1. burnwaygta4
    "Qualitative modification of the player"
    I made a modification of the player that lifts the sound to TOP portable players. Details here(http://www.head-fi.org/t/447479/teclast-t51/1380#post_9326082)
  2. AlexRoma
    "Best sound quality from the least money paid"
    Pros - Great SQ, powerfull amp, good size, 10 hours playback, can be upgraded in may ways, can be used while charging
    Cons - So-so user interface (i've seen much worse), useless EQ, bright signature, low reliability, Chinese service
    So, what does make T51 such a unique and relevant music (and video) player after all ? 
    The combination of :
    * Great SQ  (on the bright side - very detailed, HUGE sound stage, lots of air and space, punchy and dry).
    * Thy on-boar amping (drives even 600 ohm Bayerdynamics),
    * proper size, proper battery life (10 hours measured), proper design and usability (memory card slot, lineout, volume wheel)
    * good, affordable  price. 
    This small DAP may give you lots of SQ when properly used, even stock (not modded) .
    After some tweeks and mods (better invertors, better op-amps, capacitors) you may get world class performance out of a 200$ DAP. The size of the dap is just right, fits your pocket.
     Design and connectivity is also good. You can use the player while charging, it's a great feature to have, considering the battery life.
    Unfortunately, there are con's related to the way chineze deal business...
     The were lots of case of defective units. But, if this DAP survives for a half a year , you'll have nothing more to worry about any longer.. Thus, It is good to have a warranty , at least for the burn-in period.  
    Highly recommended for power-users with skills in electricity, or at least for those with friends good in ectronics hardware. 
  3. turokrocks
    "Teclast T51 "
    Pros - Sound, Sound , Sound
    Cons - Everything Else!
    If you want a DAP for the best sound quality and value look nowhere. 
  4. fnzeee
    "Not the cadillac, but a strong value"
    Pros - Sound Quality, line out, supported audio file formats
    Cons - Interface, battery life, weight
    I really enjoy this player....it has become my primary DAP.  The SQ of this player is extremely good, especially at the price point of ~US $130.  I wanted a very clean source to play through my tube amp and am very impressed.  For my purposes, the limited video capabilities and somewhat kludgey interface are not issues.  The build quality is relatively high, it plays FLAC and AAC (as well as others), has a true line out, and its architecture has been implemented well.  It also has plenty of power for even demanding headphones. 
    I would recommend this player to anyone wanting very HQ audio without carrying a separate DAC/AMP.  If you are looking for more of a video player, go with the cowon.  The touch screen is decent and has excellent resolution, but its not as sensitive as an ipod, droid x, or my P2. Honestly, the interface (v2.30 on my T51) is about as good as my Samsung P2 before I flash ugraded it....actually less buggy.  Battery life is short compared to other players (6 to 8 hours) due to the abundance of chips in this thing...also the reason it weighes 3x more than my P2.  The T51 also only has a few settings/options that are confiigurable compared to other more mainstream players.  Navigating larger music collections via the interface is also a bit cumbersome, but tolerable.  
    The text-to-speech eBook reader is a nice addition and works surprisingly well despite having only one english speaking TTS engine.  One gripe is that it reads only txt and not PDF's.
  5. Killmassacre
    "Amazing sq, but thats about it."
    Pros - Great sq through HO and amazing sq out of LO, especially in consideration of it's price. Also has good screen quality and plays multiple formats.
    Cons - Battery life is very short, and the user interface is one of the worst I've ever used. Slow memory. The screen also scratches very easily.
    When I first got this player I was amazed at how good the sound quality was, it truly is one of if not the best DAP's out there in terms of sq. However there isn't much to say about the Teclast T51 other then sound quality, because other then that this player is utter garbage. The user interface is dreadful, it has a mere 8 hours of battery life, adding files to the system is horrendously slow and updating the firmware is a nightmare. When uploading files to the main memory of the unit, I average about 3 mbps which is absurdly slow, and reading files from micro SDHC cards can take forever. Also the system lags constantly and while your waiting for it to load if you accidentally hit part of the screen it will automatically register the input and apply it once its loaded. And if you have lots of folders like I do this can get very frustrating as you accidentally click the wrong one because it lags, then you have to start from scratch and the beginning of all the folders as theres no way to go back to previous folders. The screen also is very scratch prone it would seem, the very first day I got this palyer I accidentally dropped it and bang a huge scratch across the screen. I've also tried updating the firmware on this player, and after some research it appears the only way to really do so is whilst connected to a computer running windows xp which unfortunately I don't have access to.  I do have to compliment the Teclast T51 for its great screen quality though and the amount of different video files it supports, I think the screen looks better then my iPod touch(provided it didn't have the scratch that is). And the ability to expand the memory with a micro SDHC card is nice as well. Overall I'd say for it's price this DAP is a bargain for an audiophile thats only interested in sound quality, however if your interested in anything other then sound quality in your DAP this is certainly not the DAP for you!