[MCM_Fan]

Nice looking start MCM_Fan. You should be okay with using a tablet as a source. Just be sure the amp is not powered on when you're connecting and disconnecting the tablet. Otherwise, you'll hear ugly ground loops and loud pops. That's usually good enough reason to have a volume pot to protect your speakers.

So, are people only hearing loud pops when physically connecting/disconnecting sources from the input jacks with the amp powered on?  Or, are there loud pops when powering the amp on and/or off.  I think I've read of both problems occurring.  The former makes sense, and isn't an issue for me as I don't physically connect the tablet to the amps inputs.  The tablet (or my phone, or my laptop) streams music wirelessly to the Airport Express.  I've tried connecting the Airport Express directly to the amp with a mini-RCA Y-cable and also from the Airport Express through an optical cable to the FiiO D03K DAC and then from the DAC to the amp using the same mini-RCA Y-cable.  In both cases, the mini-RCA Y-cable always remains plugged into the amp when it's powered on.  Again, no loud pops or clicks, just an occasional very faint "snick" sound - regardless of the volume setting on the tablet.

If the latter, I have also not experienced any loud pops when powering the amp on/off.  I've tried turning the amp on/off by plugging/unplugging the wall outlet, plugging/unplugging at the amp and turning the switch on/off and hear absolutely no loud pops.  Usually, I don't hear anything, but if I do, it's a very faint "snick" like sound that I probably wouldn't even notice if I wasn't specifically listening for something.

So, are others actually hearing a loud pop through their speakers when turning the amp on/off.  If so, how are you turning your amp on/off?  Are you using a switch, plugging/unplugging the AC input of your supply, using a power strip with a switch to supply AC power to the brick, or plugging/unplugging the DC at the amp?

[matt_garman]

So, are people only hearing loud pops when physically connecting/disconnecting sources from the input jacks with the amp powered on? 

I don't think I tried that, but can't remember now...

Or, are there loud pops when powering the amp on and/or off.

I definitely have that on my blue YJ board if the inputs aren't connected or the inputs are connected but the source device is powered off.  The pops are loud and scary, as I can see my woofers moving substantially.

So, are others actually hearing a loud pop through their speakers when turning the amp on/off.  If so, how are you turning your amp on/off?  Are you using a switch, plugging/unplugging the AC input of your supply, using a power strip with a switch to supply AC power to the brick, or plugging/unplugging the DC at the amp?

I have a smart power strip, where one plugged in device is the "master".  When the master is turned on, all the other outlets ("slaves") on the strip turn on.  When the master is off, all the slaves are off.

So my preamp acts as the master, and the tpa3116 is the slave.  This ensures that the amp only turns on when the input source is on.  Turning off, I seem to just get lucky... it appears that the amp shuts down exactly when the preamp shuts down (i.e. if there was a delay, as in, pre-amp off, delay, power-amp off, I would expect a pop).

The other solution I had in mind was to just leave the amp on at all times, since it uses so little power when not in use (very little when in use as well).  But if I turn my preamp off, but leave the amp on, then I get an audible "hiss" coming through the speakers.  Haven't found a solution for that yet.

[DaveC113]

matt, you might want to leave it on all the time, many digital devices take a while to sound good after being powered on... something to experiment with at least.

rajacat, thanks for the link, I think something like that would be a better choice... those woofers are capable of WAY over 112 dB, I want peaks in the 120 dB range! 

[Poultrygeist]

Thanks, that was what I was thinking...

The Class D Yung plate amps from PE are hard to beat for driving woofers in a bi-amnped system.

[Poultrygeist]

A friend who has the green board 3116 says it has a mute circuit which silences the "thump ".

[matt_garman]

In case you haven't seen this, here's some more eye-candy tpa311x builds: Flea Watt.

Changing gears a little, just out of curiosity: for those of you using these amps, what does your complete system look like?

I'll start.

Living Room system:
Linux HTPC -> optical SPDIF -> Emotiva XDA-1 -> power amp -> Salk Songtowers
Power amp here is either Class D Audio SDS-470 or the TPA3116 build I posted a few days ago.  This used to be my main system for listening, but we moved to a new house recently.  The new house seems to have bad acoustics, and it has in-ceiling speakers that, despite lower sound quality, the wife and kids prefer for listening to music.  So opportunities for critical music listening on this system are so rare as to be non-existent.  All the components except the speakers qualify as C&C.

Office desktop/nearfield system:
Windows PC -> optical SPDIF -> Cambridge Audio DACMagic (original) -> tpa3110 -> Overnight Sensations DIY speakers
I posted pics of my tpa3110 build a few pages back.  Between work and family I still don't have a lot of time, but this has become my "go to" system for critical listening.  All C&C components.  Really like the sound, but think there's room for improvement.  I'm afraid I'd have to get out of C&C territory to get a marked improvement on the DAC, so I'm thinking about upgrading the speakers.  Thinking really hard about a Mark Audio Alpair 7.3 based system (likely a DIY flat-pack build from Planet10).

[thaddeussmith]

I have this amp (YJ blue) in my 2-channel system. All music is CD quality or Hi-Res FLAC, stored on an unRAID NAS. My source is a 2009 MacBook Pro running JRiver Media Center with remote control on my iPad Mini. Currently using my MBP's internal DAC, but will eventually pick up a raw ODAC board and insert it into my amp chassis and connect it directly to the amp's inputs with just an inch or so of wire. Speakers are '83 Klipsch Cornwalls with newly refreshed B-2 crossovers in a battery biased configuration. Everything is setup near field @6ft. That's it.. no preamps, no unnecessary sources, zero complication. Using a vintage HAM 13v/7A linear power supply.

This combination has made for a VERY revealing system with good balance across the frequency spectrum. The only thing that's really lacking is a vast soundstage, but that's because I have it setup in near field. It does have great depth, the musicians just sound a bit squished together at times. Dead silent at the listening position, and I can hit 105dB with just a few watts. Tons of bass, super clear mids and highs. I'm a happy camper and have very little money invested in the setup.

[Wind Chaser]

Having been very impressed with the 3116 red board ($13.99) I decided to splurge and buy the complete/encased 3116 black board ($88). Just took delivery but won't get a chance to hear it for a few days. The thing is much bigger and heavier than I would have thought. Build quality looks good. 

[MCM_Fan]

I definitely have that on my blue YJ board if the inputs aren't connected or the inputs are connected but the source device is powered off.  The pops are loud and scary, as I can see my woofers moving substantially.

I don't think I've actually tried this - and now I don't think I want to!  I just powered on my first YJ 2.0 blue/black board yesterday morning (open frame) and installed it in the case last night.  Most of the listening I've done so far, as previously mentioned, has been streaming through an Airport Express (with, and without, FiiO D03K DAC).  The only other source I've tried is a Sansui TU-919 tuner, but that one was also always powered on when turning the amp on/off.

Two of the three TPA3116 amps I'm building will be gifts and used exclusively for streaming via Airport Express.  So, those should always have something connected to the inputs and can just be left on at all times.

The third, will be for my bedroom system.  That one will be more elaborate as I plan to try one of the 6N3 tube preamps and add a 3 or 4 input selector so I can attach multiple sources (Magnum Dynalab FT101A FM tuner, Sony DVP-NS3100ES SACD player and Airport Express through FiiO D03K DAC for streaming).  I may even add a remote control to that one.

I have a smart power strip, where one plugged in device is the "master".  When the master is turned on, all the other outlets ("slaves") on the strip turn on.  When the master is off, all the slaves are off.

In this system, I have a Panamax M5300-EX 11-outlet power conditioner that provides power sequencing, both at power on and power off.  It powers up the sources first and lets them stabilize before powering up the amp and subwoofer.  When shutting down, it powers the amp and sub off first, and then shuts down the sources.  That way, the sources are always powered on and stable when turning the amp on and off.  It also has some always on outlets.  I use one of these for the Airport Express.  That way, it's always on and I don't have to wait for it to boot up and connect to the wireless network every time I turn my stereo on.  I never knew how much I needed one of these until I found one at my local Goodwill!

[wired4sound]

A friend who has the green board 3116 says it has a mute circuit which silences the "thump ".

Would you happen to know the exact module? I have been looking for one. Thanks!

[Poultrygeist]

Would you happen to know the exact module? I have been looking for one. Thanks!

Don't see any today on ebay ( maybe sold out ) but they're easy to spot as they're bright green with a large heat sink.

[ClefChef]

Don't see any today on ebay ( maybe sold out ) but they're easy to spot as they're bright green with a large heat sink.

The eBay seller is Audiobah, and for some reason he stopped selling these boards after selling just 2. In my opinion this board was the best of all available. I built several "blue boards" and this "green board" which I kept for myself.

All of these boards require upgrading of PS decoupling capacitors. I also recommend bypassing them with small wima caps underneath the board - it smooths out the high frequency response and reduces that digital glare.

I must say that when my 3116 is driven by my Aikido tube pre I get the impression that it sounds almost as good as my 2a3 monos, with better bass.
When 3116 is fronted with a  simple Alps volume pot the sound becomes strident and flat, stepped attenuator sounds somewhat better. I just can't get past the idle noise issue on my 95db speakers, so it may never make it from "backup" amp into the main rack.

For the price I don't think I could get anything better than this.

[thaddeussmith]

i get a very slight pop when I plug/unplug the amp, but nothing close to what I would consider a woofer killing thump. odd.

could it be because my power supply is only 13v/7A?

[ClefChef]

i get a very slight pop when I plug/unplug the amp, but nothing close to what I would consider a woofer killing thump. odd.

could it be because my power supply is only 13v/7A?

The "thump" is usually caused by power supply capacitors being charged on the power up, the larger the caps - the bigger the thump. Most of us modify those boards by replacing PS decoupling capacitors with larger ones, and that makes the thump problem worse. I suppose lower voltages help to mediate this effect. There is no "soft start" circuitry on these evaluation boards (that's what they really are, 3116 eval boards copied from TI) so no protection from large DC offset caused by initial current inrush.

I purchased several inexpensive "speaker protection" modules on eBay that will be installed on my next "blue board" builds.

I would speculate that Audiobah was selling 3116 OEM boards on eBay (they seem to be a lot more complicated with bunch of SMD components, including transistors, on-board, and good quality output coils) and got "nabbed" 

[rhing]

Rhing: can you post a picture of lower part of Chengzhi board taken from straight above it? Or could you tell to what pins of tpa chip the added transistors (circuitry) lead?

This is about as good a photo as I could get with my iPhone. As for what pins are connected to the added circuitry, I cannot tell unless I pull the amp off the standoffs and check with my DMM. That is not going to happen soon, because I am enjoying the amp in my system right now.

[Markvdv]

Chengzhi did some noise prevention, resistors near input, a good thing most others neglected. Also seems the transitor on the right is mute circuit like the green audiobah. But 2 transistors on the left side, is he doing something with sdz chip-pin2 to alter startup time (and switch off time) maybe??? And what about the 2 added larger lytics, mmm... I did buy this pcb from alieexpress, but only cost money and never got pcb, alieexpress/alibaba ignore complaints, never respond, they did do a partial refund (they advertise full refund) but transfered the money to my bankaccount and guess what....transfer cost I had to pay were equal to the partial refund...lesson learnt, no more buying from alieexpress for me

[Doublej]

I paid just under 11 dollars shipped to US and I bought it through buychina.com Taoboa agent.

http://www.buychina.com/products/18668674029

Must have been a while ago. It's showing as unavailable and the few items I clicked on have a insurance plus shipping plus fee of  $1.65 + $6.30=$7.95. Still a bargain at $16.43 delivered if/when it becomes available.

[rhing]

Chengzhi did some noise prevention, resistors near input, a good thing most others neglected. Also seems the transitor on the right is mute circuit like the green audiobah. But 2 transistors on the left side, is he doing something with sdz chip-pin2 to alter startup time (and switch off time) maybe??? And what about the 2 added larger lytics, mmm... I did buy this pcb from alieexpress, but only cost money and never got pcb, alieexpress/alibaba ignore complaints, never respond, they did do a partial refund (they advertise full refund) but transfered the money to my bankaccount and guess what....transfer cost I had to pay were equal to the partial refund...lesson learnt, no more buying from alieexpress for me

You must be correct, because this amp has the least noise (faintest hiss) of the TPA311x amps I have. There is no turn-on/turn-off pop using the power switch on my Astron linear power supply or when I have the power supply powered on and I plug and unplug the DC power connector on the amp. I've never experienced the turn-on thump with any if my amps, and the turn-off thump is a very faint thump (really a tick) that does not cause my woofers to move. I always have my source (line stage preamp) plugged into the amp. The power amp is the last to be powered on and the first to be powered off. I don't use any line conditioners or surge protectors. I have a Wire Mold 9-outlet power strip that I bought years again when I had Naim gear.

[Markvdv]

The eBay seller is Audiobah, and for some reason he stopped selling these boards after selling just 2. In my opinion this board was the best of all available. I built several "blue boards" and this "green board" which I kept for myself.

All of these boards require upgrading of PS decoupling capacitors. I also recommend bypassing them with small wima caps underneath the board - it smooths out the high frequency response and reduces that digital glare.

I must say that when my 3116 is driven by my Aikido tube pre I get the impression that it sounds almost as good as my 2a3 monos, with better bass.
When 3116 is fronted with a  simple Alps volume pot the sound becomes strident and flat, stepped attenuator sounds somewhat better. I just can't get past the idle noise issue on my 95db speakers, so it may never make it from "backup" amp into the main rack.

For the price I don't think I could get anything better than this.

removing your bypass wima's would be first advice, for right ch audiobah c5 and c12 are the onboard double bypasses, which you triple bypass by wima's, effectively lowering the frequency which they can filter powersupply. some really smart audiodesigners might even say that TI's original already double bypass is more fashionable then effective... regarding iddle noise: check gain if you didn't already, with preamp one 5.6k resistor should be all that is needed, 16/12/6dB lower iddle noise could be in there???

[shadowlight]

Has anyone looked at the audiobah boards and figured out how to run them in monobloc mode?  I have 2 sitting here and hoping to use it as mono bloc mode or even turn the two Chengzhi boards into monobloc.