Phase Lead: C or RC compensation

[GEirin]

Hi all
Question:Which Phase Lead?
In Pass A40 amplifier use Capacitor compensation (C4).
And JLH 100W use RC compensation (R5/C6).
Which is better or which is design criterion. Pros and cons.
Thanks
GEirin

 

[h_a]

There are many free application notes available on stability just google

D. Feucht, 2-pole compensation
R. Mancini, SLOA020A from TI

and more. These cover the technical side of things, for listening impressions you need to dig the forum.

Have fun, Hannes

 

[AndrewT]

Hi,
in a later version of the JLH he adopted a variable resistor for R5 and said trim until the squarewave was the most accurate shape. But he had 5 different locations where he installed comp in this one amplifier. Crimson also has multiple comp locations.

This type of compensation is very common in British designed amplifiers. Much less common outside the UK.

Notice the ratio of nearly 3:1 for r20:r14, the delay on the q9 protection and 4locations for comp.

What is the purpose of C4?

 

[gaetan8888]

Hello

Here is the link to the two articles of D. Feucht about 2-pole compensation:

Part 1:

http://www.analogzone.com/col_0628.pdf

Part 2:

http://www.analogzone.com/col_0719.pdf

Bye

Gaetan

 

[GEirin]

h_a, AndrewT and Gaetan8888
Thanks very much for yours replys.
GEirin