Cary V12 and other tubes

I too have a Cary V12R and the bias should be about 238. I need new tubes so I'm going for a full set of Rubys. 2 AX7's and 2 el-84's. The amp just makes a loud hiss when I flip on the operate switch on the Cary SLP98P, so I must have 1 or 2 bad tubes. I have moved some of them around and it does not help. The system sounds great when it works, and the amp does run hot normally.

I figured out what the problem was.....my meter was inaccurate in reading the bias. My faulty meter read 275 in reality it was reading 180. With the bias now set propery....it's a different stereo, WOW, plenty of bass, and gobs of power....

Thanks Bmotorcycle....I bought these used but were supposedly not used. It does sound like BS about "breaking in" but there must be some truth because you hear that alot. Good tip about the bias also, I would have never known. I'll let the system break in for a while and let you know. I'm new to he hi-fi end so this is all new to me, expecially tubes.....David

Kdi40, are these amps new or used. My findings with cary Equipment, especially amplifiers, they need at least 50 hours before they even start to open up and 100 hours to really start sounding good. I know it sounds like "BS" but it is true. Also, the 275 bias point which you are set at is to high. I know the manual says 275 but Cary told me that the manual was incorrect, the the amp should be biased at 230-250ma you may be over saturating the output tubes, try backing the bias down and letting the amps break in. Hope that helps..........Bob

I just bought 2 Cary mono block V12i's and are hook up to new sophia 2's. Also a Cary slp98 preamp. Every tube is original stock. I hooked everything and to my ears was dissapointed in the sound. Lacks bass pretty bad, and sound just doesnt seem to open up as I were to hope for. Also I have to crank up the volume knob to about 3 o'clock just to get about 80db's. I have the tubes biased at 275. Am I doing something wrong? Your help is greatly needed.

Please note my comments here are referencing the V12 with the KT88 tubes only, not with the EL34 tubes. So please take these comments in reference to that setup. I had just auditioned a used V12 (no letter version) that I was interested in buying. It had KT88 tubes in it. Based on that audition, I took it back. Constricted and not to my liking. When I took it back, the salesperson at the store said they had that impression on their listen also, even after warm up (my session was after 8 hours warm up time. The bias settings recommended in the manual or from Cary would not work for the KT88 tubes. I could not get the LED's to light at the 225 to 250ma that Kirk at Cary told me to set up for these. They need at least 250ma and really, to get all the led lamps to light, I needed 260 ma. I even tested all the tubes and all were very strong. It still didnt sound too good to me. I emailed Dennis Had with my impressions asking for comments, but he didnt respond to my email other than sending me a reference to a recent review of the six pacs. I love Cary stuff having an 805C and 300se sigs. So the experience with this amp was surprising to me. I did look under the chassis and it is very complex looking compared to the SLM-200 model which was designed to use KT88/6550. Maybe that is why I like the SLM better (other than the higher power fact). I also found the V12 transformers with these tubes ran hot hot hot. And the output transformers on the stereo version were smallish to my eyes.]. My 2 cents, this amp is probably good with stock EL34 tubes based on the reviews, but I didnt have the opportunity to listen to it that way. Only with the Svet KT88 tubes. My 2 cents, hope this helps.

Thanks Aisip, I will definitely e - mail you about the Svetlanas.

It seems to me as if Cary is not recommending the correct bias settings for the tube, but what do I know?

Trelja, I concur. I was also puzzled by the result. I biased the amp exactly as recommended by Cary. A friend of mine has the V12i monos. He also tried the KT88's and arrived at the same conclusion. Another friend tried a set on his Jadis DEFY 7, the result was magical! The tubes he replaced were 6550's. I think I still have 10 matched pairs of Svetlana KT88's. Email me directly if you're still interested.

Aisip, are you sure the amp was biased correctly when you substituted the KT88s? And, if so, were the same values as the EL34 used?

The only reason I am asking is that the description of the change in sound you have provided flies exactly in the face of what happens when one moves from the EL34 to KT88. Number one, the sound should open up a great deal and become more clear and refined, at the expense of that luxurious midrange. Number two, the dynamics, power, and slam should increase by one quarter to one third, and this will most notably be apparent in the lower frequencies.

I don't mean to be contrary, just that things seem out of kilter.

And, if you have the KT88 available, would you be interested in selling a quad or octet? I will be needing to retube my Jadis, and would like to go with either EL34 or KT88, just really haven't decided on which yet as I love both. Thank you,
Joe

Stick with the EL34's. The V12's sound with the KT88's (Svetlana's) was bland and lifeless. Dynamics were also squashed and constricted. Don't waste your time and money! I still have the Svetlana KT88's with only a few hours on them just gathering dust! If you still want to experiment, contact me and I'll sell them to you cheap! FYI, the Svetlana EL34's are much better than the stock RUBY's. In my opinion, this is a much wiser and significant upgrade than fiddling with other tube types. Good luck!