F5 power amplifier

Jump to Latest
#4,583
f5 w/Parallel Output IC

I am trying to create my own pcb for the first time and I would appreciate any and all advice or critique of the attached layout. I am laying out a board for an F5 with parallel output trans and no limiting circuit.

I am using free software from express PCB, but is there a better inexpensive program.

Cheers Nick
 

Attachments

  • f5_ll_v1_1.jpg
    f5_ll_v1_1.jpg
    80.6 KB · Views: 968
#4,584
#4,585
Re: f5 w/Parallel Output IC

npapp said:
I am trying to create my own pcb for the first time and I would appreciate any and all advice or critique of the attached layout. I am laying out a board for an F5 with parallel output trans and no limiting circuit.

I am using free software from express PCB, but is there a better inexpensive program.

Cheers Nick
Click to expand...

When considering a layout, the run from the drain of the JFET's to the gate-stopper resistors, and the run to the MOSFET gates from these resistors should be as short as possible.
 
#4,586
Jack, thanks for that tip

However if I was using stripboard, I'd need to connect Q5, R3, R15 and P1 to the junction of Q1 and R13 (I'm assuming short connections are required here too, if they are not it makes life a little simpler). This automatically makes it a pretty long trace (5 -6 holes on a stripboard, the pot will take 2-3). The second condition is more easily fulfilled, I can probably solder R13 directly to the gate.
 
#4,587
Stereo-Layout

Hello everybody, i am new here.
Are there any concerns about this following Layout?
Should each side have its own connections, or can i try this?
Please let me know.

Just used a copystation, a red marker, and prog. "Paint".
 

Attachments

  • shared connections.jpg
    shared connections.jpg
    67 KB · Views: 939
#4,590
Re: Re: f5 w/Parallel Output IC

jackinnj said:


When considering a layout, the run from the drain of the JFET's to the gate-stopper resistors, and the run to the MOSFET gates from these resistors should be as short as possible.
Click to expand...

Thanks for the advice. Which side of this is most critical, the jfet to gate-stopper or gate-stopper to MOSFET? I think I will most likely only be able to accomplish one side of this recommendation since I am hoping to distribute the MOSFETs further apart on the heatsink.
 
#4,594
I have a run of 0.300 inch (7.6mm) from gate-stopper to mosfet. The F5 layout shown on 6-moons spreads the MOSFET's heat better. Still I have 4 of these guys running -- from mounting hole to mounting hole the spread is 3.800" = 96.5mm and eyeballing the First Watt amp it would appear to be 2x this at least.
 
#4,595
Jack, what about the other end? I can probably get within a few millimeters myself on the gate side, but will be difficult on the drain of Q1. There are at least 4 solder connections to be made on that 'track', and this will make it really tough to get better than 15mm or so, maybe a bit more.
 
#4,596
I can definitely get shorter traces from the jfet drain to the g-s resistors if I move the jfet further toward the MOSFETs, but this gives me a much longer input trace from R1 to the jfet source. Should I worry about the input trace length? I was trying to keep it as short as possible.

N
 
#4,597
npapp said:
I can definitely get shorter traces from the jfet drain to the g-s resistors if I move the jfet further toward the MOSFETs, but this gives me a much longer input trace from R1 to the jfet source. Should I worry about the input trace length? I was trying to keep it as short as possible.
Click to expand...

I wouldn't lose any sleep over it.

😎
 
You must log in or register to reply here.
Top Bottom