Hi Bonsai,
I bought mine off of eBay some time ago, i’d have to check who it was from but it was an Asian source that is for sure. I tested them out worked okay. Does not seem to be one that they fake since they are really cheap and plentiful.
I designed a new power supply for the old Pioneer SX-1980, it uses a PA3004 that was a special, prices for it have escalated because the old stock has depleted, glad I designed in the UPC1237 as an alternative option.
Cheers
PS how’s your new phono preamp design going? Are you going to share that with us?
I bought mine off of eBay some time ago, i’d have to check who it was from but it was an Asian source that is for sure. I tested them out worked okay. Does not seem to be one that they fake since they are really cheap and plentiful.
I designed a new power supply for the old Pioneer SX-1980, it uses a PA3004 that was a special, prices for it have escalated because the old stock has depleted, glad I designed in the UPC1237 as an alternative option.
Cheers
PS how’s your new phono preamp design going? Are you going to share that with us?
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There is tons of them on Ebay, and while most likely they are fakes, they work fine,
and they are very cheap.
I bought a lot of these chips from Ebay, and never had any problems.
and they are very cheap.
I bought a lot of these chips from Ebay, and never had any problems.
What brand were they? I know Unisonic from my time living in Taiwan and think if its from them then they'll be ok.
Hi Minek,
Can you explain to me how can they work, if they are fakes? "while most likely they are fakes, they work fine"
Bonsai,
On the ones I have, there are no marking to indicate whom the mfg was. I bought them from two sources,
1) Marked "C1237HA"
"NXN1820"
This one I tested, since I marked one as being used.
2) Marked "C1237HA"
"China KK16L"
I do not remember if I tried out 2) 🙂
Mine do not look like the ones in the link above.
Rick
Can you explain to me how can they work, if they are fakes? "while most likely they are fakes, they work fine"
Bonsai,
On the ones I have, there are no marking to indicate whom the mfg was. I bought them from two sources,
1) Marked "C1237HA"
"NXN1820"
This one I tested, since I marked one as being used.
2) Marked "C1237HA"
"China KK16L"
I do not remember if I tried out 2) 🙂
Mine do not look like the ones in the link above.
Rick
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By 'fake' I meant that BRAND name is fake, unknown, or irrelevant.
The chips are, I guess, the same as original, at least from functional point of view.
I tried at least 4 different batches of them, from Ebay, each of them from different seller, with different
markings, but as far as I can tell, they all worked the same...
If you buy this kind of stuff from Ebay, it doesn't really matter what brand it shows..
If it shows "NEC", it's not "NEC". It's a fake.
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Andrew, I bought 5 from ebay, out of the bunch only 2 worked 100% as expected, The other 3 works, but not as they should, timing problems.🙂
If you are buying dud’s, let us in on who from? I guess I should test all of mine out in a proper test fixture = more work but not today
Hi my dear minek, i hope you have an nice day. Today i test my speaker protection board with an power supply 12v DC from my wireless router and i can work with this speaker protection with two channels (left and right). First i hook (+/-) from the amp to speaker protection board and (+/-) from the speakers to the speaker protection and it work, but i have one problem. I explain, when i turn the volume up from the amp the sound it's breaking, but i when i connect only one (-) from the amp to the speaker protection (left channel), leaving the right channel only with (+) from the amp, and the (-) of the amp i connect directly to the speaker terminal, the problem it solve. I can turn up the volume from the amp without any break on music. Finally, i can use this speaker protection with two channels (left and right). I use a simple connection, from the amp i use the left channel (+/-) plug in on speaker protection board, and for the right channel i plug only (+) into the speaker protection, and the (-) of the amp from the right channel directly to the speaker terminal. For speakers, i connect my left speaker (+/-) into the speaker protection and for right speaker only connect the (+) into the speaker protection and the (-) from the speaker i connect directly into the amp, and it work with this connections. The problem with my buck converter perhaps don't isolate the (-) and for this reason the speaker protection doesn't work. Only work with my external power supply from my wireless router but it work. I consider buy only one AC 220v to DC 12v and the problem it solved.
Only one question, my power supply from my wireless router is AC 220v to DC 12v 1A, do i need 12v 1A or it will work with 12v 0.4A?
I consider buy the module from the picture i shared, it's fine or do i need more the 0.4A? Can you help me on this?
Many many thanks for your time helping me my dear minek.
Best regards and good health for you.
Keep safe and good weekend for you.
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The speakers are working when only one (-) is conencted to the board,
BUT the board WILL NOT DETECT problems with speaker,
and it WILL NOT turn them off when needed.
So it's useless as a protection.
Hi my dear minek, i hope you have an nice day. If i understand, using this speaker protection with this connections i made only protect one channel (left or right speaker), i'm right? Fix if i'm wrong.
If i disconect the (+) from one side it don't give me any sound through the speaker, why this connection don't protect the two channels (left and right)?
And if i buy other speaker protection for BTL amp, can i use a AC 220v to DC 12v 1A or do i need more more than 1A?
Can i connect the AC 220v to DC 12v 1A directly from my power socket of my amp?
I consider buy one of this power supply 12v (pictures bellow), what is the most suitable for power up the speaker protection?
I hope you can help me on this.
I will wait a answer from you soon as possible.
Best regards and good health for you.
Keep safe and good weekend.
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>If i understand, using this speaker protection with this connections i made only protect one channel (left or right speaker), i'm right?
Correct.
>And if i buy other speaker protection for BTL amp, can i use a>AC 220v to DC 12v 1A or do i need more more than 1A?
1A is enough. You don't need more.
>Can i connect the AC 220v to DC 12v 1A directly from my power socket of my amp?
Yes
>I consider buy one of this power supply 12v (pictures bellow), what is the most suitable for power up the speaker protection?
Any of them should be fine.
=============
That's why I recommended the more expensive board (#4, few posts back) because it came with built-in PSU - that makes everything easier and overall cheaper.
Correct.
>And if i buy other speaker protection for BTL amp, can i use a>AC 220v to DC 12v 1A or do i need more more than 1A?
1A is enough. You don't need more.
>Can i connect the AC 220v to DC 12v 1A directly from my power socket of my amp?
Yes
>I consider buy one of this power supply 12v (pictures bellow), what is the most suitable for power up the speaker protection?
Any of them should be fine.
=============
That's why I recommended the more expensive board (#4, few posts back) because it came with built-in PSU - that makes everything easier and overall cheaper.
Following item from Aliexpress worked fine, even though the board layout was not very convenient for me. I would like to run this off of the main power rails (rather than a secondary winding), but I could not figure that out since it came with no schematic.
AIYIMA Amplifier Rectifier Filter Power Supply Board Speaker Protection Rectifier Filter Diy Kit|Amplifier| - AliExpress
AIYIMA Amplifier Rectifier Filter Power Supply Board Speaker Protection Rectifier Filter Diy Kit|Amplifier| - AliExpress
Yes, it is speaker protection based on UPC1237 and an amp power supply combined. It came with everything except reservoir capacitors. Speaker protection requires a separate secondary winding though (12v or so). I prefer it to be shared.
I don't think quality is always proportional to the price. I think the price is reasonable considering the terminals are of cheap quality, and there are not too many components in the kit either. Also, I used a different bridge rectifier sourced from Mouser.
I don't think quality is always proportional to the price. I think the price is reasonable considering the terminals are of cheap quality, and there are not too many components in the kit either. Also, I used a different bridge rectifier sourced from Mouser.
Dear all,
Excuse me for Reviving this old thread.
I had purchased few UPC1237 from different sources, both locally+ Aliexpress at different points of time. They all differ in packaging style, but all are semi-functional.
My problem is that power ON delay & instant OFF after power failure function is working fine (AC detect),
But the DC detect function is not working at all. I tried this on a vero board before making 12 PCBs
I tried with different external DC source , swapped all ICs,. Still the problem remains
I used 28VDC to power UPC1237 datasheet circuit , 12V relay with a dropout regulator or with a 24V relay with small series resistor.
I watched several YouTube videos , apparently their kit's DC detect using single AA 1.5V battery is working fine
So please can anyone verify if their UPC1237 DC detect function is working?
Excuse me for Reviving this old thread.
I had purchased few UPC1237 from different sources, both locally+ Aliexpress at different points of time. They all differ in packaging style, but all are semi-functional.
My problem is that power ON delay & instant OFF after power failure function is working fine (AC detect),
But the DC detect function is not working at all. I tried this on a vero board before making 12 PCBs
I tried with different external DC source , swapped all ICs,. Still the problem remains
I used 28VDC to power UPC1237 datasheet circuit , 12V relay with a dropout regulator or with a 24V relay with small series resistor.
I watched several YouTube videos , apparently their kit's DC detect using single AA 1.5V battery is working fine
So please can anyone verify if their UPC1237 DC detect function is working?
I purchased 3 batches of these chips from Ebay (different sellers), 30 pieces in total, and tested all the boards I made (5 so far), and the chip
was working correctly, including DC detection. That was 4 years ago.
was working correctly, including DC detection. That was 4 years ago.
