19 volt 4.6 amp laptop SMPS brick, or 19 volt 3.6 amp brick. Lot's of these lying around. I am finding that the ones with grounded plugs are quieter (no surprise there).
I was also considering putting two of the 12 volt 5 amp smps bricks ($3 ea) in series to get 24 volt 5 amp supply (these need to be the non-grounded bricks to work).
http://www.amazon.com/Replacement-Monitor-Adapter-Power-Supply/dp/B004HVHM36/ref=sr_1_5?s=electronics&ie=UTF8&qid=1365026395&sr=1-5&keywords=12v+power+supply+lcd
I was also considering putting two of the 12 volt 5 amp smps bricks ($3 ea) in series to get 24 volt 5 amp supply (these need to be the non-grounded bricks to work).
http://www.amazon.com/Replacement-Monitor-Adapter-Power-Supply/dp/B004HVHM36/ref=sr_1_5?s=electronics&ie=UTF8&qid=1365026395&sr=1-5&keywords=12v+power+supply+lcd
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Doofus question here. What kind of source do you find suitable for testing speakers? Would Youtube videos make the cut?
http://www.youtube.com/watch?v=y-AGXIMemz8
http://www.youtube.com/watch?v=y-AGXIMemz8
I like to use a high quality cd player deck (a good one will have rca outs, digital fiber optic output, and independent headphone out with volume control, a low distortion DAC). A good high quality cd recording (preferably made from 24 bit 96 khz master). Having said that, I am sometimes surprised at how good the sound quality from some YouTube videos are (HD ones typically). If you convert them to MP3's at high bit rate, they are good enough for much casual listening or even rough testing of speakers. Many sound like cr@p though so YMMV.
If you have a good (or at least decent) soundcard and/or DAC connected to your computer you should try some high res recordings, like 24/96 or 24/192.
Lots of free stuff to be found on the web, but here's a random search result that google gave me:
Free Legal High Resolution Music Downloads
Lots of free stuff to be found on the web, but here's a random search result that google gave me:
Free Legal High Resolution Music Downloads
Update: I have tested this for many hours now with music volumes at pretty high levels and the copper ring barely gets warm. So I think that this is really all the heatsink that is needed for a practical application. In case you are wondering how I made it: I used a hacksaw to cut a ring at two different angles to get a narrow portion to solder to the IC pad and the larger portion to increase heat transfer area. I used standard half inch copper plumbing tubing. No worries about this chip ever overheating now.
Fortunately, the looks have nothing to do with the sound. I also built the equivalent version with nice PCB and it sounds no better so I have to say that as an experiment to see if SMD can be prototyped on paper it was successful. Ugly looking? Well, that wasn't the point to have s pretty looking dead bug circuit.
I have been auditioning my new TPA3123 for the last 3 days, on all day without any heatsink. According to ti, this chip requires no heatsink for music reproduction.Update: I have tested this for many hours now with music volumes at pretty high levels and the copper ring barely gets warm. So I think that this is really all the heatsink that is needed for a practical application. In case you are wondering how I made it: I used a hacksaw to cut a ring at two different angles to get a narrow portion to solder to the IC pad and the larger portion to increase heat transfer area. I used standard half inch copper plumbing tubing. No worries about this chip ever overheating now.
This little jewel is far better than the TA2020+ amps, which I have several of. I gave up trying to receive fm with the above, just too much interference. With the Muse TPA31xxd2 board, not even in a metal case, fm is super quiet.
I'm using a Muse tpa3132d2 bridged
I could not use a Lepai 2020A+ or an SMSL SA S1 2020A+ for fm input. I just could not pull in any stations but for the strongest and they very weak and noisy. I tried putting ferrite beads on input and speaker cables with no success. Even the reception a portable fm radio would degrade as it got closer to the amp.
I'm guessing that d-amps have progressed since the introduction of the Tripath?
The finished board was $16 delivered, no other reason. It just seemed too good to pass up.
They look to be sold out.
2x50 w Stereo Class D Audio Power Amplifier Circuit Board TI TPA3123 | eBay
2x50 w Stereo Class D Audio Power Amplifier Circuit Board TI TPA3123 | eBay
There is another option. You could buy a completely built Muse M50 based on the same TPA3123 chip. I don't know how well they are built or how much they could be improved by some judicious tweaking but could be an interesting project.