I've been needing a good quality headphone amp to drive my HD-600's. My Creek OBH-11 has been a bit disappointing. Trolling through the posts I came upon the Lehman Linear and later the Lovely Cube. I'm working and living in China so I starting looking at the Chinese Ebay/Taobao. I found the boards that go with the lovely cube but found a circuit board that was a little bigger and looked to be of higher quality then the lovely cube.
I had about half of the parts on hand which included the 50W transformer, Riken resistors, Wima MKP-10 1.0 uf, and the Mills `10 Ohm for the output.. I ordered the case and some misc parts on Taobao and got the transistors, power supply caps, IRC signal path resistors and op-amps from Digikey when I was visiting family this summer in the States. I added the stepped attenuator. "I always prefer them to Alps pots".
I started with dual OPA134 op-amp's and then several other op-amps but I am sticking with the LME47920HA. Will do some experimenting with class A bias soon.
So how does it? I've been sitting with a smile every evening for the last couple weeks. Sound stage is wide and the information that is coming through is remarkable. Bass is well controlled. I bought an Objective 2 pcb in the States and will build that soon for comparisons. System used includes the Sennheiser HD-600 Mogami W3106 wire and Esound Reference Platinum CD player.
I'm not sure how it compares to the original Lehman or the lovely cube? I only have 2mv DC offset and it sounds great. Best of all it was fun to build.
Edited by nanchangbob - 9/10/12 at 5:13am