diyAudio (
-   Tubes / Valves (
-   -   PCF801 Suggestions (

Juergen Knoop 21st August 2009 09:28 PM

PCF801 Suggestions
1 Attachment(s)
I have a bunch of PCF801 (combined pentode/triode w. common cathode) lying around and would like to build my first tube preamp with them.
Thought about a buffer+grounded grid circuit with heavy negative feedback. :cool:
Should I use the triode connected pentode as buffer or the triode?
The frame grid triode may be less affected by low anode voltages, so it may better be used as the grounded grid part.
I want as much open loop gain and less open loop distortion as possible.
Any suggestions?

AND would it work at all? :confused:
simplified schematic attached....

kavermei 21st August 2009 09:47 PM

You could get some inspiration here:

Juergen Knoop 28th August 2009 09:19 PM

thank you, I already hate this tube...connected cathode...grrrr

kavermei 29th August 2009 06:55 AM

Looks like that guy in the link is thinking in the same direction as you are with the GG configuration.

Just try it... you would have something unique...!

Boeing 8th September 2009 02:50 PM

It is great if you build it with Mu stage schem. Easy to drive the next power tube.
Try it so you will happy on it.
Good luck.

aardvarkash10 8th September 2009 08:41 PM

anti-triode, anyone?
swinging around a CCS tail, triode input side, pentode as anti-triode in a p-p VERY low output amp or a headphone amp?

jerluwoo 9th September 2009 12:33 AM

1 Attachment(s)
Here's a good starting point for ya. I based it on the standard operating points from the datasheet so it should work out fairly close.

All times are GMT. The time now is 02:24 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2