Details:

PRT-07B preamp is reference the famous Marantz M7 preamp Circuit , The sound quality is mellow, the medium frequency is sweet and natural. tube tastes very strong. PCB size: 152*177*1.6MM FR4 Works voltage: 0-220V AC >=15mA （200-220V all ok)， 0-14V AC >=0.8A (12-14V all ok) Gain: about 11 times. This preamp are using 3pcs 12AX7 Tubes. （note: the defalut are not include the tubes)

Note：

Bare pcb：just 1pcs pcb ，have no any parts Diy kit：all the parts need yourself to solder.（not included 3pcs tubes） Assembled board：have tested well，（not included 3pcs tubes）

Recommend transformer: https://www.ebay.com/itm/353283816611