TPA3118 60W Power Amp Module

[bretvh]

Yeah, I just ran the ground to the board ground and the input jack, I believe. I have not noticed any heat issues, but I haven't pushed mine very hard or used it a ton. And I've only run it into a 16ohm cab so far. Here is a pic of mine, but it's really messy, so apologies in advance. I kind of threw it into this old rotisserie motor housing I've had laying around forever and it really was not a good fit or placement so I just crammed everything in there as a temporary measure. I'll likely rehouse it some day down the line!

 

[Elijah-Baley]

Cool!
I took of this power amp from the cart in my last order because I have really nothing to power it up.
Unfortunately, I don't have any PSU laptop, it seem hard to be answered but, what PSU I could buy for it.

 

[stevel]

I completed the TPA3118 based amp today. I found another version of the schematic, and it properly showed how the DC plug should be configured. The one linked above was cut out of the one I attached here (which is the stereo version), but in the mono schematic, the negative side of the DC plug was not connected to a ground (and it should be). I suspected that was an issue, and wanted to verify before completing the project, which this stereo schematic did for me. I also discovered that the pot is wired backwards in the diagram. It got louder to the left and quiet to the right. So I've reversed it in my build. And finally, I also left out the 4700uF cap. The largest I have on hand is 1000uF, and could tack it in, but not sure I need it yet. We'll see.

I am using a laptop power supply for a laptop I just disposed of yesterday. The PS output is 19v at 3.4A center positive. I put together a polarity switching adapter since the amp is setup center negative like most of our other devices.

As expected, it sounds pretty bad without something feeding it. But I certainly knew to expect that. But, when fed by my Line 6 POD GO, it sounded pretty good. I only just finished it, and only did a brief test so far. I will have to play with it some more to see if it is fine as is, or perhaps I will set the global EQ in the modeler to tweak things a bit. Funny thing - first time I played through it, it sounded bright and harsh and terrible. Then I remembered that I was playing through a real guitar cabinet, and had to disable the cab simulation in the GO

How loud is it you ask? (I know, you didn't actually ask).

Well, like all solid state wattage specs, it is VERY misleading. Direct from the guitar (no preamp), it is not loud at all - wouldn't even wake a sleeping child. But driven by the POD GO, it reaches levels that might actually be loud enough for my basement band rehearsals. I would imagine that the same would be true with a variety of other preamp types as well (buffers, boosts, etc) in front of this little amp. Frankly, for me, the volume pot on the amp will never be set much below max unless I am playing at home and want to keep things pretty quiet. But it is loud enough for what it is for sure.

Just for the hell of it, I've ordered and will try the TPA3116 (100 watts, "yea right") to see if it is noticeably louder. It might suit me better. or it might be more of the same.

Thanks for pointing me to the original schematic - it helped a lot in getting to this point.

 

[bretvh]

Cool!
I took of this power amp from the cart in my last order because I have really nothing to power it up.
Unfortunately, I don't have any PSU laptop, it seem hard to be answered but, what PSU I could buy for it.

I bought this one and it’s worked out well so far:

SUPERNIGHT 24V Power Supply, AC 100-240V to DC 24V 3A Power Adapter Transformer Converter for LED Strip Light, CCTV, Router, ADSL https://www.amazon.com/dp/B0759JPVVP/ref=cm_sw_r_cp_api_i_a7PZEb29TYMTB

 

[stevel]

I've been using the little amp based on the TPA3118 mono board with my modeler, and it sounds pretty good, and it is pretty loud. I am using a 24V supply, into an 8ohm 1x12 cabinet. But it is certainly not as loud as 60 watts would suggest. Now I know very well that SS watts and tube watts can't be compared. But still, the volume is not blowing me away - I think my 12 watt Princeton is louder. I also bought a TPA3116 mono board (100 watts), and built the same amp circuit using that board. And it is also not super loud. I find I am putting these amps on about 3 o'clock (75%) to get them to be fairly loud.

So here is my question -- maybe these power amps really need a preamp to reach their full potential -- any thoughts on that? If you think that is the case, what preamp board would you suggest?

 

[bretvh]

I noticed a big bump in volume when I ran my Sansamp into it. Not enough to push it into "playing with a drummer" territory, but a noticable difference for sure.

 

[stevel]

I noticed a big bump in volume when I ran my Sansamp into it. Not enough to push it into "playing with a drummer" territory, but a noticable difference for sure.

Yea, for sure. Same here with my POD GO or HX Stomp. Although, if I put the amp on 10, it might be able to hang in with a drummer. It's hard to tell at home in isolation. But it almost seems like I shouldn't have bothered to install the volume pot

 

[Warmdrive]

I haven't worked all the math at this point, but no, this would not be powered by a charge pump.

I've powered it from a 9V 1-Spot (1.7A max) plugged into my 4 ohm Fender Twin cab and it would absolutely take your head off. I couldn't comfortably bring the volume above 1/3. Higher ohm cabs would benefit from a 24V supply.

The first revision will be a basic "clean" power amp that would require (or at least benefit from) a preamp in front, basically a power amp for the end of your pedal chain. As we move forward I do plan to work on complete "amp in a pedal" projects that include everything, possibly even some multi-channel projects. There's even been discussion of some tube-based preamps.



In the cases where 9V (or lower) circuitry is required we'll use a regulator so everything plays nicely together.

I have seen and heard the Joyo American sound and the Tech 21 Blonde used in front of this amp module with really good results.
I would really like to see a Pedal PCB version of the American sound and the California sound in a 125B six knob format to use with this amp module.
Thank you for all the work and effort to bring great projects to life.

 

[stevel]

I think my next test will be to run my modeler into a separate boost pedal and then on into the amp. I want to see if it has enough headroom to take a bigger signal without falling apart. If so, I may try to mod one of the boxes I’ve already built up to include the booster. My thought is to set the boost level with a board mounted trim pot to the highest level possible before breakup. Maybe I’ll have a little time to experiment on Sunday. I’d really love to be able to use this with the band either for rehearsals or as a backup amp at a gig. If it gets loud enough, it could even be the primary amp at a gig.

BTW - the 100 watt TPA3116 was not significantly louder than the TPA3118, which is to be expected. But perhaps it will have more headroom than the 3118....

 

[stevel]

I think my next test will be to run my modeler into a separate boost pedal and then on into the amp. I want to see if it has enough headroom to take a bigger signal without falling apart. If so, I may try to mod one of the boxes I’ve already built up to include the booster. My thought is to set the boost level with a board mounted trim pot to the highest level possible before breakup. Maybe I’ll have a little time to experiment on Sunday. I’d really love to be able to use this with the band either for rehearsals or as a backup amp at a gig. If it gets loud enough, it could even be the primary amp at a gig.

BTW - the 100 watt TPA3116 was not significantly louder than the TPA3118, which is to be expected. But perhaps it will have more headroom than the 3118....

Well, I found the time to do a quick experiment today. I have a cheap Donner DI box, which includes a -20db / 0db / +20db switch. So I played through my POD Go into the DI into the amp, and I tried the DI in the +20db position. Holy crap! Placing that +20db boost in front of the amp made it super loud (well of course it did, 20db is a lot). With the volume pot on the amp set below 75% on the amp, the tone was mostly the same as when the DI was on 0db, but louder. From 75% up to full blast on the amp, the sound got thicker and a bit more driven sounding, which is not really a surprise. While pure transparent tones all the way up would have been better for my needs, I can live with this performance. By that point it was so loud, I didn't need anymore anyway.

So I could just front end the amp with this DI since I already own it, or I could try building a tiny clean boost right into the amp enclosure, perhaps with something less than 20db of boost. Ideally, it would be as transparent as the boost in the DI. But that might imply a more complex circuit, and I really want to build something tiny enough to go onboard between the input jack and the amp pcb. Of course, doing it outboard is MUCH simpler as I can power it with 9v even though the amp is powered with 24v. Onbaord implies dropping the voltage to the boost, AND if I ever power this amp with a 9v supply, the boost won't get enough power unless I make that dropping string switchable.

If anybody has a suggestion on a boost circuit that would be high headroom (not overdriven from my modeler), VERY transparent, really tiny, and maybe boost by about 9 to 12db, please let me know. And if you have any cool ideas on the voltage drop part of this, fill me in on that as well.

More to come.

 

[stevel]

Well, I found the time to do a quick experiment today. I have a cheap Donner DI box, which includes a -20db / 0db / +20db switch. So I played through my POD Go into the DI into the amp, and I tried the DI in the +20db position. Holy crap! Placing that +20db boost in front of the amp made it super loud (well of course it did, 20db is a lot). With the volume pot on the amp set below 75% on the amp, the tone was mostly the same as when the DI was on 0db, but louder. From 75% up to full blast on the amp, the sound got thicker and a bit more driven sounding, which is not really a surprise. While pure transparent tones all the way up would have been better for my needs, I can live with this performance. By that point it was so loud, I didn't need anymore anyway.

So I could just front end the amp with this DI since I already own it, or I could try building a tiny clean boost right into the amp enclosure, perhaps with something less than 20db of boost. Ideally, it would be as transparent as the boost in the DI. But that might imply a more complex circuit, and I really want to build something tiny enough to go onboard between the input jack and the amp pcb. Of course, doing it outboard is MUCH simpler as I can power it with 9v even though the amp is powered with 24v. Onbaord implies dropping the voltage to the boost, AND if I ever power this amp with a 9v supply, the boost won't get enough power unless I make that dropping string switchable.

If anybody has a suggestion on a boost circuit that would be high headroom (not overdriven from my modeler), VERY transparent, really tiny, and maybe boost by about 9 to 12db, please let me know. And if you have any cool ideas on the voltage drop part of this, fill me in on that as well.

More to come.

I also tried my old trusty AMZ MOSFET booster in front of the TPA3118 amp, and found it behaved quite similarly. And its board is tiny. So I built up a board to install inside of the amp enclosure. I had to order a couple of parts to complete the install, so it will take a while before I can report any results and show any photos. This one will end up being a prototype as grafting on the AMZ board may not be so pretty. But pulling it all apart and rebuilding it neater will be worth it if I like the results. I don't expect to have to drill any holes, which is a good thing.

I am also going to experiment with a 50k linear pot instead of the 50k audio pot in their right now. I think if the sweep of the pot wasn't so weighted to the end of the rotation, I'd like it better. Maybe. Easily reversed if I hate it.

I expect to use this amp for the first time on Tuesday night at a band rehearsal. I usually use a VOX MV50 Clean into a 1x12 open back cabinet loaded with an 8ohm speaker (if I remember correctly), with all amp modeling turned off. This time, I will use the TPA3118 amp into that same cabinet with the amp modeling turned on (cab modeling turned off). If it is able to achieve similar volume levels without the AMZ board installed, it will be a YIPEE moment.

 

[stevel]

Band rehearsal went really well with this little amp driving my 1x12. Amp was set on about 1 o'clock, and I had no problem keeping up with the 2nd guitar, bass and drums. Room to spare on the POD Go's volume control as well. I've built 3 of these now - 2 with the TPA3118 (60 watts), and 1 with the TPA3116 (100 watts). I plan to install the AMZ MOSFET Booster board into the TPA3116 version, maybe on Sunday. I have another enclosure on the way so that I can build another of the TPA3116 versions as well. I like to have spares especially at gigs. And these spares will fit in my backpack. Awesome stuff.

 

[stevel]

Question regarding Class D amps:
We all know that 100 tube watts is MUCH louder than 100 solid state watts. So does that mean that my speaker can handle MORE Class D watts safely than it can handle tube watts? For example, would my 100 watt 12" speaker be able to handle say 150 or even 200 Class D watts?

 

[Nostradoomus]

No, a watt is a watt. Tubes are able to push more clean volume than a solid state due to a variety of factors (Total Harmonic Distortion etc) but don’t use a 200w amp with a 100w speaker.

 

[kg250zw7]

Any update on when this will be available?

 

[c.h.u.d]

I put one of these together and have been running it into a 2x12 at 4 or 16 ohms with a Joyo British Sound in the front. I am getting some great sounds out of the setup but I am finding the joyo doesn’t play so well with other od/distortion pedals in this context.

I was considering putting together a ROG tonemender but was curious if anyone could recommend a cleanish preamp/eq that might work for me.

Also here is an obligatory gutshot. I could have planned the cap location better but such is life.

 

[zgrav]

I built the ROG Umble and use that in front of a small solid state amplifier. http://www.runoffgroove.com/umble.html

 

[phi1]

The ROG tone mender is designed to emulate the passive tone stack in fender, box, or Marshall amp. The tone will effectively have a mid scoop, except when bass and treble are both at minimum. It can’t boost the mids at all.

Many people like it though. I breadboarded the circuit at one point and found it generally too bright for my taste (which makes sense, treble sounds boosted relative to mids except when treble is at minimum).

 

[stevel]

Given the schematic I posted earlier in this thread, how would I prevent the loud pop that occurs when powering on the amp? I've been turning down the volume prior to hitting the power switch, but that is getting old. I know there is a mute on the board, but I'd rather not add a "standby" switch. I am hoping that by placing a resistor to ground from somewhere in the circuit would bleed the transient off, or some other solution like that.

 

[temol]

stevel - maybe something like this? Or google for turn-on delay / speaker protection / speaker soft start circuits.