To "tube" or not to "tube"

thanks again, nsgarch. i found a dealer in wisconsin and got a good deal on a 275. i may buy a c220 as well.
i am also considering an audionote m2 and a navison mk 3. hopefully one of them will be warm enough.

Tennis, did you get a IV or a V? If a IV, I can send you some pics showing a slick way to hook up fat speaker cables. Either way, I know you'll love the amp. It's actually quieter and more detailed than many top notch SS amps -- which I don't expect you to believe until you hear it (with Telefunken 12AX7's ;--)

Neil
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hi neil, i don't expect to use telefunken 12ax7. i will use mullard 12ax7 or ge 5751 or rca 5751. i hope the amp is not too detailed. i may also try mullard 12at7 or rca 12at7.
hopefully the amp will be come with 6550, not kt88. i have no idea which 6550 tubes are mellower than current tubes. any ideas ? i am purchasing a mark V, new.

Tennis, congrats! You're going to really love that amp! The power tubes the MC 275 comes with are KT88, either Electo Harmonix (round holes in the plate) or Svetlana Winged "C" from the St. Petersburg plant (square holes in the plate.) The Penta KT88SC copy (SC stands for "strict copy") of the GEC Gold Lion/Gold Monarch KT88 are suposed to be the ones to have. I just ordered a new matched quad from a member for $100 shipped. I'll let you know on those. As for 6550's, you can also run them in this amp, but for my money, they're not as nice sounding a tube as the KT88. (Maybe a teentsy bit more power though.) The amp has neither bias adjust nor auto-bias; it's not necessary for the Unity Gain circuit design. It's good though to have matched pairs of power tubes and gain multiplier tubes in each channel.

For the 9-pins, I will be trying Mullard, GEC, and Amperex/Holland in addition to the Teles (what's up with the RCA's?). All I know is, the McChina's suck, IMO ;--) The tubes that make the most difference in sound are the three 12AX7's. Or just the two 12AX7's in V2 and V5 if your using the balanced inputs.

I'll be anxious to know how it sounds driving 1.6's. However, mine sounded like crap for the first five hours! Tubby, boomy bass and grainy mids, yuk! So do give the amp a 50-70 hour break-in before you evaluate it ;--)

hi neil:

what fo you think will happen if i use lower gain 12ax7, namely 5751 ??

according to mcintosh, changing tubes will not change the sound of the amp very much. a dealer told me that the 6550 gives a more romantic sound than the kt88. in any case, i won't be getting the amp for about 10 days.