linky
Ad says:
While not a true 5881 (it’s actually a servo tube once used in Soviet military aircraft), the Sovtek 5881/6L6WGC can be installed in any application where a 5881 or 6L6GC is called for. The Sovtek 5881 is exceptionally rugged and is recommended for amps with higher plate voltages. This is the wafer-base version, which has been the factory output tube in the Soldano SLO 100, the 6L6 outfitted Marshalls of the 1990s, and is also rebranded by Mesa-Boogie as their STR-425. Otherwise identical in construction to the full-base Sovtek 5881WXT found in current production Fender amps.
Ad says:
While not a true 5881 (it’s actually a servo tube once used in Soviet military aircraft), the Sovtek 5881/6L6WGC can be installed in any application where a 5881 or 6L6GC is called for. The Sovtek 5881 is exceptionally rugged and is recommended for amps with higher plate voltages. This is the wafer-base version, which has been the factory output tube in the Soldano SLO 100, the 6L6 outfitted Marshalls of the 1990s, and is also rebranded by Mesa-Boogie as their STR-425. Otherwise identical in construction to the full-base Sovtek 5881WXT found in current production Fender amps.