Amplifier Board Recommendations

[rocknbil]

I've spent two days reviewing amp chips and amp modules and am hoping someone can help sort this out. Looking for a single channel 100w amp module, does anyone have recommendations? Should I stick with the TDA3116D2 and hope I get a good one next time or should I look at a different chip?

• 100w capability (outside project, need all the boom I can get)
• Sources are DFMini players, tested individually using SPK1 and SPK2 (this was all working)
• Currently 19v 3.5A computer dongle power source (shielded)
• Pyle 200w 4 ohm PLG54 speaker

<TL;DR>

I bought one of these, TDA3116D2 chip, "Subwoofer"

Worked absolutely great, sound loud enough to scare the cat (LOL.)

For about two weeks. Sound started acting up, now I get a low distorted signal, pretty sure something on it is toast and I have zero clue how to "fix" it.

No knowing what is wrong, I am now gunshy about using a TDA3116D2 chip. I've no idea if it's a bad choice of the chip, poor components, shoddy manufacture or all three. What I've looked at are modules with the following chips:

tda3116D2 12-24v 100w (what I have now, many variations of these)
tda7293 12-32v ac 100w
tpa3221 100w

Over powered (and over priced)
tpa3223 24-48v 200w
TDA7498E 15-36 recommend 32/8a 160w
TPA3255 36-48 +10a 600w

Dayton KABD 100w x 4 (price off the hook for my needs, only need one channel

The output of these chips are likely all too low.
LM386
tda2030 18w
tda2024 12v 15w x 2
tda7297 15w
yamaha yda138 12w
lm1875 30w
pam8403 3w
tda2822 .1-5w

Been to hundreds of sites - reviews, videos, manufacturers - and what I'm finding is nearly all of these modules are basically the same and made in China with no paper trail for specs or schematics. It's basically ya' get what ya' get. I wouldn't "cheap out" and would be willing to pay more if I had a few with reliability but it's just not there.

What say you, should I bite the bullet and just buy backups knowing they'll fail or is there a reliable source for these?

[Railroader]

How does this involve Arduino?

[rocknbil]

@Railroader

How does this involve Arduino?

SoftwareSerial Doesn't Allow Multiple Instances - Workaround?

In the end, this was the ultimate solution: Solid, reliable, no more bruises from banging my head against the wall. In the back of my mind I kinda new some sort of hardware switch would be required, but I was too busy ignoring what many of the more experienced engineers here have been saying, the management of serial communications via software is flaky and unreliable. Wouldn't you know it, I only had two of any kind of transistor, and it's a major overkill but I do have som…

The cliff notes: the DF Players are all worked out, now I'm just trying to find a suitable (and semi-reliable) way of amplifying the signals. I was almost done LOL

[DVDdoug]

Parts Express sells some higher-power amplifier boards (and complete amplifiers).

..Of course the power has to come from the power supply. I'm going to throw a little math at you. (I made myself a spreadsheet.)

Power is calculated as Wattage = Voltage x Current, or from Ohm's Law you can derive Power = Voltage squared / Resistance.

With 20VRMS you get 100W into 4-Ohms.

20VRMS is 0.707 x peak, so 20VRMS is about 60V peak-to-peak, so you need a 60V power supply, plus any losses through the amplifier. (Or a dual +30V and -30V power supply.)

That's assuming a "regular" single-ended amplifier with a ground connection to the speaker. With a bridge amplifier (two differential hot connections to the speaker) you can double the voltage (with the same power supply) for 4 times the power.

Of course, you should also calculate the required current (with Ohm's Law). In case you don't know this, the power supply can be rated for more current than you actually need.

[rocknbil]

@DVDdoug

20VRMS is 0.707 x peak, so 20VRMS is about 60V peak-to-peak, so you need a 60V power supply, plus any losses through the amplifier. (Or a dual +30V and -30V power supply.)

Thanks again Doug, this is the stuff that trips me up . . . by this math what they are saying below is not possible, you'll never get 100 watts? Like this one, most of the ones I've looked at function from 12-26 VDC (of course, less power output when you use less voltage.)

https://www.parts-express.com/WONDOM-AA-AB31184-100W-Mono-Amp-Board-320-3341

EDIT: Parts Express is also on eBay selling that one for a few bucks more + free shipping.

[DVDdoug]

100W at 2 Ohms. Half that at 4-Ohms and 1/4 of that at 8-Ohms.

I couldn't find the information but it's probably a bridge amplifier.

It says Power output (w/ 21 VDC power supply): 100W x 1 (2 ohms, THD 10%), 87W x 1 (2 ohms, THD 1%)

With a bridge amplifier the theoretical maximum is almost 15VRMS and my spreadsheet says 110W into 2-Ohms. (That would be without any voltage-loss in the amp.)

You get more power as you push the amp into clipping (distortion). "Worst case" you can "push" a sine wave until it becomes a square wave. A square wave has an RMS value equal to peak so you can get double the wattage (at 50% distortion)! Or if your signal happens to be a square wave you can also get double the theoretical power, but normal audio is more-like complex overlapping sine waves and not squared-off at the peaks.

100W at 21V is about 5 Amps (assuming 100% efficiency).

[rocknbil]

For those looking, maybe this could be an "add amplification to my Arduino project" thread. Since posting I've bought quite a few boards and here's my input. Note that all of these boards except the last are cheapo dime-a-dozen made in China boards.

All of these boards are mono boards but some of them support stereo. All of then have operating voltage of 12-24VDC.

The audio part of the project itself is driven by 3 Mini DF players as the source. I used DF players because they provided a cheap and easy way to get a little better sound quality for output. Some details here.

The project is powered by two off-the-shelf power supply boards, a 5V 500 ma supply for Arduino, LED's, and relays, a 24V 4-6amp supply for the amp boards, both fused.

The first board is as shown above:

This is a TPA3116 chip and has a pretty aggressive lowpass filter - too aggressive for my project, making the "cannon booms" sound a little muffled. I think it might be great for a bass boost in car stereo apps.

Next up I tried this little bugger, also a TPA3116 chip:

This one gives a little more mid range but was not as loud as I'd liked and has no volume control. I will circle back to it later as I have lots of projects coming involving audio. It has a very small footprint, barely 2" X 3". Heat sink is very small as you can see.

This one is about the same as the previous, except that it has a volume control and has a TDA2050 chip. Also very small heat sink and similar footprint.

This one is the one I chose for the final project. Also a TPA3116 chip, it seems to have the clearest sound and loudest output. I like the low profile and large heat sink (it might survive my amateur hacking LOL.) You can see it does have an onboard volume control which I desoldered for a wired log pot to reach the front panel, but of course . . . now I have a low hum, not real loud but there, at low volume. Being an outdoors project, it doesn't kill the project but I'll probably address it.

The last one, the Wondom/Sure AA-AB31184 is more of an investment and I have not tested it yet because I cannot find a suitable preamp for it. It is made in Malaysia.

Mostly, this board is too good (and too expensive) for my project, I'm saving it for something special. It's a work of art with a thicker PC board and multiple terminal points, but it has no volume control. I contacted Parts Express for a suitable preamp and their response was "call support." Sheesh I may have to build one LOL