F5 pcb group buy...

[tjolle62]

F5 Pcb kit.

Hello Peter, Sorry if i missed some vital info for not reading all postings,
Is there still available pcb's for this great amp ?
If yes please give me a price for all boards that i need for this project and
where can i find a component list ? i downloaded the manual but didn't find
anything there exept for a schematic ,
Best Regards from Sweden
Kjell.

 

[Peter Daniel]

I have plenty of boards available. Amp boards have been listed here: http://www.diyaudio.com/forums/showthread.php?t=140306

The matching PS boards here: http://www.diyaudio.com/forums/showthread.php?t=149672

You will need one amp board and one or two (if dual mono) PS boards. All additional info will be included with the boards.

 

[kp93300]

bridge rectifier and monoblock transformer ?

Hi Peter
See the attached image -Will this do ?
I am planning to build F5 as monoblock.
Will 2 EI transformers of 0 18 Vac output at 10 amp per transformer sufficed ?
Thanks

kp93300

 

[Peter Daniel]

The bridge rectifier is fine.

Since each transformer produces single 18V, you would need two of them either per mono amp or stereo amp.

 

[ra7]

Peter,

Do you have any F4 boards left over?

 

[Peter Daniel]

I only have two sets left and keep them for my personal use.

 

[Jaac]

Boards are in thank u !

 

[kp93300]

dimension and layout

Hi Peter,
Planning to copy your design for the build.
Hope you can see the attached image and give me the dimension .

Thanks
kp93300

 

[kp93300]

Position of th1 and th2

Hi All,
If i lay out as in the picture attached. The Q3 and Q4 is fixed to the side of heatsink and the board is on the bottom of the chasis. The link is by extension wires.
If I lay out as described,do i need to shift the position of Th1 and Th2 onto the heatsink also?
Thanks again
kp93300

 

[vdi_nenna]

Hi Peter,

I was checking out your F5 board ground scheme and was wondering if it's ok to send the power supply ground to earth ground. I see that the F5 speaker output ground is tapped off the power supply ground. Should they not be connected at the same earth ground point? Does it matter?

Thanks,

Vince

 

[Peter Daniel]

Power supply ground should be connected with Chassis/Earth ground through thermistor as per F4 PS schematic (page 15): http://www.firstwatt.com/downloads/f4_om.pdf

Power supply ground is your main output ground reference and that's why it's tapped off the PS.

On the amp board you will only see input signal ground with two pads: one to connect ground from RCA socket, the other for a wire to PS ground (reference).

 

[chatziva]

sorry to impose, I am selling my f5 and other stuff below, if somebody is interested

http://www.diyaudio.com/forums/showthread.php?p=1923747#post1923747

thanks

 

[vdi_nenna]

Hi Peter,

Been thinking about building another F5 (using your boards), but this time with only 1 power supply and transformer, ultra-fast diode bridge and no circuit protection. Probably will use Caddock or Vishay. Never used these before and wonder about their sound qualities.

Have you tried the F5 without the protection circuit, if so, is it worth the risk of shorting the amp? Would you keep the 4.7k thermistor out of the circuit?

Aside from a binding post to chassis short and speaker + - wires shorting, anything else I should be worried about? ...I guess that's bad enough!
Any and all connection wire changes should be made with the amp off?

Thanks,

Vince

 

[Peter Daniel]

Actually, I removed protection circuitry right on a first day I've built the amp and there was a noticable difference (to me it seemed for a better).

I've built another amp also without protection. This picture shows the board without protection parts

I don't think there is much risk in shorting binding posts, you can always spread them 2" or so to be shure

It's always a good idea to turn the amp off when doing connections.

 

[toufu]

I agree with Peter, I took out the current limiting circuit and it sounds a lot better, more clean, and more musical (for the lack of a better word).

 

[vdi_nenna]

Ok, thanks Peter. I will be placing an order for a stereo set, 1 power supply and 2 bridge rectifier boards for TO-247 type diodes.

Thanks Peter and everyone,

Vince

 

[Peter Daniel]

Got your payment and will ship tomorrow. Thanks.

 

[Sangram]

Hi Peter, I've not yet received my boards - did you ship them recently or back when I sent the payment?

Thanks for your help

 

[Sangram]

^^Please ignore the above. It is painfully obvious that I have to post something like this an hour before the postman drops it off. Thanks for the PCBs

Edit: And double thanks for the rectifier boards, a nice bonus even though I am using the KBPC-style monolithic rectifier. I'm sure I'll find a use for these at some point, so thanks again

 

[vdi_nenna]

Antek Tranformers

Anyone know if the Antek Group buy price is still available for the F5?
I emailed, but no response from John at Antek.