Have a general question. Is there a way to mod the amp for more power output? My pf 800 goes into thermal protection. Idk why. 2x15 “1,200 watt” chained to 4x10 “800 watt” both cabs 8 ohm. I’m not able to play at full volume. Maybe 3/4. Anything more it goes into thermal protection
Thanks for the video. Gave me some new things to check! Mine works but the volume is too low. i have to crank it up to max to get half the volume of an Ampeg B115 (150w) volume in the same speaker. Checking some voltages I found that i'm getting +80v/-80v where, according to the schematics, should be +55v/-55v. But i cant find anything faulty. I think this overvoltage is burning the R98 and R94 next to the Q10 and Q13. I must be missing something.
@@GrumpytechieNet Humm thanks. It is weird. I think +-80v is suspicious be because of the frying of these R98/R94. everytime they are in. Why would schematic says it is +55? ... Maybe its the revision difference. the pad is the first thing i checked. It is ok. I will check the preamp section now. thanks for the tips
Yeah, seems so, but I'm still unsure what made it pop like that as I can't find any other problem with the amp, and even shorted FETs in the power amp doesn't cause that fuse to pop as the power supply is very well protected. My only theory is that someone selected the wrong line voltage.
Looks like the slot in front is to help push some of the hot air out of the box, along with the holes in the bottom.
Have a general question. Is there a way to mod the amp for more power output?
My pf 800 goes into thermal protection. Idk why. 2x15 “1,200 watt” chained to 4x10 “800 watt” both cabs 8 ohm.
I’m not able to play at full volume. Maybe 3/4. Anything more it goes into thermal protection
Thanks for the video. Gave me some new things to check!
Mine works but the volume is too low. i have to crank it up to max to get half the volume of an Ampeg B115 (150w) volume in the same speaker.
Checking some voltages I found that i'm getting +80v/-80v where, according to the schematics, should be +55v/-55v. But i cant find anything faulty. I think this overvoltage is burning the R98 and R94 next to the Q10 and Q13. I must be missing something.
Hmm, I seem to remember that the rails were around 80 volts on mine as well. Could it be a problem with the preamp or that the pad is engaged?
@@GrumpytechieNet Humm thanks. It is weird. I think +-80v is suspicious be because of the frying of these R98/R94. everytime they are in. Why would schematic says it is +55? ... Maybe its the revision difference.
the pad is the first thing i checked. It is ok. I will check the preamp section now. thanks for the tips
A lot of People have the same problèm with the fuse
Yeah, seems so, but I'm still unsure what made it pop like that as I can't find any other problem with the amp, and even shorted FETs in the power amp doesn't cause that fuse to pop as the power supply is very well protected. My only theory is that someone selected the wrong line voltage.