Headphones sound harsh with Reflex-M, suggestions?

In addition to the above, and from a technical point of view, the grounding regime of a headphone amplifier can have undesirable effects depending on the headphones being used. In particular, the long-forgotten "stereo-loop distortion" which plagues op-amp headphone amplifiers which use separate chips. This causes annoying asymmetrical distortion in the input grounds, but can be cured by the designer if power amplifier techniques are used.

And, I did note that everything is alright with your speaker amp.

Most of us designers fall into the trap of looking at a headphone amp as a preamp, simply because that was the original intention of headphones (back when Noah was a lad). However, things change, and rather than headphones being high impedance, they can range from 5 ohms to 2000 ohms, for what reason, I do not know.

A high impedance headphone will not exhibit the same harshness as a low impedance headphone should there be a stereo-loop in the ground distribution.

The above might well be the reason for the mania for balanced headphone outputs, which might effect a "half cure."

One might ask, then why only with a particular phono stage? The answer to that is where the stereo grounds meet. If they meet at the output, which is incidentally wrong, then the possibility is that any stereo-loop distortion is minimised, because it is referenced to a larger signal. If the stereo grounds meet at the input, as on the Reflex and all our phono stages (the correct way), then it is referenced to a much smaller signal. Therefore the stereo-loop distortion becomes more prominent.

Your speaker amp, simply because it is much more current hungry, and grounding errors exhibit themselves more aggressively, and as such the designer understands the grounding much better, will be grounded correctly such that the source ground will be expected to be at the input of whatever that source is.



Another reason for a different phono preamp enabling lower stereo-loop distortion would be its use of tree-trunk grounding, which, for good reason, the Reflex doesn't do.

I should try and be a bit clearer by what I mean when I say harsh. It is not that the sound is bad, if anything it is extremely detailed, the mids and base are good, but the highs are what is causing the problem, they are more forward and overpower the other frequencies. 

I am not familiar with the headphone amp you have.

Edited by CageyH - 29 Mar 2020 at 8:33am