ZOLA

About the ZOLA

The BorderPatrol ZOLA is a high-end digital-to-analog converter designed around a true non-oversampling (NOS) R-2R architecture using an Analog Devices AD1865 converter chip. It omits digital upsampling, interpolation, noise shaping, and reconstruction filtering, instead emphasizing a short, minimally processed signal path. A 5687 dual-triode tube output stage operates without negative feedback and is capacitor-coupled to the analog outputs. The DAC uses separate power supplies for its digital and analog sections, with tube rectification in both supplies; the high-voltage supply uses choke-input filtering. The chassis is primarily painted copper with an aluminum front panel. Tube rolling is supported, allowing compatible 5687/E182CC, 7044, and 7119 types, plus 12BH7 and 6463/6350 tubes with suitable adapters. The ZOLA supports high-resolution PCM up to 32-bit/384 kHz through USB, up to 24-bit/192 kHz through coaxial or BNC S/PDIF, and up to 24-bit/96 kHz through optical TOSLINK. Available evidence indicates that the ZOLA is a current BorderPatrol product rather than a discontinued model; reports of discontinuation refer to earlier BorderPatrol DAC SE/SE-i models.