Bottlehead Forum

General Category => General Discussion => Topic started by: bgf on September 16, 2024, 12:36:35 PM

Title: bee pre running hot
Post by: bgf on September 16, 2024, 12:36:35 PM

hi, replaced tubes with psvane 300B-TII matched pair after two LPs metal is almost to hot to touch.  this was not a problem with the other tubes.  filament current measured is 1.2 A and plate current measured is 65 mA.  any suggestions thanks

Title: Re: bee pre running hot
Post by: Paul Birkeland on September 17, 2024, 04:30:38 AM

The filament current in the BeePre 1 is the predominant factor in how hot the chassis plate gets, and you've measured that it's about the same.  Using the small isolation O-rings will potentially slightly reduce the heat transfer between the glass of each 300B and the chassis plate, though the ceramic bases themselves are usually pretty good at doing that on their own.

Title: Re: bee pre running hot
Post by: bgf on September 17, 2024, 04:49:53 PM

Thanks.