iBasso AMP13

Placed on Amp13's voltage gain stage where it will yield the biggest sonic difference, this Nutube's small output then gets boosted by a Toshiba FET buffer. This preserves Amp13's triode square law, and grants it enough juice to drive the rest of the solid-state output stage. 

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iBasso built Amp13 with dual 3.5mm outputs. The hybrid Nutube section directly feeds Amp13's low noise, low output port (2.5Vrms) for sensitive IEMs.

Meanwhile, an intermediary solid-state driver stage gets added for the high output port (4.1Vrms) to push Focals and Fostexs needing more gain.

DX340's dynamic range spec is maintained through NJR's NJU72315 digitally-controlled analog volume part, and iBasso hide yet another trick up their sleeve: forcibly driving the ground signal of Amp13 to increase output power and reduce noise.

The separate 2,000mAh analog battery aboard the DX3XX line supplies the backbone of power for Amp13's high operating voltages, with four clean, individual DC power sections for crucial parts of the module.

The anode packs 21 volts of supply, while eight volt output rails continue to maintain excellent open-loop linearity before negative feedback.

Such is expected of a high-performance iBasso Amp13 module that yields excellent distortion and noise specifications, while capturing the romance of tubes in DX340. Also view Amp12 here, all of iBasso's other portables here, and our music player catalogue here.