Posted new P-P power amp design

[vinylkid58]

Originally Posted by nic6paul

I still have a full assembled board sitting here, just haven't gotten around to firing it up. I have it modified to run the 6HJ5s as well.

I just finished my board, all I have that will work are 6JM6's.

Do I need heat-sink compound for the n-channel MOSFET's? The data sheet doesn't mention anything about this.

jeff

[rknize]

Compound will help thermal conduction. You don't need an insulator, though.

[nic6paul]

Originally Posted by rknize

Compound will help thermal conduction. You don't need an insulator, though.

So the tab on the chassis mounted mosfets are not carrying any voltage?

**Just remembered mine are a different then the ones prescribed in the BOM. Mine are not the fullpack version If I remember correctly. It has been a while since I lasted looked in that box.

[bigwill]

This board is like the chevy small block of tube amps

[vinylkid58]

Originally Posted by rknize

Compound will help thermal conduction. You don't need an insulator, though.

Ok, thanks.

jeff

[athos56]

Originally Posted by pmillett

If there is enough interest, I'm not adverse to spinning a version of the board that has octal sockets... and making some other changes, within reason.

Food for thought...

Pete

I would buy 2..

[tubelab.com]

So the tab on the chassis mounted mosfets are not carrying any voltage?

If your mosfets have a metal tab, ASSUME that it is hot with voltage. It usually is. The mosfets that are totally encased in plastic are safe to use without an insulator. If you can get any rading with an ohm meter from the metal tab to board ground, an insulator is needed.

This board is like the chevy small block of tube amps

Hey, I'm a Mopar guy! But I will admit to tweaking a 350 or two, and even a 5.0, but the only V8 I currently own displaces 446 CI (a .030 over 440) and makes well over 500 HP.

I just finished my board, all I have that will work are 6JM6's.

With a little hot rodding (a hot cam and headers maybe) any of the 17 watt tubes can do 40 to 50 WPC.

[rknize]

Originally Posted by nic6paul

So the tab on the chassis mounted mosfets are not carrying any voltage?

**Just remembered mine are a different then the ones prescribed in the BOM. Mine are not the fullpack version If I remember correctly. It has been a while since I lasted looked in that box.

Right sorry. If you used the described part it doesn't need an insulator. If it has a metal tab, it needs to be insulated with a pad or mica+grease.

[rsumperl]

As long as we're talking Mopars..... I worked for Chrysler in Highland Park in the radio design group back in the mid 80's. Been a Mopar fan since. My toy is a 93 Sundance with a 3.8L V6 from a 2003 van. Heads are ported and polished, nitrous, and 5 spd from a 2003 Stratus w/the 2.7L V6. ECM has been custom calibrated. Exhaust feeds a catalytic, then straight back. Pipe size is 2 1/2".

Originally Posted by tubelab.com

If your mosfets have a metal tab, ASSUME that it is hot with voltage. It usually is. The mosfets that are totally encased in plastic are safe to use without an insulator. If you can get any rading with an ohm meter from the metal tab to board ground, an insulator is needed.



Hey, I'm a Mopar guy! But I will admit to tweaking a 350 or two, and even a 5.0, but the only V8 I currently own displaces 446 CI (a .030 over 440) and makes well over 500 HP.



With a little hot rodding (a hot cam and headers maybe) any of the 17 watt tubes can do 40 to 50 WPC.

[rknize]

Originally Posted by vinylkid58

I just finished my board, all I have that will work are 6JM6's.

I got 60WPC out of the "little" 6JN6's, but that was pushing B+ to 500V. At a more sane 450V, 40-50WPC should be a piece of cake. Very early in this thread, Pete mentioned that he had also tried higher voltages but opted back off in the name of hobbyist success rate (and probably reduced mortality rate).