|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: CCS and high plate R vs CCS etc the why is it ... posted by wlee on July 2, 2006 at 12:44:50:
Picture the bottom tube as a conventional grounded cathode amplifier, whose plate resistor ra is equal to (mu+1)(rp+rk+ra), where mu, rp and rk refer to the top tube and ra is the anode resistor of the bottom tube.This way it's easy to see the benefits of CCS and of using a high mu tube on top since it's the mu of this tube that effectively multiplies the value of the plate resistor of the bottom tube.
Thus if a highish value of plate resitor is used (compared to the tube's internal resistance, rp) then ra's effective value can be approximated to ra*mu.
The effective value of ra becomes so large that rk of the bottom tube is relatively insignificant and for most practical circuits the overall circuit gain of a CCS is a little less than the mu of the bottom tube, even if rk is not bypassed.
Hope this simplifies things a little.
Naz
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- It may help to look at CCS this way ... - Naz 19:21:54 07/02/06 (2)
- Re: It may help to look at CCS this way ... - wlee 11:07:15 07/05/06 (1)
- Re: It may help to look at CCS this way ... - Naz 22:24:12 07/05/06 (1)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
