Cary Audio CAD-280SA V12R

@oldhvymech
He was a Mac tech for his daily job, but did mods and built amps all kinds of crazy rebuilds and such on his own.  Retired now.  Built all his own amps, that kinda guy. I helped him on design and build of three pairs of large horn Altec/Onken copy  speakers, so she shared a little over the years. Was fun to listen to little updated 2A3 and 300B amps he modded.  He helped me to make my former V12R sing, was really nice.

Yes, "R" larger trans and "Bz7" TV tube, funny.  

Monos:
I'm not as up on the V12 mono blocks. Slightly different layouts.

Since KT150s came out I went a completely different direction, never pursued it any further with Cary monos after. 

I don't even run the 12BZ7s, maybe some like um, sure a lot better tube to choose from, I have some chinese 12ax7 that blow the doors off them
less than 5 bucks a valve...same cheap valve Mac uses in their new stuff.

I just received a 12 pack of 6V6s and 2 8 packs of 6L6 under 200 for the whole lot.

Installed the little 6V6s, hour or so of playing... Just wonderful, transformer is running cool a could be. Whole unit dropped 30 degrees.
looks like there is a good summertime combo after all. Although the 4 Volvo el34s were pretty impressive.  A dozen ways to go...Seems like there all pretty good..

Regards..

I have a V12R I've owned for a number of years and would like to do the Hexfred Rectifier installs.  I already replaced the coupling caps but wasn't sure about where the Hexfreds go so I left it alone. Could someone shed some light on which of the existing parts should be replaced with the Hexfreds and how many? Do you happen to have a pic of the Hexfreds after they were installed? Thanks.

Hexfreds, like a schottky.  I think I know what your talking about, at least what they look like.  Is it for a power supply upgrade? fast acting quick recovery diode. I think this unit has it, but that would be strange that the silver fish audio 1 would still be there.  I took a few pics, the audio 1 are a good cap.  I call it "The Marantz sound", they were famous for those things..
Sound good actually, not sloppy, but VERY tubie..

So which caps did you use in your V12?

Need someone that has had it done AND knows what it looked like before and after, I'll find a pic or two.. Keep lookin' someones bound to chime in..

There is a guy named Mike Samra, one smart cookie, red sock, green sock guy.  Look up the name, big Mac guy..He might know about it and will talk your ear off once you get hold of him..Walk you right through it..

I'll see if I can find him..


Regards

A couple of the posters above had mentioned they had the Hexfred upgrade done so I was hoping one of them could shed some light.
I replaced all the electrolytic caps with generics of same values and replaced all the non-electrolytics with Mundorf MCAP ZN 630VDC caps of same values.
I have always biased each side at 210ma. Below 210ma the sound degrades but above I don’t hear any improvement. Above 250ma and you will start blowing fuses.

You MUST get a digital multi-meter that measures milliamps as that analogue looking dial meter Cary sells is not precise. You have to wire one of those larger headphone type jacks to plug into your amp and connect to your multimeter. Cary advises that you disconnect everything from amp before biasing, even the speakers. You will not damage CARY amps running them without a speaker load connected.
Also, the 3A Filament Fuse should be a 4A slow blow. Cary printed the wrong value on the back of the unit. In the schematic for the V12R is confirms it should be a 4A slow blow.