ProxxAmp


Some day i found a simple TDAxxx based amplifier module in one of my parts bins. I guess i ordered one on eBay because they are so cheap. I also happened to have a broken Proxxon power supply. Luckily, the actual transformer was working well. I decided too build a replacement for my Rat Amp out of these parts.

It fits, but only just. The is from a super-socket-7 system (cut in half), rectifier and smoothing cap are soldered flying. It looks as if it should fry itself in no time, but it actually runs pretty cool. The TDA is quite efficient and the transformer does not provide that much current anyway. Well, if fed a 1khz sine wave and cranked all up it gets hot quite quickly. If fed some nice drone and cranked up just below distortion it keeps lukewarm, but not very loud.

Yes, the very small switch is rated for 250V. Oh, and there is a fuse. Its soldered into one of the primary connections and wrapped n shrink tube. As are all primary side connections.
The double throw switch on the top is intended to switch inputs. Currently it switch between the hard connected 3.5mm plug and nothing ;)

Behold the wonderful ASCII schematic!


  -  -----
2  ()     |   12V AC
2  ()   _/ \_________________
0  ()  | \ /    |            |
V  ()  |  |     -          |\
  -  -----     | |  In L --|  \--- Out L
       |        -   In R --|  /--- Out R
       |        |          |/
       |________|____________|

Cute but stupid!
total: 131.1ms (include: 2.45, request: 0.88, trace: 0.4, init: 3.6, load: 0.01, parse: 120.25, menu: 0.94, template: 2.51, minify: 0.06)