Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Eros Tape => Topic started by: xcortes on December 12, 2010, 05:25:54 AM

Title: Driver current on Eros tape and phono
Post by: xcortes on December 12, 2010, 05:25:54 AM

Why is the driver current different on the tape and phono versions of the Eros? Just curious.

Title: Re: Driver current on Eros tape and phono
Post by: Paul Joppa on December 12, 2010, 08:26:04 AM

It isn't. You're looking at the first stage C4S, right? The tube is paralleled with a load resistor, 75K or 200K depending. The extra current feeds the 75K resistor, the net current through the tube is the same.  :^)

Title: Re: Driver current on Eros tape and phono
Post by: xcortes on December 13, 2010, 04:22:58 AM

Thanks Paul,

I guess this is a sample of the intrincacies of designing a direct coupled amp that has an eq network.