During last 6-8 years that I've been using A75 and Zen amps, I had quite a few rectifier bridges failures. It always happened at start up, when one bridge just blew, tripping fuses. I have four A75 and 2 Zens and it happened on all those amps. The fact is, I was using CL-40 as inrush protection (as it was recommended in original article) but my capacitor banks were not really big (80,000u on average). I was also using surplus bridges, however, they were rated 35A.
So now when I'm using that elaborate discreet bridge on my upcoming Aleph X I would like to avoid any future failures and make sure my inrush protection works fine. The total capacitance per channel would be 130,000u. Is CL-60 enough protection? I was experimenting yesterday with resistors, but it looks like with class A amps fixed resistors don't work well, because of a voltage drop. For instance on my A75, 70ohm resistor generated 70V drop and the amp was only receiving 40V AC. So it looks like thermistors are the way to go. I was considering putting two CL-60 in series just to be safer.. Is it worthwile?
This are the bridges I was using so far.
So now when I'm using that elaborate discreet bridge on my upcoming Aleph X I would like to avoid any future failures and make sure my inrush protection works fine. The total capacitance per channel would be 130,000u. Is CL-60 enough protection? I was experimenting yesterday with resistors, but it looks like with class A amps fixed resistors don't work well, because of a voltage drop. For instance on my A75, 70ohm resistor generated 70V drop and the amp was only receiving 40V AC. So it looks like thermistors are the way to go. I was considering putting two CL-60 in series just to be safer.. Is it worthwile?
This are the bridges I was using so far.