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hifix

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About hifix

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  1. hifix

    Class-D Amplification

    I wasnt aware of that particular amp either. I came across it in a youtube clip https://www.youtube.com/watch?v=VedRT3dCDnk
  2. hifix

    Class-D Amplification

    Hi Zaphod Beeblebrox, Given the nature of the class d amp, this is one area that it will lack. I dont see the introduction of GaN FETs completely solving this issue either. My issue with all this is with the heavy bias against this type of amp. And the thinly veiled criticisms as pointers. You dont see the push against vinyl on this forum with the majority of pressing having lows summed < 100Hz (possibly higher). I'm looking at my vinyl as i type this. You dont see meaningless arguments of increased thermal noise from the heat soak of class a operation. etc. Just look back in the thread and its clearly obvious. There is even a contributor to this thread who even gripes about faulty designs of the past. The arguments and criticisms are not taken to the diyaudio forum. It isnt taken to the any of Class D related threads. Just here, where the push back is limited (and they know it). No one willing to help with parts selection for even minor gains in snubber efficiency to help ditch more out of band noise ? No one in industry that can offer help with voicing the boards ? Power supplies ? Anything ? Just phase, square waves, not as sexy etc. Strong language and talking things down. The tone of some the replies are plenty clear.
  3. hifix

    Class-D Amplification

    Its sad that some people will selectively post against the tide when it comes to Class D. From the "distortion" of square waves...to phase issues. Phase variation with expensive input transformers is "euphonic character"... phase variation with Class D is just plain terrible. And who doesnt like listening to square waves ? I understand that the current pricing of some class d offerings can be offensive to those on the hifi totem pole. Heres one that i'd really like to have (Jeff Rowland Model 925 - "Class D"). But these are "a bit expensive" and that must make them... just fine
  4. hifix

    Class-D Amplification

    Thats a nice build. 👍
  5. hifix

    Class-D Amplification

    Hi Misternavi, Sorry to hear about the 125asx modules... How are you finding them ? There was a lower powered one which i was tempted to try some time back.
  6. hifix

    Class-D Amplification

    I ruined my last one by connecting the power the wrong way around. 😖
  7. hifix

    Class-D Amplification

    Hi Schliden, I have not heard that amp board before so i am unable comment on it. A lot of the stuff from the orient uses questionable parts and the quality of the boards arent overly flash. If you didnt mind stretching the budget abit you could try the "allo volt +d". It is a stereo board without a sub out. The bonus is that it has a capacitance multiplier module in it. The capacitance multiplier functions to clean the supplied power. Plug in a laptop power brick and it should be there or there abouts. While it costs abit more than the boards from the orient - its better made, better voiced and some setups its the main amp. I've owned the older volt+ (non "d") and found it to be the best complete "turn key" TPA3118 amp out there (and to be mod free, its the only one i'd be comfortable recommending). https://www.allo.com/sparky/volt-plus-d-amp.html If you didnt need the extra power of the TPA3116, a real gem is the TDA7297. Its not class D but it sounds better than some TA2020 tripath amps (the tripath is class d - but they called it "t"). Its about $5 delivered and if you like tweaking you can go to town with that too. Its class A/B and well worth the money for a small amp. It also runs on 12v. I've had a TDA7297 paired up with a pair of Kef Q60s and it sounded fantastic. If you are interested, it might be an idea to buy 2 just incase you get one with a dodgy volume potentiometer (i did). https://www.ebay.com.au/itm/TDA7297-Digital-version-Power-Amplifier-Board-2-0-channel-stereo-double-12V-M2O1/253213312564?epid=13012462401&amp;hash=item3af4b08634:g:U3gAAOSwnlFaXKFo:rk:1:pf:0 https://www.ebay.com.au/itm/DC-9V-To-15V-TDA7297-Digital-Amplifier-Board-Double-Channel-Noiseless-15W-High-F/263757863447?epid=21024673395&amp;hash=item3d69319a17:g:SHQAAOSwJqNbIq36 Here is an old forum thread incase you want to tweak it. https://www.audiocircle.com/index.php?topic=121423.0 Hope it helps.
  8. hifix

    Class-D Amplification

    My apologies Mwhouston. I replied to your msg after checking the texas instruments data sheet (both pins here have the same bias). I just had a look at the TK2050 pdf and there is no rating for the negative pin. From what little i've read Tx coupling does not seem straight forward with this chip.
  9. hifix

    Class-D Amplification

    The negative input is also at a 3v bias so there will be no current through the windings. When i started out building things, i started out with the altronics metal flims... these were terrible. I went on to Koa Speer which were better. Then the Naim suggested SFR25 and a few others. Now its mainly Takman Rex / Kiwame, depending on how things balance.
  10. hifix

    Class-D Amplification

    Hi Mwhouston, You're spot on. Given the the price of the amp, i figured that i could mod to the hearts content and try for myself the difference between various input coupling caps, solder, traces etc and not be too upset if i destroyed a board. A new board is $22 & a month of waiting (i didnt want to pay for the more expensive shipping). While i was hoping to eventually like this amp, what i wasnt expecting was to have my existing amp to go the classifieds with this one in its place. As bizzare as this might sound, a TPA3116 (set at 32db gain) amp board is running 86 & 87db 8ohm speakers in my setup: Rapsberry Pi (moode & craap) with some hardware tweaks & Audiophonics i-sabre DAC board --> Passive Attenuator (shunt) --> TPA3116 @ 22.5v One litmus test for the amp boards (for me) is 70's disco. It must play disco with the scale, groove and flow as i remember it. If it thins out here its not good. With a passive control and a switched mode supply i found the overall balance with these boards quite lean sounding out of the box but with a using a 2x Panasonic Oscon 330uF (with its 5A ripple current rating) right next to the chip and a stiff voltage rail did wonders. Voicing my shunt attenuator with a carbon film resistor was also critical to the overall sound. I'm tempted to try the input transfomers. While this input coupling brings the setup to an entirely different DIY cost bracket - its also been at the back of my mind for some time now. I dont know how long i can hold out for. If you decide to try them, i'd love to know what your thoughts are. The input pins have a 3v bias on all of them (from memory). When i get the room, those altec horns are something i'd really like to try one day.
  11. hifix

    Class-D Amplification

    Hi Schliden, Its a Yuan Jing board without a potentiometer at the input. https://www.yuan-jing.com/tpa3116-class-d-2-0-stereo-amplifier-board-50w-50w Capacitor coupled & with through hole components (except for the main IC, bootstrap caps and inductors). Without tweaks its a nice sounding board for what it costs. After adding the cost of clean power, time and effort required to tweak the boards, prep a chassis and wait for free shipping to arrive etc... it remains a good recommendation for the diy enthusiast as you get to voice the board to suit. There are many build efforts on diyaudio and audiokarma forums for inspiration. Heres a build with a transformer input (see #4867): https://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-487.html For critical listening, component swapping is necessary and a bootstrap snubber has to be added to the underside of the board. From my findings, different components of the same value for the snubber can result in a unpleasant output. In some cases, a backward step. This has also been noted by others in the diyaudio forum. For me, this was most difficult part to get right. This particular board is now "old school" with newer & more powerful boards out. The newer boards also have an opamp input stage (which may / may not be to your liking). There are positive reviews of the 3e audio TPA3251/55 board. 3e audio also make a power supply so no tweaking / modding is needed. There is also the texas instruments evaluation board. If you want an old school board without tweaks, ALLO have well built and well voiced boards. They have a a dual chip board (Allo Volt +D) with a capacitance multiplier before the power rail of each chip. I have not heard the new ALLO board, but it has good feedback (the older single chip Allo Volt + sounded pretty good). Hi Mwhouston, I tried purchasing from YJ directly but i much prefer dealing with the ebay seller (with slower shipping). https://www.ebay.com.au/itm/TPA3116-amplifier-assembled-board-50W-50W/111297057819?hash=item19e9d2541b
  12. hifix

    DIY for a beginner

    G'day Barzy, DIY hifi / audio can be incredibly rewarding but unless you have good tremendous self control think twice thrice before getting into it. It can be a very slippery slope. I also wanted to try my hand at speaker building from a PE kit (c-notes) but just couldnt get my head around the relative shipping cost.
  13. hifix

    Class-D Amplification

    I'm on my 10th possibly 11th Class D amp. No tweeter damage.
  14. hifix

    Class-D Amplification

    The undertones of some of the posts here are obvious. If some want to denigrate tech to make themselves (or others) feel better, fantastic. If we want to carry on an about the short comings on current topology, even better. But what might be best could be helping those interested in class d technology to get the best out of it. If class d isnt your brand of barbeque, find something that does the job. My old "reference" Class D integrated amplifier of TA2020 vintage fame with its seperate power module, both of SMSL distinction sounded grand in a right setting as i'm sure the SI TA2024 did before it and the "Amptastic" after it. (stereophile and hifipig reviews are online). My current hand assembled, Spanish designed, Class D reference amplifier board with its bespoke chassis is a joy to listen to. The board is cheap, cheerful and from ebay. I cannot help with the brand of metal polish for Dan D'agostinos best. But, if there is room for discussion to get the best out of cheap boards - i'm in. If others are willing to share about what is new and grand that would be brilliant too.
  15. hifix

    Class-D Amplification

    Are you certain about this ?
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