AudioRoundTable.com: Thermionic Emissions

Home » Audio » Thermionic Emissions » amp input stage

Show: Today's Messages :: Navigator :: Polls
E-mail to friend

some test results... [message #8909 is a reply to message #8885]

Sun, 17 April 2005 07:39

PakProtector
Messages: 935
Registered: May 2009

Illuminati (2nd Degree)

Hey-Hey!!!,
I removed the 150k grid leak resistors from the input stage of my amp and replaced them with 15k. The 20 cps output Z of my linestage is dictated by its 7.5 uF coupling cap, so a 15:1 ratio of input Z to linestage output Z seemed OK from a filter/freq response POV.

I find the system a bit cleaner now. It's not a big difference, but subtle ones are OK with me at this point. Same type of resistor, a 1/2 watt carbon film from Radio Shack.

After listening for a while, I keep thinking that the change was worth it. A worthwhile deviation from std. practice if a system analysis looks to support the change. I would not suggest trying this if a Dynaco PAS 3 were the linestage. A 12AX7 and .22 uF or so coupling cap is not going to cut it I suspect...
regards,
Douglas

Report message to a moderator

[Message index]

		amp input stage By: PakProtector on Sat, 09 April 2005 05:42
		Re: amp input stage By: Manualblock on Sat, 09 April 2005 06:49
		Re: amp input stage By: PakProtector on Sat, 09 April 2005 10:58
		Re: amp input stage By: Manualblock on Sat, 09 April 2005 11:31
		Re: amp input stage By: Wayne Parham on Sat, 09 April 2005 08:14
		Re: amp input stage By: Steve on Mon, 11 April 2005 21:49
		some test results... By: PakProtector on Sun, 17 April 2005 07:39
		Re: some test results... By: Steve on Wed, 01 June 2005 20:22

Previous Topic:	Cathode drive
Next Topic:	November 2005 Vacuum Tube Valley Southern California Audio Festival

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Mon May 13 16:23:53 CDT 2024