I’ve had three different Orange Amps…a Thunderverb 50 (pair of EL-34’s), an AD-200 (quad 6550’s) and a Rockerverb 50 (pair of EL-34’s) that failed due to arcing between the tubes’ Plate and Heater pins (3 & 2) on two of the amps (Thunderverb & AD-200) as well as on a Rockerverb 50 tubes’ Plate and Screen pins (3 & 4).
Ceramic octal tube sockets on each amp, and in each case, the arc-over burned into the ceramic base, leaving a carbonized conductive path. Also carbon deposits on the base of the tube’s header. It took grinding away the carbon deposit with a Foredom hand grinder with a carbide burr to get to clean virgin material. And, after cleaning up the tubes (only one tube had failed of the 3 amps), I swapped tube locations to eliminate any further re-occurrence at the same tube/socket. No other damage occurred, amps worked fine after surgery.
I’ve only seen this happen on the Orange Amps with the ceramic octal tube sockets they use. Any clues as to why this occurs? I don't have any details on what speaker cabinets were used with the amps or other specifics, like mismatching loads. All are within CenterStaging,LLC's backline gear rental inventory
I posted this prior to seeing there was a thread on Power Tube Arcing from 2008.
Ceramic octal tube sockets on each amp, and in each case, the arc-over burned into the ceramic base, leaving a carbonized conductive path. Also carbon deposits on the base of the tube’s header. It took grinding away the carbon deposit with a Foredom hand grinder with a carbide burr to get to clean virgin material. And, after cleaning up the tubes (only one tube had failed of the 3 amps), I swapped tube locations to eliminate any further re-occurrence at the same tube/socket. No other damage occurred, amps worked fine after surgery.
I’ve only seen this happen on the Orange Amps with the ceramic octal tube sockets they use. Any clues as to why this occurs? I don't have any details on what speaker cabinets were used with the amps or other specifics, like mismatching loads. All are within CenterStaging,LLC's backline gear rental inventory
I posted this prior to seeing there was a thread on Power Tube Arcing from 2008.
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