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Is there a EE in the house?
04-22-2010, 09:30 AM
Or someone with some idea of electronics. Cos when I'm not working etc I'm nutting out this:
![[Image: 43c26d71ce95d0d97b8d8eb8fedcc32985e28a5d.jpg]](http://www.accessdenied-rms.net/forums/forumimportfiles/43c26d71ce95d0d97b8d8eb8fedcc32985e28a5d.jpg)
A stereo amp for headphones powered from a USB port and using 2 LM386 op-amps for processing. The main reason for the RFH is that I feel that what I've come up with is missing something and I'm probably reinventing the wheel in regards with this circuit.
And that image could be better, a PDF's available....
--Rod.H
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i'm not an ee, but i tossed this together last night:
http://www.xkcd.com]![[Image: circuit_diagram.png]](http://imgs.xkcd.com/comics/circuit_diagram.png)
... does that help? 
-Z, Post-reader at Medium
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If architects built buildings the way programmers write programs, the first woodpecker to come along would destroy civilization.
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You're reinventing the wheel.
http://www.tangentsoft.net/audio/cmoy-tutorial/
http://octopart.com/blog/...g%253A-doublet-amplifier
behold, wheels!
pictures of in-progress and results required.
"No can brain today. Want cheezeburger."
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Bmull - yessssssss. perfect.
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bmull Wrote:Here's another option: http://www.zipplet.co.uk/index.php/cont ... usbheadamp Dangnam it!! That's pretty much what I've been looking for. The Cmoys just kept on popping up no matter how I searched. Now the only trouble I'm gonna have is locating a source for the chip used in that one, unless I figure out a way to use the ones I have instead.
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Zojojojo Wrote:i'm not an ee, but i tossed this together last night:
http://www.xkcd.com]
... does that help? No..... you cheater
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http://www.mouser.com/Pro...jO%2fJg2U%252b9uBQ%3d%3d
Just because I know my luck on these sorts of things, I'd buy 10. Not because Mouser is bad (I've never had problems with them), but because that's the next step up from 1 and I always blow my first IC when kitbashing. At that, it's still cheap.
--sofaspud
-- "Listening to your kid is the audio equivalent of a Salvador Dali painting, Spud." --OpMegs
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Rod H Wrote:No..... you cheater
cadging from someone else's work is the mark of a TRUE engineer! i'm just being efficient
-Z, Post-reader at Medium
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Sofaspud Wrote:%[link=http://www.mouser.com/ProductDetail/STMicroelectronics/TDA2822M/?qs=NP3vpjCFX6jO%2FJg2U%252b9uBQ%3D%3D]http://www.mouser.com/ProductDetail/STM ... 9uBQ%3d%3d]
Just because I know my luck on these sorts of things, I'd buy 10. Not because Mouser is bad (I've never had problems with them), but because that's the next step up from 1 and I always blow my first IC when kitbashing. At that, it's still cheap. Um ya. The component is cheep. The shipping is not. 40 bucks for a 1 buck item ($10 if I buy ten). That's if I buy from there luckily http://australia.rs-online.com/web/sear ... -_-1594720]RS components is a valid option for me.
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$40 shipping? Uh. Whoa?
I checked shipping to both the US and Canada and it was offering me $8-$10. Dunno where the $40 came from.
Edit: Given your link, I'm guessing Australia. Didn't know that. So, uh, yeah, Mouser's not the best bet for that. 
--sofaspud
-- "Listening to your kid is the audio equivalent of a Salvador Dali painting, Spud." --OpMegs
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Sofaspud Wrote:$40 shipping? Uh. Whoa?
I checked shipping to both the US and Canada and it was offering me $8-$10. Dunno where the $40 came from. It's the shipping cost to Australia.
I keep forgetting the a fair share of people on this board are not in the USA...
Reminded me of my previous comment on another thread: "As long as you have internet access, you're never too far away."
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Quote:"As long as you have internet access, you're never too far away."
I cannot send resistors via email 8(
"No can brain today. Want cheezeburger."
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damnit, it's 2010. Where are my teleporters?
-Terry
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sweno Wrote:damnit, it's 2010. Where are my teleporters? Backordered, unfortunately.
Heh... it needs the same part you're looking for.
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Huh, the teleporter needs a resistor or a TDA2822M.....meh I've got plenty of the first and a couple of the other.
So I've managed to get a hold of some TDA2822Ms from the local version of Radio Shack who are getting out of the electronic component biz. I've breadboarded the circuit and powered it up to the sound of nothing and a warm chip. A quick troubleshoot revealed why, I missed wired the chips' ground connecting it to the power rail.
Still it works nice, needs some minor tweaks. I just wish someone would release the TDA2822M footprint for Eagle so I could get a decent PCB made up.
![[Image: cfe16d1794067fdbb0b7428b741d9240c7370da8.jpg]](http://www.accessdenied-rms.net/forums/forumimportfiles/cfe16d1794067fdbb0b7428b741d9240c7370da8.jpg)
With the spares I've got I'm thinking of building one for inside my PC, the first one's going on my Xbox.
--Rod.H
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Adding an update to this. I've posted an RFC/A 'bout this over at the SparkFun Electronics forum and as it doesn't have an Arduino nor requires waving a dead chicken, isn't a Cmoy and I'm using "antiquated technology" it's not apparently attracting much interest.
Meh, it's doing the job I need at the prototype stage and I'm waiting on parts so I can get it down to size. I might contemplate submitting this to the only hobbyist electronics rag in the country and see what they think. Supposedly the last time they've had something which used the guts I've used was sometime in the early 1990s. Probably after some more tweaking.
I mean its not like anyone else uses headphones while playing their 360.
--Rod.H
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what are headphones?
I kid, I kid. I'm missing my old setup, though, a thousand watts of 5.1 channel amplification and some delicious Sony SS-series speakers fed by an Onkyo receiver generated large amounts of happiness.
now I'm down to like 70 total watts into 5.1 with a set of Logitech X-540. Le Sigh.
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Well this rig's just 1 watt of pure stereo, I'm also in a non-speaker friendly environment hence the headphones.
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1 watt in the right place makes a massive difference..
I'll snap a pic or two of my 1 watt pre-amp I built for my mp3 player (iRiver lacked enough grunt out the headphone port for make happy when hooked to aux input).
Have you considered hand-drawing your PCB, or are you fixated on laser-toner-transfer etching?
"No can brain today. Want cheezeburger."
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Wiredgeek Wrote:I'll snap a pic or two of my 1 watt pre-amp I built for my mp3 player (iRiver lacked enough grunt out the headphone port for make happy when hooked to aux input). Sounds like a permanently set volume version of what I'm building.
Wiredgeek Wrote:Have you considered hand-drawing your PCB, or are you fixated on laser-toner-transfer etching? I'm most likely to just build it on some vero or similar board and http://workmanship.nasa.gov/lib/insp/2% ... wires.html]greenwire any missed bits. The fancy PCB designs are mainly a learning experience for me and something I'd leave to the experts. Doesn't mean I wouldn't mind a proper board done. Heck, I'd be happy with a complete kit, it's just no-one makes one even remotely close to what I needed.
--Rod.H
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![[Image: 6e9256c58b1b4e4d98bde368e34f2a6a676c6c6.jpg]](http://www.accessdenied-rms.net/forums/forumimportfiles/6e9256c58b1b4e4d98bde368e34f2a6a676c6c6.jpg) ![[Image: b9e158541bea95d4c9e7ebf31d083015a0837fb.jpg]](http://www.accessdenied-rms.net/forums/forumimportfiles/b9e158541bea95d4c9e7ebf31d083015a0837fb.jpg)
1w, stereo, sourced all the parts that didn't come with the kit from the bits bin. External regulator (not pictured) dropped the 14.5-9v from the car to 5v for the system.
"No can brain today. Want cheezeburger."
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Wiredgeek Wrote:
1w, stereo, sourced all the parts that didn't come with the kit from the bits bin. External regulator (not pictured) dropped the 14.5-9v from the car to 5v for the system. I think I've found the kit you used at http://www.electronickits.com/kit/compl ... /ck704.htm
They've appeared to have revised it since you built it. The new version has a volume control. And I'm still discovering more evidence that I'm reinventing the wheel. The only new thing I appear to be adding new to the circuit is a USB port and a LED and both of those elements are standard.
I guess I'm an Engineer then, cos I'm cutting & pasting to make something work!
And HUH!?! I didn't know Lindt chocolate came in sea salt flavour.
--Rod.H
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