Abbas Esoteric Audio DAC 4.0 Please note, I'm selling the fully operational circuit board without the housing. Please feel free to ask for more information or pictures. I'm shipping for free. This is a custom built non-oversampling (NOS) DAC by Abbas Zulfugarov, the designer of the more mainstream (but lower end) SW1X DACs. It is arguably Abbas' highest-end offering, built around two new-old-stock Burr Brown PCM58P R2R (multibit resistor ladder) chips. The now-discontinued PCM58P had the highest true bit depth of any mainstream R2R chip owing to its unique outboard trim pots that allows each chip to be individually compensated at installation. The presentation is a bit more honest/less romantic than TDA1541 and PCM63. This DAC has one of the most natural timbres of any DAC I've tried. Far superior to Hugo products, Metrum's Pavane/Adagio gets closer but I still think Abbas wins on naturalness. This DAC sounds analog! It is not souped up and edgy like the delta-sigma Mytek stuff. The output stage of this DAC is a copy of Kondo's Audio Note SRPP stage, based on matched 6bl7 tubes. I have a spare set that I will include. It uses Black Gate capacitors around the DAC chips, and AudioNote Tantalum resistors in the audio path. Abbas is known for his fanatical devotion to parts selection, virtually all of which are discontinued or vintage, salvaged from old German and ex-Soviet equipment. Everything is discrete and oversized—you will not find any surface-mount nonsense inside. I can accept PayPal friends and family, please let me know if this is the option for you.