[jdkJake]

So, not sure if you can tell or not from the photos. The smaller of the two boards, the one the boards are actually mounted on is 12inches by 12inches.

That should give you some idea of scale. It is also the exact size of the Par metal case I am considering.

 

[jdkJake]

Hmmm. I think it is in the right orientation on the rails PS schematic. Is this the one you mean? Anode should go to ground and cathode to the -30V rail. Yes? No?

The schematic is right. I read it wrong. Sorry for the fire drill. User error on my part.

 

[sachu]

Nice..i just ordered a 12x12x4 par metal enclosure for this amp.

 

[runeight]

So, Jeff, how does the amp sound after a few hours? Was it worth the build?

 

[jdkJake]

So, Jeff, how does the amp sound after a few hours? Was it worth the build?

Shhh.... I am still listening, one of my favorite songs just came on....

 

[funch]

Quote:

Shhh.... I am still listening, one of my favorite songs just came on....

     Now that's funny right there.  BTW, what's the board's dimensions?

 

[jdkJake]

     Now that's funny right there.  BTW, what's the board's dimensions?

About 4 and 1/4 inches by about 5 and 7/8 inches. The actual measurements are posted somewhere in this thread, but, that should give you a general idea.

 

[runeight]

Board is 110mm W x 150 mm L
 
Edit: change to 110mm

 

[jdkJake]

Okay, seems to be warmed up again. I had to shut it down to use the stove to make dinner.

In any case, the heater voltage and MOSFET bias is steady as a rock. No issues there. As for the heatsinks, keep in mind these are 2 inch heatsinks and room temp is 77 degrees F (25C). Measure is at the top center of each heatsink:

MOSFETS: ~45 to 47C
PS: ~40 to 42C
Heater PS: ~35C

 

[cobaltmute]

Quote:

Okay, seems to be warmed up again. I had to shut it down to use the stove to make dinner.

In any case, the heater voltage and MOSFET bias is steady as a rock. No issues there. As for the heatsinks, keep in mind these are 2 inch heatsinks and room temp is 77 degrees F (25C). Measure is at the top center of each heatsink:

MOSFETS: ~45 to 47C
PS: ~40 to 42C
Heater PS: ~35C

Seems not too bad - especially for the PS considering that is a 32V transformer as opposed to a 30V.
 
Current outside temp is 11C.  I just need to open the window to keep it cold.

 

[jdkJake]

Lucky dog. We have the AC cranked to get it down to 25C. Brutal summer this year after a most cold winter (at least for Florida).

The power supply is barely breaking a sweat. The torrid itself is pretty warm. The flat washer on the center screw that holds down the top plate is running about 51C.

 

[jdkJake]

Time to call it a night. I didn't get to measure the DC offset as I said I would. As they say, tomorrow is another day. I will do it then and post the results.
 
Thanks to all for the kind comments regarding the build. It was a fun build. I really had a blast!
 
Couple of parting shots (as I cannot help myself

)...
 

 

 

[fishski13]

Jake,
looks great!

 

[stixx]

Yes, excellent work...
 
The measured temp on the toroid hold down screw and washer keeps me thinking... will overspec the transformer to 400mA most likely...
51C is a lot and you have yet to case it up.

 

[fishski13]

Quote:

Yes, excellent work...
 
The measured temp on the toroid hold down screw and washer keeps me thinking... will overspec the transformer to 400mA most likely...
51C is a lot and you have yet to case it up.

screwing the TX into aluminum vs wood chassis will bring the temp down a bit, but yes, 51C is quite warm.