www.mouser.com
Resistors:
72-TS53YL-5K
TS53YL502MR10
5K OHM 5MM SEALED
Unit Price: 1.28
Quantity: 2
71-CMF558K6600FHEK
CMF558K6600FHEK
1/4watt 8.66Kohms 1
Unit Price: 0.15
Quantity: 1
On-Off Switch:
633-M201303
M2013SS1W03
ON-OFF-ON PC SPDT
Unit Price: 3.31
Quantity: 1
Capacitors:
647-UKA1V472MHD
UKA1V472MHD
35V 4700uF
Unit Price: 4.35
Quantity: 1
647-UKL1E222KHD
UKL1E222KHD
25volts 2200uF
Unit Price: 2.16
Quantity: 2
Note: The capacitor below is not needed since it can just be removed from the signal path.
667-EEA-GA1A101
EEA-GA1A101
10volt 100uF 6.3X7mm
Unit Price: 0.3
Quantity: 2
Transistor:
844-IRL510PBF
IRL510PBF
N-Chan 100V 5.6 Amp
Unit Price: 1.22
Quantity: 2
And here comes another tube amplifier. I was very skeptical when I saw this thing on ebay at first. “$86 shipped for a tube amp?â€, I thought. It must be a piece of sh**. But I wanted a tube amp for my office at work. It had to be something small. So I started to research about this tube amp and a couple of other amps on ebay. After a bunch of research and being guided by the following thread
http://rockgrotto.proboards.
Based on the thread it was obvious that the tube is OK sounding device as is, but could be made in a fantastic headphone amp if a couple of mods are made. I decided to take a plunge and buy the little thing. I got lucky and found it on ebay used. All together with shipment was $50!!!
I got the amp, plugged the tube it came with and as expected, the sound quality was very average. The tube it came with ShuGuang was a piece of crap, so the results were not stellar. I plugged my good NOS 12au7 tube into it and the sound transformed immediately, but you could hear that there was a lot missing extension and details wise.
The next step was to mod. All the mods with 2x extras cost me about $33 (see here for the complete list of items from Mouser with parts number). Did all the mods that are described on the board and lo and behold, the amp transformed into beauty from a beast (although it looks like a beast after the mods J ). The background noise went all the way down to none existent (depending on a tube). Details opened up beautifully. High frequencies went through the roof – figuratively speaking J
One mode I was not really sure about is changing bios resistor for a trim-pot, but I was happy that I did at the end. Without the change, the amp would only accept tubes from 12au7 family. With the change, I was able to feed it with tubes from 12ax7 & 5751 family!!! Plug a tube, adjust bios on both channels and you have a great working amp. It was funny to see $200 tube in a $50 amp, but sound it was able to produce was superb.
So in conclusion, don’t buy the amp if you are not planning to make the mods. But go for it if you can solder (it would take about 2 hours for all the mods – with a lot of verifications in between – DO THE MODS ONE AT A TIME!!!). Get a good NOS 5814 tube and you are set. You will be amazed, but the sound that’s coming out of that little monster! I compared it to sound from McIntosh 275 and 300B monoblocks – the sound quality is on par!!!