That’s an excellent question, Mesch. And in fact some balanced amps, such as most or all of the the Audio Research Reference series amps, won’t work properly when provided with unbalanced signals via adapters. In those cases apparently only half of the balanced signal path within the amp would see a signal, resulting in a drastic reduction in power capability among other consequences.
However the manual for the VK-200 indicates that it can accept unbalanced inputs via adapters. So presumably its input stage has both differential inputs and differential outputs, which when provided with a single-ended input would provide the rest of the amp’s internal signal path with a balanced pair of signals, although presumably 6 db lower in volume than if a balanced pair of inputs were provided.
Sunnyjim, I would have some concern about subjecting the Sphinx’s RCA output connectors to the weight of an RCA to XLR adapter plus the weight of the XLR connector on a cable and the weight of the cable itself. So I would either purchase an adapter cable as has been suggested, or use RCA cables in conjunction with adapters such as this one at the amp’s inputs.
You might also consider a Jensen Transformer, configured to provide RCA inputs and XLR outputs, although the cost would obviously be much higher than the cost of a pair of adapters. It would convert the unbalanced signal for each channel to a true balanced signal pair. In doing so it would eliminate the possibility of ground loop issues, and provide noise rejection comparable to the performance of a fully balanced interface.
Best regards,
-- Al
However the manual for the VK-200 indicates that it can accept unbalanced inputs via adapters. So presumably its input stage has both differential inputs and differential outputs, which when provided with a single-ended input would provide the rest of the amp’s internal signal path with a balanced pair of signals, although presumably 6 db lower in volume than if a balanced pair of inputs were provided.
Sunnyjim, I would have some concern about subjecting the Sphinx’s RCA output connectors to the weight of an RCA to XLR adapter plus the weight of the XLR connector on a cable and the weight of the cable itself. So I would either purchase an adapter cable as has been suggested, or use RCA cables in conjunction with adapters such as this one at the amp’s inputs.
You might also consider a Jensen Transformer, configured to provide RCA inputs and XLR outputs, although the cost would obviously be much higher than the cost of a pair of adapters. It would convert the unbalanced signal for each channel to a true balanced signal pair. In doing so it would eliminate the possibility of ground loop issues, and provide noise rejection comparable to the performance of a fully balanced interface.
Best regards,
-- Al