TK2050 Extremely successful modifications -- list, pics, review

Hi Gripracer

I also acquired the TK2050 kit from Sure Electronics. When googling to find forums talking about people tweaking it, I found your post. Surprisingly enough, we have nearly done the same changes (cool guys think alike ;))
I've been doing a long job on this kit. I started by changing the input

- remove the surge protection component in the rear of the pcb (totally useless)
- remove the SMD input caps and go for a 2.2 µF film type

Then I checked out the 6 x 330 µF decoupling caps and changed them for 6 x 470 µF from ELNA (audio type). The 100 nF film decoupling caps in parallel was changed to film type WIMA 470 nF

The input and output caps around the LM317 where changed : input one ELNA 100 µF and the ouput is 470 µF, ELNA too, instead of the 100 µF recommended by TRIPATH TC2000 application note.

The ouput filter was changed to WURTH SMD high current inductors, 10 µH, the caps are now 470 nF film types from ELNA, and the differential cap is now 100 nF from ELNA too. Please all note the SURE original values are wrong and give an unuseful lower cut-off frequency.

I must point out that all those changes where not done together, this is my final system.

Originally, I had done them all except the input / output caps of the LM317 which are also the decoupling cap of the TC2000 processor. I ended having a wonderful stereo effect, wall shacking bass (if any in the cd of course), crips metallic trebles, wonderful voices on female ones. But the sound was lacking of density in the high bass, low mids. For example, male singers sounded in mono, and hidden in the background of the scene. With electric guitars playing low notes, I could only hear the harmonics of the note, not the fundamental frequency of it. Sometimes, it could lead to aggressive sound at high listening levels (the sound was no more balanced between bass, mids and trebles)
At first I thought it could be a problem with the transit time of the output filter that was favoring too much the highs. But then I recalled that the output filter does not work at all in audio band but is just there to clean the noise. Even if its Q factor was miscalculated, the overshoot would be well after 20 Khz, probably 4 or 5 times more.
I was losing hope, thinking I had reached the best of those TRIPATH chips.
This is when I had a few days later the idea of tweaking the LM317 surroundings too. What a mistake it was to neglect that ! After the tweaking, this lack of density disappeared totally, male vocals where back in the game, guitars sounded right, piano lower notes had impact, everything was back in place.

To be totally sure I told you guys all about my setup, I would like to end with the power supply. I've read many pros and cons, based on magic / believings more than science, regarding linear power supply (regulated or not) vs switching power supplies.
After testings them all, I ended up choosing a toroid transformer followed by strong decoupling with low impedance caps. This filtered voltage is followed by LT1084 regulator. The end of it is also decoupled by 2 x 470 µF ELNA caps in parallel, to further decrease ESR.
The cost of it is same as a good quality switching power supply, but without the noise of it.

Finally, I acquired a second kit of TK2050, which for those who never used them, are stereo. Why that ? Because out of curiosity I wanted to hear if any difference using 2 kits in mono.
So I used my 2 SURE kits, but using one channel only (thee other channel left open both at input and output). Each is used in pure mono since each one has its own power supply. Compared to the single power supply with one stereo kit only, the image improved. Not that it is much "wider", it is more that it has a different shape that sounds more spacialized to me


Keep tweaking !
 
Mods

Hi,

I'm Ryan and new to this DIY thing. I bought a Sure TK2050 board and am waiting for a toroid power supply and a Power PCB with built-in speaker protection. I tested my Sure PCB with and without the Sure Rotary Volume PCB (louder without) and I'm pretty pleased with the sound compared to my Marantz PM7200.:) So I decided to built a full replacement for the Marantz.:eek: So I'm thinking about putting this all in a Dun Mei chassis (black) with only a 4-position selector switch. The only thing I cannot do myself is modify the board like you guys did. I don't have any experience with soldering small PCB (parts) and I examined my PCB and it looks like the layout may be different. Because the capacitors that can be removed have different numbers I think, but as a complete noob I'm not sure. :confused:So if it's impossible to do myself is there a place or somebody who does mods for a reasonable price?:D
 
You can also use input transformers, which is a nice way of going capless.

Nope you can't, it's dc biased at the input. You don't want the secondaries on a permanent DC voltage source because it'll just burn up.

john, I am taking nothing from anyone's back. any knowledge I have gained here was given freely. You're acting like I'm forcing people to buy my amp. The only person who has plugged my amplifier has been you.

And someone who wasn't that satisfied with it at all, through this 'customer' of yours I discovered even the charge current of the battery wasn't taken care of properly giving a 25% overcharge on an SLA. That's fire and/or explosions waiting to happen in someones livingroom! If you haven't even got the knowledge of electronics to get that right how come you think you can start to mod a class D amplifier?? Let alone the output filter section!!

I know it is super cool to mod, hearing the differences in sound appear and gaining some experience with electronics. Only you won't become half as good in the matter as when you study the basics first. Actually you shouldn't even start modding until you have at least gained some knowledge on safety.

Then if you are a nowbie modder, start at the place that does the least harm, the power supply section and input section. The effects of mods are great there and at least don't turn it in to a hazard that quickly.

Then if you are brave and most of all wise enough to work on the output section you must have basic knowledge of radio frequencies, transmitting, parasitics and last but not least power.

I have just read on the other mod thread that someone ordered the 2 channel amp and got the 4 channel amp that they are selling with 2 channels disabled instead. It seems that Sure is determined to get rid of the defective 4 channel amps no matter what.
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http://www.diyaudio.com/forums/clas...path-board-tc2000-tp2050-104.html#post2084994

Does this really surprise you? How much profit do you think they actually make on this sweatwhop product? Any fraction of a penny cheaper component is their first choice, guaranteed!

Anyone ever discovered why it runs so insanely hot by the way? Anyone measured for oscillations?