Thursday, 28 April 2011
Completed the Elekit TU-882
Last night, I had the opportunity and time to fully assemble and complete the last steps of the Elekit TU-882R headphone amp. Firstly, I have to say that the quality of components and fit are top rate. The chassis work is extremely nice, though it may not be your taste, one cannot complain about the quality. I myself, like it, and will most likely leave the tube guard off, as I like to look at the tubes, and also do some tube rolling. More on that later.
Check out the progress build photos below. You will notice that I have put to use the stock 0.1uF polypropylene coupling caps to good use. I have used them as the PSU electrolytic shunting.
I had about one hour last night to listen to the amp before I had to retire for the night. Firstly, it worked! On first impression, the sound is quite relaxed, but what I noticed most was the bass control. A lot firmer than the Ear+. Anyway, more on that later, but I discovered an interesting problem.
There is sever noise or ground contamination. This is the situation. When the volume is all the way down, I can hear hum on both channels. Relatively loud, and doesn't go away when I connect or disconnect the source, or when I touch the chassis. When I turn the volume 2 clicks on, I can hear some strange buzzing on the left channel, with the hum still on in the background. As I turn the volume up, the buzzing doesn't get any louder. Until about the top two clicks, the buzzing disappears immediately, and is replaced with noise on both channels (the white random kind). I can still hear the buzzing at the top three clicks, but it is getting progressively softer. Meanwhile, the noise is also getting softer the further away from full volume, within the first 2 or 3 clicks, it is gone.
The strange buzzing is heard through the music, quite annoying. Now, I did not use the stock supplied PCB for the volume control, and this may be attributed to that, but I am sure it has something more to do with the ground scheme. Perhaps, I have to get the saw out earlier to get the IEC with a proper ground connection done sooner. Anyway, will be speaking with Victor about this, and see if he has come across this before, and find a solution.
Otherwise, this has spoilt a good and fun kit to build. And whilst the music is playing, but minus the buzz or hum, it is quite enjoyable and pleasant. More to come soon!