DIY: Pass F5 turbo v2 initiated

Hi Friends,

From a long time, it was in mind to have nice class A amplifier. Pass Amplifiers don't need my introduction. It's well known to DIY circles. I am churning out all available material on forums.

As subject states I am referring this - http://www.firstwatt.com/pdf/art_f5_turbo.pdf

I went ahead buying PCB for my build. But unfortunately I find some issues as PCB tracks are thin as well as they are 305mm long, 5mm more than my heat sink. So I designed with following thought in mind.

1. For power and output it is both sides will be overlapping. size will be approx 295mmX42mm (subject to change)
2. All heat producing devices are equally distributed at one edge.
3. using thick copper with wider tracks on both side.
4. Avoid in-out crossing to avoid oscillation, mind this is wide band amplifier.

These are my layout with two proposals -
Proposal 1: This will have input at center and will be same layout used for left and right channel.

By boundry at 2012-08-17

Proposal 2: This will have input at once end and left - right will have different symmetric PCB.

By boundry at 2012-08-17
Let's discuss pro's and con's of these two approaches. Further story will unfold as this project make progress.

Thanks,

Subscribed!

Hi Om,you are now master of PCB layout.I request all members to provide your feedback.You may need to download pics and zoom to see them properly.

Regards,
Sachin

My view is that one should keep it simple. My vote is for centre input based Pcb. No point in having mirrored pcbs. Also please do not underestimate the heat produced by the outputs. It gets very very hot and requires absolutely well suited heatsink with vertical fin alignment.

Nice to hear that you have taken up the F5 project. I'm looking forward to you taking this forward to the build stage. I've subscribed to this thread.

I second Anilva's suggestion on having a single PCB. I have felt the heat that his F5 produces. In addition I am currently battling with a project having a heat sink and I am re-learning all my physics and electronics. Consider this - for F5 you would need a significantly sized heat sink, made of good quality material to absorb and dissipate the heat EVENLY, these are not very readily available. You would have to do with the ones available in the market. Their composition is not even, hence dissipation is irrregular. Hence to maintain the temperature steady would take some time. Anilva has more experience on F5 and can throw light better, but my current project, takes a long time to get up to stability and by then it is time to end my listen !!! So I have to switch on at least 30 minutes before listening time.

Of course the F5 turbo circuit may behave differently.

The second aspect is about aesthetics - the heat sink, since it is quite a large part of the amp has to be presentable. Of course here individual tastes matter, but then this is a matter to be considered.

I also would like to have an amp which I can build well, tune and forget. I dont want to monitor the bias day in and day out. It should remain rock steady. I expect others in my family to use the amp - not just me....

Ultimately I feel most of these can be achieved my making it simple.

A single PCB, devices on the edges, inputs in the center is good, but we have to make sure on the spacing.

My random thoughts....

Om,

Is it difficult to get the heat sinks made locally? There should be lot of small establishments who may drill aluminum piece into a heatsink of any shape and form, isnt it?

I am really looking forward to this project and hope to build F5 turbo some time in future.

Thanks

how to make your own heatsink - DIY Heatsink

doesnt look all that difficult. might give better results as you control everything, instead of buying whatever available from the market.

Talking of heat dissipation, a noob question. Why can't stuff like cooler master be used here? If they can work for gaming PCs they can work here as well.

Here's a crappy pic for inspiration :-)
The cigarette pack is for scale & the heatsink has its brother at the back