WTB: F4 PCB boards

[korben69]

F4 Boards

Hi all !

If it's not too late count me in for 2 amp boards and 2 PS boards

Thank for your help.

Phil

 

[winslow]

I would like a pair of amp and PS boards too...whom do I need to contact?

 

[Peter Daniel]

When I receive the boards, the payment info will be posted. There should be enough for everybody. No need to contact me now.

 

[jleaman]

I would like a pair of amp and PS boards too...whom do I need to contact?

Peter Daniel 😀

 

[winslow]

Cool cool...sounds like a fun project!

 

[Jaac]

Yes, he did. I'm sending the files for boards fabrication today. Attached is the final version of the layout, the size is 2.35 x 3.35"

Peter I'm looking at your pcb but it looks like the two input resistors are not correct ?? R2 seems to connected to the wrong side of R1 In the original schematic R2 goes from imput to ground what schematic did you used ? F4r0 ?

gr Jaac

 

[Peter Daniel]

Indeed, in the latest schematic shunt resistor is directly at the input, while for that section I was using schematic from F4 manual where shunt resistor is connected directly to gates of intput FETs.

 

[chrismercurio]

Heat sinks

http://www.diyaudio.com/forums/showthread.php?s=&threadid=52637

Would the heat sinks at the above link be adequate for the F4?

C

 

[jleaman]

Re: Heat sinks

http://www.diyaudio.com/forums/showthread.php?s=&threadid=52637

Would the heat sinks at the above link be adequate for the F4?

C

no, to small.

 

[chrismercurio]

that's what I thought

the price is not too bad though,
C

 

[Variac]

I think 2 per channel would do it, but I'm no expert.
It would be easy because the output devices are split- 3 to each side.
As you say, they aren't a bad price.

 

[marsupialx]

It would be nice to hear a status report. Pretty quiet around here.

 

[Peter Daniel]

Last time I checked, the boards were in production. When I receive them, I will make an announcement here.

 

[twitchie]

which jfet

Just wondering which jfets people are planning to use here - I tried to find 2SJ108BL, but didn't have much luck (so I have 2SJ74BL instead).

Stephen

 

[chrismercurio]

Output devices...

I don't have the ability to buy and test output devices to match them in quantity for this project. Are there any takers who are willing to do such a thing?

Also, I mentioned in an earlier post that I put together a BOM and only one person asked for it. I wasn't just offering it to be cool....I was also hoping to receive feedback on accuracy. Thanks,

C

 

[Zen Mod]

Re: Output devices...

I don't have the ability to buy and test output devices to match them in quantity for this project. Are there any takers who are willing to do such a thing?

.....................
C

http://www.diyaudio.com/forums/showthread.php?postid=935102#post935102

 

[korben69]

As a newbie I need your help... Would you please have a look at my BOM, taken from Nelson's F4 Service Manual. (thank's Nelson)
For some parts there's no refs specified... fell a little bit lost 🙁
I suppose Q8 to be 2SK370 and Q9 a 2SJ108, not shure...
What kind/brand/series of caps are you using, same for the 35A/200v bridge ?
Thanks.

 

[chrismercurio]

See...

http://www.diyaudio.com/forums/showthread.php?postid=1198333#post1198333

 

[twitchie]

As a newbie I need your help... Would you please have a look at my BOM, taken from Nelson's F4 Service Manual. (thank's Nelson)
For some parts there's no refs specified... fell a little bit lost 🙁
I suppose Q8 to be 2SK370 and Q9 a 2SJ108, not shure...
What kind/brand/series of caps are you using, same for the 35A/200v bridge ?
Thanks.

As Chris points out, there was a mistake and Q8,Q9 got skipped in the numbering for Peter's layout

I used Panasonic FC caps for the amp boards and Panasonic THSA for the PSU (and get 35V or higher, not 25V)

For my bridges, I used IXYS

From your BOM, you could get away with a single 330VA for both channels, but you'll need 2 bridges - provided the transformer is reputable like Plitron maybe (Nelson stated he uses 300VA)

If you're going to use 6 caps, try for higher value like 20000 - NP's power supply uses 8 caps @15000 for 120 000 total.

 

[korben69]

Thank you twitchie.

Your highlights my ignorance !
Q8 and 9 are not used and it doesn't matter just as Peter says here Post #139.

I'm in trouble, I don't understand Peter's PSU board.
I see 3 groups of caps : C1 to C4 - C5 & C6 - 4 big caps untagged.
Can't find values in Nelson manual. I was just thinking, is it a CRCRC model ?

I see R1 to R4, but R9 & 10 are missing too.

For the IXYS, would you please give me the ref...

I'm planning two mono PSU and two transfos, so do I really need a 330Va for each channel (BTW 2 bridges). Is it correct or could I reduce the Va value ?

Sorry if I annoy you. My skill is weak as you can see. 🙁