APL HIFI DSD-GR – DSD digital-to-analog converter with tube output

APL HIFI DSD-GR is a new Pure DSD, “Galactic Reference” DAC, using a transformer-coupled tube differential Class-A output stage. The device is built on a fully balanced scheme and offers a proprietary asynchronous USB input module.

Next in the signal chain, the proprietary 64 bit PCM to DSD converter module with DSD256 and DSD512 capabilities (non oversampling NOS mode without filtering is also present). Digital-to-analog conversion is entrusted to the proprietary assembly of Pure DSD conversion module using non-magnetic resistors. APL HIFI DSD-GR is also equipped with RJ-45 input woking in balanced I2S mode.

The design of the APL HIFI DSD-GR uses an audiophile element base - custom Lundahl interstage and output transformers with oxygen free copper windings. Pure Class-A, differential output stage operates on the ECC99 tubes. Only non-magnetic resistors are used in the circuits of the device, op amps are not used, negative feedback is zero. Internal wiring is made of oxygen free copper cables featuring Esprit Audio cables for the critical paths. The main power supply of the model is based on an custom R-Core balanced main power transformer with OFC windings; Lundahl choke used for the tube power supply.