Headphone Amp using 6418 Tube
Jul 19th, 2010 by AnA
Happen to come across this fine headphone amp. It is using 2 pcs of 6418 tubes. I ordered this K272A amp from ebay and it took a while for the amp to arrive. After a long wait, on 4th June 2010; the amp finally arrived and I was overjoyed to receive it.
On 12th June 2010 saturday morning, I started fixing it up. Upon turning on the amp, I noticed the 6418 tubes started to grow a little. The dim light of the filaments cannot be seen clearly; it has to be in a very dark room inorder to see the grow of the filaments.
Excited moment came…I plugged in the headphone. But, to my disappointment, I noticed pretty loud ‘hiss’ noise. I thought it was due to my soldering faults or connection faults. But, after some query from the forum and understand that it seem to be normal for this amp. Anyway, for me, I noticed that by changing the headphone to a higher impedance does help to ‘reduce’ the hiss noise. So now, I am using the 60 ohms headphone to reduce the hiss nosie. The hiss does not actually disappear; it is still there but the impedance of the headphone just covered the noise up.
Anyway, beside the hiss noise, this can be considered as a fine sounding amp in my opinion. For just about AU30. I think it is a good buy. At the mean time, I am not going to let the hiss problem bother me. I just enjoy the music for now. Cheers!
