Excessive White Noise on +3

[DeLorean_4]

Hello,

I have a Spectrum +3 which had the audio distortion mod applied in addition to some fresh electrolytic capacitors.
However, the sound output has a lot of white noise.
This makes saving BASIC programs problematic (maybe 1 in 3 success rate), and saving files generated by programs (ex: Sim City game saves) absolutely impossible (zero success rate).

I reviewed the workmanship of the audio mod on my machine and it looks good.

I have zero issues loading programs that were recorded to cassette via my smartphone with the "PlayZX" app, so I can rule out my tape deck (WHSmith CPD-8300 with level meter).
The loading issue is only with programs/files saved by my Spectrum +3, and I suspect the omnipresent white noise is what's causing it.

Would anyone have any suggestions to remedy the condition?