Geshelli J3 Pro DAC with Sparkos and Sbooster mods

Measurement Results

Geshelli J3 Pro – Sparkos Sbooster

Geshelli J3 Pro – Sparkos Netgear Switchmode

Geshelli J3 Pro – Stock opamp – Sbooster

Geshelli J3 Pro – Stock opamp – Switchmode

Conclusion measurements

Measurement-wise, we see that the Sparkos has lower noise (quite a lot even) and distortion (significantly lower THD). So in practically all measurements the Sparkos comes out better. Nice! No nonsense then!

What’s really weird is that if we look at the differences between the power supplies, it’s all pretty close together. From this we can only conclude that measuring and listening can sometimes be quite far apart and that we are not ‘looking’ the right way with standard measurements. Yes: you can pick out technical ‘errors’. But we obviously cannot show the sound difference between an Sbooster and Netgear 12V switching power supply.

What is also fascinating is that while we hear differences in quietness and richness between the standard opamp and the Sparkos, the difference between the power supplies is actually greater. And the opamp is measurable, but the power supply only marginally …

Extra: XLR measurements (with stock opamp)

What we noticed is that our measurements are far from those on the Geshelli website. What we think is that they must be measuring with Sparkos opamps and via the XLR output. Because then they could be correct. That in itself is not a deception, but it would be helpful if they named it. Because you don’t achieve a signal to noise ratio of 120dB with the RCA output. Nor with the sparkos opamps. Neither do those distortion figures.