TWO The Fisher 7591A Tubes / Amplitrex Tested = Good But Not Great / Base Damage

- Best for tube amp builders or restorers seeking affordable 7591A replacements who accept tested singles rather than a tight matched pair.
- Used condition with base damage noted; tubes test functional but below excellent spec (6950 and 8070 micromhos versus 6630 pass threshold), suitable for non-critical amp positions.
- Seller doubledtoobs has 1355 feedback ratings at 100.0% positive, established vacuum tube specialist.
- Free shipping, in stock and ready to ship.
- Two Fisher 7591A tubes, United States origin, both tested on Amplitrex AT-1000 fixed bias mode; not matched pair but confirmed working singles.
- Before purchase, confirm base damage does not affect tube function in your specific amp circuit and verify 7591A socket compatibility with your amplifier model.