So what I'm doing is setting up a tri-amp for a cornscalla like build using an active or digital cross over. (D220ti+D405+15" 8ohm woffer") the crossover and amps will live with each speaker.
I stuck together a breadboard with 3 lm3886's reference circuits. It had some issues caused by the single breadboard and shared PSU with the crossover. it was just a proof of concept, worked good enough!
Moving forward I'd like to grab 6 kits (one for each channel), While I have the tools and knowledge to do up a layout and spec parts, order the parts and get OSHpark PCB's made.... I'm short on free time.
So. Are there Any Decent Ebay kits currently available? Just something that uses the reference design, or maybe a DC servo would be fine. But it has a pretty good layout! I don't need anything to crazy. Through hole or SMD is fine.
Thanks
-Levi
I stuck together a breadboard with 3 lm3886's reference circuits. It had some issues caused by the single breadboard and shared PSU with the crossover. it was just a proof of concept, worked good enough!
Moving forward I'd like to grab 6 kits (one for each channel), While I have the tools and knowledge to do up a layout and spec parts, order the parts and get OSHpark PCB's made.... I'm short on free time.
So. Are there Any Decent Ebay kits currently available? Just something that uses the reference design, or maybe a DC servo would be fine. But it has a pretty good layout! I don't need anything to crazy. Through hole or SMD is fine.
Thanks
-Levi
A few years ago, I spent quite a while trying to find a good LM3886 kit on eBay. The best (or perhaps least bad) layout I was able to find based on the eBay pictures was the XY LM3886 Kit. I chose this kit because it looked the most promising on eBay and quite a few people here were using it, usually hacking the board to get a bit better performance.
You can see my measurements and review of the XY LM3886 Kit here: XY LM3886 Kit Review & Measurements
As you can see, it gets nowhere close to the data sheet performance of the LM3886. But then you're not out much. I think I paid $12 including shipping. I can't even buy the parts for that, never mind ship them, so you gotta wonder exactly what you're getting.
Another popular kit is the one by ChipAmp.com. Unfortunately, they disappeared without a trace and left their customers hanging. You can get a sense of that in these threads:
Chipamp.com are they for real or scam ?
Chipamp.com people around?
You may be able to find a pair of boards in the Swap Meet as they do pop up there from time to time. Unfortunately, the ChipAmp board layout is not fantastic as they bring in the supply connections from either side of the chip, thereby separating the supply traces as much as possible. This is the worst case for supply-induced distortion. The XY board does this better. That aside, the ChipAmp boards are probably pretty decent and there's no shortage of threads about their implementation here.
Anyway. All this prompted me to develop my own board. You can see it here: LM3886 Done Right
I do charge more than the eBay vendors (DUH!), but I also deliver more. Most importantly, with my boards you can at least see what you're getting as I provide a full set of measurements of my implementation. My LM3886DR actually beats the data sheet performance of the LM3886 by a bit in some areas.
If you prefer to develop your own, I suggest starting with the LM3886 data sheet. Then study my Taming the LM3886 article series. Also have a look at the open source layout effort by '00940' here. While not perfect, it's certainly better than the many eBay implementations.
Good luck!
Tom
You can see my measurements and review of the XY LM3886 Kit here: XY LM3886 Kit Review & Measurements
As you can see, it gets nowhere close to the data sheet performance of the LM3886. But then you're not out much. I think I paid $12 including shipping. I can't even buy the parts for that, never mind ship them, so you gotta wonder exactly what you're getting.
Another popular kit is the one by ChipAmp.com. Unfortunately, they disappeared without a trace and left their customers hanging. You can get a sense of that in these threads:
Chipamp.com are they for real or scam ?
Chipamp.com people around?
You may be able to find a pair of boards in the Swap Meet as they do pop up there from time to time. Unfortunately, the ChipAmp board layout is not fantastic as they bring in the supply connections from either side of the chip, thereby separating the supply traces as much as possible. This is the worst case for supply-induced distortion. The XY board does this better. That aside, the ChipAmp boards are probably pretty decent and there's no shortage of threads about their implementation here.
Anyway. All this prompted me to develop my own board. You can see it here: LM3886 Done Right
I do charge more than the eBay vendors (DUH!), but I also deliver more. Most importantly, with my boards you can at least see what you're getting as I provide a full set of measurements of my implementation. My LM3886DR actually beats the data sheet performance of the LM3886 by a bit in some areas.
If you prefer to develop your own, I suggest starting with the LM3886 data sheet. Then study my Taming the LM3886 article series. Also have a look at the open source layout effort by '00940' here. While not perfect, it's certainly better than the many eBay implementations.
Good luck!
Tom
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Tom thank you very much for the info.
I wouldn't risk using any of the IC's from a Chinese Ebay kit.
Thank you for the review of the XY kit! its not a great kit, but for the price it's not as bad as I would have expected.
I have looked at your kits, as well as a bunch of your write ups. I do chuckle a bit that it would cost me more to build a 6+ channel amp with your pre built kits than buying an ATI built AMP... However I might still pick up a pair or more of your boards...
At the power levels I require %99 of the time, the difference in kits is pretty minor...
00940's design looks interesting, but for being "open source" the source files seem to be missing... So pretty hard to get the boards made! I lack the free time to sit down and do board layout based on his pictures.
Thanks!
-Levi
I wouldn't risk using any of the IC's from a Chinese Ebay kit.
Thank you for the review of the XY kit! its not a great kit, but for the price it's not as bad as I would have expected.
I have looked at your kits, as well as a bunch of your write ups. I do chuckle a bit that it would cost me more to build a 6+ channel amp with your pre built kits than buying an ATI built AMP... However I might still pick up a pair or more of your boards...
At the power levels I require %99 of the time, the difference in kits is pretty minor...
00940's design looks interesting, but for being "open source" the source files seem to be missing... So pretty hard to get the boards made! I lack the free time to sit down and do board layout based on his pictures.
Thanks!
-Levi
If you trust the design "as is", you can have the eagle files (or gerber if you don't have eagle). I planned to release the files once I've tested the design, which isn't quite finalized too. Just drop me a pm with your email.
Yeah. But my Modulus-86 performs much better than anything ATI has to offer. A better comparison would be the Benchmark ABH-2 ($3k). You can build a stereo Modulus-86 with power supply and chassis for around $400-450. Less if you make your own chassis.
For the various LM3886 kits that's probably true. However, my Modulus-86 is an entirely different animal as it uses error correction to drive the distortion of the LM3886 output stage to practically zero.
The difference between the naked LM3886 and the Modulus-86 is pretty stark - even at low listening levels.
Tom
If you want the best chip amp go for Tom’s, if you want the second best...
Based on Mauro Pensa’s work.
My_Ref Fremen Edition - Build thread and tutorial
http://www.diyaudio.com/forums/showthread.php?p=3452148
Based on Mauro Pensa’s work.
My_Ref Fremen Edition - Build thread and tutorial
http://www.diyaudio.com/forums/showthread.php?p=3452148
The XY boards can do pretty well if you use genuine TI ICs instead of the ones in the kits. I've used a few of the PCBs for subwoofer builds without issue, but you need to be willing to make a couple changes to how you implement the board, I'll try to find the thread that shows the modifications, unless someone else knows the thread offhand. Not a bad choice for a quick and dirty build if you're like me and have a pretty big stash of parts to pull from, and don't need too many leading zeroes after that decimal point
The Modulus boards from Tom, chips straight from TI (free US shipping with their sample option!) And an order from digikey will get you going pretty quick, then its just chassis and power transformer selection really. Or, just buy the whole kit from him
The Modulus boards from Tom, chips straight from TI (free US shipping with their sample option!) And an order from digikey will get you going pretty quick, then its just chassis and power transformer selection really. Or, just buy the whole kit from him
Other option out of ebay is Akitika, by Dan Joffe.
Akitika Preamp and Power Amp Kits
GT-102 Stereo Power Amplifier
The questions are how much do you want to spend and if you listen good/very good recordings. To listen modern commercial music (very bad recorded and with low DR) you do not need/want to spend much money I think.
Akitika Preamp and Power Amp Kits
GT-102 Stereo Power Amplifier
The questions are how much do you want to spend and if you listen good/very good recordings. To listen modern commercial music (very bad recorded and with low DR) you do not need/want to spend much money I think.
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Do you mean this one?
Bought a XY LM3886 Kit.
I was browsing through that too, because I'm building a 3-channel amp with the XY boards. I actually have the kits, so I'm interested to see how they perform. Not sure about the chips, looks like the labels might be laser cut, so they might be genuine? The are kind of brownish and have sharp edges. But when you look the price, there is a doubt.
But I'm going to test the boards as they are, before any modifications
The modifications start around the end of page four-
Bought a XY LM3886 Kit.
and here-
http://www.diyaudio.com/forums/chip-amps/207971-bought-xy-lm3886-kit-6.html#post2959949
I'm in the US, and it's easy enough to order sample quantities of chips straight from TI, but for international builders I would always recommend buying all components (especially active devices!) from a reputable supplier in your area whenever possible... With the only exceptions being for certain passives like those cheap metal film resistor assortments, or the odd case or certain connectors.
The chinese kits are not the best choice, but the PCBs are cheap enough to be worth the effort for a cheap and cheerful project. If you are looking for vanishingly low levels of THD they may not be the best choice, but for many uses they end up as a perfectly acceptable and quality build, so long as you do things right, and are willing to cut a few corners for the greater good
Back when I was still messing around with chip amps with regularity I found decent numbers using the XY boards as a base, but I only used real TI chips, and bought all my own parts to populate them. They measured a bit better than tom's listed numbers, which I attribute more to the fact that the chips shipped with the kits may not be genuine, and the fact that layout and grounding are rather important. Power currents will have a measurable effect on the signal wiring, so separating the grounds at the board and tying them in only at the PSU can definitely help.
Bought a XY LM3886 Kit.
and here-
http://www.diyaudio.com/forums/chip-amps/207971-bought-xy-lm3886-kit-6.html#post2959949
I'm in the US, and it's easy enough to order sample quantities of chips straight from TI, but for international builders I would always recommend buying all components (especially active devices!) from a reputable supplier in your area whenever possible... With the only exceptions being for certain passives like those cheap metal film resistor assortments, or the odd case or certain connectors.
The chinese kits are not the best choice, but the PCBs are cheap enough to be worth the effort for a cheap and cheerful project. If you are looking for vanishingly low levels of THD they may not be the best choice, but for many uses they end up as a perfectly acceptable and quality build, so long as you do things right, and are willing to cut a few corners for the greater good
Back when I was still messing around with chip amps with regularity I found decent numbers using the XY boards as a base, but I only used real TI chips, and bought all my own parts to populate them. They measured a bit better than tom's listed numbers, which I attribute more to the fact that the chips shipped with the kits may not be genuine, and the fact that layout and grounding are rather important. Power currents will have a measurable effect on the signal wiring, so separating the grounds at the board and tying them in only at the PSU can definitely help.
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All,
Thank you for the input! I have a 2ea of tom's projects on the way, along with a mouser order. These will likely be paired with the speaker build. Or in areas where sound quality maters, office, bedroom, listening area etc...
I still plan to pick up some ebay kits for the PCB for pairing with cheap second hand speakers in areas where sound quality is not very important ( work out room, work shop, kitchen etc..)
Thanks!
-Levi
Thank you for the input! I have a 2ea of tom's projects on the way, along with a mouser order. These will likely be paired with the speaker build. Or in areas where sound quality maters, office, bedroom, listening area etc...
I still plan to pick up some ebay kits for the PCB for pairing with cheap second hand speakers in areas where sound quality is not very important ( work out room, work shop, kitchen etc..)
Thanks!
-Levi
A few years ago, I spent quite a while trying to find a good LM3886 kit on eBay. The best (or perhaps least bad) layout I was able to find based on the eBay pictures was the XY LM3886 Kit. I chose this kit because it looked the most promising on eBay and quite a few people here were using it, usually hacking the board to get a bit better performance.
You can see my measurements and review of the XY LM3886 Kit here: XY LM3886 Kit Review & Measurements
As you can see, it gets nowhere close to the data sheet performance of the LM3886. But then you're not out much. I think I paid $12 including shipping. I can't even buy the parts for that, never mind ship them, so you gotta wonder exactly what you're getting.
Another popular kit is the one by ChipAmp.com. Unfortunately, they disappeared without a trace and left their customers hanging. You can get a sense of that in these threads:
Chipamp.com are they for real or scam ?
Chipamp.com people around?
You may be able to find a pair of boards in the Swap Meet as they do pop up there from time to time. Unfortunately, the ChipAmp board layout is not fantastic as they bring in the supply connections from either side of the chip, thereby separating the supply traces as much as possible. This is the worst case for supply-induced distortion. The XY board does this better. That aside, the ChipAmp boards are probably pretty decent and there's no shortage of threads about their implementation here.
Anyway. All this prompted me to develop my own board. You can see it here: LM3886 Done Right
I do charge more than the eBay vendors (DUH!), but I also deliver more. Most importantly, with my boards you can at least see what you're getting as I provide a full set of measurements of my implementation. My LM3886DR actually beats the data sheet performance of the LM3886 by a bit in some areas.
If you prefer to develop your own, I suggest starting with the LM3886 data sheet. Then study my Taming the LM3886 article series. Also have a look at the open source layout effort by '00940' here. While not perfect, it's certainly better than the many eBay implementations.
Good luck!
Tom
Why do you put this board to Ebay or Aliexpress. Then we can buy this more easily!
Why should he, what is difficult about it now? He provides international shipping and you can pay with PayPal. What more do you need?
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