I'm not posting the schematic but look here:
https://vianegativa.wordpress.com/2012/ ... schematic/
If they kill it, PM me and I'll send it.
Anyway, R39 was roasted just beyond identification just like here and various other places:
https://www.blackstaramps.com/forum/vie ... 5&start=10
Reffering to TR2 & TR3 on the right side of page 2, I changed the stock STK830s with more STK830s even though the schem says IFR830s. Changed R38 & 39 with 2 watt replacements (had these on hand). Good enough, right?
No! I drilled some small holes between the pads for TR2 & TR3 and cleaned them out. I did see some quirky continuity between them in the 9K range prior but not after. See the pic below.
Set the bias. 46mA across R33 (according to the factory). Set the balance at -21.3v per side of the pot.
Now time to test it. It had no sound from the speaker jack before, now I get "decent" sound... BUT:
TR2 & 3 are now radiating 194 degrees F... no heat sinks on these stock. The two above mentioned resistors are carrying a little less than 1/2 watt. No sweat there. Should I get some IFR830s instead?
I don't see any reports of that high of a temp on those transistors (I hate even typing the word out let alone dealing with their demise).
Does this sound insane? 194 degrees F... Am I just paranoid? Heat sinks maybe? Not much room but I will do it. Thoughts? How do I use the datasheet to determine if I use the heatsink?
It may be the rum talking but you do know that I love you guys, right?
