Well really, it is a design using the Korg SP1 Nutube that Pete Millet came up with. What I have found out so far is that the combination of headphone/amp is very important here. The Ori is not the best match. The Hi-Fi Man HD600S is not the best match. By far, the Grado SR225e is the phone that sounds best with this amp. In my world that is great because until now, I didn't care much for the Grados. They were just too bright. The midrange was a touch forward. Not anymore. This is as good as it gets in this price range. The kit runs about $120 plus any upgrades that you want to add.

Had this cigar box given to me, and it turned out fine.

Ok, since this amp has some possibilities given the price, I figured why not try out a 'new and improved' power supply? I went from a switching supply to a linear supply, and this is the same except for better specs. It is a tongue in cheek idea, but I like to experiment so here goes. A shot of the regulator that may be used in the new power supply:

Man, this has gotten interesting. This headphone amp has an output to be used as a pre-amp. I ignored it until I was done with my tinkering with the power supply, resulting in what I preferred for a headphone amp. So, last night, I added some RCA connectors to the output, and hooked it up yo Rachael. The good news is that I am listening mostly to the pre-amp, and it's differences through my system. I like this because, I already know what Rachael sounds like, and have a bit less to process in the evaluation. Here is the interesting part. There is a midrange presence that is added which I really like. It doesn't make sense because part of that is what I am trying to tame about my speakers. It does add quite a bit to the presence of the hall. But Wait A Tick, something is quite different here. There is too much 'hall effect' that wasn't present before on my Lyle Lovett CD. THEN it dawns on me. The hall effect may very well be the microphonic aspect of these tubes! MAkes sense. CD plays music through system, speakers make sound, sound hits tubes causing the 'microphone' to be excited, microphone sends signal back through system... you get the idea. Kind of like owning an amp with a delay, almost echo. I will try this at lower volume today, and set the pre-amp away from the front of the speakers. Coll, but not cool, ya' know?