Better place for noise to put the Global Feedback resistor

[ygg-it]

Hello, since the GNF wiring is long, is better to put the feedback resistor (in parallel with a pF capacitor) close to the cathode or close to the OT output?

 

[Merlinb]

Close to cathode.

 

[rayma]

Hello, since the GNF wiring is long, is better to put the feedback resistor (in parallel with a pF capacitor)
close to the cathode or close to the OT output?

Yes, close to the cathode. Always minimize connection lengths to higher impedance circuit nodes.
At the same time, keep the other end of the feedback resistor away from the low level circuitry,
to minimize coupling from the amplifier output.

 

[kstagger]

This may be overkill, but I often use shielded wire from the secondary to the feedback resistor.

 

[SY]

This may be overkill, but I often use shielded wire from the secondary to the feedback resistor.

So do I. It also allows the common of the output to be returned directly to the bottom of the input stage cathode resistor, which is the right place for it.

 

[famousmockingbird]

So do I. It also allows the common of the output to be returned directly to the bottom of the input stage cathode resistor, which is the right place for it.

I will have to try this. I usually just ground one side of the shield.

 

[SY]

Make sure that this is the only ground path for the secondary.

 

[famousmockingbird]

Make sure that this is the only ground path for the secondary.

Yes, thanks SY for clarifying.

 

[zigzagflux]

Good application for cheap coaxial cable.