Details:

PRT07B preamp refer 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 x177 x1.6MM 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

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

Image 1 - HiFi 1PC PRT07B Tube Stereo Preamplifier Board Pcb Refer Marantz M7 Circuit

Image 2 - HiFi 1PC PRT07B Tube Stereo Preamplifier Board Pcb Refer Marantz M7 Circuit

Image 3 - HiFi 1PC PRT07B Tube Stereo Preamplifier Board Pcb Refer Marantz M7 Circuit

Image 4 - HiFi 1PC PRT07B Tube Stereo Preamplifier Board Pcb Refer Marantz M7 Circuit

Image 5 - HiFi 1PC PRT07B Tube Stereo Preamplifier Board Pcb Refer Marantz M7 Circuit


Assembled board ，just for reference：

图片 01 - 高保真 prt07b 12ax7 前置放大器前置放大器板套件基础上马兰士 m7 前置放大器电路

图片 2 - 高保真 prt07b 12ax7 前置放大器前置放大器板套件基础上马兰士 m7 前置放大器电路

图片 3 - 高保真 prt07b 12ax7 前置放大器前置放大器板套件基础上马兰士 m7 前置放大器电路