Anyone built ESP P68 300W amp?

Tazzy said:
I'm building it to power a Infinity Kappa Perfect 10 in a sealed enclosure.

About the P68:

I'm building it with the extra output transistors.
For the PSU I'm planning to use a 500va with double secondairies at 40v. I'm planning to use 2x 56uF and a 2Mh coil between the caps for each rail.

At the risk of being padantic, surely you mean 56,000uF (56mF) and 2mH (2MH = 2,000,000H!! as apposed to 2mH = 0.000002H).

Just correcting so the new guy doesn't make the craziest decisions for his amp parts.

Hope this helps. ;)
 
And I am Jonathan M :)

Just signed up :)

Feel free to post comments/questions etc. Rod was very helpful whilst building (though I didn't bug him too much :)

I just used the 6 output devices, and it's running off a 300W amp with 6000uF of filtering per rail.

Have yet to receive the driver for the sub, so can't comment too much on the power output etc.

For the Heatsink, it's a 300x75x50mm job from Dick Smith Electronics here in NZ (Cost US$15) It was drilled and tapped.
Heatsink get's warm, but no where near hot. One thing to watch is the driver heatsink. I originally made mine to Rod's specs, but have found it gets quite hot as it is. (You can hold on to it, but it is uncomfortable) I bolted the smaller one onto a piece of aluminium U-tubing and now it runs quite a bit cooler. I'd suggest making a bigger driver heatsink and bending it so as it bolts to the main Heatsink.

PM me if you want more info on anything.
 
Re: And I am Jonathan M :)

Jonathan M said:
Just signed up :)

Feel free to post comments/questions etc. Rod was very helpful whilst building (though I didn't bug him too much :)

I just used the 6 output devices, and it's running off a 300W amp with 6000uF of filtering per rail.

Have yet to receive the driver for the sub, so can't comment too much on the power output etc.

For the Heatsink, it's a 300x75x50mm job from Dick Smith Electronics here in NZ (Cost US$15) It was drilled and tapped.
Heatsink get's warm, but no where near hot. One thing to watch is the driver heatsink. I originally made mine to Rod's specs, but have found it gets quite hot as it is. (You can hold on to it, but it is uncomfortable) I bolted the smaller one onto a piece of aluminium U-tubing and now it runs quite a bit cooler. I'd suggest making a bigger driver heatsink and bending it so as it bolts to the main Heatsink.

PM me if you want more info on anything.


Where did you get your toroid?
 
Toroid...

Hey Optical,

Got the toroid new from Jaycar for $70 - they had a sale a while back. Around $95 (Same as DSE) normally. It's only a 300VA job - you'd probably need more if you are using the extra output transistors for some more power.

Most of the rest of the stuff was from Surplustronics and Sicom - all new. Went to surplustronics today but didn't see any cheap toroids there :(

Jonathan
 
skinnyboy: best thing to do when you have questions of that kind is to get the data sheet for the device from national semiconductor!

I've built this amp, but I made a huge booboo and botched some power supply wiring. I'm pretty sure I fried at least a couple of those BIG transistors (finding mica washers for devices that big turned out to be difficult!). Therefor now the amp is on my shelf where I can look at it and mutter to myself.

JohnR: yep they are sortof sandwiched, and yep it's most advisable to tap the hs, if not at least drill some little guide holes and somehow self tap.

Those of you aussies who are going to build it, don't waste your $'s getting a huge toroid from Jaycar! Try Harbuch electronics who you can visit here . even when you include freighting it, they are the cheapest source (by far) that I've found.