Modified Sonic Impact 5066 T-Amp

Modified Sonic Impact 5066 T-Amp

This article originally was originally published in Affordable$$Audio E-Zine in the April 07.  With kind permission of Affordable$$Audio and the Author Robert Powell I am pleased to re-publish it here.





  • Ming Da MC7 Valve Pre-Amp
  • Cambridge 640Cv2 C.D player
  • LiTe Dac Ah Non-Oversampling DAC
  • Musical Fidelity:-X-10D, X-Tone, X-LPs, X-Psu
  • Rega P3 with Rega Super Bias Cartridge  (up-graded motor and Michel Technoweight modification).
  • Fostex 206E in 208 Sigma Back Loaded Horn Cabinet.
  • Q.E.D Genesis speaker cable.
    Mission 773e speakers  (speakers used for this review)
  • GLL Small cube subwoofer set mainly to anti-phase to counter a slight room boom at around 80 – 100 Hz
  • Chord Cobra 3 and Atlas Equator interconnects.
  • Price: $29

productshotIt took me a long time to catch on to the Sonic Impact phenomenon. It was not until November 2005 that I read an article which described the modifications that could turn this “giant killer” into a Giant Killer!


I initially ordered two of them, one from the U.K and one from the U.S, of course the U.S one arrived first! In anticipation of their arrival I made some adaptors to enable me to use my large bore Q.E.D cable and found a small jack plug to two phono sockets to enable me to connect my pre amp. In my parts box I had a 12v 1200ma adaptor.


The amp duly arrived and my first impression was the weight. It had no weight. Was the box empty? On taking the 5066 out of the box the second thing that struck me was the size of the amp. It was obvious that all photographs that I had seen had been enlarged or that my understanding of the size was grossly distorted.


{include_content_item 45}The Sonic Impact amplifier measures 1.5” by 6” by 3.5” HxWxD. On the front there is a combined volume control and on/off switch on the front. If you have bananas for fingers you may find operation a little tricky. On the rear are two sets of spring clip terminals for the speaker connections. These will only take thin gauge wire and so some adaptors were made as mentioned previously.


There is 3.5mm jack socket to take the signal feed from the Mp3 or C.D player and a 12v power socket for an external supply. The unit is has an under tray which takes eight AA batteries. However I did not try the unit with alkaline batteries. 


It took no time at all to get it connected up and then switch on time. The third thing I noticed was a pronounced “hiss” from the speakers. Having read that there was no discernible bass from the stock 5066 I left the subwoofer off to get a proper impression.