VERY CHEAP AND VERY GOOD TOY AMP !!!

My interest in toy amp started after completion of the markaudio 12p fullranger. it is 92db/w sensitivity and benign impedance make it an ideal platform.
I resurrected Trend audio 10.1 and after a bit of modding , sounds very good and surprising dynamic with  deep bass that is enough to play the Jiang Zhou drum cd.
TPA series of amplifier class t chips amp are designed for TV audio use. 
I bought a similiar version  of this amp

http://www.ebay.com/itm/2X50W-STEREO-CLASS-D-AUDIO-POWER-AMPLIFIER-circuit-board-TI-TPA3123/291067921693?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222003%26algo%3DSIC.FIT%26ao%3D1%26asc%3D20131003132420%26meid%3D5398927452331033461%26pid%3D100005%26prg%3D20131003132420%26rk%3D1%26rkt%3D6%26sd%3D251036250293&rt=nc

The build quality is adequate for the price i pay. The rca  input pins broke on arrival and the volume pot is defective. The sound from the stock  board is surprising good for the price but the 36 db gain is too much for my monica dac from diyparadise.
 I use the voltage diver to make the volume pot usable.
I tried  ceramic disc bypass cap for the power supply caps around the TPA 3123 and this improves the amp quite a bit.
I input caps was a 10uf electrolytic and was changed to 10 UF smd caps retrieved from broken hard disk !!!
I build a regulated linear power supply with LM 338 and improves it further when compared to the smps power supply. I am running it on 18 V regulated dc power supply.
I am thoroughly enjoying the sound at present. The outstanding signature is very very good timbre for music instruments. it has tube sound signature.
several layers of music are resolved with live recordings.
The sound from the demo cd Throne is very impressive. the test drum sound real  and believable. string instruments have very nice decay and resonance from guitar is easy to hear
i hope my experience will entice more people into diy .
I try to post some pictures of my amateur work. please do not laugh !!    

 cheers
kp93300

 great mod.

https://2img.net/h/oi57.tinypic.com/5kkdjs.jpg

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Nice!!! 

I bought another board to fool around.
I want to change to better power supply caps around the chip and planning to use  Pana FC caps .
Maybe try to lower the gain by changing the gate logic of the chip.
Any other modding ideas from other diyers?

Last night , 3 buddies came and commented very favourably on the sound . They were impressed by the amount of detail and the bass quality that is deep and well controlled.

cheers

kp93300

Hi kp93300,

Can you share something on your Mark Audio 12p full range speakers. Are you using single ended tube amp to drive these speakers? How is the performance and sound quality?
Thanks

Regards,
Yeo

Hi Yeo,
I am using Trends audio 10.1 and this el cheapo board to drive it . it is loud enough in my 200 sq ft room. i will try some other diy class a and class  ab in future. I will report back with Audiosector LM 3875 gainclone soon. This is still in the diy workshop !
Yeo, I have not diyed any glass amp yet .Future project .
about 10 hi fi kaki has auditioned this  and all the comments are very positive.  The overall comments is there is no lack of mid ,  treble and bass. It sounds very refined and vocal rendition is very realistic and detail.
Most think that it betters my V2, Ob5 speakers from GR research at Audiocircle. these are driven by different diy amps though.

FYI, many of this seasoned kaki has interconnect that will buy my entire set.

cheers

kp93300

Hi Kp93300,

Thanks.

Regards,
Yeo