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Czech Republic 9090DB driver amp pirate posing as ToliToms

Hipocrates said:
all circuitry is 50 years old technology implemented by a defunct company several decades ago
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Yup, it's pretty much true but a funny thing... I've worked 5 different stereo receivers and AVR's in the last month - all from the end of the 80's to as recent as 10 years ago. Marantz (SR4023), Yamaha (HTR5040), Rotel (RA820), NAD (7100) and a little Kenwood KR-A4020. All share the same amp architecture (well, the NAD is a little different with that 'soft clipping' circuit but not that much different). If you can find your way through the Sui's F2624 driver amp, you're pretty much bound to get cozy with many of these to this day.
 
tnsilver said:
Yup, it's pretty much true but a funny thing... I've worked 5 different stereo receivers and AVR's in the last month - all from the end of the 80's to as recent as 10 years ago. Marantz (SR4023), Yamaha (HTR5040), Rotel (RA820), NAD (7100) and a little Kenwood KR-A4020. All share the same amp architecture (well, the NAD is a little different with that 'soft clipping' circuit but not that much different). If you can find your way through the Sui's F2624 driver amp, you're pretty much bound to get cozy with many of these to this day.
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Sometimes I don't explain myself well, my apologies, I did not mean obsolete nor in a derogatory way, more like widely available and that is have been available for quite a while, therefore not subject to intellectual property.
 
I don't have much to add but i think it's great that people are making new replacement boards for these old receivers. There's someone else who's been on AK making boards for a number of Pioneer units.

Of course, it's not so great that people are trying to run scams off this effort.
 
tnsilver said:
pictures from the old eBay listing
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I encountered the same thing, FWIW. I make discrete PCB repros of an unobtanium Yamaha module, and once, quite some time ago, decided to try to ebay them. Not long afterwards, some seller based in the Orient put up a listing with the Yamaha part number and the picture of my PCB. It's not remotely possible that the other seller had replicated the design, so I have no idea what (if anything) would have been delivered if someone bought one.

Entrepreneurship without ethics is a hell of a thing.
 
tnsilver said:
^ Yes, we've used 1K for R03/04 too. I'm not complaining just a little concerned though. When we've developed our own reproduction (already a decade ago) we've had some clear objectives from the get go. We wanted the product to look and feel familiar and to introduce as little as possible design changes in order to avoid any notable sonic differences. We basically wanted a better, more robust driver amp with the best and quietest components available - but with as little changes as possible in the process. I've personally reiterated through Mouser's bill of origin to make sure the pedigree of each and every component meets our expectations and standards. Toli was testing parts of the design in the university labs and at some point I've shipped an entire 9090DB unit for him to test on. When we finally had a working version - I've sent samples to some prominent techs around here, fresh out of the mint. @DougBrewster had actually saved our behinds with more than one very valuable rejects (IIRC we've missed the pinout of some transistor, and some other minor issues) and there was other important feedback from techs and customers. We've swapped to an improved V2 upon receiving feedback from just the first 5 customers and implemented the bias overshoot safety LEDs. In other words, this was an iterative community development process with a genuine peer review.

So, I'm not complaining but just a little baffled... How can this new reproduction had been developed with, as far as I know (and I don't really) an under-the-radar process?
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People can have the same ideas at the same time, and not have so much as a hint of each other. Plus some keep things "under the radar" so copycats don't swoop in and steal their work. As far as we know, this guy could have been working on these for a few years working out any kinks. You and Toli came up with the LEDs, so why couldn't another good tech figure that out too? I don't need any more boards anyways. I still have a couple of Toli boards, plus a few factory ones as spares.
Plus, that guy is working on the 8080/9090 driver boards as well. His first name is Mike. This is his message to me...

Thank you for the information. Funny you should write me at this time. Today I will receive new blank boards for 8080 or 9090 receivers. This will be the second revision. Hopefully I will be able to offer new 8080 /9090 boards. Shortly.

Thanks,

Mike
 
Skywatcher said:
You and Toli came up with the LEDs, so why couldn't another good tech figure that out too?
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Neah, it's unlikely. That took some nifty calculations and it's a specific frequency and voltage drop LED. That's why they're white. These LEDs don't just light up to warn against excess bias current, they actually swallow up some of it, and provide the clumsy owner some alert and extra invaluable time to amend their ways with the bias trimmers - prior to a catastrophic failure (which is still possible). This alert system was conceived due to the high rate of biasing routine accidents reported on this very forum. It's Toli's signature idea. It's all in Toli's blog, right here. There's also a zip file with the latest version schematics.

BTW: I've just talked to Toli (he's a PhD EE now and a fresh daddy) and we have absolutely no issue with anyone following up on any of this - but I think credit is due where it's due. Toli has his own handle around here (albeit he seems shy of using it) so I won't be speaking on his behalf.
 
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tnsilver said:
Neah, it's unlikely. That took some nifty calculations and it's a specific frequency and voltage drop LED. That's why they're white. These LEDs don't just light up to warn against excess bias ...
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Nice trick! I worked with a guy like that. Not a PhDEE, but he didn’t need it. He was a master at circuit tricks like that! I learned SO much from him!
 
PabloX said:
I don't have much to add but i think it's great that people are making new replacement boards for these old receivers. There's someone else who's been on AK making boards for a number of Pioneer units.

Of course, it's not so great that people are trying to run scams off this effort.
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I did an F-6013 driver board for a couple of 5000 receivers that I picked up. They had dead F-1040 boards, but were otherwise in nice shape. They both work good now.
 
Hey Tom et al,

I discovered the Christy NJ version on my search for a 2624 so let Toli know in my communication with him. I don't have an issue with others trying to design their own soloution, providing it's their own work :)

I am fortunate to be a proud owner of a ToliTom's original 2624 (V2 I think? May 28 2015) PCB. Before I discovered Tolitoms project, I too fell for the eBay clone from Czech. I have both on my bench now and boy, what a difference. They are like chalk and cheese and that clone will be stapled to the workbench as a sad reminder. I've also seen clones out of Thailand and Italy, all on eBay.

Anyway, this will be my first ToliTom's build so I am hoping to start another thread to share my experience of building it and saving a 8080DB.

Cudos to Tom and Toli for creating this engineering masterpiece and allowing us to keep these magnificent receivers off the trash pile. There's so much I love about this design, I don't know where to begin so will leave it for my own thread ...

BTW Congrat's to new Daddy Toli!!

Cheers,
Brad
 

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bubhardy said:
Unfortunately, you can’t copyright a board layout, or a circuit.
This is why I can do reverse engineering.
But I restrict myself to obsolete industrial stuff that is no longer manufactured.
Morally it’s wrong, but there are no laws against it.
Unless it’s patented, and you can’t patent a board layout, either.
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'Right to make spare parts', it is an established legal right. Nothing morally wrong with it as long it is safe to use! Like with aftermarket auto parts! But never let it unknown or lie about the authenticity of the part as if it is origional while it is not an official Sansui, Pioneer, Mercedes for example spare part! Permission is never needed.
Now in your case you got pirated identity theft(ed) including your unique replacement design. That is internationally protected under idear (in USA only) and global copyright laws and model and trademark and tradename laws and under the legal term 'unfair competition'. You got thus a legal (criminal even) case against that guy from chech republic in this case! Damages lost revenue etc! Not only because he stole your design, but acted as if he was you(re design)!
 
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^ eBay took care of it right away. Before they did, I had a chance to toy with that guy for a little bit. It was so easy, I felt sorry for him. I stopped because I got the vibe he's a real limited individual. He had refunded everyone and would never do it again. He did not steal our design, just our listing, pics and links. I think we're even steven.
 
tnsilver said:
Do you mean like lifted rails, scorched real estate, broken structure?
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No, no! One pair of F-1040 was what I’m calling “Frankensteined”. Rewired somewhere along the way, but wires hanging off them with electrical tape, too. Parts hanging off. A real mess, I’ve got photos somewhere. The other pair had corrosion on the bias diode holders and bias diodes and their transistors-the TO1 metal cans had corrosion, and a couple of the leads, too. No traces burnt or lifted, though. Never caught fire.
I just figured that, all in all, it was better to put in some new boards. So, I did an F-6013 layout, and had the boards fabbed. I did board layout for over 30 years, as part of my job. I have the software and the experience-and I still love to do board layouts. So, why not? Both receivers sound real good now.
 
tnsilver said:
Neah, it's unlikely. That took some nifty calculations and it's a specific frequency and voltage drop LED. That's why they're white. These LEDs don't just light up to warn against excess bias current, they actually swallow up some of it, and provide the clumsy owner some alert and extra invaluable time to amend their ways with the bias trimmers - prior to a catastrophic failure (which is still possible). This alert system was conceived due to the high rate of biasing routine accidents reported on this very forum. It's Toli's signature idea. It's all in Toli's blog, right here. There's also a zip file with the latest version schematics.

BTW: I've just talked to Toli (he's a PhD EE now and a fresh daddy) and we have absolutely no issue with anyone following up on any of this - but I think credit is due where it's due. Toli has his own handle around here (albeit he seems shy of using it) so I won't be speaking on his behalf.
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I just received my Toli board. Very nice design and improvement compared to the original.
I'm perplexed about which LED to use, the one Toli has on his BOM is no longer available. BradWil tried to substitute,and was unsuccessful.
I could always omit it, but sure seems like it would help prevent any accidents.
 
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