on top of the by @Jaethan and Ian aka @Torq mentioned RME ADI DAC´s balanced control,
you could have a look at the SPL Phonitor X(Pre-amp and hf-amp) / Xe´s(hf-amp) “balance” control. It is very sophisticated. Here you can finetune on top of a software/plugin or if you use a phono stage without any digital chain…
SPL calls it “Laterality” control and it would be analog, which I´d always prefer, to have.
depending on the differences with your left/right hearing capabilties - the Laterality control, could be not strong enough. Please, someone correct me if I am wrong, but it is about 6db or even just 3db adjustable. I was not able to find it.
Edit:
out of the SPL manual:
“Laterality
Laterality refers to the deviation of sound perception to either side of the ears. With the Laterality control (10) you
can compensate perceived volume differences between channels that may be due to a hearing impairment.
This control differs from conventional balance controls. If one channel is attenuated, the other one is increased at
the same time. This means that, e.g. when hard left, the level of the left channel increases
by 2.25 dB while the right channel is attenuated by 2.25 dB.
This control has a narrower range than conventional balance controls. Its resolution is very
fine, which means it can be peciseley adjusted.
Set the MODE switch to LATERALITY to control the laterality (see above).”