Lampizator Big7 as a preamp

I borrowed Lampi Big7
and I am little disapointed
First : build quality is like DIY product( especially in this price )
sonically is good, colourfull with weight and body, but resolution and detail is better in Berkeley
The most important: quality of build in preamp is much better in Berkeley, directly connect to my active speakers /power amplifier no contest BADA wins

It was 300B Psvane version, so better than standard