Make/buy rumble/warp filter for pre phono inputs?

This is possible, and I had hoped another member would offer a suggestion by now. I hesitated because I think this is a terrible idea.

Any low pass or rumble filter means cutting off the bass. Unfortunately this occurs over a much larger frequency than you might imagine. I have heard filters that affected the lower midrange, when they were aimed as solving excessive woofer excursion.

I had a phono stage that a manufacturer was experimenting with. He had gotten complaints, primarily from Japan about woofer movement.

Bottom line is that he put the "fix" on my phono stage and I went crazy looking for problems (tubes, set up, etc.) for days. I finally called him and told him my problem and he confessed he had tried the new circuit. After removing it my sound was perfect again.

If you have a good system, I would forget about the filter. If you have a turntable that excites the system excessively, spend the money to repair or replace the source of the problem, rather than filtering it.

Zaikesman, now I understand. I admire you for caring enough about music to save these less than perfect favorites, and now your filter idea makes perfect sense.

The problem is that putting a network of resistor and capacitor at the input of your RIAA stage can mess up the phono cartridge load and the input impedance of the preamp.

I suggest calling Conrad Johnson and tell them your situation. They have engineers that have probably already addressed this problem for others. My guess is that the filter should be in a tape loop. Other possibility is an equalizer, allowing you to cut and add for each situation as needed.