questyle sigma bluetooth headphone amplifier usb c rechargeable dac amps | [mfi certified] portable bluetooth 5.4 usb amps with 3.5mm and 4.4mm dual outputs pcm768/dsd512 for smartphones/pc/laptop is up for auction in Electronics. The current bid is $26.00, 96% below the $599.00 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.