guess--the 230v goes to the power switch. the black wire connects to the power chord--not sure what color yet.
The two red secondaries go to the board to the rectifying diodes.
Green goes to the light and then to pin 4 of v2 and to 4, 5, 9 of v1.

how far am i off?

:)

sorry if this beginner level is annoying. I feel like i am almost there!! Will be a dream if i can get this to work!

Thanks again!
 

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Len058

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Depending on what kind of sockets you've got in your country, you don't have to worry about the polarisation of the wires. Green/Yellow is ground. The rest can vary. I live in the Netherlands and we can plug in a power cable, two ways. You never know which wire is neutral and which is live. It's really important to properly ground the amp but for the rest it will work either way.

You can always use a simple current finder tool to find the live wire, if you can only plug in one way. The live wire should go to the fuse first.

The green heater goes to 4 and 5 on V2

Best to get a multimeter, you'll need it to check the voltages. To be safe you can start with the red and black from the transformer. If the voltages on the tubes are too low you can use black and purple.

Tip: Uncle Doug on youtube. He explains how to measure stuff and how it all works


Simple current finder touch the metal dot in the red cap with a finger, touch the connection you want to check with the screw side of the thingy, if the light glows there's current.:

spanningszoeker.jpg
 
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RicciAntoni_07

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Depending on what kind of sockets you've got in your country, you don't have to worry about the polarisation of the wires. Green/Yellow is ground. The rest can vary. I live in the Netherlands and we can plug in a power cable, two ways. You never know which wire is neutral and which is live. It's really important to properly ground the amp but for the rest it will work either way.

You can always use a simple current finder tool to find the live wire, if you can only plug in one way. The live wire should go to the fuse first.

The green heater goes to 4 and 5 on V2

Best to get a multimeter, you'll need it to check the voltages. To be safe you can start with the red and black from the transformer. If the voltages on the tubes are too low you can use black and purple.

Tip: Uncle Doug on youtube. He explains how to measure stuff and how it all works


Simple current finder touch the metal dot in the red cap with a finger, touch the connection you want to check with the screw side of the thingy, if the light glows there's current.:

View attachment 1009834
thanks. I'm in France. Not sure if we have the same as you, but i would guess it's the same. I"ll get this thing.

for the rest, i think i understand, except the neutral--in the photo it looks like the power cable neutral wire is connect to a wire on the PT. Would that be the 0v on the PT?
 
Last edited:

RicciAntoni_07

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Location
europe
Depending on what kind of sockets you've got in your country, you don't have to worry about the polarisation of the wires. Green/Yellow is ground. The rest can vary. I live in the Netherlands and we can plug in a power cable, two ways. You never know which wire is neutral and which is live. It's really important to properly ground the amp but for the rest it will work either way.

You can always use a simple current finder tool to find the live wire, if you can only plug in one way. The live wire should go to the fuse first.

The green heater goes to 4 and 5 on V2

Best to get a multimeter, you'll need it to check the voltages. To be safe you can start with the red and black from the transformer. If the voltages on the tubes are too low you can use black and purple.

Tip: Uncle Doug on youtube. He explains how to measure stuff and how it all works


Simple current finder touch the metal dot in the red cap with a finger, touch the connection you want to check with the screw side of the thingy, if the light glows there's current.:

View attachment 1009834
hello again, probably a dumb question, but in order to find the live wire will i need to plug in the power chord?

also--in the photo it looks like the power cable neutral wire is connect to a wire on the PT. Would that be the 0v on the PT?
 

Len058

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for the rest, i think i understand, except the neutral--in the photo it looks like the power cable neutral wire is connect to a wire on the PT. Would that be the 0v on the PT?
Yes, correct. The neutral goes to black.

in order to find the live wire will i need to plug in the power chord

Yes, be careful not to touch the exposed wires with your body.

France has polarised sockets (the ones with the pin). As I understand, the rules are not very strict but the live wire should be on the right. It should be the brown one but as I said, you can't really trust how the stuff is connected..
 

RicciAntoni_07

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Yes, correct. The neutral goes to black.



Yes, be careful not to touch the exposed wires with your body.

France has polarised sockets (the ones with the pin). As I understand, the rules are not very strict but the live wire should be on the right. It should be the brown one but as I said, you can't really trust how the stuff is connected..
thanks!
 




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