And mucking around with bridge rectifiers. (look at that bodge with the matrix board)
Maybe some extra context is necessary
I only got this amp 2 weeks ago and most of the mods had already been done by the previous owner, including those rectifier bridges.. Many of the mods I would've never thought of and some I have reverted in the meantime. The diodes are definitely not cheap and they do the job so I'm just going to leave them be. At least the aluminum piece offers some decent cooling. He also had added 2 AC line filters which didn't make any sense to me. One was sticking out at the back and he had also completely changed the wiring around the transformer/power switch...
As for the film caps: he had installed some cheap 600V LCR monsters (see pic). His reasoning was that this capacitor position was in the signal path. I did consider Wima's, but can't install them at this position with their short leads. The smaller 160V Mundorfs, for audio use, seemed like a good compromise. They're not much larger than the 100v Wima's and they have long leads which made them easy to solder (with the necessary isolation on the leads of course)
I must say, when I just received the amp, I was a little disappointed compared to my Quad 405-2 which I had just sold. The Rotel sounded pretty harsh.
I only just finished working on it yesterday. I got rid of the outboard ac filter, did a full recap - this time including the power filter caps and reverted all the wiring to original, according to the service manual.
This is going to sound very cliché, but after all the work it does sound in fact sound remarkably better. It has more body and the harshness has been reduced into nice presence & sparkle. All in all I'm very happy with the way it sounds now so no regrets about the Quad anymore.
I'm still thinking about replacing the small orange pp caps with polystyrenes. Any other suggestions welcome!
!! Old picture of the state I received it in