Have been searching the forum for opinions of the ebay 2.1 Class D amps, but haven't really found much... (my previous experience is only with "normal" 2.0 stereo modules).
So, a short question: does anyone have any recommendations (based on experience) for an 2.1 amp (e.g. various 2x50w + 100W amp modules) available through "usual suspects" (ebay, aliexpress, tc...)?
I'm thinking about a new project, and need a compact 2+1 amp, not necessarily too powerful - but it has to be 2+1 ("normal" stereo plus subwoofer). Planning to power it from a "laptop brick" (18-19V, perhaps 4-5A), so it definitely won't reach the declared power, anyway
I'm leaning towards this one from sanwu:
TPA3116 2x50W+100W 2.1 Channel Bluetooth Digital Subwoofer Power Amplifier Board | eBay
- since I've found a couple of positive opinions about it....
Thanks in advance for any recommendations!
So, a short question: does anyone have any recommendations (based on experience) for an 2.1 amp (e.g. various 2x50w + 100W amp modules) available through "usual suspects" (ebay, aliexpress, tc...)?
I'm thinking about a new project, and need a compact 2+1 amp, not necessarily too powerful - but it has to be 2+1 ("normal" stereo plus subwoofer). Planning to power it from a "laptop brick" (18-19V, perhaps 4-5A), so it definitely won't reach the declared power, anyway
I'm leaning towards this one from sanwu:
TPA3116 2x50W+100W 2.1 Channel Bluetooth Digital Subwoofer Power Amplifier Board | eBay
- since I've found a couple of positive opinions about it....
Thanks in advance for any recommendations!
^ I have one of those. I posted here about it. The bass output cuts off completely if one of the bass control knobs is turned more than just a little bit from full counter clockwise. I later also noticed that changing the overall volume causes one of the satellite speaker cones to move drastically. I don't know if I just got a defective unit, or if it's a bad design.
Here is a common 2.1 board. I'm using this in a 2.1 boom box. Driving an 8" woofer and two 5" full range speakers rnning at 24+ volts. Lots of power and has held up to many days on the beach at loud volumes (80 W into the sub channel plus the L-R full ranges).
I modified the ".1" LP filter to suit my needs by replacing two poly box caps in the filter circuit thus changing the filter's Fc and Q.
Note that others here have received boards where the filter components were miss-populated with parts of the wrong values. This caused the LP filter to be unusable without mod's. On the flip side, both boards I ordered worked well out of the box. No hiss. Check out this link for a analysis.
TPA3116 2.1 Amp - Step by Step Modifications - Techtalk Speaker Building, Audio, Video Discussion Forum
I modified the ".1" LP filter to suit my needs by replacing two poly box caps in the filter circuit thus changing the filter's Fc and Q.
Note that others here have received boards where the filter components were miss-populated with parts of the wrong values. This caused the LP filter to be unusable without mod's. On the flip side, both boards I ordered worked well out of the box. No hiss. Check out this link for a analysis.
TPA3116 2.1 Amp - Step by Step Modifications - Techtalk Speaker Building, Audio, Video Discussion Forum
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Posted this here :
"Now listening for a few months to a $20 TPA3116 2.1 amp and I'm really blown away: real 2x50W+100W and the sound is so detailed, and just very NICE! And this 10oz (?) amp is more powerfull then the 25lbs Yamaha...
It runs fine with an old laptop adapter (+/- 19v >3A) The varable crossover is about 80-500hz. The solderingjob is among the best I have ever seen.
As subs are best run in mono and you can also run 2 fullrange bi-amped speakers from it.
Only 'negative' thing I've found is the noisefloor, but even with big sensitive PA speakers connected, I can hear it just a little within a foot when nothing is playing, so still good."
"Now listening for a few months to a $20 TPA3116 2.1 amp and I'm really blown away: real 2x50W+100W and the sound is so detailed, and just very NICE! And this 10oz (?) amp is more powerfull then the 25lbs Yamaha...
It runs fine with an old laptop adapter (+/- 19v >3A) The varable crossover is about 80-500hz. The solderingjob is among the best I have ever seen.
As subs are best run in mono and you can also run 2 fullrange bi-amped speakers from it.
Only 'negative' thing I've found is the noisefloor, but even with big sensitive PA speakers connected, I can hear it just a little within a foot when nothing is playing, so still good."
The pots are nearly always 50K Logs. This is denoted by B50K. B for B Taper (Audio Taper) and the number for the resistance.
I do have to say 10K pots work better.
THIS video is Certainly the solution. I did it to all three of my boards and it's 100% fixed. This works on other boards too because it's a principal issue, and not chip specific.
YouTube
I do have to say 10K pots work better.
THIS video is Certainly the solution. I did it to all three of my boards and it's 100% fixed. This works on other boards too because it's a principal issue, and not chip specific.
YouTube
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Yes sir, almost always 50K. I've seen that video. That's (why I asked about the pots.
And he's working on the board I used in my "boombox". My contribution was in the sub channel, changing the two box poly caps to get an Fc and Q on the fixed LP to suit your needs and eliminating / reducing the sub's 34 Hz HP to reasonable levels.
That chip reads: 78M05 DN1718 and I measured ~ 44k Ohm on the volume and treble pots with a cheap multimeter.
btw. The little switch selects if the mains crossover or play fullrange.
I don't know much of amps, but I noticed there are a lot more smd resistors and other components on this board in comparison with simular boards.
//edit: I won't be doing any mod for the noisefloor because it's good enough. Nice to read there is a 34Hz HPF which can be altered.
I measured temperatures after playing for hours and nothing gets warm at all; max 35 celcius.
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I have this same amp that I am using in my Bluetooth speaker project,first the amp itself works great,I am very impressed how silent it is when no music is playing. The bad is the annoying voice that announces the Bluetooth is ready. So maybe get one without Bluetooth and just add a newer 4.2 Bluetooth module to it like I am doing to this amp.
I think it’s a great buy for the money and maybe I was lucky and they made mine correctly
Yes you are correct, the title says Bluetooth but none is present on that board. I assumed it was the same as mine ,only the amp chip is the same.
In fact I kinda wish I had this one
The bluetooth implementations are problematic on many boards like this; beter buy an amp without bluetooth and a separate bluetooth module.
I really recommend (post #5) the one I have with the 5 knobs and variable crossover. I'm going to order an other one soon and put it in a nice little box and bring it over to friends with a little sub so they can hear what they are missing (instead of talking about it) and get some musicians among them a bit more interested in the technical side of sound.
I really recommend (post #5) the one I have with the 5 knobs and variable crossover. I'm going to order an other one soon and put it in a nice little box and bring it over to friends with a little sub so they can hear what they are missing (instead of talking about it) and get some musicians among them a bit more interested in the technical side of sound.
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I recently acquired one of the Sanwu 2.1 TPA3116 boards.
I recall seeing somewhere a few years back that some amp vendor was selling pre-made input cables that fit the three-pin header as seen on this board. Does anyone know who that was, or where I could easily get some?
Thanks!
I recall seeing somewhere a few years back that some amp vendor was selling pre-made input cables that fit the three-pin header as seen on this board. Does anyone know who that was, or where I could easily get some?
Thanks!
Attachments
Sorry, don't know where you can get the cable.
But if you do get one, I would remove the RCA input assembly. On a nearly identical Sanwu board, the metal in the RCA inputs seems to pick up a lot of switching noise from the chips - acting like an antenna.
I cobbled together something to see how it would work. I butchered the aluminium chassis I had that just barely contained the board... I don't have the necessary tools to do millwork.
I think the amp works quite well. I agree that the bass level and frequency seem not very sensitive, but I found a spot that integrates my open air woofer with my TC9FD Karlsonators.
The gain must be set pretty high, because I have to turn down my source (old Squeezebox 2) to get a usable volume range.
So far, I'm pretty happy with it and recommend it as a simple 2.1 solution. In retrospect I should have gone for the five-pot board to have more control over the fullrange-bass balance.
If only there were a ready-made enclosed TPA311x 2.1 amp that worked great like the plate amp recently discovered, but in a normal desktop format...
I don't have the necessary tools to do millwork. I think the amp works quite well. I agree that the bass level and frequency seem not very sensitive, but I found a spot that integrates my open air woofer with my TC9FD Karlsonators.
The gain must be set pretty high, because I have to turn down my source (old Squeezebox 2) to get a usable volume range.
So far, I'm pretty happy with it and recommend it as a simple 2.1 solution. In retrospect I should have gone for the five-pot board to have more control over the fullrange-bass balance.
If only there were a ready-made enclosed TPA311x 2.1 amp that worked great like the plate amp recently discovered, but in a normal desktop format...
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The gain must be set pretty high, because I have to turn down my source (old Squeezebox 2) to get a usable volume range.
I was testing a similar amp and here's what I found ...
The inputs go through 4X gain op-amp circuits before the master volume control. And the Op-Amps are powered by the same 5 V regulator that's used to drive the TPA chips' TTL level control signals. So any input signal higher than a few hundred mV starts to clip in the op-amps.
I think the thought was to enable full power out of the chips set to the standard 26 dB gain (20x) gain. Without the 4X gain, many sources don't have a high enough signal level to drive the chips to full power out. Powering the op-amps off the main DC PS voltage would solve the issue.
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