Ordered one to use for burn in purposes. Of course I will give it a go in main rig out of curiosity. For $56 no need to use my preamp to burn in cables.
Please remember passive preamps do not fit all systems. For optimum performance the source [ CD/DAC ] requires a minimum of 2V output. The more the merrier. Then ones Amp should have a low input sensitivity. They will work without these requirements however not their best.
I have owned several passive designs. Promithius, Stevens & Billington which are transformer based. As well as several other resistor based ones. I prefer the transformer based.
For $56 again well worth a spin. Let ya know what I hear. Will be comparing to a Lamm LL2.1 preamp. Yes unfair but informing.