I ran with that XH-M190 board for a while. It has waaay to high gain setting. Lower the gain by removing the R2 mentioned in TI's datasheet(Not necessarily R2 on PCB). Will lower the hiss substantially! Have not tried this on my own XH-M190 because I ended up using 3118 mono boards, because mine blew 2 of the 4 caps. Other people have also reported the 4 caps on the XH-M190 board blows up. Change these to brand name ones same value(or higher) but 35V instead. Especially if you are running 24V. Would probably also improve sound.
I would not like that my speakers where hissing 24/7. Then the coil is "working". Can't tell you if it actually will cause damage, but I don't like the idea. The potentiometer have 2 thru hole legs by themselves behind the 6 for volume control. These 2 are mute. Wire a relay to these or a switch and you mute the board. Does the chromecast turn on and off? Maybe this could trigger a relay?
The Marantz pm17 probably needs fresh electrolytics, the Elna's used by Marantz do not age well.
I don't use external speakerprotection and have some 3116/18 driving >$5000 speakers.
4 1000uF's should last a while if psu doesn't add trouble. Two ampboards I check sometimes run 24/7 over 2 years now without noticed deterioration. The original 470uF's and psu (brickstyle) electrolytics were replaced within 2 months though, probably because electrolytics in the bricks had given up and made life even harder for the 470's next to 3116. Both these ampboards are behind television screens powering mainspeakers. Hiss is below roomlevel noise normally, but inputs are connected 24/7 too, offcourse.
I don't use external speakerprotection and have some 3116/18 driving >$5000 speakers.
4 1000uF's should last a while if psu doesn't add trouble. Two ampboards I check sometimes run 24/7 over 2 years now without noticed deterioration. The original 470uF's and psu (brickstyle) electrolytics were replaced within 2 months though, probably because electrolytics in the bricks had given up and made life even harder for the 470's next to 3116. Both these ampboards are behind television screens powering mainspeakers. Hiss is below roomlevel noise normally, but inputs are connected 24/7 too, offcourse.
Interesting pointer on the PM17 Caps - I haven't opened the innards in a decade I guess .. Will check that out
On an unrelated note, the volume knobs on the Pm 17 seems to be scratchy although I always thought that was a digital vol control - Any pointers on that?
As for the 3116, the PSU is a dell lapotp charger so I presume the power from them should not pose a problem for the 3116
Should have seen this post earlier coz I ordered BTL protection boards off an online chinese freight agent ( I somehow can't trust Aliexpress) - they were sub $10 so nothing to lose and having them can't hurt...
As for deterioration, I wasn't concerned about the lunch money Amp (actually 2x lunch or 1x dinner money amp since I am in India
)I was thinking more of the speakers and if the 24x7 hiss would cause the tweeters to deteriorate over a year . I don't expect them to last more than 3-4 yrs anyway as the kitchen would be a harsh environment anyway.
Based on your post, I guess not
I just received a $5 ebay board that I did a few mods on but the power output has me a bit confused.
The board is powered from a 19V supply and my source (cell phone) has a 0.64Vrms output. I'm only measuring 6.3Vrms on the outputs though. It has 20K/100K gain resistors which should give 12.77Vrms output with a 0.64Vrms input if the gain is 26dB. So it's outputting almost exactly half of what it should.
Am I missing something here? Looking over the datasheet it seems almost like the PLIMIT has been set but I can see on the board that it's directly connected to GVDD.
EDIT: I just realized that I replaced the 1uF ceramic GVDD cap with a 3.3uF film cap. There are 4 caps right next to each other by the input terminal so I assumed they were all the input caps. I wonder if it's messing up PLIMIT.
The board is powered from a 19V supply and my source (cell phone) has a 0.64Vrms output. I'm only measuring 6.3Vrms on the outputs though. It has 20K/100K gain resistors which should give 12.77Vrms output with a 0.64Vrms input if the gain is 26dB. So it's outputting almost exactly half of what it should.
Am I missing something here? Looking over the datasheet it seems almost like the PLIMIT has been set but I can see on the board that it's directly connected to GVDD.
EDIT: I just realized that I replaced the 1uF ceramic GVDD cap with a 3.3uF film cap. There are 4 caps right next to each other by the input terminal so I assumed they were all the input caps. I wonder if it's messing up PLIMIT.
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Ok, I fixed the cap mix up. For some reason now my cell phones output is measuring 1Vrms so I get 10Vrms on the amp outputs. Still getting exactly half of the power I should be getting.
Other than the 1/2 power issue, it works perfectly and is dead quiet with no input. No heating. This is the board...
TPA3116D2 2x50W DC24V Dual-Channel Stereo Audio Digital Amplifier AMP Board
Things I changed...
Replaced 50k pot with a 10k
Replaced supply caps with 470uF 35V Panasonic FC
Replaced output inductors with SER1360-103L
Replaced 1uF ceramic input caps with 3x parallel ECPU1C105MA5 per input.
EDIT: I think my math was wrong. Since I'm getting 10Vrms it looks like I'm only short a few V. Should be closer to 13Vrms?
Other than the 1/2 power issue, it works perfectly and is dead quiet with no input. No heating. This is the board...
TPA3116D2 2x50W DC24V Dual-Channel Stereo Audio Digital Amplifier AMP Board
Things I changed...
Replaced 50k pot with a 10k
Replaced supply caps with 470uF 35V Panasonic FC
Replaced output inductors with SER1360-103L
Replaced 1uF ceramic input caps with 3x parallel ECPU1C105MA5 per input.
EDIT: I think my math was wrong. Since I'm getting 10Vrms it looks like I'm only short a few V. Should be closer to 13Vrms?
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I was testing with a 20Hz sine. My speakers don't play that low so they sound distorted anyway. I did this intentionally as to not upset the neighbors. If I stick my ear to the tweeter I don't hear any clipping/distortion from them though.
I'm not going to worry about it. 10Vrms is more than I need anyway and the board was just a cheap experiment to try the TPA3116.
So my brother in law purchased me an amp for Xmas. I just opened it about a month ago. I have been playing around with it and finally decided to make an enclosure for it. I did a basic layout in autocad transferred my panels to CamBam and cut out on the CNC. I had salvaged some palates and found a couple of nice pieces of Oak that I cut my pieces from.
Here are what I came up with.
Here are what I came up with.
Test at 1Khz. If your measurements there are close to your calculations, than their may be a drop in the lowest freq.'s due to the decoupling caps sizing. It creates a low freq., HP filter (like an old style rumble filter).
I don't think that's the problem, but I could try it with a resistor dummy load. The board came with 1uF input caps but I had replaced them with 3.3uF caps which is what TI recommends for the current gain setting.
Without a volume pot.
Thanks
Would be interesting to know which is the recommended board with a volume pot though, even though I won't need it for my purposes.
Judging from their good track records on the 3118 and 7498 , I would suggest the Sanwu 3116 boards. I personally have used this one and I like the sound
https://world.taobao.com/item/24601...spm=a312a.7700824.w4002-14563565405.35.Jd5VOL
as compare to the few others that I have used.
Hope it helps.
Regards,