Topping A70 Proheadphone ampfeedsSennheiser HD 660 S2headphones
Used together in 2 real systems
Strong match
Topping A70 Pro + Sennheiser HD 660 S2 is a strong match — no compatibility concerns worth flagging.
What the compatibility check found
Headphone Impedance Matching
Pass✓ Excellent impedance match (damping factor: 3000.0)
Physical Connectivity
Couldn't verifyConnector matching does not apply to this pairing