No worries none - especially with Benchmark DAC 2 or 3 as they have switched mode power supplies.
Benchmark DAC 1 uses an old linear style power supply so there could be a small risk of 60 Hz hum (from the transformer) if it got too close to the TT arm.
Benchmark DAC 1 uses an old linear style power supply so there could be a small risk of 60 Hz hum (from the transformer) if it got too close to the TT arm.