Are you talking about the input tubes or the output tubes. The difference is significant. The amp uses 3 different input tubes per channel 12AX7 12AU7 and 6922 and the output are 6550s. In the review I read, the manufacturer recommends using the amp for 2 weeks and rebiasing the tubes. He did not say how many hours 2 weeks translates into. As a rule of thumb count on needing 200 hours of play time. The input tubes will need about the same to stabilize. BTW it sounds like a great amp from the review
The output will likely run for approx. 2,500 hours before replacement. The input will likely last 5,000 hours and maybe as many as 10,000. If you can find them, use NOS tubes, they make my gear sound great. With the various inputs tubes, you can experiment rolling tubes in this amp. I always prefer the sound of KT-88 outputs over 6550s, I would ask Ken Stevens, if you get sub them in. They are usually interchangeable. The Gold Lion reissues are IMO fantastic and will take the amp that much further.
In the review the author used the CAT preamp with great success, why not use it? I happen to really love the sound of 6SN7s so I use a Cary preamp. You can buy a new SLP-05 from Kevin Deal at upscale for that kind of money. Otherwise it really depends on what you are aiming for, there are so many to choose from. I happen to think that an SS pre is not out of the question. The tube magic will be obvious from the tube output stage which is critical in my mind.
The output will likely run for approx. 2,500 hours before replacement. The input will likely last 5,000 hours and maybe as many as 10,000. If you can find them, use NOS tubes, they make my gear sound great. With the various inputs tubes, you can experiment rolling tubes in this amp. I always prefer the sound of KT-88 outputs over 6550s, I would ask Ken Stevens, if you get sub them in. They are usually interchangeable. The Gold Lion reissues are IMO fantastic and will take the amp that much further.
In the review the author used the CAT preamp with great success, why not use it? I happen to really love the sound of 6SN7s so I use a Cary preamp. You can buy a new SLP-05 from Kevin Deal at upscale for that kind of money. Otherwise it really depends on what you are aiming for, there are so many to choose from. I happen to think that an SS pre is not out of the question. The tube magic will be obvious from the tube output stage which is critical in my mind.