TPA3118 60W Power Amp Module

Mike McLane

Active member
Anybody have a minimalist layout of what would be required to get one of these guys working? I've seen pics with added circuitry for volume, EQ or some kind of buffering/preamplification, etc. but could I get away with wiring an outboard preamp and appropriate power supply directly into the TPA3118 and wire it directly to speakers?
 

stevel

Member
Anybody have a minimalist layout of what would be required to get one of these guys working? I've seen pics with added circuitry for volume, EQ or some kind of buffering/preamplification, etc. but could I get away with wiring an outboard preamp and appropriate power supply directly into the TPA3118 and wire it directly to speakers?

I use these boards in a small pedal sized enclosure with just an input jack, an output jack, a power jack, a power switch, an LED and a volume control. I am attaching the diagram I followed (I only built half of this 2 channel diagram of course). I've used this same diagram with the 30, 60 and 100 versions of these boards. There is one diode and one capacitor off-board in this configuration (I didn't use the electrolytic cap - it really wasn't needed). I play a Line 6 HX Stomp or POD Go or a Strymon Iridium directly into this amp, and then connect it up to my 1x12 guitar cabinet. I hope this helps.
 

Attachments

  • TPA3118 Power Amplifier.jpg
    TPA3118 Power Amplifier.jpg
    235.8 KB · Views: 59

Mike McLane

Active member
EXACTLY what I'm looking for!! Thanks!! How do you like working with the HX stomp? I have one that I've been using to run my acoustic thru. . .works great, IR host and all of the FX I need in one very portable box. May be doing some electric gigs and have perused all of the feedback on modelers for live use. The cork sniffers seem to poo-poo 'em, but there are some good, demanding pro players around here who I have talked to and they have had great results.
 

stevel

Member
EXACTLY what I'm looking for!! Thanks!! How do you like working with the HX stomp? I have one that I've been using to run my acoustic thru. . .works great, IR host and all of the FX I need in one very portable box. May be doing some electric gigs and have perused all of the feedback on modelers for live use. The cork sniffers seem to poo-poo 'em, but there are some good, demanding pro players around here who I have talked to and they have had great results.
I love the Stomp. I play mostly electric, but I also have an acoustic IR or two for when I do acoustic stuff. I have a Morningstar MC6 MKII MIDI controller too, which lets me control more Stomp functions since it has just 3 footswitches built in. Very cool stuff. Once you build up one of the amps, post your results :)
 

Mike McLane

Active member
Thx!! I assume that the 3A power diode is a 1N5817? The mute is just a SPST (on/off) that bridges the connections on the Mute eyelets. Also, how would the power LED be wired in?
 
Last edited:

Mike McLane

Active member
From reviewing other schematics it appears that the power LED runs: +9vdc --> LED(A) / LED(K) --> 4K7 resistor --> to GRD. It appears as though the order of resistor & LED is immaterial. Pls confirm.
 

stevel

Member
From reviewing other schematics it appears that the power LED runs: +9vdc --> LED(A) / LED(K) --> 4K7 resistor --> to GRD. It appears as though the order of resistor & LED is immaterial. Pls confirm.
You can place the resistor either in front of the LED or after it. Either way, it will limit the current flowing through the LED, which is the purpose. I usually put it on the +9V side, and connect the other side of the LED directly to ground.
 

stevel

Member

Paradox916

Well-known member
I just got a 1N5402 under the assumption it would be more than enough... but If I burn anything up I’ll let you know🤣.
By the way how is that little amp holding up?
 

stevel

Member
I just got a 1N5402 under the assumption it would be more than enough... but If I burn anything up I’ll let you know🤣.
By the way how is that little amp holding up?
1N5402 will be fine. The main difference is that it handles up to 200V where the 1N5408 that I used (because I had them on hand) handles up to 1000V. With a 24V power supply, I think you'll be safe ;)
 

stevel

Member
I have a couple of Lenovo laptop power supplies that I would like to modify to use with these amp projects. I mainly want to cut off the plug, and solder on a more common 2.1mm x 5.5mm plug oriented the right way.

These power supplies have a ferrite bead very close to the existing plug. Is it needed in this application? If I leave the bead in place, I will have VERY little room for error when putting the new plug on. I might not even have enough space for the plug jacket. Can I cut off the bead and then solder on my plug or will that basically ruin the power supply for my intended use?
 

Mike McLane

Active member
Just finished one of these buggers (like the layout pictured above) and I can say it works, but right now that's about all I can say. I'm powering it with a 19vdc 3.4 amp laptop power supply. I plugged my HX Stop into it and ran the speaker output to the WGS ET65 in my amp. Sounded OK, but I quickly discovered that it can be finnicky. You can push it too hard and it distorts. Turn up the volume past mid way and it gets very shrill and somewhat garbled. Since this is a bubble gum & bailing wire sort of build there may be some deficiencies in the build, but I'm guessing that the unit has some limitations in terms of I/O that must be respected in order to get proper performance. It'll be nice when PPCB puts something out around this board. Also, FWIW I'm wondering if the 60W board is gonna have enough ummmph to be more than a bedroom product.
 

temol

Well-known member
You should keep the input signal level low enough to avoid amp output signal clipping. In an ideal world you need a signal generator, oscilloscope and a load. So you have source of a sinewave with a known level, known load (4 or 8 ohm). On the oscilloscope you see the moment when the output sinewave starts to clip. Then you know what's the safe input signal level range (with clipping free output signal).
 

Paradox916

Well-known member
I know the quality consistently had been mentioned with the TPA3118s on several occasions the one I built using this same schematic that has been floating around seems to operate fine without clipping running it off 12v-18v and pushing a 4x12 cab (that’s all I got for now tell I can come up with a single 12 cab) .is it 60w?... not by a long shot..lol. With a decent preamp it sounds pretty good and with a couple of decent pedals, I think it sounds better that the spider v30 collecting dust in the corner 🤣. But I just don’t see the TPA3118 being anything more than that. It’s an impressive little piece of tech with its own set of limitations. Just my 2 cents for what it’s worth ( which is about 2 cents not counting for inflation.)
 

Mike McLane

Active member
I noticed that the Seymour Duncan Powerstage has LED's to signal clipping on both input and output. Don't know how complicated that is to include in a PPCB design, but it would be nice to have a simple way to "calibrate" input signal levels. I noticed that when I had it set at what appeared to be a "workable" level it would still distort when I banged out an open E chord. One simple solution may be just to over-design the unit with much more horsepower such that you could operate it at well under max input and output levels and still get the volume you desire.
 

PBWilson1970

New member
Looks like this has potential to go along with my Alembic F2-B style preamp or the Intersound IVP I'm getting ready to assemble.

On a semi-related topic, are there any Class D modules (ICEpower maybe?) that might work like these for a higher powered power amp? I like the idea of a backup amplifier on my pedalboard or a relatively inexpensive guitar or bass power amp.
 

fig

Well-known member
Something like this?

 

PBWilson1970

New member
Something like this?

I looked at that particular module and the many others on the ICEpower site and unfortunately I'm not knowledgeable enough to determine which one might be work-able for a Class D power amp with a switch and LED, single input, single pot for level, integrated power supply so I could use an IEC connector and one or two output jacks. Sites like this and a few others have allowed me to "paint by numbers" and build dozens of pedals and a few amplifiers without a great deal of knowledge to go it alone.
 
Top