I will check idle current next - my Fluke 101 seems to have lots of handy features as I am discovering.
Lazy me, do you remember idle current per specsheet of the top of your head?
Lazy me, do you remember idle current per specsheet of the top of your head?
I used a 0.3254ohm shunt resistor (as measured with LCR meter), measured 58mV across it at idle (Fluke 101) for 4 amps connected in parallel.
I=V/R, I=0.058V/0.3254ohm = 178mA/4 = 44.5mA ea @ 23.7 volt SMPS.
So there is a filter - what do you do to calculate filter current?
I=V/R, I=0.058V/0.3254ohm = 178mA/4 = 44.5mA ea @ 23.7 volt SMPS.
So there is a filter - what do you do to calculate filter current?
That is low:
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-744.html#post4368854
Idle inductortemp measured in 3251 thread I believe was very high too. more than 15 above room if I remember correctly, but doctormord did that heatphotograph too I believe
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-744.html#post4368854
Idle inductortemp measured in 3251 thread I believe was very high too. more than 15 above room if I remember correctly, but doctormord did that heatphotograph too I believe
irribeo, 3251 is AD-modulation, 3116 is (normally) BD-modulation, so heat generation/filter loss can't be compared here directly.
xrk971, so you have 4.2W idle loss, no wonder it gets that warm. Won't worry about. Decreasing switching frequency will also decrease idle loss a bit.
xrk971, so you have 4.2W idle loss, no wonder it gets that warm. Won't worry about. Decreasing switching frequency will also decrease idle loss a bit.
I will live with it - 4.2 watts makes sense why it feels warm - but no worries. The switching frequency is already at 400kHz so don't think can go any lower.
If measurements are comparable the Sanwu looks very good, idle, equals 20V filterless in table.
For the 3251 idle, main cause of heat was the Coilcraft inductors, if I remember correctly. Temperatures at high output were the same or even dropped in inductors, I don't remember clearly, but the photos reminded me of YJblueblack and also earlier in 3116 thread I think xrk replaced inductors on Ybdz? for Coilcrafts that also run warm idle, so I wouldn't think of Coilcraft to improve an ampboard. The Coilcraft inductors might not be very suitable for classD?
For the 3251 idle, main cause of heat was the Coilcraft inductors, if I remember correctly. Temperatures at high output were the same or even dropped in inductors, I don't remember clearly, but the photos reminded me of YJblueblack and also earlier in 3116 thread I think xrk replaced inductors on Ybdz? for Coilcrafts that also run warm idle, so I wouldn't think of Coilcraft to improve an ampboard. The Coilcraft inductors might not be very suitable for classD?
My Ybdz is the coolest idle board. No sign of any warmth at all on anything.
My YJ blue black was the hot idler. Changing to coilcraft did not help.
I suspect it is some sort of residual self cancelling output at idle that makes these warm but they are in spec.
I wonder what Ybdz does right to keep it cool?
My YJ blue black was the hot idler. Changing to coilcraft did not help.
I suspect it is some sort of residual self cancelling output at idle that makes these warm but they are in spec.
I wonder what Ybdz does right to keep it cool?
TPA3118D2
It was not because the Coilcrafts in general but because the construction of the inductors + additional heat from the 3251. So different brand, same construction will result in same temps. Maybe soft saturation cores perform different.
Warm inductors wouldn't indicate a bad thing here. Again, it's not a brand specific "problem" but the way the inductor is made. (And 3251 is different modulation, AD is always higher idle loss)
But yes, the MSS series is introducing more distortions than I.e. the ICE (class-d) inductors. (MSS is not specially made nor optimized for class-d but for switching regulators)
Those ICE are optimized for class-d as some Coilcraft series are as well, so one can't say Coilcraft is bad and ICE is good. 🙂
xrk, which Coilcraft series/model did you tested?
It was not because the Coilcrafts in general but because the construction of the inductors + additional heat from the 3251. So different brand, same construction will result in same temps. Maybe soft saturation cores perform different.
Warm inductors wouldn't indicate a bad thing here. Again, it's not a brand specific "problem" but the way the inductor is made. (And 3251 is different modulation, AD is always higher idle loss)
But yes, the MSS series is introducing more distortions than I.e. the ICE (class-d) inductors. (MSS is not specially made nor optimized for class-d but for switching regulators)
Those ICE are optimized for class-d as some Coilcraft series are as well, so one can't say Coilcraft is bad and ICE is good. 🙂
xrk, which Coilcraft series/model did you tested?
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More info here:
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-387.html
MSS1583-103MEB was what I used.
22uH inductors on Ybdz, that helps too.
I am not comparing AD to BD, if I would, BD freq would be set to twice AD frequency.
Even educated people like doctormord can pick bad performing Coilcrafts, and he doesn't pick blindly I assume.
I am not comparing AD to BD, if I would, BD freq would be set to twice AD frequency.
Even educated people like doctormord can pick bad performing Coilcrafts, and he doesn't pick blindly I assume.
I am not missing anything with 22uH on my Ybdz's - maybe I should look for amps with 22uH or swap out to see if it helps bring temps down? I guess you need the 10uH for driving 4ohm or 2ohm loads though?
Well, when saying, those Coilcrafts add more distortion, it's not like they perform really bad but there are others which perform better.
If i remember the measurements from 5th element correctly, we were comparing 0.1% vs. 0.02% (above 10kHz) at higher levels or so. Will have to look for the plots.
Audible? You decide..
If i remember the measurements from 5th element correctly, we were comparing 0.1% vs. 0.02% (above 10kHz) at higher levels or so. Will have to look for the plots.
Audible? You decide..
On your Sanwu idle consumption is as low as in doctors table filterless, so I don't think inductors can really bring down idle heat here, but doctormord might have better idea.
Normally, idle consumption should be lower with filter than with LC-filter or without. (With load connected)
Sorry for a noob question: Would be sufficient with a stereo log pot, and two sanwu blue to make two active speakers. I am still considering making two active 0,4x Karlsonators with 3fe25. And what would be the best sq, two sanwu blue + quality pot or a tda7297.
Thanks for bearing with me.
Thanks for bearing with me.