Do source bypass electrolytic capacitors kill musc?

 At your risk.

Experimenting with the Pleiades 3 K117 RIAA phono preamplifier it was found that removing a source bypass capacitor reduces gain as we know so the sound was much softer but it was also more much real. Like the real thing. For example treble detail sounded so real as when having one's ear near the stylus while playing back a record. 

If a gain at say 1st stage is reduced by 26dB, the input headroom is increased by the same amount. If the stage is low noise enough for example by low drain (JFets) or anode (electron tubes) current, it is possible that headroom is increased by removing the source, cathode electrolytic capacitor.

These experements when done by playing the LP Dromos - Mimis Pleasssas, Lefteris Papadopoulos recorded live stereo mix by Stelios Yiannacopoulos at EMI Coloumbia Athens studios:

So at this time the Pleiades K117 phono preamplifier has evolved to 3 stage K117 with no electrolytic capacitor bypassing the source resistor of any stage! The 2nd stage seems to be receiving an equal amount of low level signal as the 1st stage since the passive RIAA network follows the 1st stage. The 470K potentiometer follows the 2rd stage and then the 3rd stage inreases the signal to a louder lever to drive the output transformer which drives the Sennheser HD-580 150 Ohms headphones.

So the headroom at the input must have been increased a lot and the potentiometer protects the 3rd stage from overload.

It is a concept simillar to making nice electron tube studio microphone preamplifiers. You have to aarange the attenuator to be as close a possible to the microphone.

Same as out ears where the 3 liitle bones connected to our ear drum control gain, overload, ie increase headrrom,  dynamic range of permissible received sounds.

But the electronics have to be top quality low noise. Pleiades experiments are done with low (say 50 microamperes) electron tube anode current or JFet drain current.

The idea of not using source or cathode capacitors comes from examining the great sounding RIAA stage of the Heathkit AA-32 integrated electron tube class A amplifier.

A NAB test record was used for feeding a 1KHz signal to the Shure 75E Encore cartridge, Metz direct drive turntable.

No bypass capacitors will also allow more meaningful comparison with the Pleiades 3 stage DC90 electron tube battery powered phono preamplifier with most grids at space potential ie nothing connected to grid except a coupling capacitor.