Turntable hasn’t shifted any. I do have a subwoofer but that pre-dates the cartridge swap. The only other change is a new phono preamp (sutherland little loco mkii). Would the pulsing change over the course of a record if it was a feedback issue? Thats what leads me to believe its an issue with the cart. On the record with the low frequency syth, the tonearm bounces slightly once every rotation and you get an audible sound I can only describe as "tshh". The more I look at the pulsing, it seems to occur once per record rotation across the board. Maybe its an alignment issue?
Phasemation Cartridge Compliance or Alignment Issue?
I think I may be having a compliance mismatch issue with the tonearm on my MoFi Ultradeck and my new Phasemation PP-300. I'm fairly new to selecting matching components in analog systems - the Ultrdeck had the mastertracker MM cartridge preinstalled. I had that cart for several years and noticed some degradation to the sound and looked to upgrade my setup with something new.
I've come across two records where I'm getting some distortion across the first song on a side. My speaker's woofers also pulse like they are trying to play a really low note. The record plays fine closer to the center.
Tracking down the mass of the MoFi tonearm was actually a challenge. From various threads that I've read online, the effective mass of the arm is different than what MoFi states in their specifications. Based on this thread, my assumption is that the effective mass of the arm is 25.14 grams.
https://forum.audiogon.com/discussions/cartridge-reccomendations-for-the-mofi-ultradeck
I was searching for a low compliance MC cartridge to match with this tonearm and came across the Phasemation PP-300 as an option. This cartridge has an effective mass of 11.1g and a compliance of 8.0x(e-6)cm/dynamic@100hz. Using an online calculator, i thought I wad made a good selection, however based on some research, I've since learned that you need to convert this figure to compliance at 10hz for proper evaluation and system matching (1.7x multiplier). Recalculating with the new figure yields a resonance of 7.0hz. Have I made a mistake going with this cartridge? Many of the records that I've played have no issues whatsoever. One of the poor performing records is a live recording and the other is an album with low frequency electronic synth sounds.
I set up the cartridge with a Dr. Feickert protractor. Looking closely at the cartridge, it appears that the headshell and cantilever are very slightly askew from each other. I aligned the cartridge to the headshell. Is it possible that a slight misalignment would make the low system resonance more problematic? I don't notice any skew to the image and both channels seem balanced to my ears but of course that is challenging to determine.
Is there anything that can be done to raise the resonance of the system to a more optimal value?
Any help or insight would be appreciated!
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- 20 posts total
- 20 posts total