I'm an idiot and repeatedly kicking myself. Here's the story.
Earlier this week I accidentally fried my Creek 4330 being careless while swapping out speaker cables. Shorted one of the channels by not noticing that the spades were touching. Loud HUM when I turned on the amp, and I did not kill power soon enough.
Upon disassembly saw that one of the output caps was obviously blown, and one of the output fuses as well.
This morning I replaced that cap and the fuse. Powered it up while it was still disassembled on my test bench, and power came back on fine.
Like an idiot, instead of taking my time (and replacing the rest of the caps as I had planned to) I reassembled everything. (It's not important but my excuse was that the kids were causing havoc and I wanted to wrap up the project & help corral them 🙂 )
Upon reassembly, power would not come back on. When I took it back apart I saw my mistake - I hadn't even clipped the legs off of the new cap before reassembling, so I obviously shorted it on the chassis.
So - what did I blow up by doing this? It's not obvious to me; all of the fuses look fine and I'm not sure how to go about troubleshooting. Any advice (other than to not be an idiot in the future?)
Earlier this week I accidentally fried my Creek 4330 being careless while swapping out speaker cables. Shorted one of the channels by not noticing that the spades were touching. Loud HUM when I turned on the amp, and I did not kill power soon enough.
Upon disassembly saw that one of the output caps was obviously blown, and one of the output fuses as well.
This morning I replaced that cap and the fuse. Powered it up while it was still disassembled on my test bench, and power came back on fine.
Like an idiot, instead of taking my time (and replacing the rest of the caps as I had planned to) I reassembled everything. (It's not important but my excuse was that the kids were causing havoc and I wanted to wrap up the project & help corral them 🙂 )
Upon reassembly, power would not come back on. When I took it back apart I saw my mistake - I hadn't even clipped the legs off of the new cap before reassembling, so I obviously shorted it on the chassis.
So - what did I blow up by doing this? It's not obvious to me; all of the fuses look fine and I'm not sure how to go about troubleshooting. Any advice (other than to not be an idiot in the future?)
Loud hum... first suspects would be that you have zapped the output transistors on at least one channel.
It would be very strange to see a 'blown' output speaker coupling cap. They can sometimes have glue on them used to prevent vibration and fatigue of soldered joints. At least the fact it is AC coupled probably saved your speakers from getting fried.
So basic checks.
1/ USE A DBT (Dim bulb tester) before going any further.
2/ Power up and check the supply voltage is OK (bulb should not be lit).
3/ Check the DC voltage on the input (plus) side of the speaker coupling caps. It should be approx one half of the supply voltage for an AC coupled amp.
Have no speakers connected while testing.
If the bulb lights brightly from the outside (edit... outside! outset) then you have either zapped the output transistors (could be other collateral damage) and/or the rectifiers as Mark suggests.
It would be very strange to see a 'blown' output speaker coupling cap. They can sometimes have glue on them used to prevent vibration and fatigue of soldered joints. At least the fact it is AC coupled probably saved your speakers from getting fried.
So basic checks.
1/ USE A DBT (Dim bulb tester) before going any further.
2/ Power up and check the supply voltage is OK (bulb should not be lit).
3/ Check the DC voltage on the input (plus) side of the speaker coupling caps. It should be approx one half of the supply voltage for an AC coupled amp.
Have no speakers connected while testing.
If the bulb lights brightly from the outside (edit... outside! outset) then you have either zapped the output transistors (could be other collateral damage) and/or the rectifiers as Mark suggests.
Does the 4330 actually have any output caps? No...the big ones are the smoothing caps for the main power supply rails; C37, C38.
BTW, BUK 555 (logic level mosfets) are unobtanium now, so if required, IRL540 type are recommended.
BTW, BUK 555 (logic level mosfets) are unobtanium now, so if required, IRL540 type are recommended.
Attachments
Last edited:
Thanks for the replies guys. As advertised - I am an idiot.
Even though "have you tested the fuse with the multimeter?" is always the first question I ask to anyone who says "the fuses are fine", I hadn't done that.
After a good nights sleep & with a clearer head & eyes, I replaced the fuses (and trimmed the capacitor legs) and all is fine now.
Even though "have you tested the fuse with the multimeter?" is always the first question I ask to anyone who says "the fuses are fine", I hadn't done that.
After a good nights sleep & with a clearer head & eyes, I replaced the fuses (and trimmed the capacitor legs) and all is fine now.
