Audiobah and Ydbz use 22uH inductors, so simple answer is 22uH aren't as likely to get warm🙂 But more powerfull 10uH's don't get warm either, which makes the Coilcraft specs suspicious maybe???
Just curious, for those of you experiencing heat on the inductors and/or TPA heatsink: how much current are you pushing through the system?
I've never experienced any heat on inductors or the TPA IC itself (even without a heatsink), but I'm generally listening at pretty low power levels... My speakers (MA A7.3) are about 85 dB/watt at one meter, which is approximately my listening distance. The free SPL meter app on my phone says I never go much over 75 dB. So I figure I'm pushing less than 1 Watt to each speaker.
If I put a Kill-a-Watt AC meter between the wall mains and my power supply, it says I'm pulling around two or three watts, though around 15 VA. My power supply is a DIY linear one (Sigma11). I'm not sure where the VA to Watts inefficiency ends up, though I would assume in the PSU. I should probably measure between the PSU and the amp, actually, I'll try to do that at some point.
I know none of this is precise, but for a ballpark/back-of-the-envelope estimate, we can see that watts-in (from the wall) is just a bit higher than watts-out (amp to speakers), which is consistent with the TPA's high efficiency.
In short, there's just not enough current flowing through my system to really heat anything up.
But for those of you with hot components, I'm curious what a similar watts-in versus watts-out exercise would look like. Heat means there is some inefficiency there, electrical potential is being converted to heat rather than speaker movement, right?
I've never experienced any heat on inductors or the TPA IC itself (even without a heatsink), but I'm generally listening at pretty low power levels... My speakers (MA A7.3) are about 85 dB/watt at one meter, which is approximately my listening distance. The free SPL meter app on my phone says I never go much over 75 dB. So I figure I'm pushing less than 1 Watt to each speaker.
If I put a Kill-a-Watt AC meter between the wall mains and my power supply, it says I'm pulling around two or three watts, though around 15 VA. My power supply is a DIY linear one (Sigma11). I'm not sure where the VA to Watts inefficiency ends up, though I would assume in the PSU. I should probably measure between the PSU and the amp, actually, I'll try to do that at some point.
I know none of this is precise, but for a ballpark/back-of-the-envelope estimate, we can see that watts-in (from the wall) is just a bit higher than watts-out (amp to speakers), which is consistent with the TPA's high efficiency.
In short, there's just not enough current flowing through my system to really heat anything up.
But for those of you with hot components, I'm curious what a similar watts-in versus watts-out exercise would look like. Heat means there is some inefficiency there, electrical potential is being converted to heat rather than speaker movement, right?
That is correct. The output power is the same so if the inductors gets warm that means the speakers are getting less power.
Note that it is not the same as amplifier efficiency as that simply draws more current from the power supply to get the same output power. This is the difference between class AB and class D for example. If both have the same supply voltage, they will have the same power output but the class AB amp will use 4-5 times the current to do so on average at maximum volumes, at lower volumes it can be 10-20-or even over 100 times as much current draw from a class AB amp with the same average output power compared to a class D amplifier.
Last edited:
Simple as inductors are, electrical/electronic inductor theory isn't simple
Putting 'em close together results in mutual inductance, not ideal ... eg: orientation & spacing with crossover inductors is reasonably critical
Inductor heat is due to losses; copper loss is the simplest one to understand... due to resistance of the small diameter copper wire & the current flowing in the copper ... look at the copper diameter in a top quality crossover inductor ... it's fat. Other losses are a bit more difficult to explain, as is mutual inductance
Maybe the Coilcrafts are rated for far less than the available current?
Maybe the Coilcrafts are duds ... very, very, very long shot but bad production batches or mislabeling has been known to happen. I've had personal experience of large bad batches with electrical equipment of a different type, from reputable manufacturers
I recently bought one of these to check out what a bog standard finished product would sound like.
New Latest HIFI 2.0 Stereo Output Digital Power Amplifier TPA3116 50Wx2 by WLX | eBay
I'm currently fiddling with the YJ blue/black and I also have a basic chip on an adaptor board for comparison when I finally get it sorted.
The HiFi 2 amp is vastly different to the YJ in it's presentation. The overall sound is slightly less bright(brittle) and there is no sibilance or on/off pop and click nonsense, but it's very musical. I'm currently hooking it up to my full range electrostatics to see how it compares to some higher priced amps.
One thing I've noticed is that these TPA chips don't have a definable sound of their own, they seem to be very varied depending on the surrounding components.
has anybody else tried the HiFi 2 boxed version?
New Latest HIFI 2.0 Stereo Output Digital Power Amplifier TPA3116 50Wx2 by WLX | eBay
I'm currently fiddling with the YJ blue/black and I also have a basic chip on an adaptor board for comparison when I finally get it sorted.
The HiFi 2 amp is vastly different to the YJ in it's presentation. The overall sound is slightly less bright(brittle) and there is no sibilance or on/off pop and click nonsense, but it's very musical. I'm currently hooking it up to my full range electrostatics to see how it compares to some higher priced amps.
One thing I've noticed is that these TPA chips don't have a definable sound of their own, they seem to be very varied depending on the surrounding components.
has anybody else tried the HiFi 2 boxed version?
I haven't tried a boxed one, I am working on a 4 monoboard version for my electrostatic hybrids after one set of mono boards really impressed me on those speakers. Inductors do get warm with electrostatic high frequency load too, I even got some temperature into the like 30A Coilcrafts, which remain cold as ice with Markaudio 4 ohm zobel'ed load. Those Coilcrafts with any load remain cold when idle btw. haven't tried 26.7 V and will not try it either with those ampboards, it is kind of useless experiment, 24V PSU could be usefull, especially if you can dial that down too. Just tried the Connex because I had one, if Sure3116 had burnt i wouldn't mind 🙂 Still won't try Sure3116 on electrostatics, uncertain about pops and cracks it produces that ordinary unprotected 3116amps do not have. I do not mind inputcapacitor pop, easy to avoid, but there are a couple of sounds like that in a sequence every time I power up or down the Sure3116, that bothers me, it might produce those pops/cracks too when protection shuts down amp, others are completely silent when protection shuts down ampboard, volume can be fully open when protection trips....
my advice, fwiw, don't risk electrostatics if there is any power on/off pop or click.
I had a kt88 which was switchable between ultra linear and triode connected and when powered off the relay that did the switching disengaged leaving a residual on whichever mode was switched out.....it was only a little pop but it arced a transformer in the stats.......when you lose one electrostatic transformer it's difficult getting a match so you might end up buying two matched.....can be expensive.
I certainly wasn't going to risk the YJ blue/black with electrostatics.....the YJ has proved a good match for fostex 206s though, in stock form, a bit too bright for alpair 10.2s in my set up though.
I had a kt88 which was switchable between ultra linear and triode connected and when powered off the relay that did the switching disengaged leaving a residual on whichever mode was switched out.....it was only a little pop but it arced a transformer in the stats.......when you lose one electrostatic transformer it's difficult getting a match so you might end up buying two matched.....can be expensive.
I certainly wasn't going to risk the YJ blue/black with electrostatics.....the YJ has proved a good match for fostex 206s though, in stock form, a bit too bright for alpair 10.2s in my set up though.
I use 8R 2 way speakers. My DAC got hot easily when playing music with SMSL36a Pro standar TDK 10uH inductors. Then after installing Bourns 22uH inductors, it only gets warm when playing music.
I have the same board (not boxed), and i am satisfied with it, have to test other boards to compare...
I should have, but didn't consider this when I swapped out inductors, thanks for reminding me. I would have made an effort to put the inductors at right angles to lower the magnetic interference.
Randy
A linear PS will have a fairly low Power Factor. That's why you see the big difference between watts and VA.
Actually the point is to maximize EMI between the inductors but only at very high frequencies so that they effectively work as a common mode choke at very high frequencies in order to minimize RFI.
I have... and wrote about it in this thread. I also rewired the mute switch to function as power switch, and added a turn-on pop suppressor (cap & resistor).
A couple of days ago I wrote about how I "smuggled" this one on a "serious" audio show, here:
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-563.html#post4104019
For those interested, here's a youtube video (about 25min, our "DIY room" starts at about 12:16):
https://www.youtube.com/watch?v=rviO2paVKIg
Back to the original question: yes, I tried it and I like it - even unmodded, it sounds quite OK. Thanks to the guys who recommended it about two months ago in this same thread, when I asked which TPA3116 ebay version sounds best unmodded 🙂
Idle the little Wurths get 5 degrees Celsius above room on Sure3116, when playing music they are a little cooler. By hand you can hardly feel they are warm. Music seems a little louder and contrasts are a little bigger. They are 4A or 5A 10uH's, smaller size (in mm) than the ones on other ampboards. They are a little higher than originals on Sure3116, haven't tried heatsink yet, but probably need to shave off a little bit bottom side round block, if I want that on chip again, topside of tpa3116 chip is 10 degrees Celsius above room when idle for 4 hours naked. Idle is wrong word here, but without inputsignal🙂
btw room 22 Celsius
btw room 22 Celsius
Attachments
Last edited:
Bit off topic but over the last few pages of posts its evident how many of us are using Mark Audio drivers with our 3116 amps. This is great as you can rely on SQ comments from people with same drivers and expect to hear similar for same mods.
These drivers, especially the 7.3, can sound bright with less than excellent sources material (whole audio chain including recording) tho when all the planets align they are stunning. Makes them a great tool in evaluating the effects of component changes. Pity my ears aren't as efficient😉
These drivers, especially the 7.3, can sound bright with less than excellent sources material (whole audio chain including recording) tho when all the planets align they are stunning. Makes them a great tool in evaluating the effects of component changes. Pity my ears aren't as efficient😉
That really didn't come out right. The point is to get the tiny amount of EMI and RFI at very high frequencies that does get out of the shielded inductors anyway to couple most effectively to the reverse polarity inductor so that the total EMI and RFI is reduced. Sorry for the confusion.
Both equally actually. Toroids are inherently "shielded" by design, ie. they ideally don't leak EMI but neither does shielded inductors, in principle at least.
Today I made a few mods on one of my boards. Also changed to 32 db gain. Only left to connect it and listen [emoji6]
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
So maybe I'm slow today, but that doesn't make sense to me.
Once EMI gets out of the inductors into the air, I wouldn't think you can cancel it out. I know that you get cancellation in conducted EMI, but I don't believe that happens in radiated EMI. I've done a fair amount of EMI testing.
And my understanding was magnetics wants to be a right angles so the magnetic fields don't couple with each other.
Randy