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

[KT]

Hi,

I just put my name on the wiki for 1 stereo pair of F3 boards.

I also put my name in for 2 PS boards. Is this the right number of PS boards if I want to have one PS board for each channel?

I look forward to the group buy.

Thanks,
KT

[khundude]

How many F4 boards do I need for a balanced amp?

[Peter Daniel]

Two boards

[gjorgji]

Added 2 PS and 2 F4.

[Tea-Bag]

Originally posted by KT
Hi,

I just put my name on the wiki for 1 stereo pair of F3 boards.

I also put my name in for 2 PS boards. Is this the right number of PS boards if I want to have one PS board for each channel?

I look forward to the group buy.

Thanks,
KT

For F3,

I think you can just break think the Power supply in half here, as it's plain C-R-C. The F4 needs a v+ and v- power supply. so can upwards of two power supplies for one amp.

I beleive the PS in Firstwatt site is wrong, but I am not sure. I think 35v tranny to CRC will give ~45 volts. the 18v +18v is near the same, but I dont think 25v caps works here.

[Tea-Bag]

Originally posted by khundude
How many F4 boards do I need for a balanced amp?

4 total or order 2 pair....

This pic from Adrej helped me with star grounding and understanding the balanced setup of the F4. I am not sure if we can do the same thing to F3. I presume not.

Adrej uses an attenuator in there, so assume just from signal to in. XLR pin 1 to right, Pin 2 to left, Pin 3 to ground.

[Zen Mod]

Originally posted by mithomas


4 total or order 2 pair....

This pic from Adrej helped me with star grounding and understanding the balanced setup of the F4. I am not sure if we can do the same thing to F3. I presume not.

Adrej uses an attenuator in there, so assume just from signal to in. XLR pin 1 to right, Pin 2 to left, Pin 3 to ground.

if you want balanced F3 - then build SUSY F3 - thread is somewhere around

[Tea-Bag]

True, True -

ZM, you can kill the horse possibly on this.
Can we use two F3 amps to make balanced F3, or is it only possible with some sort of related negative rail thing?


Yes, I plan on Susy F3 thingy as soon as someone else agrees first to build it. Also thinking about LU head amp vis EUVL as well - something for work.

[MEGA-amp]

mithomas,

The pic of the balanced setup for F4 is way to small, would it be possible to post a bigger one?

thanks,
John

[Zen Mod]

Originally posted by mithomas
True, True -

ZM, you can kill the horse possibly on this.
Can we use two F3 amps to make balanced F3, or is it only possible with some sort of related negative rail thing?


Yes, I plan on Susy F3 thingy as soon as someone else agrees first to build it. Also thinking about LU head amp vis EUVL as well - something for work.

as I said in related thread - you can make SUSY F3 without neg leg in supply , paying the price with implementing input caps ...........

and - yes - you can make one SUSY from one stereo F3 , just toss these redundant parts out , and solder few more as dead bug on heatsink