Top-of-the-line tube E280F / 7722 Special Quality (SQ) pinched waist pentodes bulk manufactured in US by Philips. 10,000 hour plus Mil.Spec. shock and vibration rated, with gold pins, these audio pentodes have an amp factor of 60.
Data sheet
Top-of-the-line tube E280F / 7722 Special Quality (SQ) pinched waist pentodes bulk manufactured in US by Philips. 10,000 hour plus Mil.Spec. shock and vibration rated, with gold pins, these audio pentodes have an amp factor of 60.