Conrad Johnson Premier 140 6922 tube swapping

OP I assume your unit is stock. Given its vintage I think money is much better spent on checking out the caps and resistors and tubes in the gain and driver stage before you risk any $ going into the hands of the too many scammers selling those so called NOS power tubes out there. Bad power tubes do not contribute to noise. They just sound dull and wimpy and eventually wont bias and may pop. Noise is from components in the gain stage.

I think you might like the Genalex Gold Lion 6922 in your CJ. I use them in my
CJ preamps. Get your 6922 first then decide on the 6550's.

Agathe79, This is starting to spin out of control. Your original problem was a noisy 6922. If you are happy with the sound of your amp except for the noise, get a new 6922 and see if that takes care of your problems.

If you can talk to the person you bought the amp from, find out how many hours the power tubes have on them. They may have plenty of hours left on them and you can take your time getting familiar with your amp and opinions on tubes before you start replacing them.

Also find out if the amp was left on all the time and how many hours it has on it. When you have that information call or email c-j customer service and find out what they think about replacing any parts before you do something like that. c-j will be glad to help you even though you didn't buy the amp new.

You can also find out if there is someone who works on c-j gear with a good reputation near you. They could check out the amp without having to send it off to c-j.

Take it one step at a time. Get a new 6922. Talk to the former owner then c-j. Take some time to get familiar with the sound of your amp. Your amp may be working just fine and not need anything other than a 6922.

01-10-13: Agathe79
Does anyone know where I could get 8 NOS Tungsol 6550 tubes?, I know it's asking alot

Do you have a clue what NOS 6550's go for if you can find them? Then which ones are you looking for? Solid Black Plates (best and my favorite) - Solid Gray Plates (close second to the black plates) or the 3 hole gray plate? I haven't heard the 3 hole ones but a friend has them and says they are not as good as even the solid gray plates but still very good. Here is a link to e-pray and if the quad of black plates is truly NOS that is an excellent price.

http://www.ebay.com/itm/Tung-Sol-6550-KT88-Black-Plate-Tubes-NOS-Perfect-Matching-Quad-/160951867413?pt=Vintage_Electronics_R2&hash=item25797a9815

Finding USED singles and pairs and an occasional quad isn't that hard. But most important you need to hear them first. In my Octave they are like great EL34's on steroids. Warm and musical. EAT KT88's are the opposite sound. Very detailed - linear and accurate (kind of like solid state). The Vintage Gec KT88's are pretty close to the EAT KT88. Depends on your preference and again why you should listen to them first - if possible. Only the EAT's are currently in production - all the rest will never be made again. All are very expensive and because EAT is currently in production they are the only ones that will give a warranty.

That being said I'll also say get used to what you have first. Then decide if you want to change up the sound a bit which way do you want to go. Changing the input tube will make a big difference too and cost a lot less to experiment.

Thanks for all the advice.
I'm going to change the 6922 first and then see how I like the sound