E19 headphone amplifier board K2381 J407 MOSFET Yuanjing Audio

[keilau]

I have a Sennheiser HD598 headphone currently used with the headphone amp section of a Tianyun Zero DAC with very good results. Just for the fun of it, I decide to build a solid state separate headphone amp. I found the YuanJing assembled board at a very good price.

https://www.yuan-jing.com/e19-class-...hone-amplifier

I was attracted to its all descrete, MOSFET output section design. It has uPC1237 Speaker Protection Chip. The producer indicated high quality parts are used. But I cannot find any schematics or circuit information.

I picked it over the Lehmann or Beyerdynamics clone. I already ordered one and it should be here in 2-3 weeks. Anyone has tried it before?

 

[keilau]

The E19 headphone amplifier board is NOT recommended for reasons of persistent hum. The hum problem is fixable, but you have a better, similarly priced, choice in Weiliang E-5 board.

I wanted a front-end input using Marantz HDAM input structure，2SK170 matching of 1% for differential input, fully complementary MOSFET output, uPC1237 Protection Chip, and at least 500 mW into 50 ohms loads. The E5 board only is getting difficult to find, but fully assembled version with case is still available at good price.

You can find the details of my E19 build log at the DIYAudio forum: http://www.diyaudio.com/forums/head...r-board-k2381-j407-mosfet-yuanjing-audio.html