[MDR30]

Thought I'd put a little light on this modest preamp you can get for 50 bucks or so. I find it practical to use mp3-players as sound sources, and sometimes their output is far from the 1-2 volts most headphone amps require. So this little device comes in handy for what it is: a preamp. I'm gonna use it as a step-up to some of my headphone amps, and so far it seems to work. When tubes are burnt in and tested I'll report about function and sound.
 
It was introduced to me here:
 
http://www.head-fi.org/t/626374/muse-tu-20-tube-amp-anyone-try-this-little-cutie#post_9348105
 
Some interesting findings in these customer reviews:
 
http://www.amazon.com/stereo-audio-amplifier-PRE-AMP-Buffer/dp/B008ICH0KA/ref=sr_1_1?ie=UTF8&qid=1365757932&sr=8-1&keywords=6n3+tube+preamp
 
(By the way, connecting the 220V transformer was no problem at all.)
 
The amp kit seemed simple enough, so I ordered one and after a little searching found a bamboo box to put it in, DIY (all you need is a drill, screws and nuts, a mains switch, cable and mains plug).
 

 

 

 

 
And now with the tubes and green leds (all included...) lighted:
 

 

 
 
 

 
Russian and Chinese 6N3P may not be the ultimate valve choice, so I've ordered a couple of 2C51 to roll with, keeping a low profile you know.

 

[MDR30]

Assembled another one and tested some Russian tubes (Chinese originally) which to my ears sound better. Listened to FLACs through this and an Audiotailor Jade (OTL) with AKG K400 and it sounds wonderful. Pure tubes all through: 6N3P, 7025 and 6AS7G.
 

 

 
The bamboo amps are quiet with no hum problems. Find them very entertaining.
 
Now I'm looking forward to those 2C51 tubes coming in.

 

[DefQon]

Nice, I've been looking at them years on fleabay thinking of doing something useful out of it if I do end up buying one.

 

[MDR30]

These military JAN5670 (2C51) tubes are smaller and sound great. Can't do without this amp now playing FLACs from my Clip and D2 through the amazing obsolete Audiotailor Jade OTL with RCA 12BZ7 and Sylvania 6AS7G. Wonderful soundstage with modified K500, K400 and K401.