A mod/trix I never seen before

[oj]

It's hardly different from LNFB achieved by connecting the small cap from the second stage anode to the second stage grid. The reason is because there will be a wide-open path from the anode of the first stage through the coupling cap (which is much larger than 47p) to the grid of the second stage. The result is a rolling off of high frequency in the second stage.

Thanks martin big time !

So is there any pro or cons with doing it this way ?
A mean I have never seen it before, and been working om amps for over 20 years, so I guess there most be a reason ?

[martin manning]

The main effect is cutting HF, very similar to a low-pass filter. I've never seen this before either, but it's an interesting trick for trimming highs, and the corner frequency is easily varied by adjusting the size of the cap. The trace below is with and without a 47p anode-to-anode for two cc gain stages with 100k Ra and 1k5 Rk//10uF.

[Andy Le Blanc]

haven't seen that one yet either, neat way to focus the amps response, no gain wasted to the top end.

[CoffeeTones]

Very similar to the Dr Z Therapy. [img760]http://medias.audiofanzine.com/images/n ... 872674.png[/img]

[oj]

The main effect is cutting HF, very similar to a low-pass filter. I've never seen this before either, but it's an interesting trick for trimming highs, and the corner frequency is easily varied by adjusting the size of the cap. The trace below is with and without a 47p anode-to-anode for two cc gain stages with 100k Ra and 1k5 Rk//10uF.

Thanks martin again !
Very nice to see that graf !
Do you think it possible to use as a cut-control in the frontend ?

[oj]

Very similar to the Dr Z Therapy. [img760]http://medias.audiofanzine.com/images/n ... 872674.png[/img]

Yes that was more and less the same amp
Dr Z is using a ppimv instead of a pre-master.
Guess is Dr Z is more rock n roll