Could you please clarify more 'pin2 SDZ' 😕
I have also the blue ChengZhe and green Audiobah boards, that seems a lot easier for building a decent d-amp, but this one is driving me crazy - sounds so good and just want to try to fix this thumb, pop, cracks 😡
I think a switch like yellow board on ebay, between gnd and pin 2 tpachip is easier but not automatic🙂
Sound difference between 10uH and 22uH boards can be big, but too large distance tpachip decoupling will add a harsh edge (ringing). Two of the boards, YJblueblack and your green have too large distance decoupling (last TI datasheet for similar amp but that includes a dac has a maximum distance in datasheet for the 0.1uF decoupling, I measured it and I think maximum distance is 2.5mm there, TI says output rings above that distance). I think Chengzhi should sound as open as YJblue without the ringing, but I also read that people like the ringing/harsh edge.
Sound difference between 10uH and 22uH boards can be big, but too large distance tpachip decoupling will add a harsh edge (ringing). Two of the boards, YJblueblack and your green have too large distance decoupling (last TI datasheet for similar amp but that includes a dac has a maximum distance in datasheet for the 0.1uF decoupling, I measured it and I think maximum distance is 2.5mm there, TI says output rings above that distance). I think Chengzhi should sound as open as YJblue without the ringing, but I also read that people like the ringing/harsh edge.
I really hate to rain on this parade, but my initial impression of this board (YJ blue/black) is not favourable at all.
Compared to my other amps, I would say it is flat, boring... Mid-Fi.
Smooth can only get so smooth before it becomes... dead. It sounds like my Yamaha R-S300. I guess when $$$ are considered, that's a compliment, but I don't intend to make a compliment with this comparison.
Compared to my other amps, I would say it is flat, boring... Mid-Fi.
Smooth can only get so smooth before it becomes... dead. It sounds like my Yamaha R-S300. I guess when $$$ are considered, that's a compliment, but I don't intend to make a compliment with this comparison.
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rain is a spotty thing.
might be raining on your parade,
but maybe not on everyone else's.
good luck.
might be raining on your parade,
but maybe not on everyone else's.
good luck.
Cogitech,
That is too bad you are not getting a favorable sound from your amp. What are you comparing it to? If you are comparing it to a tube amp because you like that sound better because it is not flat and dead, it could be that your psychoacoustic propensity is to favor second harmonic distortion (which many people like as a euphonia). The TPA3116D2 is very low distortion so it could be that it is flat. What speakers are you driving? Try measuring the freq response and distortion with both amps and see if there is more 2nd harmonic with the "good" amp. It may also be that you have a lemon. The experiences that many of is on this thread have had has been pretty good and far from dead sounding. Also, what are you using for the power supply?
Regards,
X
Hi,
I have the YJblueblack, any suggestion how to remove the heatsink ? I want to see if I can move the 0.1uf decoupling cap to the pin. I do still experiencing some harsh edge (ringing) on highs after these mods:
Power cap to 330uf Pana (forgot the type)
Input decopuling caps 2.2uf MKP10
Bootstrap caps 0.22uf
Output filter 1nf with LCR
Inductors is still original
Cap bank (330uf 50V x 40) between the PCB power input and the 12V 4.0A
SMPS brick
Turn-on thump is only very slight but I always turn the volume all the way down before turning on.
I have the YJblueblack, any suggestion how to remove the heatsink ? I want to see if I can move the 0.1uf decoupling cap to the pin. I do still experiencing some harsh edge (ringing) on highs after these mods:
Power cap to 330uf Pana (forgot the type)
Input decopuling caps 2.2uf MKP10
Bootstrap caps 0.22uf
Output filter 1nf with LCR
Inductors is still original
Cap bank (330uf 50V x 40) between the PCB power input and the 12V 4.0A
SMPS brick
Turn-on thump is only very slight but I always turn the volume all the way down before turning on.
Let me guess. You are listening to a stock board with no mods whatsoever despite the fact that this 18 month long thread is more or less centered around modifying stock boards and tossing the questionable quality components used on many of these boards.
Hi X,
I've compared it to 3 amps so far; 1) the aforementioned Yamaha R-S300, 2)a Sure 2x100w TC2000+STA508 Class D, and 3) a 25wpc EL34 p-p tube amp. Both the tube amp and the STA508 are miles ahead. The tube amp is heavily modified, but the STA508 only has input caps replaced - otherwise stock.
Listening to the 3116 reminds me of the time I installed WIMA MKS input caps (of questionable authenticity) into my tube amp. I learned what "smear" meant, in audio termininology. It sounds like a funeral.
P.S. MarkAudio Alpair 10.2 and 10P. Power is Omron 24v 4.5A SMPS, which normally powers the Sure beautifully well into the 40wpc range.
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You are correct. I do have plans to modify heavily. My first experience has me skeptical but certainly convinced of the necessity of major mods. I'll begin with input caps, as I have several different ones handy to try.
Hi abraxalito,
What size of cap you normally used to build your cap bank? How do you handle the startup inrush of current ? Can it be splitted into multiple banks and use timer relay for each sub-bank to turn on one after the other ?
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Heatsink is glued on with flexible white unconductive (bathroom?)glue. If you take a plier to grab the heatsink and while doing apply a little heat to it with solderiron it will come off very easy.
Alpair10's without Zobel would be a 10 ohm load rising to 20 ohm, I would start with trying a 10ohm outputfilter, YJblue has a 4 ohm outputfilter.
I've already done without soldering iron. Do not pull the heatsink with pliers, but gently rotate it several times in one direction and in the opposite direction.
At the start is a bit hard to rotate the heatsink, but after a while it comes off. It takes about one minute.
My 2 cents..
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Cogitech,
It might be the mismatch of the LC filter nominally designed for 4 ohm loads vs your driver which is 8 ohms. A 22uH and corresponding cap may be in order as well as the input caps which are stock as 1 uF MKP. If you have any 4 ohm speakers give that a try before doing anything.
Mods that seem to be good value bang for the buck:
0. Check gain that your system likes - if comparing to other amps - this is one area that may cause the lifeless sound is too low of gain. YJ blue/black is 26dB setting.
1. Input caps to higher quality and larger value. 3.3uF 250V metalized poly film for example.
2. Power rail caps switch to high quality Panasonic. OSCON's seem to be current favorite for ultra low ESR. Don't use too large of value (keep below 560 uF)
3. Inductors to proper value and high quality to ensure linearity and resistance to saturation. Coilcraft, Bournes, etc. That can handle at least 4 amps.
4. Bootstrap caps to 0.22uF 250V x7r ceramics
Your power supply is probably fine - might want to adjust output voltage to 19v to 21v for optimum sound quality.
Good luck!
X
Generally I use 3300uF and 4700uF though for the lowest frequencies I have built some arrays with 15000uF caps. The ESR of the 3300uF and 4700uF for normal cheap Chinese caps equals the capacitive reactance around 1kHz. So above this freq they're not so great - to decouple up to 10kHz I find I need to use low ESR Japanese types (Nichicon, Rubycon) which are normally two or three times the price.
They are fed from my bench supply which has a variable current limit up to 3A. So that current limit setting determines how fast they charge up, but I normally leave them on as the quiescent dissipation is under 6W for all four channels (two AB, two classD). I'd not recommend feeding cap banks this size direct from a transformer - rather an SMPSU or linear regulator via a series choke or two to act as filter.
I have some 20 x 4700uF Rubycon and planing to feed them with the SMPSU, do I need a Power Choke in between and what value ?
The SMPSU will be putting out a fair amount of ultrasonic switching noise which you need to attenuate to get the deepest soundstage. Try a choke about 220uH with a DCR no lower than 50mohms or it will cause peaking.. The combination of this choke and your 20 paralleled caps should give around 80dB attenuation by 20kHz.
Thanks Sharpi for your comment on the transformers. I tried to install them yesterday, but only got some hum and/or a very faint signal. When you have got your Lundahls, a little description would be very appreciated. I am using the blue/black board, but the input should be similar with all boards.
Hi Jogi, have you traced the input pins for the TPA3116 on the blue/black board and connected the transformer secondaries to those directly? See below for instructions on how to do this for the Audiobah board - the connection points will no doubt be different on your board but process the same.