Mouser:
PTD902-2015K-A502 (Bourns, 5k, 20%, log)
PTD902-1025K-A103 (Bourns, 10k, 10%, log)
I normally use these, which wont fit your board:
RV122F-20-15F-A10K (Alpha, 10k, 5%, log)
10k works for almost all circuits i build.
PTD902-2015K-A502 (Bourns, 5k, 20%, log)
PTD902-1025K-A103 (Bourns, 10k, 10%, log)
I normally use these, which wont fit your board:
RV122F-20-15F-A10K (Alpha, 10k, 5%, log)
10k works for almost all circuits i build.
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Without making an actual power switch on the amp, you won't avoid the sparks. Reboxing it could work as you could add a DC power switch between the SMPS and the amp. There are a few anti-pop circuits or suggestions around in this topic.
J.
A switch just hides the spark within the switch. To solve this problem you'll need a softstart to limit the inrush current, which actually sparks.
(Like a NPN+PMOS High-Side switch with an time-constant made by an RC)
(Like a NPN+PMOS High-Side switch with an time-constant made by an RC)
Got a nice box from China today. First impressions of the mono PBTL board are very good. I got mine from seller "kiss_buy" and it appears to have genuine nichicon caps (or at least heat shrink that says nichicon on it). The stock gain setting seem very low, so far I have only tested with my phone as an output device, but at max volume it is much quieter than my other 3116 amps using the same setup.
Overall sound is very clean, I need to put them in a real setup that isn't dangling by wires to do a true comparison, but I would say at least as good as the dual chip board, probably as good as the sanwu 3118. Right now I am running with 8-ohm Polk TSX110B speakers, so I wouldn't see a power boost anyway.
Anyone know the best way to remove the white heat sink glue so I can get a shot under the sink without pulling the chip with it? I think the only thing hiding under there are 2 little ceramic caps, but a nice high res photo so people smarter than me can reverse engineer it would probably be good.
Overall sound is very clean, I need to put them in a real setup that isn't dangling by wires to do a true comparison, but I would say at least as good as the dual chip board, probably as good as the sanwu 3118. Right now I am running with 8-ohm Polk TSX110B speakers, so I wouldn't see a power boost anyway.
Anyone know the best way to remove the white heat sink glue so I can get a shot under the sink without pulling the chip with it? I think the only thing hiding under there are 2 little ceramic caps, but a nice high res photo so people smarter than me can reverse engineer it would probably be good.
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I just tested my board (which looks identical to Jerms). With or without a 6800uf cap installed ... after the DC connector is plugged in, I applied power (24V) by touching wires to connect the PS. There's no spark when repeatedly touching PS wires to complete the circuit and power on the unit (whether the front switch is in the standby or on position).
Then I tested 3 different DC power plugs, two spark, one did not.
This leads me to believe there is some an issue with the DC jack on the board.
However, I also measured the resistance between the +- rails on the board while inserting in the DC plug and could not get a low impedance reading at various degrees of insertion.
In standby, the unit draws about 37ma in standby, 75ma when on. The 75ma is on par with the quiescent current for two chips on the board. The 37ma in standby mode is a little under spec.
32dB gain, negative input probably needs to be grounded at source or through solderblob bottom, for differential input the couplingcaps are a little different. There isn't much to see probably, silksceen labels and two ceramics but heat will make it easier to twist heatsink off.
Hmm, will try shorting the solder blob properly, I did short it with my screwdriver while the amp was playing which helped, but normally at full source volume it is uncomfortably loud, this was just normal loud.
Thanks Mike.
Just took a picture of my amp.
it does look VERY similar to your board, but not quite the same
have a look here.
Imgur: The most awesome images on the Internet
I'm almost sure about the xover on the middle, but I haven't plugged my sub for a while so I've been using the speakers volume knob only.
I'll test it tonight.
the cap you're talking about, is the big electrolytic one? just remove?
I might give that a go, if it's as simple as that.
PS: does anyone know the impedance for speakers and Sub? I'm using a dual coil sub, and I wire it as 4 or 8 ohms.
Alright, so I can happily report bridging the solder pad to ground signal minus worked to fix my volume. Now I may actually want to turn the gain down a bit to 26dB. Sound quality is FANTASTIC. I would put it on par with the sanwu 3118 boards personally, my ears are pretty insensitive though.
I also like the little smps boards I got with them, 24V, 6A cont. 9A max. Can't recommend the bluetooth module yet as when it plays music there is horrible interference which I need to work out. It's the type of sound you get when you put a cell phone near unshielded signal input lines, only it is constant while the music is streaming.
I also like the little smps boards I got with them, 24V, 6A cont. 9A max. Can't recommend the bluetooth module yet as when it plays music there is horrible interference which I need to work out. It's the type of sound you get when you put a cell phone near unshielded signal input lines, only it is constant while the music is streaming.
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This is mainly due to the BT chip is disabling its outputs when not streaming. Seems to be a common problem. You may want to try to remove the one ground wire going to the psu, it's then grounded via the amp only. You actually build a nice GND-antenna.
Next, I'd link the amps ground planes together at their mounting holes (If they're ground-connected) and remove the ground-wire of the top amp.
Next, I'd link the amps ground planes together at their mounting holes (If they're ground-connected) and remove the ground-wire of the top amp.
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The mounting holes are not grounded, but I will link them up locally between boards with a nice fat wire. They are linked also by the signal ground pin and the signal minus pins (again ground, just another attachment point).
Thanks for the tip on the BT board, I will try that. If that fails, I will see if I can build some shielding onto the board with a makeshift metal can or something. The bluetooth board was just thrown on the order for fun though because I hadn't tried this one. So it is low priority.
This is nowhere near the final setup either. I plan to use the Sanwu 3118 board to run the full range 8-ohm speakers, and the 3116 boards will run a 4-ohm woofer. Each 3116 + 3118 pair will have its own SMPS, and be located within the speaker tower, essentially creating powered speakers.
Thanks for the tip on the BT board, I will try that. If that fails, I will see if I can build some shielding onto the board with a makeshift metal can or something. The bluetooth board was just thrown on the order for fun though because I hadn't tried this one. So it is low priority.
This is nowhere near the final setup either. I plan to use the Sanwu 3118 board to run the full range 8-ohm speakers, and the 3116 boards will run a 4-ohm woofer. Each 3116 + 3118 pair will have its own SMPS, and be located within the speaker tower, essentially creating powered speakers.
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Lies! I am obviously trying to pick up and listen in on the Voyager space craft. Ideally I think a big copper bus wire for the ground, bridging all the ground pins between both boards in a single run would be the way to go. I may do something like that between the 3116 and 3118 boards in the final setup.
If you remove signal ground completely, does it still work and does the noise go away?
Not saying this is a recommended config..... I ended up getting a GLI. But then, I'm no student of electronics....
Not saying this is a recommended config..... I ended up getting a GLI. But then, I'm no student of electronics....
Yes, this is a different board. Sorry, I thought another picture was the "breeze" board you mentioned. I haven't seen this layout before.
It may well have a variable sub x-over, can't tell with reverse engineering the circuit.
Can you generate single sine wave tones for testing? That's the easiest way to verify whether the sub pot is sub volume or sub x-over.
I wouldn't remove the cap (purple can near the outputs) as I don't think it is causing the spark (I had to remove mine to fit the third of 3 screw terminals on the speaker outputs for testing). It will go back when final assembly is complete.
The TPA3116 is a dual channel chip. Each channel is good down to 4 ohms. Your board has two chips. One chip is using its two channels for L-R stereo good down to 4 ohms. The second chip has its two channels in PBTL mode for the sub and can support impedance down to 2 ohms.
In PBTL (Parallel Bridge Tied Load) mode, an option on the chip is set and the chip sync's both its channels together. It accepts signal from only one of its inputs to insure both channels are using an identical signal (the L-R stereo is summed on the board and then passes through the LP filter before presenting it to the chip for the sub amplification). So with both channels operating in tandem, it can support the lower impedance.
Can you post the link you used (or similar) to purchase of your board?
Hi All,
i am planing to buy few power supply SMPS300RS.
i am going to china in 2 weeks, then i realize that possibly these boards are made in china, and it would be much cheaper to by them during my trip.
i can not find any information about the manufacturer ion the web .
does anybody knows where they are located ?
Cheers
i am planing to buy few power supply SMPS300RS.
i am going to china in 2 weeks, then i realize that possibly these boards are made in china, and it would be much cheaper to by them during my trip.
i can not find any information about the manufacturer ion the web .
does anybody knows where they are located ?
Cheers
Connexelectronics is located in Hong Kong, no info if they have a storefront. You could try to contact them on their website or Cristi - connexelectronic()gmail.com. More likely than not, they are just online so no public access to their facility.
Hifimediy is also located in Hong Kong but no info on them as well.
Perhaps time going through custom, taking taxi or MTR to location is not worth the money saved on shipping. There is probably no discount unless you buy in bulk.
Anyhow, good luck and have a safe trip.
Hifimediy is also located in Hong Kong but no info on them as well.
Perhaps time going through custom, taking taxi or MTR to location is not worth the money saved on shipping. There is probably no discount unless you buy in bulk.
Anyhow, good luck and have a safe trip.
Thanks trashcanz for your answer!
In the past i used to travel more often in china, and few times I purchased locally some electronics that i payed 10 times cheaper than it would be in Europe. For that i got some help from Chinese colleague to make the order and to get the stuff shipped too my hotel ! shipment their .. for example 1kg parcel through the country cost about 50yuan / 8USD, and you get it after 2-4 days .
all the stuff we buy in our countries, which are coming from mass-production in china, are at source very inexpensive. and even after custom fees paid you get very good price!
i understand that everybody has to make some profit when selling something, but sometimes these huge differences in the price are not justified! but that is the import/export business!
well, that is not the aim on this forum to talk about that !
happy modding !
In the past i used to travel more often in china, and few times I purchased locally some electronics that i payed 10 times cheaper than it would be in Europe. For that i got some help from Chinese colleague to make the order and to get the stuff shipped too my hotel ! shipment their .. for example 1kg parcel through the country cost about 50yuan / 8USD, and you get it after 2-4 days .
all the stuff we buy in our countries, which are coming from mass-production in china, are at source very inexpensive. and even after custom fees paid you get very good price!
i understand that everybody has to make some profit when selling something, but sometimes these huge differences in the price are not justified! but that is the import/export business!
well, that is not the aim on this forum to talk about that !
happy modding !