Tube question - need new ones

c-j tells you that you should only use tubes purchased from them. They may test their tubes more than others but there is nothing unique about their tubes. You can buy tubes from other vendors and many people do.

Many people also tube roll in c-j amps and preamps and often find tubes that they prefer from manufacturers other than the ones c-j uses.

There may be a problem with the warranty if you use tubes not purchased from c-j so I would ask them about that. I don't know if there is any problem or not, but if you have to send anything back to c-j for warranty work make sure you have c-j sourced tubes in the gear.

if cj factory asks to send amp with tubes for warranty service, you should keep originals, but use any so you can send them unit back.

I have excellent feedback with Jesse Brent. Superb service and a thorough gentleman. highly recommended.
When I had a CJ amp I bought/replaced the 6550s from a variety of online dealers at a fraction of the cost quoted by CJ. YMMV

How about a shout for Roger Modjeski? He does tubes specifically for CJ and his RAM tubes are always good one's. tubeaudiostore.com is the address and the prices are good for what you are getting.

RAM tubes are graded for noise and you pay for that. Some of the tubes are inexpensive Chinese but he tests them like no one else. If you need supremely quiet tubes he might be the right guy. All that testing and rooting out less than the best of the lot is not free however. He prints his prices so you don't have to guess.
I have bought many tubes on the open market and it is really a crap shoot (emphasis on crap). Unless your willing to lose your money and have a high aggravation level response I would avoid it.
I will give you this bit of advice, you generally get what you pay for. Most of my really good tubes were not inexpensive. A couple here and there but it is the exception to the rule. Such as not overpaying for the manufacturer's tube sets.