I have a Project Debut III turntable which I use with Shure M97x MM cartridge and Project Phono Box as phono stage.
From my local dealer I took for a trial Project Tube Box II SE to see if there will be any sonic improvement. After I set it up I turned on the system and the sound was really better than before. Very ppen with a strong punch and much louder than with the previous phono stage....
However, I than realized that by mistake I had the phono stage switched to MC...switching back to MM (the correct one !) was rather disappointing as I lost everything that I described earlier.
I'm a little bit puzzled now and I need your advice ?
Why is this happening (to my previous phono stage - the basic Project Phono BOX - if I switched on to MC the sound was hummy, muddy and basically wrong and unusable. It seems that in this case I get exactly the opposite effect ?
Can I continue using the Tube Box switched to MC, even though I have an MM cartridge as I like the sound ?
You need to use the phono pre amp as it was designed. A MM cartridge has much higher output and different loading requirements than a MC cartridge. The most likely explanation of your experience is the lower priced pre amp has a lower overload point and your MM cartridge pushed it into distortion.
Choosing the set up that is wrong is not uncommon when the level jumps up due to the higher gain of the MC circuit. If you truly believe this is not just gain change that is repsonsible for your reaction, then I would suggest you investigate whether your cartridge benefits from other than standard MM loading.