Hi everyone,
I just salvaged a few LM4766T and a 25-0-25 transformer from an AV amplifier that someone was getting rid of.
Then, I ordered a board on eBay to have some fun building a gain clone.
I'm far from being an EE, all I have is a bit of knowledge reading this forum in my break time.
It's just a board, I will have to order all the parts to populate it, but I also found a picture of an assembled board.
The picture of the board I get is only one side but by looking at it I have a few questions, and I also would like to hear any comment anyone might have, it's always useful.
1: The two inductors (Thiele network I guess) they don't attach to the same position. One goes to Rout and one goes to Gnd. Why is it like that?
2: The two 1k resistor looks like capacitors on the assembled picture. Am I mistaking?
3: 470uF seems like a very small filter cap. Would that be OK?
4: Looking at the assembled picture it looks like the missing resistor value would be 2k. Does that make sense?
When I'll receive the board (two week waiting already) I'll post pictures of the real board with both sides of it.
I just salvaged a few LM4766T and a 25-0-25 transformer from an AV amplifier that someone was getting rid of.
Then, I ordered a board on eBay to have some fun building a gain clone.
I'm far from being an EE, all I have is a bit of knowledge reading this forum in my break time.
It's just a board, I will have to order all the parts to populate it, but I also found a picture of an assembled board.
The picture of the board I get is only one side but by looking at it I have a few questions, and I also would like to hear any comment anyone might have, it's always useful.
1: The two inductors (Thiele network I guess) they don't attach to the same position. One goes to Rout and one goes to Gnd. Why is it like that?
2: The two 1k resistor looks like capacitors on the assembled picture. Am I mistaking?
3: 470uF seems like a very small filter cap. Would that be OK?
4: Looking at the assembled picture it looks like the missing resistor value would be 2k. Does that make sense?
When I'll receive the board (two week waiting already) I'll post pictures of the real board with both sides of it.
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The joys of kits !
I remember my first Maplin kit in 1980.
Two components swapped on the parts list caused havoc......
Cant you get in touch with seller ?
I remember my first Maplin kit in 1980.
Two components swapped on the parts list caused havoc......
Cant you get in touch with seller ?
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I suspect that the Lout is actually Gnd and the position the inductor goes to is actually Lout. As to the missing resistor I'm not sure.
To be honest the layout doesn't look great anyway. You may be as well to find a complete kit for a first effort.
To be honest the layout doesn't look great anyway. You may be as well to find a complete kit for a first effort.
I agree. The connections to the low-value R's bear it out. Just relabel those points.
Jan
It's possible that 470uF for decoupling close to the chipamp is ok. I think a lot of people use 1000uF there, and it's possible 470uF may work just as well on many circuits.
Some use a smaller value to decouple also. Using a 220ufd or 330 ufd close to the chip to give stability.
I like a 470 ufd with a 22 ufd right to the power pins is what I have been using on the last half dozen builds. Makes me feel better.
I like a 470 ufd with a 22 ufd right to the power pins is what I have been using on the last half dozen builds. Makes me feel better.
Thanks everyone
nigelwright7557 I will do that.
ubergeeknz once I get the board it will be Easter to verify. And the goal is to give those LM4766 a second chance so I’ll cross my fingers but a complete kit would defeat the my purpose.
Jan.didden, thanks for reinforcing ubergeek point.
Panelhead, lol makes you feel the bestest😉 do you have a picture of the 22 uF placed on a board? Would 2.2 uF works too?
Tcpip I’ll stick with 470 thanks for confirming their OK.
nigelwright7557 I will do that.
ubergeeknz once I get the board it will be Easter to verify. And the goal is to give those LM4766 a second chance so I’ll cross my fingers but a complete kit would defeat the my purpose.
Jan.didden, thanks for reinforcing ubergeek point.
Panelhead, lol makes you feel the bestest😉 do you have a picture of the 22 uF placed on a board? Would 2.2 uF works too?
Tcpip I’ll stick with 470 thanks for confirming their OK.
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