Hello.
I have used a pair of MA20SE speakers for some 10 years now. I used to drive them with Krell KRC pre & KSA-150 power combo. with a Trichord modified Teac P-700 transport Theta G3 DAC. Wires were home made using a combination of silver & copper conductors. Sound balance in my previous place (10 x 15 ft room) was OK, slightly on the lean side. The 20SEs do have a slight tendency to sound lean, with a "clang" (as described by Martin Colloms in his review from many years ago) in the presence region which solid state electronics can exacerbate.
Now that I have moved to a bigger place, the balance became too lean. To correct, I have tried various cable changes - interconnects from Tara Labs Air 1s; to Siltech SQ28 G5 and Speakers from XLO to Audioquest Gibraltars. I finally settled on Eichmann Express 6 I.C. & bi-wired speakers. I would say the richer sounding cables amongst the ones I tried were the Tara Labs Air 1 I.C. & the Audioquest Gibraltars. However, I would also add that changing cables to correct tonal balance is rarely 100% successful. It sound like your problem is caused by that change in the front end. In my case, I can tell you that the most beneficial effect I had in making the sound less lean was in changing the Theta G3 for a Musical Fidelity Trivista 21 DAC. So you might consider trying alternative CD/DAC combos too.
One last thing, if your 20SEs have been filled with sand in the base cavity, remove them. Sand filling leans out the sound even more.
I have used a pair of MA20SE speakers for some 10 years now. I used to drive them with Krell KRC pre & KSA-150 power combo. with a Trichord modified Teac P-700 transport Theta G3 DAC. Wires were home made using a combination of silver & copper conductors. Sound balance in my previous place (10 x 15 ft room) was OK, slightly on the lean side. The 20SEs do have a slight tendency to sound lean, with a "clang" (as described by Martin Colloms in his review from many years ago) in the presence region which solid state electronics can exacerbate.
Now that I have moved to a bigger place, the balance became too lean. To correct, I have tried various cable changes - interconnects from Tara Labs Air 1s; to Siltech SQ28 G5 and Speakers from XLO to Audioquest Gibraltars. I finally settled on Eichmann Express 6 I.C. & bi-wired speakers. I would say the richer sounding cables amongst the ones I tried were the Tara Labs Air 1 I.C. & the Audioquest Gibraltars. However, I would also add that changing cables to correct tonal balance is rarely 100% successful. It sound like your problem is caused by that change in the front end. In my case, I can tell you that the most beneficial effect I had in making the sound less lean was in changing the Theta G3 for a Musical Fidelity Trivista 21 DAC. So you might consider trying alternative CD/DAC combos too.
One last thing, if your 20SEs have been filled with sand in the base cavity, remove them. Sand filling leans out the sound even more.