Update. September 13 2005:

This site gets a lot of traffic (just see the counter below) and I get a lot of email from all around the globe.
It is my pleasure to help other DIYers modify the Sonic Impact amp. This cheap little amp is capable of AMAZING results with a little help. Check thru this site for ideas and facts on upgrading your amp.

Below are some comments from people who have followed my mods and found a wonderful amp hiding in that little plastic shell.

"This is the best value ever in all my life! 2 months ago I would have paid $3000 for such a product!"
FL- Paris

"The sound now at over 100 hours use is incredible, comparing favorably with my Art Audio Symphony 300B SE ( I would say the T-amp is more detailed, less euphonic ) crazy as it may sound I am in no hurry to reinstate the Art Audio."
DL-London

"What Glorious Sound!!!! I christened it with Wagner."
JA-USA

"I took the Tea- amp over to a friends house. He owns a 2A3 SET amp that he was in love with. The T amp stomped it into the ground, he was stunned and slacked jawed. The bass with the T on the Hammers (Dynamic speakers) was phenomenal! We put on a Bermister demo CD with a pipe organ piece on it and shook the room. Ha,ha,ha! Impact, Attack and detail were superb, the soundstage was wide, the imaging was almost as good as the SET but in every other category it ate its lunch. You will see the 2A3 SET on Audiogon next week."
TS-Atlanta

See? DIY Audio is the way to go!

There are 3 basic versions of the input modifications. All work well.
I am now using version 3, but versions 1 & 2 work very well.

In this version we will be bypassing most of the input circuit. All that remains is the feedback resistor. The new components can be wired "in air" hanging from the input RCA connectors and the volume pot, if used.

Dr. Fred was kind enough to supply a drawing for those of you who wish to modify the input section of your Sonic amp.
(I have modified his drawing slightly)

Below you will find photos that show the connection point I used as well as an alternative idea. My modification bypasses the input RFI filter. You may want to leave it in place.

If you use my connection points you will need a resistor to replace R1 & R2. I used a 22K ohm resistor in series with the replacement caps. If you use polypropylene caps, they will be VERY LARGE. The Panasonic CG series is the smallest I've found so far. Blackgate caps work even better and are very small, but the ultimate cap would be a film and foil type. I have used Auricap, Audiocap and Musicap all with very good, and very similar, results. Any good cap will be a big improvement over stock

VERSION 2 -- "JUST THE CAPS, MA'AM"

In this version you will be replacing ONLY the input caps. You will retain the input resistors as well as the input RF low pass filter. A good thing. Wire wrap wiring works well for jumpers to large new caps. You may be able to solder Blackgate caps directly to the empty pads.

To remove the SMD caps, heat the ends with the soldering iron and flick the caps off the board. Too much heat and you will lift the pad, too little heat and you will tear the pad. Go easy, please.

Connect your new caps to both sides of the now vacant pads. The pad toward the PCB edge is positive, if you are using an electrolytic. Same top and bottom. Note. There was a typo here before! The above is correct. No problem is you are using film caps, but be careful with polarized!

VERSION 3 "STEALTH"

We sneak into the PCB ahead of the RF filter.

The forum thread is here: