Silvergsx,
Switching your preamp to mono may be helping in two ways:
1. Many preamp mono switches act as HF rolloff filters, so HF problems simply become less audible.
2. Summing to mono may prevent distortions resulting from L and R information that's at the same (high) frequencies but every so slightly out of synch or phase with each other.
It is VERY difficult for an amplification chain to cleanly reproduce two (or more) similar or identical waveforms that should be marching along as individuals, so to speak, without "glomming" them together into a distorted mess. The higher the frequencies and the greater the amplitudes, the tougher it is for the system to keep all the separate waveforms separate. Blending to mono before amplification begins greatly simplifies the job (and the music, naturally).
Your Grado is unquestionably part of the problem, but your amplification from phono stage to power amps may (or may not) also be contributing. Best guidance IMO is to try a more resolving cartridge first, to see how far it gets you and whether or not you like the new direction.
Switching your preamp to mono may be helping in two ways:
1. Many preamp mono switches act as HF rolloff filters, so HF problems simply become less audible.
2. Summing to mono may prevent distortions resulting from L and R information that's at the same (high) frequencies but every so slightly out of synch or phase with each other.
It is VERY difficult for an amplification chain to cleanly reproduce two (or more) similar or identical waveforms that should be marching along as individuals, so to speak, without "glomming" them together into a distorted mess. The higher the frequencies and the greater the amplitudes, the tougher it is for the system to keep all the separate waveforms separate. Blending to mono before amplification begins greatly simplifies the job (and the music, naturally).
Your Grado is unquestionably part of the problem, but your amplification from phono stage to power amps may (or may not) also be contributing. Best guidance IMO is to try a more resolving cartridge first, to see how far it gets you and whether or not you like the new direction.