Foam Core Amplifier - Listening Impressions
I connected a 19V x 3.6 amp (60 watt) switch mode brick from an old laptop to the foam core TPA3118D2 amplifier. This should have plenty of power given that this amp is 25 w/channel. I still don't have a heat sink yet but this chip is supposed to be thermally protected so it should be OK. I connected my Philips CD player to the input, and connected my FH3-inspired http://www.diyaudio.com/forums/full-range/227460-fh3-inspired-foam-core-mini-build-3.html foam core speakers (Vifa TC9FD drivers) to the amp's outputs. I put in my usual mix of test CD's which include female vocals, jazz, classic rock, pop, big band, alternative rock, and simple Baroque classical. I know what these speakers sound like on a stock Lepai 2020A+, and with a Yamaha 45 w/ch class A/B amp.
After listening to a few songs at soft levels I decided to push the amp to volumes that were fairly loud - about the max I would comfortably listen to for enjoyment. I was expecting the thermal shutdown to trip... No it stayed on and worked like a champ.
How does it sound? It beats the Lepai hands down. The clarity of the vocals is better, the sound was more "open" and lively, the bass is deeper. I am hearing certain sounds that I did not notice before on some tracks. Compared to the Yamaha, I think the bass is about the same but the amp sounds more open, the sound stage was very clear and it seemed enhanced the imaging on certain tracks that were designed for good spatial imaging.
I stopped the CD player to check for background noise or hiss - very low, almost imperceptible - less than the Lepai and about the same as the Yamaha. It was important to connect earth ground to the amp's ground connection though to achieve the low noise. Without it, there was 60 Hz hum.
In conclusion, I think that Texas Instruments has a winner in the TPA3118D2. Great sounding amp, very low cost, very efficient and low heat output.
Here are the speakers I tested them with:
Here is a closeup again.
My next project will be the 50 w/channel brother, the TPA3116D2.
I connected a 19V x 3.6 amp (60 watt) switch mode brick from an old laptop to the foam core TPA3118D2 amplifier. This should have plenty of power given that this amp is 25 w/channel. I still don't have a heat sink yet but this chip is supposed to be thermally protected so it should be OK. I connected my Philips CD player to the input, and connected my FH3-inspired http://www.diyaudio.com/forums/full-range/227460-fh3-inspired-foam-core-mini-build-3.html foam core speakers (Vifa TC9FD drivers) to the amp's outputs. I put in my usual mix of test CD's which include female vocals, jazz, classic rock, pop, big band, alternative rock, and simple Baroque classical. I know what these speakers sound like on a stock Lepai 2020A+, and with a Yamaha 45 w/ch class A/B amp.
After listening to a few songs at soft levels I decided to push the amp to volumes that were fairly loud - about the max I would comfortably listen to for enjoyment. I was expecting the thermal shutdown to trip... No it stayed on and worked like a champ.
How does it sound? It beats the Lepai hands down. The clarity of the vocals is better, the sound was more "open" and lively, the bass is deeper. I am hearing certain sounds that I did not notice before on some tracks. Compared to the Yamaha, I think the bass is about the same but the amp sounds more open, the sound stage was very clear and it seemed enhanced the imaging on certain tracks that were designed for good spatial imaging.
I stopped the CD player to check for background noise or hiss - very low, almost imperceptible - less than the Lepai and about the same as the Yamaha. It was important to connect earth ground to the amp's ground connection though to achieve the low noise. Without it, there was 60 Hz hum.
In conclusion, I think that Texas Instruments has a winner in the TPA3118D2. Great sounding amp, very low cost, very efficient and low heat output.
Here are the speakers I tested them with:
Here is a closeup again.
My next project will be the 50 w/channel brother, the TPA3116D2.
The chip is actually mounted upside down, the powerpad (or slug as you call it) is normally on the bottom side meant for soldering to the ground plane. I flipped the chip so that the pins stick up for ease of soldering with dead bug techniques. I do not have a heatsink yet for attaching to the rectangular metal pad that you see above. When it is running, if you put your face near the chip, you can feel a little radiant heat coming off.
Thanks, amazing comments for that chip. I hope some company will pick it up and use it for small amps like the SMSL SA-50. I certainly liked the pics of the components, looks like a quality build. But with a chip like the TPA3118D2, I'd be very interested. (More bass and clearer sound sounds so encouraging.) 
Thanks, amazing comments for that chip. I hope some company will pick it up and use it for small amps like the SMSL SA-50. I certainly liked the pics of the components, looks like a quality build. But with a chip like the TPA3118D2, I'd be very interested. (More bass and clearer sound sounds so encouraging.)
Another amplifier you could look at if you want to stay with the Texas Instruments theme is the Muse M50 which features the TPA2123. I am not familiar with this unit and there are very few comments about it across the internet. It could possibly be an overlooked sleeper.
Good going X!
It sounds like you've achieved the goal of good sound and of making it look like a squashed bug!
Are your eyes all wacky and look like spirals ????
Thanks Mark. My eyes already started out wacky looking, so this had no effect!
I think the paucity of comments regarding the TPA3118D2 (its siblings the 3116/3112) on the Internet has to do with how new it is (July 2012) and the fact that it only available as a $150 eval board so very few people were willing to take the plunge without prior positive comments. Hopefully this build may help set some folks over the edge to take the step towards building. I know that Dug has built the 3116 and has favorable comments on its sound.
I don't have the words to describe the feeling I had when I first listened to it on my Yamaha 849's...xrk971 will know...and some others for their projects.
I found the bass controlled the speaker very well...had force behind it...
(I designed with a low end 3dB point at about 3Hz.)
Even driven with an ipod it sounded great.
Rush's Zanadu...tweeting birds sounded great
Oh Yea by someone I don't remember...from Ferris B's Day Off...bass control.
I worked with the 3116 because it was available as a free sample
I have a bunch of 3886's that I will put into something but only because I have them and board I made for them but future major projects will be class D.
When I have mine in a box I will start a thread for the project.
Interesting build xrk971, I am glad it worked.
I found the bass controlled the speaker very well...had force behind it...
(I designed with a low end 3dB point at about 3Hz.)
Even driven with an ipod it sounded great.
Rush's Zanadu...tweeting birds sounded great
Oh Yea by someone I don't remember...from Ferris B's Day Off...bass control.
I worked with the 3116 because it was available as a free sample
I have a bunch of 3886's that I will put into something but only because I have them and board I made for them but future major projects will be class D.
When I have mine in a box I will start a thread for the project.
Interesting build xrk971, I am glad it worked.
Nicely done X. Look what I found Integrated Circuits (ICs) | Linear - Amplifiers - Audio | DigiKey at these prices I see lots of DIY builds in the near future. Shipping is reasonable as well $2.95 up to 8 oz.
Someone mentioned a break out board for $10, do you have an estimate for the rest of the parts?
Prices for all SMD external components was $9 ($12 including shipping) from Digikey. TPA3118D2 is about $5, but as Dug mentioned free samples are available. The terminal strip and wiring I had from my collection of parts already.
Great job. These chips need to get more notice. TPAs sound way way better than Tripath.
Mark,
Sorry to respond so late, I just saw your post after going through this thread again. Here are the goggles I bought <$7. They work well. I added a padded foam strip to where the flip down rim of the goggles touch your forehead to make them more comfortable. I generally use them with both rectangular lenses in place for 3x. For final checking I use the 9.5x loupe.
SE MH1047L Illuminated Multipower LED Binohead Magnifier - Amazon.com
Speaker Amplifier and Modulator - Mid/High-Power Amplifier - TPA3110D2-Q1 - TI.com
For those more knowledgeable than me in amps, can you say if a chip like this can be used for stereo subwoofers as well as 2-way speakers? (4 channel using two for subwoofers and the other 2 channels for two 2-way speakers.) I'm less concerned about the power because I tried a HiVi 5 inch woofer rated at 35 watts/70 watts max and it was moving like crazy just being pushed by a Lepai 2020A+ amp.
For those more knowledgeable than me in amps, can you say if a chip like this can be used for stereo subwoofers as well as 2-way speakers? (4 channel using two for subwoofers and the other 2 channels for two 2-way speakers.) I'm less concerned about the power because I tried a HiVi 5 inch woofer rated at 35 watts/70 watts max and it was moving like crazy just being pushed by a Lepai 2020A+ amp.
Darkstar and Wushi:
Thanks for the kind words. I was crazy for trying this but so glad it worked! I listened to them some more today and put some Blues Traveler on - man it sounds really good! I listen to the big sound, nice bass, awesome detail and sound stage, and then I look down at my circuit which is mostly air (foam core) and little flea like smd resistors and caps connected to a chip the size of microSD card, stare in disbelief at how much power and the quality of the sound that comes from it. I am powering this with a PS that you can buy for less than $5.
Rakuten.com - Hp Compaq Pavilion Dv7-1240Us Notebook/Laptop Power Adapter -19V - 4.74A
Still amazed it runs sans heatsink or solder pad without shutting down. I am guessing I am pushing close to 10 watts music through it. Pretty substantial volume.
Build this amp guys! You will not be sorry.
Thanks for the kind words.
I was crazy for trying this but so glad it worked! I listened to them some more today and put some Blues Traveler on - man it sounds really good! I listen to the big sound, nice bass, awesome detail and sound stage, and then I look down at my circuit which is mostly air (foam core) and little flea like smd resistors and caps connected to a chip the size of microSD card, stare in disbelief at how much power and the quality of the sound that comes from it. I am powering this with a PS that you can buy for less than $5.Rakuten.com - Hp Compaq Pavilion Dv7-1240Us Notebook/Laptop Power Adapter -19V - 4.74A
Still amazed it runs sans heatsink or solder pad without shutting down. I am guessing I am pushing close to 10 watts music through it. Pretty substantial volume.
Build this amp guys! You will not be sorry.
The 3110D2 is a smaller chip with only 10 watts at 10% THD. If you want low THD, probably good for 5 watts. I don't think this is a good idea for the HiVi 5 inch driver. Why not go with the new 3116D2 or even this 3118D2 at 25 watts and 0.1% THD? You can run it in bridged mode for mono at double the power.
These are so small and cheap, it is easy to make bi-amps for separate tweeters and woofers with variable active x-overs.
Don't get me wrong, the 3110D2 is an excellent chip to drive a small 3 in full range driver if all you need is 5 to 8 watts.
I believe the 3116/3118/3130 are the siblings you are referring to. The 3112 is an older chip. I did notice that a 24V/8A power supply is recommended for the 3116 and 3118 and a 24V/6A power supply is recommended for the 3130. These chips seem very amp hungry. Most people will probably end up under powering them.
Yes, my mistake it is 3130. If you don't need the full power potential, the 19 v bricks are the way to go for a budget approach. These amps are not power hungry - they are in fact super efficient. They are just capable of delivering a lot of power so need big supplies if you want to have that capability. A 24 v 8 amp supply is nearly 200 watts, at 90% efficiency for 2x50 watts, it doesn't seem to require anything close to that.