pse help, unity µ triode as a phase inverter

[oldeurope]

#60

Hello jane,

QUOTE]Originally posted by jane


What are the main differences between the "gyrator" stage in your drawing and an ordinary mu-follower?

Jan E [/QUOTE]

The gyrator replaces a coil ll resistor in my drawing.
A mu-follower provides µ-gain.
Strange question, is this a pitfall?

Darius

 

[jane]

Re: #60

The gyrator replaces a coil ll resistor in my drawing.

I suppose you could say the same thing about a follower?

An externally hosted image should be here but it was not working when we last tested it.

In a mu-follower with fixed bias the driver tube will see ~Ra as the load at f<<fc and ~(Ra x mu+1) at f>>fc. You may replace the upper tube in this follower with a coil with Rdc=Ra and a parallel resistor Rs=(Ra x mu+1).

Jan E.

 

[SY]

Jan, I had never thought of a mu follower as a gyrator before, but that makes perfect sense.

 

[oldeurope]

#62 #63

Ok, let's feed the troll.

Originally #62 posted by jane


I suppose you could say the same thing about a follower?

http://www.glass-ware.com/tubecad/TP1.gif

In a mu-follower with fixed bias the driver tube will see ~Ra as the load at f<<fc ...

Jan E.

In this case, it isn't a mu-follower.

I suppose you could say the same thing about a follower?

http://www.glass-ware.com/tubecad/TP1.gif

In a mu-follower with fixed bias the driver tube will see...~(Ra x mu+1) at f>>fc. You may replace the upper tube in this follower with a coil with Rdc=Ra and a parallel resistor Rs=(Ra x mu+1).

Jan E.

The question here is:
Is (Ra x mu+1)>> ra of the bottom tube?
In this case it is a mu-follower.

In my circuit (Ra x mu+1)<< ra,
thus it isn't a mu-follower.
http://bp3.blogger.com/_oCEpds9YoPw...14Ucs/s1600-h/Gyrator_pre_2008_Darius+001.png
http://line-pre.blogspot.com/2008/07/der-gyrator-im-line-preamp-2008.html

If you want a technical discussion, you must give more detailed
information. But I am sure you and SY do know this.link

The following picture gives an example.
This is a mu-follower:
http://bp0.blogger.com/_oCEpds9YoPw.../6080_phase_inverter_line_pre_2008_Darius.png
http://line-pre.blogspot.com/2008/07/unity-gain-inverter-der-phaseninverter.html

Kind regards,
Darius

 

[oldeurope]

@ Don

Originally #23 other threadposted by smoking-amp
sorta OT: Say Darius, I recall you were looking for a tube with a Mu of 1 a while back. I just ran across a data sheet that mentions just that (bottom 1st page):

http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6AH6.pdf

But probably rather high rp with this tube. Could try g3 drive with some low rp pentode instead.

Don

Thanks Don

Kind regards,
Darius