Parafeed amps, noise and PS Cap Upgrades

[Jamier]

(This has probably been asked before)If parafeed SE amps shield the OT primaries from PS noise, is there any benefit to be had by upgrading the PS caps to films?

 

[Paul Joppa]

The potential benefit is smaller than with series-feed circuits, but still greater than zero.

Film caps are much larger than electrolytics, which makes it tempting to reduce the capacitance.  But the capacitance still plays a role, so I discourage changing the value - unless you recognize it's an experiment that might fail.  :^)

 

[Jamier]

This is a little off topic, but if you can reduce hum by altering, say, the input tube connection, then that noise would not be due to the PS, right (or wrong)?

 

[Jamier]

Altering is a bad choice of word(s). I should have said "improve" the input tube connection.

 

[Doc B]

The proper wording is shorting the input. If the noise floor drops when the input is shorted the noise is coming from upstream of the amp.