With a very good system like yours, I have to agree with Dave_b that cables and power cords will have a major impact on the amount of detail and also the harmonic texturing.
Right now, I am comparing two Synergistic Research power cords, a Precision AC and a T3 UHC. Both are excellent power cords but each sounds different on my amp. Using your violin/cello scenario, I can hear more emphasis on the plucking of the string with the former (more detailed and leaner) and more of the body of the instrument with the latter (less detailed, warmer and richer).
Although you have good cabling currently, you might experiment with others to see what the effect is. You can guess which brand I prefer.
Right now, I am comparing two Synergistic Research power cords, a Precision AC and a T3 UHC. Both are excellent power cords but each sounds different on my amp. Using your violin/cello scenario, I can hear more emphasis on the plucking of the string with the former (more detailed and leaner) and more of the body of the instrument with the latter (less detailed, warmer and richer).
Although you have good cabling currently, you might experiment with others to see what the effect is. You can guess which brand I prefer.