Examine the JM LAB Cobalt sensitivity and impedance curve. Also consider how loudly you listen and the size of your room. All these considerations factor in to the answer to your question.
If the speakers are low sensitivity (below, say, 88db) and if they have low impedance dips (say down to 3 ohms), and if you listen at volumes in the range of upper 80s-lower 90s dB, then you may reap benefits with a higher power amp that doubles its power output into 4 ohms. Otherwise, stick with what you have.
For further research, I recommend Robert Harley's "The Complete Guide to High End Audio". Every audiophile should own this book, IMO.
If the speakers are low sensitivity (below, say, 88db) and if they have low impedance dips (say down to 3 ohms), and if you listen at volumes in the range of upper 80s-lower 90s dB, then you may reap benefits with a higher power amp that doubles its power output into 4 ohms. Otherwise, stick with what you have.
For further research, I recommend Robert Harley's "The Complete Guide to High End Audio". Every audiophile should own this book, IMO.