Conrad Johnson Premier 140 6922 tube swapping

c-j will tell you to only use replacement tubes from them, but I have not heard of anyone having problems because they used tubes from other sources.

The 6922 is a member of the 6DJ8 family of tubes along with the 7308. Many people consider the tubes in this family to be interchangeable but you probably should stick with a 6922 (E88CC in European designation) until you become a little more knowledgeable about tubes and your amp.

If you want to buy current production tubes like the EAT google Jim McShane and give him a call. Many people sing his praises here on Audiogon. He is away until next Friday though (I just checked his website).

If you want to experiment with vintage tubes, I can recommend Upscale Audio, Andy at Vintage Tube Services, Tubemonger or Brent Jessee. Be prepared to tell them what kind of sound you want from your amp and they can fix you up with the right tubes, probably - no guarantee exactly how a given tube will sound in your system.

The prices that these dealers will charge are quite a bit higher than what you can find on Ebay but believe me, in the end it will be cheaper to buy from them.

Although a bit off topic, I would suggest you make sure that amp has the upgraded film caps in the regulated power supplies. The old polystyrene caps have issues. If one shorts, and they do trust me, it takes out the whole regulator and it's not a pretty picture or a cheap repair.

If you can find matched Tungsrams they won't disappoint. What are the stock tubes?

Well I thought the 6922 I had in the 140 was a stock tube but it is a Electro Harmonix 6922

I had one of these--great sounding amp but mine was problematic--and rolled a few tubes in it. I even bought some vintage Tung-Sol 6550's which made an enormous difference, more than the 6922's. I thought the Siemens CCa was the best sounding 6922 variant but the Tungsram mentioned above is also good, as well as some Ediswans I bought at Upscale Audio.