I had posted some preliminary impressions in my previous post about the Edcor TTPC15k/15k transformers:
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-628.html#post4175155
This combination was good, but not as good as the modified YJ blue amp with the CineMags. The soundstage was not as large and deep, and the bass was not as well defined. My friend who borrowed both amps felt this combination was a bit fatiguing. In my system, it was not so much fatiguing, but a bit noisier and less resolving than the modified YJ blue amp with the CineMags. Still, the Edcors made significant improvements over the single-ended configuration with the stock caps. Using the input transformers also eliminated the obnoxiously loud turn-on/turn-off pop and faint buzz noise with the minimally modified Sure TPA3116 amp (OSCON caps).
Interestingly, the modified YJ blue amp with the Edcor TTPC15k/15k transformers was no better than the modified Sure TPA3116 amp with the CineMag CMLI-15/15B. Compared to the sound quality of the same YJ blue amp with the CineMags, the soundstage was less three dimensional and the top end lacked the smooth, liquid treble. The tone was a bit brighter with less warmth than before. Keep in mind, I use a modified Dynakit Stereo 35 6BQ5/EL84 as my main amplifier.
Just to be clear, the modified YJ blue amp is not the end-all for TPA3116 amps. I have the DUG PBTL amp boards, which I still need to complete. gmarsh is also developing the "proper" TPA3118 amp, which should be worth evaluating.
I assume you are using an unregulated power supply and perhaps not adequately dimensioned (insufficient power), whose voltage drops a lot when you turn up the volume.
If the voltage fluctuates a lot, the capacitor begins to discharge and recharge following the supply fluctuations and consequently the mute switch on and off the chip.
100KOhm instead of 150KOhm could worsen the situation, in any case you could try to increase capacitor value from 4.7uF to 10uF to see if increasing the capacitor discharge time, fixes the problem.
Obviously with 10uF, the delay after power-on, will double.
I hope this will help!
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Not familiar with Monacor transformers, but you should probably look for 1:1 line input transformers with 10k-15k input impedance.
Hi rhing - After a few months absence from this forum, I thought I would jump back in. I have this particular board and was wondering if you made any mods to it, or using it stock? I have not hooked it up yet, but thot I would ask how it sounds. Seems like it has a good layout. What voltage are you using with it? I like your roomy layout and space. 🙂
-Rick
Hi Rich, not to be thick in the head but I don' think I am understanding these impressions well; do you not think using the Edcor transformers with a modified YJ board is worth the money or trouble? My YJ is like yours, except I have Bourns inductors.
Hi Rich, not to be thick in the head but I don' think I am understanding these impressions well; do you not think using the Edcor transformers with a modified YJ board is worth the money or trouble? My YJ is like yours, except I have Bourns inductors.
I did eventually modify that Yuan Jing 2.0 TPA3116 blue amp:
- Panasonic SEPF OSCON DC decoupling caps
- CoilCraft SER2915 inductors on output
- TDK X7R multilayer ceramic bootstrap caps
- Bootstrap cap snubber circuit
I used this in my main system and brought it to a friend's home to audition. We compared this amp paired with my modified Astron RS-12A regulated linear power supply to his 300B Direct Reactance Drive (DRD) SET monoblock amps which he built at a DIY class held at the Randall Museum in San Francisco. My friend was floored by the fact that playing most music including complex orchestral arrangements, the modified Yuan Jing amp sounded better than his 300B amps.
I loaned him the amp for a week, and when I came back to reclaim it, he offered to buy it from me. I sold it to him at my cost. As I mentioned in earlier posts, we've since compared my other similarly modified Yuan Jing blue amp with the CineMag CMLI-15/15B input transformers, and this amp has convinced him to purchase a pair of input transformers for his amp.
I have another identical Modushop Galaxy enclosure like the one shown in the first photo. I will use that chassis once I settle on the "ultimate" TPA311x amp complete with input transformers. It could be the DUG TPA3116 PBTL amp modules or the "proper" TPA3118 amp that gmarsh is developing.
http://www.diyaudio.com/forums/class-d/267039-proper-tda3116-pcb.html
The fun never ends.
I'll make it easier for you to understand.
Modified YJ Blue + CineMag >> Modified YJ Blue + Edcor == Modified Sure + CineMag >> Stock Sure >> Stock YJ Blue
The Edcors make improvements in sound quality, but I think it's worth the extra bucks to get better transformers like the CineMags for my system.
Save up your money and buy dug's mono block. They sound better stock relative to any Chinese 3116 pcb mod'd with cinemags. If you get mono's with cinemags like I have. IMO, you will have reached the pinnacle or darn near of the what the 3116 IC is capable in SQ as a class D.
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Which one of the 2.1 boards would you recommend? Which is of the best quality?
Should I go for tge 2.1 feixiang or one of the 2.1 YJ boards (which?). I might mod it later but I want to use it as it is, first.
Should I go for tge 2.1 feixiang or one of the 2.1 YJ boards (which?). I might mod it later but I want to use it as it is, first.
Thanks for the advice. I measured the voltage while changing the volume. The voltage stays between 25,2 V and 25,4 V while music is playing. While being silent when it is stuttering it peaks to 25,5 V. I don't think that this is the problem. As I don't have a 10 µF capacitor am I able to try it with an 22 µF, 63V too? The delay will be four times longer then but it should be okay to check if the problem remains or not.
A different approach would be to use a loudspeaker protection circuit. I tried the WLX-7 speaker protection but it looks like it doesn't work with YJ blue (it works with my SymAsym so the speaker protection itself is okay). Is there a circuit that is confirmed working with the YJ blue 2.0 pcb?
You don't think it is the problem but overvoltage protection 3116 is 27V -10%, so actually 24.3V could have protection tripping
It confuses me that without the delay circuit to prevent power-on pop there's no problem with stuttering. So without it and a working LS-protection I would be happy again 😀. But I will try the bigger capacitor this afternoon and report back.
I guess that if my psu triggers the overvoltage protection on the chip itself it would trigger it without the delay circuit too. But that's not the case. I only have obvious problems with the delay circuit.
But as I am still searching for an answer I put "add regulator to linear psu" on my todo-list. I think around 21 V as output voltage should be okay.
Dr J
I put the same board in a boom box with enclosed sub; It has blown away everyone who's listened to it. Not just loud, but incredible fidelity and even sound stage with the tweeter/mids only about 20" apart. I Now have 3 more waiting for me to incorporate into new projects. Do you know how the tone/crossover control works? I Can make it sound great by balancing this with the sub volume, but I don't know why.