F5 Turbo Circuit Boards

[lhquam]

Originally Posted by a.wayne

20 x12 heatsink is not enuff......

Sorry, somehow the attachment got lost. Try again

I agree, unless you use a fan.

Here is a simulation using a single HeatsinkUSA E007 12 inches long with an air velocity of .679 m/s. The table show results with other air velocities.

[6L6]

Originally Posted by labjr

Anyone know if I can build 7 channels inside of one chassis for my home theater?

Yes, it's possible.

The heatsinks required would be jaw-droppingly large, even with a lot of forced air. Perhaps this would be a good application of wasted-water cooling, but your water bill would be immense.

The PSU would also be a challenge, but not insurmountable. Sourcing a big-enough transformer or two would be interesting.

[a.wayne]

How much Class-A bias ...?

[camshaft]

I realize I'm likely missing something, but I'm not sure why people are planning on trying to fit these amps into a single strangely large and unwieldy case rather than doing monoblock amps as many did with the Alephs running at similar wattages to F5T? Monoblocks allow you to simply have 2 more reasonably sized cases without having to worry about things like 20"-long heatsinks, where to buy them, how to combine them to get the size, how to assemble them in a case that isn't an eyesore, etc. Oh, and monoblocks have that 'serious business' look to them.
I guess I had wrongly assumed that monoblock cases would be typical for most F5T builds.

Austin

[ungie]

Originally Posted by camshaft

I realize I'm likely missing something, but I'm not sure why people are planning on trying to fit these amps into a single strangely large and unwieldy case rather than doing monoblock amps as many did with the Alephs running at similar wattages to F5T? Monoblocks allow you to simply have 2 more reasonably sized cases without having to worry about things like 20"-long heatsinks, where to buy them, how to combine them to get the size, how to assemble them in a case that isn't an eyesore, etc. Oh, and monoblocks have that 'serious business' look to them.
I guess I had wrongly assumed that monoblock cases would be typical for most F5T builds.

Austin

Plus you can split the N and P channel devices so that they are on separate heatsinks. This is exactly what I'm doing and is also why I'm doing my own PCB layout. That being said, I do appreciate the effort UKToecutter has been putting into this!

[Dane]

The heatsink concerns are making me nervous. Plus no help with matching devices from TECH DIY...
But I have a nice collection of PCB's for other amps so:
I'll take 4 amp and 2 PSU.

[ungie]

Originally Posted by UKToecutter

Also, It would be good if somebody could sanity check the BOM's for me.

Q7 and Q8 are reversed on the BOM.
Also, the Mouser part reference for R25 (10k) brings up a 10k7 part that is not stocked. The do have this part in 10k.

[camshaft]

Yeah, I definitely think it's great that UKToecutter and the others quickly got on this to come up with a working board! I just wondered what the arguments were in favor of a single big case vs monoblocks given the heat dissipation.

[skunark]

For the thermal simulations, is the mosfet placement considered here? If we could find the optimal placement on the heat sink that is chosen, then the PCB layout should reflect that.

[nrg2009]

Ungie has an idea. My aleph2 has large sinks with only 3 mosfets per sink. Splitting the board, or at least providing that option would be a plus.