F5 power amplifier

[tinitus]

Are they not usually in the smaller range, alike C-core

[gaborbela]

Hello

If you com pair the two picture you can found many great information .


Greets

[tinitus]

I wonder, is it really wise to mount switch diode bridge on same heatsink as outputs
It gets quite hot

[tinitus]

Originally Posted by gaborbela

If you com pair the two picture you can found many great information .

They appear to be different, regarding the Q5/Q6 limiter and trim pot
I didnt know Cviller made more versions

[gaborbela]

Hello Tinitus
You right , but the rest of the layout is the same .
I said I found many great information because I was searching some information how and were to connect the ground !
The resistors on the Smyslow board for me is a great help .
Now I know more now about the F5X ground due to the pictures , so I can go on and make my PC board for the high power F5X . I have the cvillier F5 board (based on the blue board ) I post the right pictures now !
You can see the rest of the board is the same .
Greets

[gaborbela]

Also these drawing can be a help to .
Just very important to pay attention probably not all the resistor values correct!

Greets

[bobodioulasso]

The 100k resistors are certainely necessary in order to state the Jfets gates dc null voltage.
The input cable ground connection is an other thing...
...The central node excepted (crossed connexion) this is twice the stock F5!
Should M1/M5, J1/J3, M2/M6, J2/J4 be matched?
Setting the biases wouldn't be a little tricky? Do you know how you will proceed?

[gaborbela]

Hello
To set up the bias I will use the resistor trim pot parallel like the original F5 .
The same way how Patrick did it .
Also you right all those parts you named must be matched .
The power mosfet(s) have to be matched as close as possible since I'm planing to use 3pair .Otherwise probably I would have offset problem and not the type of sound I 'm looking for .
Also I will fallow Patrick calculation on the resistor values .
I believe it is possible to be done to get the X advantage .
Greets

[bobodioulasso]

I was speaking about matching the two sides of the X.
I am thinking about one way to set the bias:
Grounding the X node momentaneously gives the equivalent of 2 stock F5.It is then possible to set the biases separately following the usual process. (may be to a lower value for starting) then unground the node.
Just an idea.
How did Patrick proceed?

[osscar]

Hello for all,

I've started the construction of F5 amp and I received almost all parts.
The supplier has sent me to me irfp9240 from Vishay and 240 from International Rectifier (IR).
Should I ask to exchange IR to Vishay (like it is in my order ) ? Or IR FETs is also ok for this amp from (sound quality i mean - datasheet 1:1 )?
Other thinks going more or less ok -case and PCB still in production PSU board is almost done here is picture :




thanks.