Mark,
I am building the TI TPA3118/3116/3130 - it is an improved 3122 with more power and very low THD and great efficiency. The spec sheet is here:
http://www.ti.com/lit/ds/slos708b/slos708b.pdf
I am doing something kind of crazy and making a SMD circuit dead bug style by gluing the SMD components onto a foam core board. I am using the circuit from the Eval board:
http://www.ti.com/lit/ug/slou336a/slou336a.pdf
with a couple of simplification mods to keep it closer to the standard circuit presented in the spec sheet schematic Fig 27.
This project is in this thread, post #16: http://www.diyaudio.com/forums/class-d/219730-tpa3118d2-2.html
I am waiting for some magnifying goggles to arrive before commencing with doing what is essentially "hand wire bonding" the upside chip to the rest of the glued down SMD components.
You may ask why foam core board and not something like a PCB? Just to say it can be done and because I don't want to mess with designing and making my own SMD PCB for a one-of. I have another thread in the full-range forum where I build speakers out of foam core, so it would be cool to have a complete foam core audio system including the amp.
X
http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures.html
I am building the TI TPA3118/3116/3130 - it is an improved 3122 with more power and very low THD and great efficiency. The spec sheet is here:
http://www.ti.com/lit/ds/slos708b/slos708b.pdf
I am doing something kind of crazy and making a SMD circuit dead bug style by gluing the SMD components onto a foam core board. I am using the circuit from the Eval board:
http://www.ti.com/lit/ug/slou336a/slou336a.pdf
with a couple of simplification mods to keep it closer to the standard circuit presented in the spec sheet schematic Fig 27.
This project is in this thread, post #16: http://www.diyaudio.com/forums/class-d/219730-tpa3118d2-2.html
I am waiting for some magnifying goggles to arrive before commencing with doing what is essentially "hand wire bonding" the upside chip to the rest of the glued down SMD components.
You may ask why foam core board and not something like a PCB? Just to say it can be done and because I don't want to mess with designing and making my own SMD PCB for a one-of. I have another thread in the full-range forum where I build speakers out of foam core, so it would be cool to have a complete foam core audio system including the amp.
X
http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures.html
Hello X,
Ah.......so the foam core stuff! Yeah, I was reading about the Cornu horns being done in foam over the weekend, and they made reference to the thread where someone was doing other speakers in foam. I never had a chance to look at it yet because I've been spending all my "mental horsepower" here on this Jerry's Amp. So, that foam core speaker stuff is you! Well, I'll have to give it a look over.
As for the new TPA3118 project you are doing --- very cool. I'm in awe. This Jerry's is the first thing I've built with a microchip. Probably won't be the last. I've been building tube amps the past 5-6 years and learning what I can. Lots more to learn of course.
The magnifying headgear will work. I'm about to get some better stuff myself. I work on Westclox Big Ben and Baby Ben alarm clocks and lately I've been interested in pocket watches where stuff is REALLY tiny! Yikes. I bought a 20X loupe not for constant wear but for those times when you want to see a specific thing, but I guess about 3-4X is right for most work. I'm looking into Optivisor brand stuff. It's pricey, but good as I understand it. I have a cheapie knock-off and it sort of gives me a headache after awhile.
I'll study your amp now.
Mark
Ah.......so the foam core stuff! Yeah, I was reading about the Cornu horns being done in foam over the weekend, and they made reference to the thread where someone was doing other speakers in foam. I never had a chance to look at it yet because I've been spending all my "mental horsepower" here on this Jerry's Amp. So, that foam core speaker stuff is you! Well, I'll have to give it a look over.
As for the new TPA3118 project you are doing --- very cool. I'm in awe. This Jerry's is the first thing I've built with a microchip. Probably won't be the last. I've been building tube amps the past 5-6 years and learning what I can. Lots more to learn of course.
The magnifying headgear will work. I'm about to get some better stuff myself. I work on Westclox Big Ben and Baby Ben alarm clocks and lately I've been interested in pocket watches where stuff is REALLY tiny! Yikes. I bought a 20X loupe not for constant wear but for those times when you want to see a specific thing, but I guess about 3-4X is right for most work. I'm looking into Optivisor brand stuff. It's pricey, but good as I understand it. I have a cheapie knock-off and it sort of gives me a headache after awhile.
I'll study your amp now.
Mark
Build a cornu if you can - very easy and very rewarding with big payoff in sound quality. Two $12 Vifa TC9FD driver and $8 of foam core is all it takes. I also play with automatic watch movements - have not taken one apart but adjust them. I have also disassembled and repaired a broken weight driven grandfather clock with a Swiss Army knife - that was kind of hairy because at one point I did not think I could remember the order of the parts to get it back together again! I got a cheapo $7 visor with LED lights from Amazon - hope it works. This is my first attempt at SMD circuits. Could be a total bust! But hey, its fairly cheap so no biggie.
Cornu foam core thread:
http://www.diyaudio.com/forums/full-range/225622-ever-think-building-cornu-spiral-horn-now-you-can.html
But hey, its fairly cheap so no biggie.Cornu foam core thread:
http://www.diyaudio.com/forums/full-range/225622-ever-think-building-cornu-spiral-horn-now-you-can.html
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I've been fascinated with those Cornus for years now. I have two Fostex 103's I should try.
You mentioned in the other thread about a ciruit board that is coming for your amp project. Where did you source that? Or was it custom?
Wow, the T.Instr. evaluation boards are expensive! Yikes. $150!
No heatsink necessary is good. So, you just plug in the power and go? No power supply filters needed? DC or AC transformers?
I watched the video. Looks like a pretty cool project.
Fixing a grandfather clock with a Swiss Army knife...........you are HURTIN' me, boy!
Mark
You mentioned in the other thread about a ciruit board that is coming for your amp project. Where did you source that? Or was it custom?
Wow, the T.Instr. evaluation boards are expensive! Yikes. $150!
No heatsink necessary is good. So, you just plug in the power and go? No power supply filters needed? DC or AC transformers?
I watched the video. Looks like a pretty cool project.
Fixing a grandfather clock with a Swiss Army knife...........you are HURTIN' me, boy!
Mark
Mark,
The Fostex 103 should work well.
It is a custom board - sourced from the generosity of another member. The price of the eval board is steep for DIY, but a deal for an engineer in a company planning to develop a new car radio or boom box that they plkan to sell a bizzillion units of - the intended target of these chips I am sure. It makes sense that they let the final designer do all the pop suppression as all car radios are micro-controller based nowadays. But the steep eval board price is what drove me to embarking on this foam core amplifier adventure, which not sure I would have done if I could have just bought the whole thing for $40.
No heatsink if you use the PowerPad soldered to a groundplane with vias. For my case, I am still trying to figure something out - maybe a copper fin fashioned from copper plumbing soldered onto the pad?
The Fostex 103 should work well.
It is a custom board - sourced from the generosity of another member. The price of the eval board is steep for DIY, but a deal for an engineer in a company planning to develop a new car radio or boom box that they plkan to sell a bizzillion units of - the intended target of these chips I am sure. It makes sense that they let the final designer do all the pop suppression as all car radios are micro-controller based nowadays. But the steep eval board price is what drove me to embarking on this foam core amplifier adventure, which not sure I would have done if I could have just bought the whole thing for $40.
No heatsink if you use the PowerPad soldered to a groundplane with vias. For my case, I am still trying to figure something out - maybe a copper fin fashioned from copper plumbing soldered onto the pad?
I missed the video - where is that?
Fixing a grandfather clock with a Swiss Army knife...........you are HURTIN' me, boy!
I think the bigger the better - as big as you can fit into the thru holes and board space. Doesn't hurt, although at some point it doesn't do any good. Cervelorider mentioned that he uses bigger ones not sure what size - doubling up is probably not a bad idea. I am using 470 uF for my TPA3118 and the spec sheet said 220 uF. I think folks always point to this cap as the first thing to upgrade in a class-D amp to get more bass extension.
When you say background hum, do you mean 60 Hz hum? Are you using a non-regulated linear power supply? That may be source of your hum, in which case it will take a huge cap to get rid of, if at all possible. Switch to a cheap switch mode power supply like a $8 19v x 4.6 amp laptop power supply brick. Those have noise but its up in the 40 khz and above and will be filtered off very well by the output inductor and input power cap.
Hi,
Yeah, 60 hz. hum. I am waiting for this power supply to come:
50W 24V DC 2 1A Regulated Switching Power Supply | eBay
But right now I'm just using a plug in the wall (wall wart) type power pack that measures 18.4VDC (under no load). The Jerry's Amp is supposed to run on anything from 12 - 24 VDC so I figure I'm OK.
You never said if a filter network and all that is necessary for the amp you're building. Or does it run directly from a DC source like most Class D amps?
I will order some larger value caps for C12 and C13.
Mark
Yeah, 60 hz. hum. I am waiting for this power supply to come:
50W 24V DC 2 1A Regulated Switching Power Supply | eBay
But right now I'm just using a plug in the wall (wall wart) type power pack that measures 18.4VDC (under no load). The Jerry's Amp is supposed to run on anything from 12 - 24 VDC so I figure I'm OK.
You never said if a filter network and all that is necessary for the amp you're building. Or does it run directly from a DC source like most Class D amps?
I will order some larger value caps for C12 and C13.
Mark
Hey X,
There's a video regarding your T.I. chip all the way at the bottom of this page:
Speaker Amplifier and Modulator - Mid/High-Power Amplifier - TPA3118D2 - TI.com
It won't tell you much though. Just promotional.
Mark
There's a video regarding your T.I. chip all the way at the bottom of this page:
Speaker Amplifier and Modulator - Mid/High-Power Amplifier - TPA3118D2 - TI.com
It won't tell you much though. Just promotional.
Mark
x,
No big filter caps or toroids? Aren't these class D's just tossing out all the rules? Crazy!
I screwed up and bought that other supply. I thought those were the good ones and the computer ones not so good. Who knew you could run an amp off something like a laptop power supply and have it sounding good?
It's hard to find one that's 24VDC and with any kind of amperage ratings. Many are around 17-18 VDC.
It's a crazy world from what things were when I started in this hobby 40 years ago!
I hope you keep me informed about the progress of your amp. Looks interesting.
Mark
No big filter caps or toroids? Aren't these class D's just tossing out all the rules? Crazy!
I screwed up and bought that other supply. I thought those were the good ones and the computer ones not so good. Who knew you could run an amp off something like a laptop power supply and have it sounding good?
It's hard to find one that's 24VDC and with any kind of amperage ratings. Many are around 17-18 VDC.
It's a crazy world from what things were when I started in this hobby 40 years ago!
I hope you keep me informed about the progress of your amp. Looks interesting.
Mark
Class D amps are a paradigm shift. Everything is smaller and done without 'big iron' or heat wasted. They will work with good linear supplies but the whole point was to get away from linear regulators that make heat or require huge transformers because the freq is now high in Mhz. Small inductors small transformers, same power.
Check out ps from here if you want power without heat.
http://hifimediy.com/index.php?route=product/product&path=61&product_id=73
Their amps are nice too.
http://hifimediy.com/index.php?route=product/product&path=59&product_id=77
Check out ps from here if you want power without heat.
http://hifimediy.com/index.php?route=product/product&path=61&product_id=73
Their amps are nice too.
http://hifimediy.com/index.php?route=product/product&path=59&product_id=77
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It will be tough to DIY that for less $ I have not bought from them myself but hear good things. Components look very nice.
Not yet
Hey there X,
No, I have not yet attempted that fix. I wrote to Jerry of Jerry's Electronics, and pointed him to this discussion. He said he was working on a circuit almost identical to the one you proposed.
I am kind of waiting on him to take the lead and determine a final "fix" before I jump in. But if I don't hear back from him soon I'll just try it.
I did receive one of those sort of open cage, regulated, switch mode power supplies for this amp however. The kind you hook your own wires to. That totally solved the minor hum problem I was experiencing before (when using a salvaged wall wart type power supply). 24VDC, 2.1 amp. It's spanking good for $13 shipped. It's dead quiet and puts out no discernable heat.
So, no I haven't scraped the connection between pins 1 and 2 and tried your fix yet. But I do appreciate it and certainly will.
Mark
Hey there X,
No, I have not yet attempted that fix. I wrote to Jerry of Jerry's Electronics, and pointed him to this discussion. He said he was working on a circuit almost identical to the one you proposed.
I am kind of waiting on him to take the lead and determine a final "fix" before I jump in. But if I don't hear back from him soon I'll just try it.
I did receive one of those sort of open cage, regulated, switch mode power supplies for this amp however. The kind you hook your own wires to. That totally solved the minor hum problem I was experiencing before (when using a salvaged wall wart type power supply). 24VDC, 2.1 amp. It's spanking good for $13 shipped. It's dead quiet and puts out no discernable heat.
So, no I haven't scraped the connection between pins 1 and 2 and tried your fix yet. But I do appreciate it and certainly will.
Mark
cheapie power supply
Hello X,
Here's one from my seller just like I got. Switch mode.
Mark
24V DC 2 1A 50W Regulated Switching Power Supply | eBay
Hello X,
Here's one from my seller just like I got. Switch mode.
Mark
24V DC 2 1A 50W Regulated Switching Power Supply | eBay
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