Nice cabinets Prezden.
However the driver in the photo looks like an EL-70. The EL-70 was also made my MA and one of Mark's earlier paper cone efforts.
Cool, I bet you cleaned right after the pic LOL. Capacitance was sometimes higher in your own DC switched units I guess, maybe the switch here does something else next to disconnecting?
Bootstrap ceramic seem entirely according to TI datasheet, as far as I remember that is a first seeing the C+R to ground there too. But maybe the 47uF's are included there aswell? For the left one in picture it is really hard to see any path to decoupling VCC.
On input side the chinese kept TI's left and right channel identification, but seems they switched again on output side, funny guys.
Bootstrap ceramic seem entirely according to TI datasheet, as far as I remember that is a first seeing the C+R to ground there too. But maybe the 47uF's are included there aswell? For the left one in picture it is really hard to see any path to decoupling VCC.
On input side the chinese kept TI's left and right channel identification, but seems they switched again on output side, funny guys.
Thanks for the quick response Giancarlo. The power-off pop happens about 2-3 seconds after I push the power switch off on the front faceplate. I have measured the output of my Astron RS-12A regulated linear power supply to be 14VDC when powered on. It does have a large Kemet (Rifa) 21,000uF/63V electrolytic cap and a couple smaller electrolytic caps. One of the smaller caps is a Panasonic FM 2,200uF/25V cap along with a ceramic disc cap in parallel on the power supply's 14VDC output.
I use the same power supply to power my Sure Electronics TPA3110D2 amp and my Yuan Jing TPA3116D2 blue amp. I do not hear the loud, objectionable pop when powering off those amps off. Instead, hear a faint click on powering those amps off.
For me, the problem may be due to non-optimal placement of decoupling capacitors (8x 470uF/25V Panasonic).
These capacitors should be as close as possible to the chip, but they are instead very far away from the chip.
Maybe even the overall capacity is excessive.
On datasheet the decoupling capacitors are only 2x220uF.
It is not an easy problem to solve.
Maybe you could start to remove the capacitors further away from the chip, but before you do anything, wait for other opinions.
These capacitors should be as close as possible to the chip, but they are instead very far away from the chip.
Maybe even the overall capacity is excessive.
On datasheet the decoupling capacitors are only 2x220uF.
It is not an easy problem to solve.
Maybe you could start to remove the capacitors further away from the chip, but before you do anything, wait for other opinions.
Rhing,
Where did you buy your amp from? Is this place any good?
SMSL SA-36A Pro 20WPC TPA3118D2 Digital Amplifier + Power Adapter - Professional Audio Store - Shenzhenaudio.com
It's a very pretty amp - I like the champagne color face plate.
pop when powering off
Cleaning was not only mentioned by me because I knew you probably did it already. But I remembered reading about it and just found it again:
TI forum question for pop when powering off tpa3123, answer:
Cleaning was not only mentioned by me because I knew you probably did it already. But I remembered reading about it and just found it again:
TI forum question for pop when powering off tpa3123, answer:
Are you sure you don't have leakage from RIN to BYPASS? If you have some flux or other gunk there, it might provide enough leakage to over-come the current source we use to discharge BYPASS...
-d2
Thanks for the nice overview! I really hope the tested board will be made available by itself on Ebay. I think it would do well. This 3116, 3118, 3130 chip family (as well as the previous 3110) is great for all kinds of projects.
.
and then ..
...you can short the input, for fun short 1 channel, and switch off. is the pop the same both channels? the reduce you'll hear is discharge of inputcap, and considering how much noise the defective 1nF in output made on my boards, 3.3uF can be scary.
...you can short the input, for fun short 1 channel, and switch off. is the pop the same both channels? the reduce you'll hear is discharge of inputcap, and considering how much noise the defective 1nF in output made on my boards, 3.3uF can be scary.
Ok, I have been browsing this thread for a while now. I must admit though I'm a little confused with all the different variations of the same amp. What is the general consensus as to the best one to buy? In the first instance I'm after a plug and play option but will probably buy a second to modify for fun.
Oh and ideally it would be two channel only to run my Klipsch chorus speakers..
Cheers
Matt
Oh and ideally it would be two channel only to run my Klipsch chorus speakers..
Cheers
Matt
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I'd say for modifying purposes, the Yuan-Jing "blue/black" board seems to the most popular. The design comes from DIYAudio member Danzz, and is mostly through-hole components, so relatively easy to hack. The low $20 price doesn't hurt either.
As for plug'n'play, I'm not sure which is best. The YJ blue/black is certainly a good contender, but I'm not sure anyone's done much comparing of off-the-shelf stock versions.
Take a look at the tpa3116 Wiki if you haven't already.
Plug and play, yuan jing has finished blue/blackboard options, rhing just received the Smsl. Related TBI Millenia would be even more plug and play.
If you look at the separate boards I would consider to buy also 1 version with 22uF inductors, thinking your speakers impedance is likely to be closer to 16 ohm then minimum 8 ohm for high frequencies.
I've noticed that some say that the sound is strained when over 21V. I have done some upgrades to my YJ 2.0 red board and running it at 25V.. But it still sounds like it distorts sometimes in the mids.. It sounds coarse nomatter the level.. I drive the board with an unregulated powersupply with a PI filter of 2x 6800uF. The toroid I use gives about 17V. I would preferably not have to mod the toroid.. So do you think the cause is the high voltage or the lack of caps? Ive tried different DACs, input caps and added ceramics to +legs on the chip. This helped overall a lot on the noise level and stability.. But I doesn't seem to get rid of that coarseness I have some alternating thumping on both channels at turn on, which came after some of the mods.. If anyone have tried running their board at 25V please let me know
I have some alternating thumping on both channels at turn on, which came after some of the mods.. If anyone have tried running their board at 25V please let me knowI've noticed that some say that the sound is strained when over 21V. I have done some upgrades to my YJ 2.0 red board and running it at 25V.. But it still sounds like it distorts sometimes in the mids.. It sounds coarse nomatter the level.. I drive the board with an unregulated powersupply with a PI filter of 2x 6800uF. The toroid I use gives about 17V. I would preferably not have to mod the toroid.. So do you think the cause is the high voltage or the lack of caps? Ive tried different DACs, input caps and added ceramics to +legs on the chip. This helped overall a lot on the noise level and stability.. But I doesn't seem to get rid of that coarseness
I ran my "unmodded" YJ red board using a 24V "brick" and it sounded fine to me. The high and mid sounded smooth and the base was solid.
I always turn the volume pot to minimum when turning off the amp. So when I turn on the amp again, no thump or pop or any noise. After I start the music, I turn up the volume to the desired level.
Regards,
Mention of six figure capacitances is a red rag to a bull However I did the search, no results found.
Later I found the original link on AudioCircle - 'does not ship to China'. Methinks a bit of a waste of low ESR caps mounting them so far distant from any load.... Also based on my listening, the bass performance of the TPA3116 is its weak point so I doubt there's much to be gained by going so extreme on the supply decoupling. To do justice to all those caps, get an NXP amp chip such as TDA8932....
However I did the search, no results found.Later I found the original link on AudioCircle - 'does not ship to China'. Methinks a bit of a waste of low ESR caps mounting them so far distant from any load.... Also based on my listening, the bass performance of the TPA3116 is its weak point so I doubt there's much to be gained by going so extreme on the supply decoupling. To do justice to all those caps, get an NXP amp chip such as TDA8932....
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