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F3 and F4 Clone PCB Reissue group buy, also F5 PCBs

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Peter Daniel said:
I'm constantly thinking how to implement CPU coolers with those boards. The task is harder than I expected, due to specific requirements for computer applications: it just can't be combined in any reasonably sized package.

For copper affectionados, this is what I came up with today: 5 kg of pure copper heatsinking, not enough I'm afraid ;)


Aint that pretty$$$$$$$$$$
 
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F3 Boards

I believe Peter has sold out of all PCB's except the F5 boards.
There were a 100 stereo sets ordered, not sure if anyone wants to give up their pair. I don't:D

You could start a different Wiki then the one mentioned in the beginning of the thread, assuming Peter is willing to make another run of 100. Occasionally these things show up in the trade or for sale section.
 
These are 15000uF / 35V....

It depends on your PS design. If you're implementing it just like in the F3 service manual, with dual 18VAC secondaries transformers + 2 caps in series / parallel and a total of 8 caps then these will be fine.

However, if you're going to use Peter's PCBs then the answer is no. These boards will have to be powered with 36VAC and your caps won't handle it.

For this configuration look for 50V or 63V capacitors.
 
F4 and F5 PS question

Hello Peter and all.

I have a few questions about the F4, F5, and the PS for bang for the buck BOMs. I have searched and searched and I am running out of time to build mine and two friends amps. I have to build three F4 and four F5 amps before I move overseas in two weeks.


1) First the PS, I have the Panasonic 39000uf big caps and 3W Vishay resistors for the PS and would like to know:
(a) Which caps to use for C1, C2, C5.
(b) What resistors to use for R1 and R2?
(c) Also, what rectifiers ould you suggest and do I need 4 or 8?


2) The F4 boards next... Are C5 and C6 just low pass filter caps?

3) F5 questions.
(a) Which thermistor to use for TH1 and TH2?
(b) Other than R5-8 and R11 and 12, can 1/4 resistors be used?
 
Here's the link for diodes: http://www.diyaudio.com/forums/showpost.php?p=1237660&postcount=240 You need 8 diodes in F4 PS and 4 diodes for F3.

On this page you will find explanation how to connect bridges to power supply: http://www.diyaudio.com/forums/showthread.php?t=99351&page=13

R1, R2, C1, C2, C5 do not apply here, this is a separate option when this PS board is used for completely different purpose (regulated supply in line stages)

C5 and C6 are additional smoothing caps on F4 amp board: you may use them or not, also, choose any suitable size that fits the board (100uF may be a good starting point)

Somebody was suggesting this Mouser part# as suitable thermistor: 871-B57891M472J I'm not using thermistors at all now.

There is no problem to use 1/4 resistors there. I recommend Dale CMF50 from DigiKey.
 
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