Hello everyone
I am a newbie to your forum and a relative newbie to diy home audio. However I do have some electronics experience.
I stumbled apon your site when i went looking on the net for a reason as to why my 2 sc480's blew all of their fuses.
Anyway from the start. Built 2 amps (SC480's) and two power supplies and one controller(Altronics kit K5562) to power 2 12" subs. Got it into a box and plug it all in to the rest of the system and it seemed to function quite well for about 20 mins with music (all but a sonic boom when it was switched on). After that I turned it off because I forgot to set the quiescent current as per the distructions in the sillicon chip mag. After doing this and getting the right voltages I decided to plug it back in.
After switch on the subs made some funny movements and then sound went really quite from them and the fuses blew at that point (I Believe) anyway checked the transistors and in circuit they look dead shorted so decided to take one out and one 2955 and 3055 on each amp we cactus.
So after this I replaced the faulty transistors and checked the rest out of circuit to make sure they were fine and they were. So anyway with no signal connected and the resistor soldered across the fuse holders I set the quiescent current and let it sit powered for 20mins and then readjusted it.
Then I plugged the signal in and turned everything on and the speaker did the same funny movement and all the fuses blown again. I have not checked the transistors but I think they will be blown again.
Any help would be greatly appreciated.
Cheers
Christian
I am a newbie to your forum and a relative newbie to diy home audio. However I do have some electronics experience.
I stumbled apon your site when i went looking on the net for a reason as to why my 2 sc480's blew all of their fuses.
Anyway from the start. Built 2 amps (SC480's) and two power supplies and one controller(Altronics kit K5562) to power 2 12" subs. Got it into a box and plug it all in to the rest of the system and it seemed to function quite well for about 20 mins with music (all but a sonic boom when it was switched on). After that I turned it off because I forgot to set the quiescent current as per the distructions in the sillicon chip mag. After doing this and getting the right voltages I decided to plug it back in.
After switch on the subs made some funny movements and then sound went really quite from them and the fuses blew at that point (I Believe) anyway checked the transistors and in circuit they look dead shorted so decided to take one out and one 2955 and 3055 on each amp we cactus.
So after this I replaced the faulty transistors and checked the rest out of circuit to make sure they were fine and they were. So anyway with no signal connected and the resistor soldered across the fuse holders I set the quiescent current and let it sit powered for 20mins and then readjusted it.
Then I plugged the signal in and turned everything on and the speaker did the same funny movement and all the fuses blown again. I have not checked the transistors but I think they will be blown again.
Any help would be greatly appreciated.
Cheers
Christian