Snubber cap

[Ukko75]

Hi!
I am trying to get my Express build to sound good. I try to get the high end to little smoother. I readed express build guide about the snubber capasitor over the plate resistor on second stage. So my guestion is wich pins on V1 I put the capasitor between?

-Pete

[Colossal]

Pete,

With the snubbing capacitor, you are bypassing the plate load resistor to bleed some high end to ground via the power supply. Look at the schematic or layout, find the second stage 100k plate load resistor and solder your snubbing capacitor in parallel with that resistor.

Here is a drawing that should help (click on the attached .png file below).

[John_P_WI]

Another approach which is for a Dumble style amp as shown, but will work with the express as well.

Check out this link:

https://tubeamparchive.com/viewtopic.ph ... highlight=

[roberto]

I don't like snubber caps on PI's plate resistors, they smooth the attack of the amp too much. I think you have to remove the harshness where it's generated (or just before).

A 470p across the plate resistor of the 100k 10k stage sounds good, but maybe you'll find it too smooth. You can dampen the effect placing a resistor in series with that cap (start with 1k).

Otherwise you can try a grid stopper on the 3rd gain stage. Use it large, remember that you have a small miller capacitance with a 100k 10k unbypassed stage.

You can also try smaller caps (10-47pF) between plate and cathode of 1st, 2ns or 3rd stage and see what you prefer.

[Ukko75]

Thank you all!
I will try them and see what works best!

[Mark]

Liverpool amps sound smoother with their 50pF treble cap. Have you tried that?

The Funk Liverpools did have a snubber on the second stage which was a cap in series with a pot.