Trying to solve an issue with a newly purchased phono stage that doesn't have a subsonic filter. Recently acquired a Modwright PH 9.0 XT which sounds great until I have a record with the slightest warp or defect, then I get a really low frequency pulse/rumble/distortion that sounds like an out of place bass note or kick drum.
I'm trying to figure out why this has only now been noticed but in the meantime, I am leaning towards the tonearm having a high mass and the cartridge is medium compliance OR I have the wrong viscosity fluid in the dampening well for the mono-pivot. I own this cartridge Reference Two Moving Coil Cartridge | Charisma Audio
http://www.charismaaudio.com/?page_id=3956 and the Black upgraded arm for an older Well Tempered Classic
https://www.stereophile.com/content/well-tempered-arm-more-rh on a Sota Sapphire table which should provide way than enough isolation to suppress speaker or foot fall interference.
This is a very custom steup but I am looking at ways to reduce the tonearm mass as I think thats the easiest thing to address right now. Anyone have tips for this process? I have added more than enough dampening fluid but unsure its the right viscosity
https://turntablebasics.com/silicone.html I ordered the 100,000 cSt type but I am now thinking I needed 600,000 cSt as no amount of fluid added to the cup seems to have any affect on the sound or my test record resonance track which seems to be vibrating around 5-9Hz.
