7581 Tungsol brown base used/75% 1964

52.5ma

Gm=4350

Good used mA range 55-70

Good used Gm range 5000-6000

Recommended for

– Ampeg VT22
– Fender Bassman 1969
– SunValley VP-3488SE
– Fender Vibrolux reverb 1971
– Fender Super Reverb 1970