[matt_garman]

I've been considering an alternative to my modified Power One MAP110-S148 SMPS power supply, so I've been researching regulated linear power supplies and battery power supplies. While browsing Craigslist, I came across an Astron RS-12A regulated linear power supply. A guy had it listed for $20. At discounted prices, these power supplies sell for almost $100. I figured I could meet the guy at his workplace, plug it in and test it with my DMM. He offered to test it for me, since he had a nice Fluke DMM at work. Without a load, the Astron's output measured 14.02V DC. The unit is in excellent shape as the previous owner has had it for years, but never really used it for his HAM radio system.

Good find on the $20 Astron, definitely cheap and cheerful!

This isn't the first time I've seen people talking about good quality clean power making class D amps sound better.

For 12V, I wonder if a modern high quality computer PSU (e.g. Seasonic) would provide good results?  They're all SMPS, but might be worth a try.  Just bridge the green and black wires on the big ATX plug to turn them on... would have to look at a pin schematic to get the 12V supply, as I'm not sure which one it is offhand.  There is a competitive market for these things, and plenty of websites do rigorous testing (check out Silent PC Review's PSU reviews).

Rhing, in your research, did you come across any higher voltage contenders that might be worth investigating for the TPA3116?  I'd like to build a higher output-capable 3116, and I'm not sure 12V will cut it.  Looks like Astron also makes 28V PSUs, but based on the DIY Audio discussion about these boards, sound degrades above 21V.  21V is kinda weird, but surely there's something Astron-like at 18V or 20V...

[rhing]

I've only been looking into 12V DC supplies of the regulated linear and battery type. With my system, anything more is overkill. I can't even go past 9 o'clock on my preamp's volume knob without blasting my ears out.

I've read where some people have used computer power supplies with good results, although it seems like you would be spending a lot of money on a power supply that is built for another purpose. Most computer power supplies are the switch mode power supply type.

What seems to be the best power supplies for these low-power Texas Instruments Class D amps are battery-based, and after that regulated linear power supplies.

[G Georgopoulos]

What seems to be the best power supplies for these low-power Texas Instruments Class D amps are battery-based, and after that regulated linear power supplies.

which is better?,battery or linear regulated?

[Folsom]

Who said either?

[G Georgopoulos]

Who said either?

me!,

[G Georgopoulos]

For low current they are good but for high current no!

[lacro]

I have been thinking about putting a TPA3110 amp into a pair of the older Pioneer BS21 speakers to give as gift to be used as all in one (idiot proof) computer speakers with volume pot and lighted on off switch.
 I was thinking of using the binding posts of the speaker with the amp to connect to the second speaker. I know this will cause the amp to speaker connections to be one short and one long.
Will this cause noise or other issues? Any possible solutions. The long wire to the second speaker won't be more than 6' probably shorter.
 Also, I should probably keep the PS outside of the speaker cabinet, but it would be nice to have it inside. Thoughts?

Thanks,
Lacro   

[rhing]

Perhaps, this can help you.

http://www.audiokarma.org/forums/showthread.php?t=375768

So today, I transferred my Yuan Jing TPA3116D2 amp into a Modushop enclosure that I've had for quite some time. I bought two at the time when they were on sale for about $45 each. I decided that this amp was worthy of putting into a nice enclosure and it matches my Audio Research gear very well.

I started out fabricating a new DC power umbilical cable to go from my Astron RS-12A regulated linear supply to the amp. I decided to ditch the small Switchcraft coaxial DC connector in favor of a Neutrik 4-pin XLR connector. I followed the standard convention of using Pin 1 for "-" and Pin 4 for "+." The cable is nothing more than a twisted pair of 16AWG Mil-Spec Teflon-insulated Silver-plated, stranded Copper wire I picked up at a local surplus electronics store. I put spiral wrap tubing over that and then a Techflex expandable sleeve on top.



I then had to drill out the holes on the chassis rear plate and bottom plate to mount the connectors, power switch and the amp.



I took my time assembling the chassis since most of it is Aluminum. I didn't want to rush through it and end up scratching and marring the surface. The Modushop chassis from Italy is extremely well made. I bought mine directly from the manufacturer, but diyAudio.com sells them now, although at a much higher price.





I know some people are thinking why such a cheap amp in an expensive chassis, and why such a large chassis? First, I really like this amp in my system, and I didn't want to see my wood-mounted prototype anymore. Secondly, this chassis can accommodate some input balancing transformers like Jensens or Lundahls, which I plan to experiment with in the near future.

[Folsom]

I'm waiting on a YJ blue. Got to say... I just threw my 7297 into my new linear PSU, and well the 3110 just sounds weak in bass no matter what. The 7297 straight up has a grip on my speakers.

[fsdaron]

What battery is recommended for the 3116. Would a 12v 7amp sla be ok.

[Folsom]

What battery is recommended for the 3116. Would a 12v 7amp sla be ok.

Yes, it would work. You might want to add a 10kuf cap to it's outputs.

[thaddeussmith]

I'm assuming that you're referring to the Yuan Jing 2.0 TPA3116D2 "blue" amp. If that's the amp, then you can purchase these parts from Mouser.com. Sorry, but links die as Webmasters keep shuffling things around on Websites.

Wima MKP10 Film Capacitors 250V 1uF 5% PCM 22.5 11X21X26.5.............PN 505-M101.0/250/5.........
2 pcs..............$2.76/pc
Bourns Fixed Inductors TOROID INDUCTOR 10uH HI TEMP VERTCL MT........PN 652-2100HT-100-V-RC...
4 pcs..............$2.19/pc

Here's JonL's assessment of the Wima MKP10 caps:

http://www.audiocircle.com/index.php?topic=54218.msg524814#msg524814

Note that the end with the outer foil is marked with the vertical black line on the face of the cap. Typically, the outer foil end should be oriented to be closest to ground, output or lower voltage to serve as a quasi-shield for lower noise and better sound quality. I would think this would be the input thru-hole for each cap, but I invite others to correct me if I'm wrong.

It would be nice if tweakaudio.com offered the modified Wima caps in 1uF values with 22.5mm lead spacing, but I have a feeling the cost would be substantially more than $10 or $11 if they did. I would consider the "original" Wima MKP10 caps with the Copper leads, but the only sellers that carry them on eBay are in China, and I am not sure how authentic those caps are.

The Bourns inductors are the ones that Wushuliu prefers. Hope he's right.

ordered these items and a pair of 1,000uf/25v Elna Silmic II caps for the outputs. If I'm understanding correctly, the Bourns inductors and Wima caps don't have polarity but should be installed in a certain way to optimize performance. Help me clearly understand what that should look like?

[rhing]

ordered these items and a pair of 1,000uf/25v Elna Silmic II caps for the outputs. If I'm understanding correctly, the Bourns inductors and Wima caps don't have polarity but should be installed in a certain way to optimize performance. Help me clearly understand what that should look like?

FYI, the 1,000uF / 25V electrolytic caps that you are replacing with the Elna Silmic II's are DC decoupling (Vcc decoupling) capacitors, and are not part of the output signal path. Mount these with the same polarity as the stock Nichicon HD caps with the negative lead indicator facing forward on the amp board.

The Bourns inductors are non-polar as you mentioned, so mount these as neatly as possible on the board while making solid solder joints. These toroids are 0.86" diameter, so you might have to orient them in a 45 degree orientation to fit them in neatly.

For the Wima MKP10 caps, some values have a black vertical line printed on the wide face of the cap body. This line will be on the side or end of the cap to indicate which of the two leads is connected to the outer foil. In signal coupling applications, you want to have this lead connected to the side having the lowest impedance. Typically, this is the input side. If you are up to it, you can switch the orientation to determine what sounds best to your ears.

[thaddeussmith]

got it. thanks for the guidance and clarification of terms/parts. I took some electronics classes way back in high school, have a decent variable temp soldering station, and have tinkered with recabling headphones and interconnects, etc to build some soldering skills. The circuit boards and part replacements are a whole new area for me though. Fortunately the test subjects are relatively inexpensive.

[Folsom]

I'm now under the impression the 3116 is superior to 3110 in choice. Not specifically in sound quality per say, but I think the 3110 has serious current limiting issues regardless of capacitance/PSU capability. That might be Sure's issue, but I can't say. At this point it seems 97db or higher efficient speakers are best paired with 3110.

[rhing]

got it. thanks for the guidance and clarification of terms/parts. I took some electronics classes way back in high school, have a decent variable temp soldering station, and have tinkered with recabling headphones and interconnects, etc to build some soldering skills. The circuit boards and part replacements are a whole new area for me though. Fortunately the test subjects are relatively inexpensive.

Well you seem to be doing fine in the school of TI Class D amp building. No failures yet, right?

To mount the Bourns inductors, the objective is to keep the vertical lead legs vertical. So if you have to mount them at an angle, you should probably bend the leads about 1/16" to 1/8" below the "mounting plane" point as indicated in the Bourns datasheet.

http://www.mouser.com/ds/2/54/2100ht_series-8038.pdf

Maybe this top view diagram will better illustrate what I am trying to describe.

[lacro]

After 3 painful weeks of waiting my 3116 board to arrive, it finally arrived today! I can't wait to give it a try.     

[thaddeussmith]

yup, makes sense. though the two outer ones are actually offset a bit more, so they may not require such extreme angles. Parts should arrive tomorrow, so we'll see.

[Markvdv]

Received my 3110 today finally:) Got to say something about comparisons with 3116 YJ: input cap on Sure 3110 reduces bass from 240hz down.... 3116 YJ blue board has better input cap choice. Whatever you "bulk in" to cure what isn't left after inputfilter....I wouldn't have thought about increasing "bulk" capacitors first, so thank you, really, because obviously that matters maybe even more...These amps have TI datasheets that are really informative and read-able. If you feel you have plenty volume ((ring on) Klipsch?) with magnifyer shorting pin 6 and 7 on tpa3110chip could be easiest/cheapest towards remedy, upgrading at least 2 out of 4 input-caps to 1uF MKS/or smaller PP could be next, after which comparison of YJ3116 blue with Sure pcb could be more interesting

[thaddeussmith]

swapped both sets of caps with no problem. but i just realized i dont know which components are the inductors. are those the little blue rectangular components immediately in front of the chip heatsink, or the square black components immediately after?

small blue components are through hole, square black components are not.