TPA3118 60W Power Amp Module

Ok, I grabbed a 3116 a while ago, powered it off a secondhand laptop power supply and just had heaps of noise with it. Didn't work well at all. Anyway, I recently grabbed a 3118 and hooked it up to the same laptop PS. Running my Mooer Preamp Live into it gives it heaps of volume and I control the volume using the MPL's master knob. However, just running one of Effectlayout's JC-120 preamp pcbs into it didn't have much volume at all, even flat out.

I'm guessing I need a booster (LPB1 maybe?) and buffer in front to get the same levels out of it.

Anyway, today I took my ghetto wiring job to band praco and ran it into the studio's 4x12 for two and a half hours..... No issue keeping up with drums at all. It's a beast of a little amp....

And a quick vid for proof of concept. Excuse the playing, it was our first runthrough as a group (and with this song)...


amp!.jpg Amp2!.jpg
 
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Let us know how this goes!
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Ok. So, I picked up a secondhand 19v@4.5a laptop supply and hooked up the new "150w" board and plugged it into a passive wedge (measuring 10ohm, 12inch speaker and horn of some sort) that I have and compared it to the little blue "60w" board. The results are thus:

Big Red:
- Turning the volume up on the board will amplify an electric guitar enough to be heard, but it's not going to impress anyone or get louder than a conversation.
- Sticking an Effectslayout Paladin (JC120 preamp/DI) pcb in front of it works too, but the volume isn't still impressive.
- Here's the kicker. Sticking a buffer in front of it after the Paladin gives you an AMP!!!. All of a sudden, the Paladin volume is barely on, whereas it was well past 12 without the buffer and still not real loud. You get the same result using a buffered pedal (a Behringer fx600 in this case) after the Paladin.
- The buffer used was Paulinthelabs' Buffered Y-splitter, but I had the same result when that was followed by a klon buffer. It's a long story, but I was using a DI/Cabsim that I built a couple of years ago. The chain inside is Y-splitter one goes directly out, the other goes to: - klon buffer - Sonic Stomp - Lart's Simple Cabsim. I'll include a pic of that.

The results were a little different with the Little Blue One:
- The little blue one has next to no volume without the buffer. However, I couldn't get it to work with the DI/Cabsim after the Paladin - it just would not work. BUT, it did work with the FX600 in front of it (both with the effect on or bypassed) after the Paladin.
- Little blue does NOT like having the input cable inserted into the jack when it's turned on (I suspect it's the same with the output too). This will cause it to shut down and you will have to cycle the power to get it working again. However, if the input was fed from the FX-600's output and kept there, you can plug/unplug the fx600's input all day long multiple times without issue.

I noticed more noise with the 150w, but I have noisy power downstairs and it's always been an issue. I haven't opened them up as loud as they can go, but based on the size and experience on Sunday with the LBO, it's a winner. Stick it in a 125b (or smaller!) on the pedalboard and you're good to go. I have another 2 of them on the way.

Edit: I went back and tried the TPA3116, supposedly 100w mono, and it worked fine with the buffer in front. It's smaller than the 150w, probably a little noiser. Didn't run it flat out, just enough to compare with/without the buffer. Again, the size is about the same width as a 125b, and would probably fit ok, but I'm not seeing any benefit over the smaller 3118.
 

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Ok, here's my 3116 based build. The vero at the bottom is a dual buffer with the volume pot wired between them, with a 9v regulator and 330n flown off it.
 

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I keep coming back to this circuit and can't wait to see it come to life as a kit or documentation to diy.

In my wish list, I'm hoping for something really simple to go out of one of my preamps (Alembic F1X clone, Intersound IVP, Acoustic 360+ or maybe one of the handful of pedal in a box projects I've made) and into a speaker cab. Not having to bring a full sized amp head will make this so nice for jam sessions at a friend's place without needing a roadie!

Any news about progress on this one?
 
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PBWilson1970 said:
I keep coming back to this circuit and can't wait to see it come to life as a kit or documentation to diy.

In my wish list, I'm hoping for something really simple to go out of one of my preamps (Alembic F1X clone, Intersound IVP, Acoustic 360+ or maybe one of the handful of pedal in a box projects I've made) and into a speaker cab. Not having to bring a full sized amp head will make this so nice for jam sessions at a friend's place without needing a roadie!

Any news about progress on this one?
Click to expand...
Dude, there's really nothing to these. Build a buffer on vero, run that to a pot, run that to another buffer vero, run that to the poweramp pcb. I don't even know if you need the 2nd buffer, but I put it there to get rid of any issues having a pot immediately before the pcb.
 
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Willybomb said:
Dude, there's really nothing to these. Build a buffer on vero, run that to a pot, run that to another vero, run that to the poweramp pcb. I don't even know if you need the 2nd buffer, but I put it there to get rid of any issues having a pot immediately before the pcb.
Click to expand...
That's great to hear. I've got a variety of buffer schems and layouts (leaning toward the JHS Little Black Box/Buffer?) and this could be a pretty useful item. Thanks for the words of encouragement.
 
Willybomb said:
Dude, there's really nothing to these. Build a buffer on vero, run that to a pot, run that to another vero, run that to the poweramp pcb. I don't even know if you need the 2nd buffer, but I put it there to get rid of any issues having a pot immediately before the pcb.
Click to expand...
Hey thanks for explaining it. Do you happen to have a diagram of how this would be wired up?

Also, I have never used vero. Do you know of any pcb buffers that would work in the same way?

I currently have 2 of these TPA3118 boards and would love to work on wiring them up and running them into a cab
 
I haven't used the tpa311x for guitar duty, but the stereo power amp in my living is my own tpa3118-based DIY job. It uses two mono tpa3118 PCBs that I made (my first-ever PCB design). They are not fancy, basically just a copy of the reference implementation in the datasheet (PDF link). The tpa311x amps were arguably the "darling" of the diyAudio Class-D forum for quite a while. When TI released the tpa311x series of class-D amps, the were not quite state-of-the-art, but very good, particularly given their price, the availability of cheap PCBs, and simple implementation. In terms of measured performance (for HiFi use), they are now outclassed by TI's own next-generation chips (e.g. tpa325x), as well as chips from other manufacturers (e.g. Infineon ma12070).

I haven't worked with this chip in a while, but some random thoughts off the top of my head:
  • The tpa3116 and tpa3118 are exactly the same circuit. The only difference is the physical package: the -8 is "power pad down", intended for lower-power applications where the PCB itself is intended to be the heatsink; the -6 has exposed metal on the package top, and is intended for use with a heatsink. (And in my experience, they simply don't get hot. Before I deployed my -8 amps, I used a -6 mono amps with tiny, glued-on heatsinks in my living room for years, driving 4-ohm speakers... they didn't even get warm. I think you have to push a sine wave through at max voltage to get the chip to heat up.)
  • I don't remember the values off the top of my head, but the amps are designed to be driven by some kind of a preamp (think in terms of hifi applications, e.g. a DAC, actual preamp, even cellphone headphone jack). The chips are designed for differential input. I don't know if the PCB discussed here has exposes the negative input pin (for differential input); but you will get a little extra volume feeding the amp a balanced signal. (If you're breadboarding a preamp, add a phase inverter too, so you can feed + and - signals to the chip.)
  • The gain of the amp is set by a voltage divider at the inputs. There is a table of gains and the corresponding voltage divider values in the datasheet. I'm not sure about the PCB discussed here, but a lot of the cheaper Chinese boards ship with the gain set to max. At least for HiFi use, this is usually unwanted, as it tends to produce a bit of audible hiss (i.e. higher noise floor). In my own PCB I used the lowest (or maybe second-lowest) gain setting. If I'm not mistaken, lower gain also increases input impedance, which should make it easier to drive.
  • There is a newer "version" of the tpa311x, I can't recall the part number now, tpa3128 maybe? But it's essentially the same measured performance, same (or very close) power, similar simple implementation, but TI improved the power-saving features. I mention it only because it might be relevant if you want to run off battery.
  • The gist of class-D amplification is that the output transistors switch off and on very quickly (typically in the 100's of kHz). This adds noise to the output signal; it is well above the threshold of human hearing, and implicitly filtered by most (probably all?) speakers. That said, usually you will find an RLC filter at the output of a class D amp. This is essentially a low-pass filter to remove most of that switching noise. Such a filter is generally required for commercial products to get various approvals, as without the filter, your speaker cables become EMI/EMF noise generators. But if your speaker cable is short enough (e.g. in a guitar combo amp), you can save on implementation complexity and cost by omitting the output filter. And if you do go with the output filter, big, quality inductors are better (this is measurable, someone over at diyAudio made a table of measured THD with different inductors).
  • I'm not sure this is measurable, but when I started playing with the cheap pre-made tpa311x boards, one of the first mods I always did was to replace the generally no-name PSU decoupling caps with quality organic polymer ones (e.g. Panasonic OS-CON). This could well be confirmation bias (because everyone on diyAudio said so!), but the better caps did seem to improve bass.
  • If you really want to get fancy, you can look into post-filter feedback (PFFB) implementations for the tpa311x amps. This will measurably improve the performance of the amp (at the cost of some gain), which is arguably only useful for hifi applications. However, the other upside is that it somewhat decouples the speaker load from the amp's output filter.

If nothing else, definitely at least skim over the datasheet. If you've got a lot of time (and I mean a lot!) you can skim the tpa311x threads over at diyAudio, there's all kinds of tips and tricks for working with these amps. I've always thought that if you had a decent preamp, you could make a respectable guitar amp out of the tpa311x. It's on my list of things I want to do someday.
 
Do you happen to have a diagram of how this would be wired up?
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Not really, but it would go like this:

Guitar - buffer - buffer out to volume pot pin 1, pin 3 to ground, pin 2 to second buffer input, second buffer output to TPA3118.

The IC buffers I've been building have worked fine. I haven't knowingly used a jfet buffer with it.
 
Just bought each of these to try your project @Willybomb.

Amazon.com: Zerone TPA3116D2 Amplifier Board, Single Channel Digital Power Audio Stereo AMP Module 150W for Audio System DIY Speakers, XR-544 : Electronics

Amazon.com: Zerone TPA3116D2 Amplifier Board, Single Channel Digital Power Audio Stereo AMP Module 150W for Audio System DIY Speakers, XR-544 : Electronics
smile.amazon.com

Thanks for sharing your experience with us. I'll have to put together the buffers and such, but that should be easy enough. Would I want to have separate power supplies on this thing (the amp calls for a much higher voltage/wattage than the buffers would)? So like, two 2.1mm jacks, one going to the amp and one going to the buffers?
 
Danbieranowski said:
Just bought each of these to try your project @Willybomb.

Amazon.com: Zerone TPA3116D2 Amplifier Board, Single Channel Digital Power Audio Stereo AMP Module 150W for Audio System DIY Speakers, XR-544 : Electronics

Amazon.com: Zerone TPA3116D2 Amplifier Board, Single Channel Digital Power Audio Stereo AMP Module 150W for Audio System DIY Speakers, XR-544 : Electronics
smile.amazon.com

Thanks for sharing your experience with us. I'll have to put together the buffers and such, but that should be easy enough. Would I want to have separate power supplies on this thing (the amp calls for a much higher voltage/wattage than the buffers would)? So like, two 2.1mm jacks, one going to the amp and one going to the buffers?
Click to expand...
I've got that power amp lying around as well. It's not bad, maybe a bit noisier than the others, certainly a bit larger.

I got around the 9v problem by including a 9v regulator and associated caps on the buffer board. On my latest effort, they're mounted directly on the power socket. I've cut the end off the PS and put a 2.1mm on that.

You won't get the full 150w out of that board, I think you'll need 24v, but the one you're getting will give you plenty of go regardless.

Watts/Volts/Amps/Ohms Calculator

Watts (W) / volts (V) / amps (A) / ohms (Ω) calculator.
www.rapidtables.com www.rapidtables.com
 
Willybomb said:
I've got that power amp lying around as well. It's not bad, maybe a bit noisier than the others, certainly a bit larger.

I got around the 9v problem by including a 9v regulator and associated caps on the buffer board. On my latest effort, they're mounted directly on the power socket. I've cut the end off the PS and put a 2.1mm on that.

You won't get the full 150w out of that board, I think you'll need 24v, but the one you're getting will give you plenty of go regardless.

Watts/Volts/Amps/Ohms Calculator

Watts (W) / volts (V) / amps (A) / ohms (Ω) calculator.
www.rapidtables.com www.rapidtables.com
Click to expand...
Yeah that makes sense. Really only interested in it as a quick and easy solid state power amp for testing pedals, so it should work well. Thanks for the info!
 
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I assume that you would just feed the 9vdc in parallel to the buffer(s) as well as the TPA3118? I made a board off of the layout shown in Stevel's entry above. Would I just insert the buffers as you described a couple of entries back (input-buffer-volume pot-buffer-TPA3118) to that?
 
So I measured the Marshall cab in the videos above at 15ohm, and I used 100Lolwhaats!? into it today. Again, plenty of volume on tap, not noisy in the slightest.

I assume that you would just feed the 9vdc in parallel to the buffer(s) as well as the TPA3118?
Click to expand...

Yeah, I hook the 24v feed up to pin1 of the regulator, and to the TPA3118 straight off that pin. Pin2 goes to ground, and Pin3 feeds 9v to the buffers. The regulator has a couple of caps across Pin1-2 and Pin2-3. I use unpolarised caps there, but you can use whatever.
hSkXmWn0fjXAIlS7bCjwf0b9E4h3i3Ry9gg3tRYg_qtGgPWAY0lVNhVozmHeiULslLquJIfD4cO2iF6234793nJ3AgY-dlJRvDVJO0Gk4irinMGpVcMDnhMijq9ZDATJIhPKSOqyufqRqg
 

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I know squat about voltage regulators. Are you talking about something like this. . . .

1639341250831.jpeg

Can you scratch out a layout as to how this integrates with the buffers?? I get the pin hookups you mentioned above, but I'm unclear as to the reference to caps.
 
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