Cary V-12 blowing capacitors


Hi,

I have a pair of Cary V12 monoblocks one of which is blowing capacitors. It was initially sent in to cary as it was the 3 Amp fuses. They initially replace the capacitors and sent it back. It worked briefly and then started blowing fuses again. It went back to Carrie and this time they replaced both transformers. It did work for a couple of weeks but yesterday when I turn it on and was in the standby mode I heard a crackling noise from inside the amp and 3 amp fuse blew again. There was a large puddle of oil in the back of the amp which is from the capacitor. So it seems like something is still not repaired correctly which is causing the capacitors to blow which maybe is why the fuses are blowing. With it being to cary twice and they are not really sure what's happening has anyone else had this issue?
whataboutbob1

Showing 1 response by decooney

The new techs there at CA need to read and relay the updated manuals they never re-published. All caps in those amps not only require replacement, the transformers are now starting fail. If there are hexfred diodes (upgrade) inside the amp, check and replace all too if they are 10+yrs old. I had a bank of them go bad in my former V12R only after a few years. A few colleagues have been having to replace their transformers in V12/Rs, melted, particularly the big transformer. Also, if anyone has been messing with the bias and driving it up too high, you cannot trust the LEDs on each bank / per side, use a multi-meter.

The original V12/R manual shows up to 280ma per side. Working with one of the prior designers there we concluded 280 was way too much, 230 was tops and 200ma per side still sounded great and helped to save output tubes. There later versions had 4amp fuses, and others higher at 5. Proceed with caution on that. A competent tech can repair it, finding one willing to do it can be a challenge in some areas, so some people end up sending it back to Cary. Best of luck.