A friend of mine expirienced a tube failure twice in his VPAs. There was no other damage other than the tube itself. Each time tubes were replaced by Nagra under their 2-year warranty free of charge.
Issues with KR 845 tubes in Nagra VPA Amps?
Have other Nagra VPA owners experienced problems with KR 845 output tubes? A couple of months ago a KR 845 tube in my Nagra VPA's failed. My local dealer no longer stocked Nagra products so I contacted John Quick of Tempo Sales. John is the national distribution representative for Nagra high end products and Verity Audio loudspeakers. John told me that the KR tubes were subject to shorting and creating collateral damage in the VPA's when doing so. John said that Nagra had created a "protection circuit" to prevent the collateral damage.
I arranged with John to have the protection circuits shipped to Steve Huntley of Great Northern Sound. For a host of reasons, I was reluctant to ship my VPA's and John was good enough to accommodate my request. (He was very helpful and responsive.)
Steve Huntley did a great job of fixing the VPA's and, so far as I can tell, the amps have never sounded better. I do not think that the protection circuits had any detrimental effect.
Have other VPA owners had problems with KR tubes and gotten the protection circuits?
I arranged with John to have the protection circuits shipped to Steve Huntley of Great Northern Sound. For a host of reasons, I was reluctant to ship my VPA's and John was good enough to accommodate my request. (He was very helpful and responsive.)
Steve Huntley did a great job of fixing the VPA's and, so far as I can tell, the amps have never sounded better. I do not think that the protection circuits had any detrimental effect.
Have other VPA owners had problems with KR tubes and gotten the protection circuits?
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