I have a notebook with built in bluetooth, makes it really nice to pull out my mouse and just have it work with no protruding dongles from my notebook.
Now if I pull out my external speakers (I work in a loud enviroment and like to listen to music off my laptop) I have to untangle the audio cable between the speakers, the audio input cable to the notebook AND the ac adapter wire.
The ac adapter actually isin't that bad, since it's easy to wind the wire around it, but the speakers... not so easy.
So I am in the process of putting together a set of custom speakers for my notebook that work wirelessly (except for the one wire between the speakers).
I ordered a bluetooth stereo receiver off of newegg.com that should do the trick as far as getting a audio signal to an amp, now I need to figure out which amp chip will work best.
I have a few thoughts about what I want, so let me tell you my thoughts, and you guys with a little more knowledge about whats available and what works good, can give me some advise.
There are 3 problems that I am trying to overcome. Usually fixing one will bring out another. They are:
1. Input Voltage Requirements.
2. Power Output.
3. Physical PCB Size.
It would be nice if the amp could run off USB power (5V) and still produce enough power to power book-shelf size speakers. I don't think that is possible (is it?), so I figure I will probably end up with a 12V DC input (8 AA or AAA batterys be best/cheapest?). Charging the batterys off USB while the speakers are not running would be a nice bonus though. Or maybe power off USB up to a certain point, then if it requires more power use the batterys? Or charge batterys if it can, otherwise use the batterys as the power source?
The PCB would have to fit in a small speaker enclosure. So would the batteries. I could possibly go with two mono amps to help save a bit of space in one enclosure (but then I would either have to have a second set of batterys in the other speaker enclosure, or run a wire just to power the other amp from the batterys in the first enclosure). I am thinking that may be best anyway so the volume of air in each enclosure will stay the same.
I would also like to build a custom sub with a small 6.5" or 8" car sub and would eventually need an amp to power that too, but right now I am just trying to get good wireless stereo sound from a small pair of book-shelf size speakers.
I see the TDA1521 is a pretty good powered amp IC? But it requires AC, how spendy is it in wattage to go from DC to AC? Are there any other IC's that I should be looking at? I would like to do as much custom work as possible to save money. If the number of components is small enough, maybe even skip using a PCB and just kind of wire all the leads together and stuff it in the box to save some money, although I would love to show off some high quality work.
Now if I pull out my external speakers (I work in a loud enviroment and like to listen to music off my laptop) I have to untangle the audio cable between the speakers, the audio input cable to the notebook AND the ac adapter wire.
The ac adapter actually isin't that bad, since it's easy to wind the wire around it, but the speakers... not so easy.
So I am in the process of putting together a set of custom speakers for my notebook that work wirelessly (except for the one wire between the speakers).
I ordered a bluetooth stereo receiver off of newegg.com that should do the trick as far as getting a audio signal to an amp, now I need to figure out which amp chip will work best.
I have a few thoughts about what I want, so let me tell you my thoughts, and you guys with a little more knowledge about whats available and what works good, can give me some advise.
There are 3 problems that I am trying to overcome. Usually fixing one will bring out another. They are:
1. Input Voltage Requirements.
2. Power Output.
3. Physical PCB Size.
It would be nice if the amp could run off USB power (5V) and still produce enough power to power book-shelf size speakers. I don't think that is possible (is it?), so I figure I will probably end up with a 12V DC input (8 AA or AAA batterys be best/cheapest?). Charging the batterys off USB while the speakers are not running would be a nice bonus though. Or maybe power off USB up to a certain point, then if it requires more power use the batterys? Or charge batterys if it can, otherwise use the batterys as the power source?
The PCB would have to fit in a small speaker enclosure. So would the batteries. I could possibly go with two mono amps to help save a bit of space in one enclosure (but then I would either have to have a second set of batterys in the other speaker enclosure, or run a wire just to power the other amp from the batterys in the first enclosure). I am thinking that may be best anyway so the volume of air in each enclosure will stay the same.
I would also like to build a custom sub with a small 6.5" or 8" car sub and would eventually need an amp to power that too, but right now I am just trying to get good wireless stereo sound from a small pair of book-shelf size speakers.
I see the TDA1521 is a pretty good powered amp IC? But it requires AC, how spendy is it in wattage to go from DC to AC? Are there any other IC's that I should be looking at? I would like to do as much custom work as possible to save money. If the number of components is small enough, maybe even skip using a PCB and just kind of wire all the leads together and stuff it in the box to save some money, although I would love to show off some high quality work.
Forget any cheap car speakers, they are all too inefficient to run off batteries or USB power.
Try to find a full range driver that does not need a crossover (saves wasted power) and also aim for 8ohm ~>96dB/W/m.
Up close this may be loud enough to monitor what is happening from a low voltage power supply.
Do you realise that the Laptop batteries will last for an even shorter time if they are asked to power a pair of external amplifiers?
What about headphones for Laptop use?
Try to find a full range driver that does not need a crossover (saves wasted power) and also aim for 8ohm ~>96dB/W/m.
Up close this may be loud enough to monitor what is happening from a low voltage power supply.
Do you realise that the Laptop batteries will last for an even shorter time if they are asked to power a pair of external amplifiers?
What about headphones for Laptop use?
The laptop itself is plugged in so it's not an issue of running the notebook battery's dead, and I don't like to use headphones because I can't hear any other part of the enviroment around me (phone ringing, people calling my name out, ect...).
Check out the Tripath class D amps like those based on the 2020 or 2024 chips. These offer very clean and detailed sound, high efficiency and low cost. There are boards on eBay, and kits from sources like 41hz.com (Look at the Amp6).
You can run them off low-cost 12v switching power supplies, or off of sealed lead-acid batteries or other types, of course. Loads of information over in the Class D forum. Come on in, the water's fine.
Good luck with the project.
--Buckapound
You can run them off low-cost 12v switching power supplies, or off of sealed lead-acid batteries or other types, of course. Loads of information over in the Class D forum. Come on in, the water's fine.
Good luck with the project.
--Buckapound
Check out Audiosector.com. Small amps and Peter Daniel (the designer of the amp and he runs a thread about the amp) might be able to help you customize this to what you need.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=123003&perpage=25&pagenumber=1
Mike
http://www.diyaudio.com/forums/showthread.php?s=&threadid=123003&perpage=25&pagenumber=1
Mike
No chipamp requires AC. The TDA1521 requires a split power supply. If you want to use a single supply or batteries it is easier to look for dedicated car audio ICs (e. g. TDA2003 for mono or TDA2004 for stereo). Of course you can buy something of similar quality cheap and ready made, e. g. like this. No 300 W of course, but 2 x 17 W into 4 Ohm or 2 x 8 W into 8 Ohm. You will find similar amps with different names at different prices everywhere. Don't pay more than 10 to 15 $ or € for it, it is not worth more. But you won't be able to DIY anything similar at that price, if you count all components, connectors and the case.jdraughn said:
Or use one of the class D amps from 41Hz. Higher price, better sound, more efficient for battery use.
What are the power supply requirements of that Bluetooth stereo receiver? Can it run off the same voltage as the amp?
You need open type headphone
The headphone you are refering too or that you probably tried must of been closed type. If you need to hear what is going on around you is an open type headphone.
An inexpensive and very good sounding headphone are the Koss KSC-75, the sound is similar to Grado SR-60 and for a fraction of the price.
Another one is the Senn PX-100, works great and you remain alert with the surrounding.
Regards,
Eric
The headphone you are refering too or that you probably tried must of been closed type. If you need to hear what is going on around you is an open type headphone.
An inexpensive and very good sounding headphone are the Koss KSC-75, the sound is similar to Grado SR-60 and for a fraction of the price.
Another one is the Senn PX-100, works great and you remain alert with the surrounding.
Regards,
Eric
Thanks for all the advice, you guys are awesome. I am going to do some more research with what you guys have told me.
As a guinie pig I took a cheap pair of powered computer speakers that I bought from a thrift store and used the built in amp module to power one of my 4x6" speakers and it sounded much, much better then the original 2" full range speaker. Even though it wasin't very effecient, it was actually louder and had much better highs. Lows actually wasin't really any different that I could hear, but that is probably because of some kind of built in high pass xover in the amp module. (they were in a temporary enclosure to at least seperate the back wave from the front wave).
The power amp ic in those cheapy computer speakers ($2.99 by the way 🙂 is a Toshiba TA8207K. Only puts out like 4 watts at 10% THD. Pretty bad, but it actually sounds pretty damn good for what it is! Makes me pretty excited to get a 10 or 15 watt amp going (with good sound quality, not no 10% THD crap).
Thanks again, I don't think I have ever had that many helpful replies in one of my forum posts anywhere, ever!
BTW. The head phones I have are Shure in ear kind not the best but at $100.00, they sound pretty good. I could go with an open ear kind of head phones, and I probably will look at going with a good pair pretty soon, because half the time im at work im in quite enviroment with others and need to keep my music to myself. The other half the time im by myself in a noisy enviroment, but still need to hear the phone or someone knocking on a door (they are both secured areas with cameras and require badges just to get into the rooms, let alone the buildings).
As a guinie pig I took a cheap pair of powered computer speakers that I bought from a thrift store and used the built in amp module to power one of my 4x6" speakers and it sounded much, much better then the original 2" full range speaker. Even though it wasin't very effecient, it was actually louder and had much better highs. Lows actually wasin't really any different that I could hear, but that is probably because of some kind of built in high pass xover in the amp module. (they were in a temporary enclosure to at least seperate the back wave from the front wave).
The power amp ic in those cheapy computer speakers ($2.99 by the way 🙂 is a Toshiba TA8207K. Only puts out like 4 watts at 10% THD. Pretty bad, but it actually sounds pretty damn good for what it is! Makes me pretty excited to get a 10 or 15 watt amp going (with good sound quality, not no 10% THD crap).
Thanks again, I don't think I have ever had that many helpful replies in one of my forum posts anywhere, ever!
BTW. The head phones I have are Shure in ear kind not the best but at $100.00, they sound pretty good. I could go with an open ear kind of head phones, and I probably will look at going with a good pair pretty soon, because half the time im at work im in quite enviroment with others and need to keep my music to myself. The other half the time im by myself in a noisy enviroment, but still need to hear the phone or someone knocking on a door (they are both secured areas with cameras and require badges just to get into the rooms, let alone the buildings).
I checked out amp kit 6 at 41hz.com. It looks to be almost exactly what I need. I really like the small size of kit 3 though. I would need to assemble myself right? Is that about the only difference is that kit 3 has very small surface mount components? I have done some soldering off and on over the last few years, but never a complete kit before. I would have to go with kit 6 in that case.
I've done 'em both, and they sound equally great.
Amp6 goes together with minimal skills and no special equipment. An easy 3 hour project at most.
Amp 3/32 is pretty much all surface mount components and they are unbelievably tiny. For that you really need a temperature-controlled iron with a very sharp tip, plenty of light and good eyes or a magnifier. And for the love of God, don't use silver solder, as it has a high melting point and poor surface tension (ask me how I know).
A flux pen is also helpful, and you'll need sharp tweezers. Once you get the hang of it, you can do it, but it's probably a good idea to order the practice board and parts. Check out the 41hz form and look around here, there's links to some video tutorials on soldering surface-mount parts.
If you're going to use a switching power supply, you can get the version without the power supply parts on-board.
Give it time to burn in before being too critical. Oh, and better input caps are probably a good idea, too.
--Buckapound
Amp6 goes together with minimal skills and no special equipment. An easy 3 hour project at most.
Amp 3/32 is pretty much all surface mount components and they are unbelievably tiny. For that you really need a temperature-controlled iron with a very sharp tip, plenty of light and good eyes or a magnifier. And for the love of God, don't use silver solder, as it has a high melting point and poor surface tension (ask me how I know).
A flux pen is also helpful, and you'll need sharp tweezers. Once you get the hang of it, you can do it, but it's probably a good idea to order the practice board and parts. Check out the 41hz form and look around here, there's links to some video tutorials on soldering surface-mount parts.
If you're going to use a switching power supply, you can get the version without the power supply parts on-board.
Give it time to burn in before being too critical. Oh, and better input caps are probably a good idea, too.
--Buckapound
Ya too was gonna recommend the Amp 6-Basic. A 12V smps to power it can be had pretty cheaply, much cheaper than a transformer which you would need for the standard Amp6. The standard Amp6 also requires winding 4 toroidal inductors which from what I've read can be quite a PITA. The 6-Basic has premade shielded inductors
More option 🙂
I currently have the AMP6 installed in our living room and it sounds pretty good regardless of the money, reminds me of a tube amp.
If you prefer AMP3 which is smaller and do dot want to venture soldering these tiny surface mount components there are some member of the 41Hz forum that do assemble the SMD kits and sells them, just check the 41Hz forum.
Another option is to buy the famous stereo amp from Sure-electronics on e-bay at $25 including shipping, it is based on Tripath TA2024 which received many amazing review, it can be powered from a single +12Vdc, 3A power supply. Output is about 10W / ch at 8 ohm. Very detailled sound, crystal clear.
Another option is to buy once again from e-bay (can't you tell I'm hooked on e-bay) a LM1875 stereo amp, it is rated at 25W but requires a +- 18Vac power source.
You can draw roughly 0.5A max from a typical USB port so not much power as you can see.
As you can see many choices out there, keep us posted.
Regards,
Eric
I currently have the AMP6 installed in our living room and it sounds pretty good regardless of the money, reminds me of a tube amp.
If you prefer AMP3 which is smaller and do dot want to venture soldering these tiny surface mount components there are some member of the 41Hz forum that do assemble the SMD kits and sells them, just check the 41Hz forum.
Another option is to buy the famous stereo amp from Sure-electronics on e-bay at $25 including shipping, it is based on Tripath TA2024 which received many amazing review, it can be powered from a single +12Vdc, 3A power supply. Output is about 10W / ch at 8 ohm. Very detailled sound, crystal clear.
Another option is to buy once again from e-bay (can't you tell I'm hooked on e-bay) a LM1875 stereo amp, it is rated at 25W but requires a +- 18Vac power source.
You can draw roughly 0.5A max from a typical USB port so not much power as you can see.
As you can see many choices out there, keep us posted.
Regards,
Eric
Right now I am leaning heavily toward the amp 3 kit with a practice board or two. I am not sure which one to get though. I don't really know a lot about power supplys.
I really want the speakers to be able to be powered by either battery, or the wall outlet if it's plugged in. And if it's plugged in I would want it to charge the batteries while also running off AC.
The AC adapter I have been using on these other speakers is 12VDC/1000mA, which from what I have read about the current draw of the amp3 will basically be ok, but it would not be enough for the peaks.
I am also curious if I could bridge the stereo outputs and put one in each speaker, or at least just have 1 for my satelite speakers and 1 bridged for the subwoofer. I will go ahead and start focusing on asking these questions on the 41hz forums. Thanks a lot for the help. I will keep you posted on the progress. The enclosures are going to be pretty cool, I plan on making them out of fiberglass and painting them glossy black to match my laptop.
I am also starting to research going with a horn driver (super high effeciency), but I imagine I would never get those to go to a low enough frequency without a pretty big horn attached to them.
I really want the speakers to be able to be powered by either battery, or the wall outlet if it's plugged in. And if it's plugged in I would want it to charge the batteries while also running off AC.
The AC adapter I have been using on these other speakers is 12VDC/1000mA, which from what I have read about the current draw of the amp3 will basically be ok, but it would not be enough for the peaks.
I am also curious if I could bridge the stereo outputs and put one in each speaker, or at least just have 1 for my satelite speakers and 1 bridged for the subwoofer. I will go ahead and start focusing on asking these questions on the 41hz forums. Thanks a lot for the help. I will keep you posted on the progress. The enclosures are going to be pretty cool, I plan on making them out of fiberglass and painting them glossy black to match my laptop.
I am also starting to research going with a horn driver (super high effeciency), but I imagine I would never get those to go to a low enough frequency without a pretty big horn attached to them.
The switching power supplies are the kind used for LCD computer monitors. There's a tom of them on eBay, usually for under $15. Go to Computers>Monitors>Accessories and there should be plenty of them. 14v is about the max for this chip.
For the battery, you will need an appropriate charger. My Amp32 will run at pretty good volume for 8-10 hours on one charge of a 5 amp-hour sealed lead-acid battery, to give you some idea of power consumption. Others have hooked up lithium cells. Each battery requires a different type of charger., so you'll have to do a little research. You'll also have to hook up some switch arrangement to go back and forth between battry and AC. If you can find an old computer UPS, you can salvage the parts out of there.
The smaller Tripaths are already bridged internally, so you can't bridge. And, you have to keep the negative speaker leads separate. Honestly, I can't imagine needing more power on a desktop. 10 watts makes a pretty good noise.
--Buckapound
For the battery, you will need an appropriate charger. My Amp32 will run at pretty good volume for 8-10 hours on one charge of a 5 amp-hour sealed lead-acid battery, to give you some idea of power consumption. Others have hooked up lithium cells. Each battery requires a different type of charger., so you'll have to do a little research. You'll also have to hook up some switch arrangement to go back and forth between battry and AC. If you can find an old computer UPS, you can salvage the parts out of there.
The smaller Tripaths are already bridged internally, so you can't bridge. And, you have to keep the negative speaker leads separate. Honestly, I can't imagine needing more power on a desktop. 10 watts makes a pretty good noise.
--Buckapound
The Class D section here is a good place to go too. That case sounds pretty cool..you know you owe us pics now when you get it done, right 😉jdraughn said:
wow a horn driver for computer speakers??jdraughn said:
Now that I gotta seeThe Amp6-Basic really is pretty small, but if you want the micro-size of the amp3, I would find some surface mount stuff to practice on first like you said. I'd recommend a BantamDAC official site, thread Check out the CableDAC configuration...signal and power all on 1 cable (no I don't work for em, tho their operation is entirely non-profit anyway) The only problem is they don't have kits..not sure if you've sourced parts before, it's relatively easy with the Bantam site. However, there is a surface mount diy dac which uses the same DAC chip and is essentially the same circuit (still 1 usb cable for power and signal) that you CAN get kits for called the Alien from a great guy named jeff rossel at http://www.glassjaraudio.com/main.sc. It's a little bit bigger, but what I think makes it ideal for you is that jeff will also solder the DAC chip for you, so I would order 2 alien kits from him, one with the DAC chip soldered and one without. That should give you a smoother learning/difficulty curve to build up to doing the fine-pitched soldering required for the surface-mount Tripath chip used on the Amp3
I should add that while the Alien/Bantam (Bantam is basically just a newer layout of the same circuit) were designed and are built primarily by headphone guys, they are just as much of a great performing external dac for speakers as they are for cans
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