Chances are that the 120 to 150 swap is not as big an issue with the ARC amps designed for the 120s as going to 120s in an amp originally designed for the 6550. The issue in my mind is the QA done by ARC on the tubes they sell and warranty. Putting 150s in w/o ARCs blessing imparts two risk factors, one that the circuitry will not handle the tube and two, that tube variation may contribute to failures due to potential incompatibility. It's all about how the individual accepts the risk/benefit ratio. On buying a used amp I would send it back to ARC for a tune up unless it was essentially new. Did that w/ my VT200 even though it was a pain.
New KT150 tubes?
Has anyone any experience with these pretty new tubes. There are already one or 2 amps I know of, that use them. The review of one of these amps in a UK magazine suggested they were a little warmer and more natural sounding than the nearly new KT120's
The article also suggested they were a straight swap for KT120 based amps, with no adjustment necessary. They are more than twice the cost of KT120's, but still not too costly compared with NOS tubes. I know changing from KT88's or 90's to 120's. did require some amp modification. I have an ARC reference 75 and might want to try the new tubes at some point, ARC don't seem to have a customer E-mail service, to ask the question
The article also suggested they were a straight swap for KT120 based amps, with no adjustment necessary. They are more than twice the cost of KT120's, but still not too costly compared with NOS tubes. I know changing from KT88's or 90's to 120's. did require some amp modification. I have an ARC reference 75 and might want to try the new tubes at some point, ARC don't seem to have a customer E-mail service, to ask the question
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- 316 posts total
- 316 posts total