Do I need a MC cartridge now? Or an attenuator?

Hello folks,

I am turning to this network of smart folks for help in an area i don't know too much about.

I have a MoFi  Electronics StudioDeck+ turntable, and a MoFi Electronics UltraTracker MM Phono Cartridge. Previously, this MM cartridge output went to my McIntosh MA252 integrated amplifier using its phono input. The range of volume was fine and I could play it at a low volume - it sounded terrific.

I now have set up a mostly Laiv Harmony system  and the signal goes to the Laiv L-Ext for phonographs, and on through to the Laiv HP2A preamplifier and then to the Laiv GaNM Monoblocks. 

The sound volume control on the HP2A ranges down to minus 59 dB and then it shows an infinity sign and there is no sound output. However, the sound coming out at -59 dB is still rather loud. There is no volume control on the monoblocks; the HP2A does that entirely. In discussions with Laiv Harmony help (which is really responsive and helpful) has provided me with a couple of options. 

He wrote: "The MoFi UltraTracker is a high-output MM cartridge (~3.5 mV), while the LExt Phono is a dedicated MC phono stage with a fixed 70 dB of gain — optimized for low-output MC cartridges (around 0.3 mV).

"Using them together results in excessive gain — similar to feeding a line-level signal into a mic preamp — which causes the signal to be overly loud, distorted, or clipped. This is likely the issue you're experiencing.

"One option is to replace the current MM cartridge with a compatible low-output MC cartridge. You can also reach out to MoFi for recommendations on suitable MC alternatives that pair well with your setup."

A second alternative we discussed was to place a signal attenuator between the HP2A and the monoblocks - I have ordered Rothwell balanced in-line attenuators (minus 10dB) for about £71. I figured that can't hurt and is affordable enough to try.

Replacing my ultratracker with a moving coil from them is an about $1,000-$1,500 experiment.

My questions:

1) Are Rothwell attenuators OK to place in the line? Possible effect on the sound?

2) I am pretty pleased with my TT - I think it is very underestimated for its quality, out performing its price point in general. But would an UltraGold MC Phono cartridge for $1500 be wasted on that turntable? I am just not well enough versed in the differencs between their top TT and the one I have, to know if this makes sense.

Tim