Details:

PRT-11A preamplifier reference - American Gary CARY-AE1 circuit, the circuit sound base is different from traditional Marantz 7, C22, etc. It has the characteristics of fast speed, large dynamic, medium frequency density and charming charm. . The PRT-11A high-voltage power supply uses a voltage-stabilizing circuit, which is adjusted by the Toshiba K2700 FET. The AC lighting method is used to supply the filament, one-point grounding, reasonable layout and routing, and the mutual interference of the tubes is minimized, and there is no noise. In terms of configuration, PRT-11A uses Hitachi high-voltage filter capacitors, chemical high-voltage decoupling capacitors, Taiwan 3W 1% copper foot metal film resistors, gold-plated electronic tube holders, and MKP coupling capacitors, which have a good price/performance ratio. PCB size: 155x177x1.6MM FR4 Works voltage: 0-220V AC >=20mA， AC3.15V -0- AC3.15V >=3A This preamp are using 4pcs shuguang 6N8P Tubes. This board with 30 seconds delay on output. can Avoid howling when power on.

Note：this is diy bare pcb ，not included any parts ！

Assembled board ，just for reference：