To be honest - same here. Perhaps this "ringing" is the result of some other component. Currently I use my YJ board in combination with the Salas B-1 buffer; source is a moded Philips CD 204 and even harsh sounding CDs are more than just listenable.
Anyway, from what has already been written above I have high expectations replacing the input caps with transformers - can't wait for them to arrive.
Anyway, from what has already been written above I have high expectations replacing the input caps with transformers - can't wait for them to arrive.
~12bit audio with a little pumping effect for "realism", I have some of them like the Beogram CDX
I have two Audiobah boards and I like them very much. No mods have been done. I plan to convert them to PBTL. I am using them with a TVC (transformer volume control) and they sound better than my original YJ Red board that has a built-in a volume pot.
Regards,
Syklab, my power caps are not smds, but bipolar silmics..but I don't think the power caps effect the ringing anymore. My input caps are 1uF 50V smd and bootstrap is 220nF. I would like to add that the sound is abit bright but the sibiliance is gone.
Guys I'm interested in this particular design, I am a complete noob to this, but what kind of mod opportunities can we see with this? I can see in its stock form, that it uses a couple WIMA input caps, larger toroid inductors and a "high speed capacitor array". Even for "stock" form, it looks like it could sound better than the blue/black board stock... thoughts anyone?
Forgot to post my link:
THE Latest 2 0 Hifi TPA3116 Digital Power Amplifier Board DIY KIT 50W 50W | eBay
THE Latest 2 0 Hifi TPA3116 Digital Power Amplifier Board DIY KIT 50W 50W | eBay
Forgot to post my link:
THE Latest 2 0 Hifi TPA3116 Digital Power Amplifier Board DIY KIT 50W 50W | eBay
That looks like a decent board to try, I will order one this week too.
Thanks for the input! Just switched to that green board in my (still) testing rig. First impressions - not much different than my modded YJ black, both are sounding great. Definitely no mods that I will do on the green one! 😉
However, on blue ChengZhe I have replaced 2+2 electrolytic caps and stopped there. Thought that inductors will go out easier than on black one, but did not, so will leave that way and eventually fix new rig for it. I think I'm going to just enjoy in music for a while, soldering iron needs some rest as well 🙂
Could you just let me know what is the value of the vol.pot. on the red one? I suppose it's 20K?
Bootstrap Snubbers Work!!!
Guys, I just had time to install the bootstrap snubber circuit and it works! Makes a huge difference in sound quality: the sibiliance on some tracks is now gone, and the test I had was a certain passage in a CD (Chopin Piano Sonata No. 2 in B-flat Opus 35) that gave me problems before. It is in a complex piano passage where many notes combine and are struck with force. Normally, the confluence of all those notes go to mush - almost like the speaker hit its mechanical stop. With the bootstrap snubber in place, I can actually hear that note now undistorted.
I am using 330pF 100V ceramics from AVX and a 1/4-watt 10 ohm thin-film resistor. I scraped off some of the varnish from the back of the YJ blue/black for ground pads and soldered the cap-resisor combo point to point from the bootstrap pin sticking through the bottom. This is a very easy and worthwhile mod. I can't believe the regular TI schematic did not include this - it is so cheap and easy yet yields big improvements.
I also think that this mod reduces the warming of the cheap stock 10uH inductors - maybe less hash for them to filter out?
The topic of what bootstrap caps work or don't work on the TPA3116D2 seems to be the hot topic. I am not sure if this has been previously asked but I just realized that when I built my TPA3118D2 "Dead Bug Point-to-Point" amp, I followed the EVM circuit schematic. If you look at the EVM datasheet (http://www.ti.com/lit/ug/slou336b/slou336b.pdf), Fig. 2 shows a 330pF 50V COG ceramic cap connected in series with a 10ohm resistor to ground tied to the 220nF bootstrap cap:
Here is a closeup of the EVM snubber shown above:
Is this to "snub" the ringing that so many folks hear and complain about? When I listen to my dead bug amp, it sounds cleaner - less sibilance and I wonder if this is the case? Should we all be seriously trying this mod next? I think it might be a simple case of butt-soldered 330pF-10ohm connected to the 220pF bootstrap cap for SMT mods on Ybdz for example, and in the case of the YJ Blue/Black a simple 330pF axial and 10ohm 1/4-watt resistor can be added easily.
For comparison, the basic circuit that all of the Chinese boards out there use (except the one EVM copy) seems to be missing and may be a big part of the sound quality. The basic datasheet is here: http://www.ti.com/lit/ds/symlink/tpa3116d2.pdf Here is a closeup of the standard filter and bootstrap circuit:
What do you all think? Probably worth trying... certainly it is very inexpensive to add.
Guys, I just had time to install the bootstrap snubber circuit and it works! Makes a huge difference in sound quality: the sibiliance on some tracks is now gone, and the test I had was a certain passage in a CD (Chopin Piano Sonata No. 2 in B-flat Opus 35) that gave me problems before. It is in a complex piano passage where many notes combine and are struck with force. Normally, the confluence of all those notes go to mush - almost like the speaker hit its mechanical stop. With the bootstrap snubber in place, I can actually hear that note now undistorted.
I am using 330pF 100V ceramics from AVX and a 1/4-watt 10 ohm thin-film resistor. I scraped off some of the varnish from the back of the YJ blue/black for ground pads and soldered the cap-resisor combo point to point from the bootstrap pin sticking through the bottom. This is a very easy and worthwhile mod. I can't believe the regular TI schematic did not include this - it is so cheap and easy yet yields big improvements.
I also think that this mod reduces the warming of the cheap stock 10uH inductors - maybe less hash for them to filter out?
Attachments
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Resistor in snubber already on YJblue is 10 ohm, TI example has 3.3R, that might differ too. SMSL is only one I have seen that uses prefilter snubber:
An externally hosted image should be here but it was not working when we last tested it.
Syklab, I looked at that board too.. but I think the signal input traces are to long(interference), and the input caps are to far from the chip. I like the other features and I think it could make a good board if one changed the input caps to smaller ones closer to the chip!
Xrk971, I will try your filter too🙂 Just have to wait on components from HK.
Xrk971, I will try your filter too🙂 Just have to wait on components from HK.
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Unless the layout from Danzz's original draft changed(post 941) I think you have to connect the snubber to the other end of the bootstrap cap.The part connected to the output coil.Guys, I just had time to install the bootstrap snubber circuit and it works! Makes a huge difference in sound quality: the sibiliance on some tracks is now gone, and the test I had was a certain passage in a CD (Chopin Piano Sonata No. 2 in B-flat Opus 35) that gave me problems before. It is in a complex piano passage where many notes combine and are struck with force. Normally, the confluence of all those notes go to mush - almost like the speaker hit its mechanical stop. With the bootstrap snubber in place, I can actually hear that note now undistorted.
I am using 330pF 100V ceramics from AVX and a 1/4-watt 10 ohm thin-film resistor. I scraped off some of the varnish from the back of the YJ blue/black for ground pads and soldered the cap-resisor combo point to point from the bootstrap pin sticking through the bottom. This is a very easy and worthwhile mod. I can't believe the regular TI schematic did not include this - it is so cheap and easy yet yields big improvements.
I also think that this mod reduces the warming of the cheap stock 10uH inductors - maybe less hash for them to filter out?
That is connected to the coil - I checked with continuity tester - it is the outside leg of the bootstrap caps. The inside leg goes to the chip. It may be confusing because there are solder pads that I scraped off for ground nearby.
I was about to do the mod and I checked the original Danzz layout(post 941) and thats where i saw the difference.If you have a chance check the original layout.Must have rerouted the layout,Thanks.
The pair of bootstrap caps leadouts on the right in your pic show the inside leg going to the coil in the original layout (post 941). Thats what I was referring to.Thanks .
Just love mods like this - cheap, simple to implement, effective. Will be trying this out ASAP.
How critical is the cap value? I have some 470pf 50v COG SMDs handy.
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Yes, this is one of the easiest mods. Takes about 10 minutes if you have the parts on hand already. One of the best bang for the buck mods.
470pF is probably Ok but I wouldn't know for sure. Give it a go and listen - easy enough to change later.