Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
In Reply to: PX-25 or PX-4 posted by setamp on January 19, 2015 at 08:05:41:
I would steer well clear of Osram globe PX4 , early versions such as these have lower dissipation than ST shaped PX4 . Genuine PX4 and PX25 have a B4 base so I don't know how these will fit a 300B amp which uses a UX4 socket . PX25 also requires a much higher impedence output transformer than 300B . Both PX4 and PX25 also have 4 volt filaments . It seems unlikely your amp can accept either unless a major rebuild/rebias is carried out or these modern 'PX4' and 'PX25' are derived from a 300B and fitted with a UX4 base and different filament .
Al
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: PX-25 or PX-4 - Al Noakes 10:41:54 01/19/15 (2)
- RE: PX-25 or PX-4 - setamp 12:13:02 01/19/15 (1)
- RE: PX-25 or PX-4 - Al Noakes 12:27:50 01/19/15 (0)