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Chip Amps Amplifiers based on integrated circuits

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Old 30th September 2021, 02:53 AM   #111
NareshBrd is offline NareshBrd  India
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Street price (single pieces) for 1875 is 20-25 US cents, 4440 about 35 cents.
2050 (ST) was $0.60 if available.
They will ask much less from China in bulk. Shipment of course will be extra, and Customs, etc.

Please do post your results after testing, it will give some information about the quality of the chips.
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Old 3rd October 2021, 07:38 AM   #112
NareshBrd is offline NareshBrd  India
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@JFM:
Any response from CRC Micro about their 2050?

The party speaker maker in Brazil may be a client for them, as in chips supplied to the maker of wheeled trolley speakers with built in amplifier.

@wg_ski: If the pins are the same, and the thing performs as expected...you have any objection if the item was actually improved, somebody took a long hard look, and decided the same result could be achieved in a different way? Maybe a smaller die, maybe better heat transfer, whatever.

So I am waiting for JMF to try them and tell us his opinion.
jbau, another member, tried a Chinese 1875, he could find no difference and ended his trial. It is here in the forum posts.

Last edited by NareshBrd; 3rd October 2021 at 07:51 AM.
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Old 4th October 2021, 12:36 PM   #113
wg_ski is offline wg_ski  United States
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I doubt that some fab making copies would make “improvements”, unless it came as a happy coincidence. Maybe the breakdown voltage of the process would be better, or that their doping profile might result in higher hfe. It could just as easily go the other way.

Redesign like a smaller die wouldn’t improve anything - thermal feedback would be worse and Tj would be higher. Die attach processes used by copiers and fakers are typically much worse than those used by the big boys (processes and material sets can be closely guarded trade secrets, and not necessarily use the cheapest materials available). They would have to go out of their way to redesign an improved functional equivalent - and that would cost more than the original. Would people buy it if they did? Maybe us audiophools, but not industry - if it cost a nickel more than a current production ST part. I wouldn’t count on it being available.

Look what happened with STK modules. The “functional equivalents” are horrible. They blow up at the drop of a hat. You can make a better one yourself.
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Old 4th October 2021, 01:01 PM   #114
Tubelab_com is offline Tubelab_com  United States
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Quote:
Originally Posted by PRR View Post
Extreme high voltage. Low-low noise.
Very good performance to power consumption and efficiency goals.

Many years ago I had designed the test board for a new type of RF frequency synthesizer chip. The chips had been designed in house and were late in arrival from one of Motorola's semiconductor fabs. Multiple heated exchanges between all parties involved had been going on when I got an email that the first engineering samples were on their way to me by Fedex.

Upon arrival I popped one in the fixture to discover zero current drain. I tested for continuity from any pin to any other pin and found none. I even soldered a wire down all the pins on one side, and a second wire down all the pins on the opposite side of the QFP package, and applied 120 VAC directly from the wall outlet (DON'T TRY THIS, a giant fireball will ensue on a good chip due to flaming carbonized plastic). I labeled the photo "ESD test" which "passed."

I sent some of the chips off for decapping and X-raying (in house capability) to confirm what I already knew.

Rather than feeding the already serious firestorm between us and the fab, I simply filled out the predetermined test form showing excellent performance to all current drain, efficiency, and ESD specs, and failure of all others. I also included a cover sheet congratulating them for the performance on current drain, but stating that all the active RF specs "need major improvement."

This actually got more action than the previous firestorm because more than one metric (delivery time) was now in jeopardy of meeting the joint project goals.
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Old 4th October 2021, 03:22 PM   #115
JMFahey is offline JMFahey  Argentina
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Quote:
@JFM:
Any response from CRC Micro about their 2050?
.....
So I am waiting for JMF to try them and tell us his opinion.
Sadly none yet, one way or the other.
Will give them 2 weeks and ask again.

As of "improving" ... not impossible but I guess main commercial goal is to be able to replace originals, period.

Personally I donīt even demand a transistor by transistor exact copy, but a functional equivalent, a small 5 pin plastic case which takes +/-25V and feeds 4 or 5A peak to a speaker without exploding even under some abuse.

Motorola style low consumption and excellent ESD performance do not need to apply
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Old 4th October 2021, 03:34 PM   #116
NareshBrd is offline NareshBrd  India
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Let me put this in another way:
We all know that Chinese factories have started by initially making things as per the original factories did abroad (that means outside China).
That can be called the monkey stage, blind emulation.
Then they started making tools, designing tools, and improving the processes, and in some cases, like cell phones, they have evolved to the design stage.
This happened in Japan, and in Korea also, all of their industries evolved.


So my thinking was, what if they actually improved or changed the design to give more yields per wafer, for example.
And JMF has answered that, he wants a functional equivalent, which is reliable in large volumes.
That is the desired result..."Quality is fitness of purpose"
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Old 4th October 2021, 04:29 PM   #117
NareshBrd is offline NareshBrd  India
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@JMF:
I just checked, the import price in 2016 was $0.01 for 2050 (200k quantity) and $0.03 for 4440 amps. (Delhi, India)

So your order for 1000 will be like $20 or so...maybe the reason for less interest on their side.
There is also an issue of low invoice value to reduce the Customs duty paid. Still, your value will be less than $200 to the maker, a lot more will go in shipment expenses.
And I have no idea of the import duty you need to pay.


See if you can get a few to try from local or Brazilian sources.

Last edited by NareshBrd; 4th October 2021 at 04:35 PM.
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Old 5th October 2021, 10:14 AM   #118
NareshBrd is offline NareshBrd  India
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$0.20, 'Triangle' mark..CRC
(Retail Price)
Attached Images
File Type: jpg 20211005_152720.jpg (444.2 KB, 77 views)

Last edited by NareshBrd; 5th October 2021 at 10:16 AM.
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Old 5th October 2021, 10:16 AM   #119
NareshBrd is offline NareshBrd  India
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2050 from same source are 12-13 Rupees here in 1000 qty.
15 Rupees is about US$0.20...
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