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AD797 Preamp based on stolen trademark
AD797 Preamp based on stolen trademark
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Old 6th April 2020, 07:25 PM   #81
Berlusconi is offline Berlusconi
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AD797 Preamp based on stolen trademark
Quote:
Originally Posted by jan.didden View Post
That's an interesting double standard.

Jan
Not really. There is no way to sell IP without disclosure. Once you put the product on market competitors will be able to reveal all your secrets without having to read DIY forums. So, depriving colleagues from information just because of "protecting" interests of big corporations is really childish.
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Old 6th April 2020, 09:13 PM   #82
keilau is offline keilau  United States
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Originally Posted by Berlusconi View Post
Thanks keilau!

You have helped me a lot and I do agree with your point of view. If there are legal issues regarding IP I am sure lawyers of large corporations should be concerned with that not we, diy-ers who purchase certain products just for fun. I don't know how my hobby may harm interests of corporations who have multi-billion annual turnovers. Often, that intellectual property is, modestly speaking "borrowed". Patents, usually protect non-existent "original" works, just to intimidate potential competitors.

I am not the one who doesn't care about intellectual property - I earn for living by marketing my own IP. However, depriving colleagues from information just for sake of protecting interests of large corporations is childish. A mirror picture of Robbin Hood.
Most of the "clone" product on e-bay steal only the name of the product, but not the intellectual property. They either do not have the IP information and use only the simplified circuit in PR literature, or the real circuit is cost prohibitive to build. Some famous designer like John Curl, Nelson Pass release their design to the public making it legal to copy. We must protect the IP of small outfit of high quality product such as the AMB Laboratories if we want those product to be continuously available to the DIY community.

A good example is the MBL6010D preamp of this thread. The e-bay clone is nowhere near the real preamp. If the buyer has to replace all the AD797, it will cost more than the clone as I pointed out in earlier post.
Quote:
Originally Posted by scott wurcer View Post
One slight correction, we did have a foundry steal masks and run parts. In that case they were technically fake but were fully in spec because they were also the same.
I am very intrigued by scott wurcer's comment.
Quote:
Originally Posted by keilau View Post
At AliExpress, I found AD797ANZ at $16 a piece and many more under US$2. Are you saying that they all work the same?
Buy AD797ANZ and get free shipping on AliExpress

Similar situation for LME49710. Have you any lab test comparison between the expensive and cheap version?

Last edited by keilau; 6th April 2020 at 09:19 PM.
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Old 6th April 2020, 09:22 PM   #83
Bonsai is offline Bonsai  Europe
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"I am not the one who doesn't care about intellectual property - I earn for living by marketing my own IP. However, depriving colleagues from information just for sake of protecting interests of large corporations is childish. A mirror picture of Robbin Hood."

So you'd get pissed off if someone stole your IP, but its ok to leverage someone else's 'IP brand' through mislabelled fake parts?

Double standards indeed.
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Old 6th April 2020, 09:24 PM   #84
Bonsai is offline Bonsai  Europe
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"A good example is the MBL6010D preamp of this thread. The e-bay clone is nowhere near the real preamp. If the buyer has to replace all the AD797, it will cost more than the clone as I pointed out in earlier post."

You make it sound as though you expect the clone to sound as good as the original but with fake parts because you're not prepared to buy the genuine article.

You deserve what you get, pal.
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Old 6th April 2020, 09:42 PM   #85
keilau is offline keilau  United States
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Quote:
Originally Posted by Bonsai View Post
You make it sound as though you expect the clone to sound as good as the original but with fake parts because you're not prepared to buy the genuine article.

You deserve what you get, pal.
Quote:
Originally Posted by Bonsai View Post
Why buy these kind of parts from AliExpress?

Even on a complex preamp you might spend 20-30 $ extra getting the stuff from a reputable distributor and you know they are golden.
$20-30 will get you 2 genuine AD797. You will need $150 of parts to populate the MLB6010D clone we are talking here.

Scott Wurcer said that some fake part from China may work the same as the genuine one. I am very interested in how to find it out.
Quote:
Originally Posted by scott wurcer View Post
One slight correction, we did have a foundry steal masks and run parts. In that case they were technically fake but were fully in spec because they were also the same.
Quote:
Originally Posted by scott wurcer View Post
I said that's for you to find out, if someone re-brands 5534's as 797's and sells them for $2 they don't work the same for obvious reasons. You can probe out a genuine 797 with a VTVM from the external pins, there is no other part that will match.
Quote:
Originally Posted by keilau View Post
The real MBL-6010D is a 77 pounds beast of a pre-amplifier costing $100,000 ten years ago.
MBL 6010 D preamplifier | Stereophile.com
Attachment 800833
I have no illusion that you can clone one for $400 (including AD797 upgrade). However, it is very interesting to see how a full function line level pre-amp at affordable cost using the AD797 can sound.

MBL demonstrated that discrete circuitry is not the only way to achieve sonic quality. I fully understand that the op-amp is not the only factor, but MBL showed that they are NOT the limiting factor. It is interesting for the DIY to explore what we can do.

Last edited by keilau; 6th April 2020 at 09:48 PM.
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Old 6th April 2020, 09:51 PM   #86
scott wurcer is offline scott wurcer  United States
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Quote:
Originally Posted by keilau View Post

I am very intrigued by scott wurcer's comment.
To be clear these are CMOS foundry parts, the process is almost not relevant.
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Old 6th April 2020, 10:09 PM   #87
Berlusconi is offline Berlusconi
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AD797 Preamp based on stolen trademark
Quote:
Originally Posted by Bonsai View Post
"I am not the one who doesn't care about intellectual property - I earn for living by marketing my own IP. However, depriving colleagues from information just for sake of protecting interests of large corporations is childish. A mirror picture of Robbin Hood."

So you'd get pissed off if someone stole your IP, but its ok to leverage someone else's 'IP brand' through mislabelled fake parts?

Double standards indeed.
I don't think you understand. Let's just agree that we dissagree on this matter.
EDIT: The only way to defeat unfair competitors is to have much broader insight into the matter and capability to convince your clients that you're the only good choice. And I would never ask anyone on internet to protect me from unfair competitors. This all IP circus reminds me to good old Don Quixote protecting his beloved Dulcinea del Toboso.

EDIT2: And don't forget, we are all friends here, sharing similar interests and are all nice to eachother. Let's be friends and share our "secrets".

Cheers, and no offense meant.

Last edited by Berlusconi; 6th April 2020 at 10:33 PM.
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Old 6th April 2020, 10:43 PM   #88
SyncTronX is offline SyncTronX  United States
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Quote:
Originally Posted by scott wurcer View Post
The 5534 nulls to V+ on pins 1 and 8. The 797 to V- on pins 1 and 5. There will be equal resistors if measured at the pins (make sure the voltage burden of your meter is <.5V or you might see an ESD diode). Jan, the fakers can't do anything about the pin out.

A real LT1028 would have 130 Ohms rather than 12K on pins 1 and 8 if it was a rebranded 5534.

Thanks Scott, as I'm unsure if your statement regarding the voltage burden of

my meter.

I assume that I will measure the pins using the meters 2 wire resistance feature,
not 4 wire kelvin connection?


Also, how would I use and ESD Diode? Where would I place it?


The meters I have are HP34401A. Looking for voltage burden didn't turn up anything in the manual.
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Old 6th April 2020, 10:48 PM   #89
SyncTronX is offline SyncTronX  United States
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I wish there was a sit back and watch immodium.
This thread is is fun to watch.


As long as I can keep it on the screen and
don't blow out anything on the back side I'll
be .


Cheers,
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Last edited by SyncTronX; 6th April 2020 at 10:53 PM.
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Old 6th April 2020, 11:14 PM   #90
scott wurcer is offline scott wurcer  United States
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Quote:
Originally Posted by SyncTronX View Post
Thanks Scott, as I'm unsure if your statement regarding the voltage burden of

my meter.

I assume that I will measure the pins using the meters 2 wire resistance feature,
not 4 wire kelvin connection?
The Ohm meter forces current and measures voltage, you want this voltage to be <0.5V so you don't forward bias any internal diodes be they ESD devices or not. VTVM's had an Ohms/Volt for each scale, modern voltmeters don't. In reality just try it you should be OK, reverse the leads and see if it is the same.
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