Cary Audio CAD-280SA V12R

I used a meter and biased them to 35ma per tube . I believe you can use the little red lights and do about the same thing . Turn the adjuster till the light comes on and then just back it off until the lights next to the tubes goes off ( or vice versa I don't remember ) . You can only bias a bank of tubes so just get it close , it will be close enough . Also , don't try to tighten the little lock nut on the bias screw . It will just throw it off , just barely tighten the lock nut before you bias , set the bias and it wont move . If you use two or 4 tubes per side either use the front 2 or 4 sockets or the rear two or 4 sockets . I had the replace the fuses in the back as they came a little too small rating from Cary , sorry again cant remember the details .  I used electro harmonix and some Russian tubes recommended by jim McShane ( cant recommend these as they had no highs ). I will see if I can remember more....lol . 

If I may suggest to those with V12Rs,

Output Tubes:
Don’t be so quick to yank/replace/chuck those Ruby’s for others, some were the actual Shuguang EL34-BSTR tube version which sounded really good in that amp 1) if it’s biased right and 2) if you have really good vintage EL84s and 6922 or 12BZ7 tubes up front 3) have the right preamp/tubes in front of the V12R.

Bias/LEDs/Meter:
My local tech was a retired 40-year McIntosh tech, helped me to upgrade my V12R. He noted it’s not necessary to crank up bias to the recommended 285ma in the original owners manual (old / false / was never updated online). We called the prior designer at Cary together and noted having to drop it down to quite a bit or risk blowing the 4amp fuse periodically. Ended up with 5amp fuses, later. BUT, no longer an issue or need when we dropped it down under 220ma. Yes, as I recall, 35ma (per tube) and 210ma (per side/channel) was about right, sounded good too. Helps the output tubes to last longer too, don’t forget that part! No need to light those LEDs up, use a good meter, and those LEDs are not all that accurate or in sync with each other.

Input/Driver tubes:
The "R" version allowed for 12BZ7 (TV tubes), and IF you get a good vintage matched pair RCA or Sylvania, it does add interesting tone, rasp, and texture to the music - something Dennis Had came up with in the R. In a brief conversation via email, Dennis mentioned he still owns one, or diid a few years ago.

UL/Triode switch:
While the Triode/Ultralinear switch was cool in the V12R, i never felt UL was at the same level of sound as a regular non-switchable Pentode Push Pull sound like my Quicksilver 120 Monoblocks paired now paired with my Cary SLP-98 preamp.

Preamp Matters! 
A really good preamp and the 6SN7s in my Cary SLP-98 along with the choice of interconnects used between the preamp-to-amp and source to preamp really helped dictate the final result for the V12R as well.

Once you put really good coupling caps and Hexfred Diodes in that amp, it jumps to a whole new level once again. Enjoy the V12R, it’s a fun piece. Sure liked mine. New owner loves it.

 As I recall. 35ma and 210ma per channel was about right, sounded good too.

So is there a place to check for the 35ma (per valve?) or at the pin # whatever. I can see how to get the 210 per rail, but kinda lost me with the 35ma, Just a reference to check but not adjust? Wish they had a good manual. 

Output Tubes:
Don’t be so quick to yank/replace/chuck those Ruby’s for others, some were the actual Shuguang EL34-BSTR tube version which sounded really good in that amp.

I'm to much of a miser (sp) to yank and dump..When it comes to valve, I've found some real gems, others just would not try. I will.. Gotta listen.

I read the same thing. With a coupling cap upgrade, the stock tubes sound really good.  I'll give them a LONG listen before I do anything.
I need to let everything settled in first, little at a time..Set the bios get the amp on a dampened, surface, cable or two..PC. Guy brought me a PC with Mcintosh written on it. # 8 or 10 wire. Never seen a Mac cord like that..Big and Green. The Hulk.. Yea those Mullard are probably worth more than the amp. EL34 guys are EL34 guys no doubt, I never have been. If it sounds better then things may change.. Even old guys like change every now and then...LOL

Hay if you could explain the 35ma per tube? How to get it. Fronts or rear I got. 4 8 or 12 valves, I got, from 285-300 down to 210-240ma, I got, but the 35ma per tube, I DON'T GOT.. LOL

Thanks for you patience...

It's just 210 div by 6, per "rail" as you noted.  If you are handy, pull lower cover, look and see if it has those four of the thin silver'ish Audio 1 coupling caps. 

It's just 210 div by 6, per "rail" as you noted.  If you are handy, pull lower cover, look and see if it has those four of the thin silver'ish Audio 1 coupling caps.

I  guess I'm thick, so if I have two valves per rail then bios at 70ma 
and 4 at 140? Am I following you? 
I'll pull the cover. Handy? LOL You mean an I Arnold with 20" arm? hee hee that is a heavy amp, mercy.

Regards