plate resistance
Yes, the effective tube plate resistance goes way up. Add another (u + 1) * Rk ohms to the "stated" value.
For example, a 12AX7 at 1mA, 150V will have an rp of about 60k. If the common cathode amplifier stage uses a 1k ohm Rk, then add another 101k for a total effective rp of 161k.
The bypass caps preserve gain and keep the output impedance lower. But often at the expense of sound.
www.hagtech.com
Yes, the effective tube plate resistance goes way up. Add another (u + 1) * Rk ohms to the "stated" value.
For example, a 12AX7 at 1mA, 150V will have an rp of about 60k. If the common cathode amplifier stage uses a 1k ohm Rk, then add another 101k for a total effective rp of 161k.
The bypass caps preserve gain and keep the output impedance lower. But often at the expense of sound.
www.hagtech.com
Resources for futher education on this and related subjects:
Bruze Rozenblit's excellent book, Beginner's Guide to Tube Audio Design.
Download the 5 part series from Audioxpress magazines website.
www.audioxpress.com
Glass audio has software that an be useful and educational.
http://www.glass-ware.com
Aud_Mot
Bruze Rozenblit's excellent book, Beginner's Guide to Tube Audio Design.
Download the 5 part series from Audioxpress magazines website.
www.audioxpress.com
Glass audio has software that an be useful and educational.
http://www.glass-ware.com
Aud_Mot
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