Question About Capacitor Upgrade in Tube Amp

And for really low values, less than a couple of ohms, nichrome wire just can't be beat.

NOS Allen Bradley Carbon comp resistors are all the rage for tube guitar amps. For their warmth and organic tone. I wonder how they fair in hifi? They do tend to drift in value a fair bit. So maybe not so good in hifi setting.

Carbon comp resistors are very noisy and add distortion. This may be (is likely) desirable in a guitar amp, but not what I want in my hifi amp. 

Does anyone know how the power supply bypass capacitor effects high end frequency response?

For example the Willsenton R300 amp uses a .33uF and is a slightly rolled off sounding amplifier while Muzishare amps are using .47uF on the filter cap and are brighter sounding amplifiers. PS audio apparently uses a .1uF

Is this power supply bypass cap impacting high frequency response? Or are the bass and treble response all in the various coupling caps and cathode caps etc in the preamp stage?

Thanks.

@calieng - the primary purpose of the bypass cap on the power supply electrolytic is to shunt high frequency noise on the B+ rail. I doubt it will have any affect on the high frequency response of the amp. The value of the cap is really not that significant as long as it is a good quality film cap. 

The biggest influence on the high frequency response will be from the output transformer and possibly from the feedback network. I wouldn't recommend changing these parts without a solid understanding of how the amp works as well as having adequate test equipment to make sure the amp is stable after the changes.

Using a higher quality coupling cap also might give you a small improvement in high frequency response if the one that is in there now is not of very good quality.  

@jaytor - Thanks for the reply!