Phase change when adding gain stage?

bereanbill · 15th May 2009, 10:40 AM

I want to add a gain stage to an amplifier by using 1/2 of a dual triode originally used as a second input. This will put the signal 180 degrees out of phase will it not ? Will I need to reverse the plate leads on the OT?

ray_moth · 15th May 2009, 08:20 PM

Assuming that the stage you want to add will be a grounded cathode stage then, yes, it will invert the phase. However, you only need to reverse the connections to the OPT if the added stage will be within a global NFB loop, to prevent the FB from becoming positive..

15th May 2009, 10:40 AM	#1
bereanbill diyAudio Member Join Date: Jan 2009	Phase change when adding gain stage? I want to add a gain stage to an amplifier by using 1/2 of a dual triode originally used as a second input. This will put the signal 180 degrees out of phase will it not ? Will I need to reverse the plate leads on the OT?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Impedance change for adding a tweeter?	porkchop61	Full Range	4	16th September 2008 09:15 PM
Adding gain to this buffer....	theAnonymous1	Chip Amps	12	3rd August 2007 05:17 PM
adding mass to change driver parameters	just a guy	Multi-Way	5	27th December 2006 12:43 PM
Heretical Unity Gain line stage PLUS a little gain ?	yagas	Tubes / Valves	7	24th January 2006 01:30 PM
Passive Preamp Phase Change Question	tschanrm	Solid State	5	6th April 2005 08:26 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

15th May 2009, 08:20 PM	#2
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	Assuming that the stage you want to add will be a grounded cathode stage then, yes, it will invert the phase. However, you only need to reverse the connections to the OPT if the added stage will be within a global NFB loop, to prevent the FB from becoming positive..

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)