Is this a real TDA1541A?

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J

JonHarrison

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Joined 2004

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tubee

tubee

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Joined 2004
tubee

tubee

Member
Joined 2004
JonHarrison said:
Tubee,



How do you know that these have been reprinted and aren't genuine ? They are certainly 'A' of some year - why not 97 ?

Regards,

Jon
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I have six 1541 dacs ordered few years ago, two are original: moulded surface and printed, four are sanded off (probably with scotch brite) and reprinted for some reason, i guess for a relabeling to "A", the production year could have been anything then.
But they sound all about the same.
 
J

JonHarrison

Member
Joined 2004
Tubee,

I have six 1541 dacs ordered few years ago, two are original: moulded surface and printed, four are sanded off (probably with scotch brite) and reprinted for some reason, i guess for a relabeling to "A", the production year could have been anything then.
Click to expand...

My JSS97 are certainly TDA1541A and not reprinted TDA1541 - they distort without the DEM cap fitted. Why would someone sand a TDA1541A and reprinted it as a TDA1541A ? Surely if they were going to the trouble they would make it an S1 or S2 ? Perhaps I am mistaken but I think that the JSS97 were printed like that in the Philips factory.

Regards,

Jon
 
tubee

tubee

Member
Joined 2004
JonHarrison said:
Tubee,



My JSS97 are certainly TDA1541A and not reprinted TDA1541 - they distort without the DEM cap fitted. Why would someone sand a TDA1541A and reprinted it as a TDA1541A ? Surely if they were going to the trouble they would make it an S1 or S2 ? Perhaps I am mistaken but I think that the JSS97 were printed like that in the Philips factory.

Regards,

Jon
Click to expand...

I will check my batch and dac's tonight and report. Have no dig. camera at hand, otherwise could show some pictures.
 
tubee

tubee

Member
Joined 2004
JonHarrison said:
Tubee,
My JSS97 are certainly TDA1541A and not reprinted TDA1541 - they distort without the DEM cap fitted. Why would someone sand a TDA1541A and reprinted it as a TDA1541A ? Surely if they were going to the trouble they would make it an S1 or S2 ? Perhaps I am mistaken but I think that the JSS97 were printed like that in the Philips factory.

Regards,

Jon
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Does the upper printed black surface have an other appearance compared to the back?: if yes it is sanded/relabelled for sure, i can see that on my JSS9721 2 batch. On your posted photo the round circles are not grinded, and more even black colored compared to the higher sanded surface.
But they can sound good, it is not a bad chip Jon.

When i upgrade a TDA1541 to TDA1541A i keep the dem cap with both chips, only pin 4 can be grounded with the "A", and pin 4 of plain 1541 is connected to BCK (4.6 or in non-os 2.8Mhz)

Here they are; (Sorry for poor photo resolution. Grabbed from an earlyer post on internet)
 

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J

JonHarrison

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Joined 2004
Tubee,

Pedja told me that Philips did a run in 96/97 in the far east which were finished in France. I believe these JSS97 are from that run and are therefore genuine.


Does the upper printed black surface have an other appearance compared to the back?:
Click to expand...

The chips are at work. I can check on Monday if the top and the bottom are the same.

My understanding was that the TDA1541 would run without the external DEM cap whilst the TDA1541A would not. When I removed the DEM cap my HSH93, HSH89 and JSS97 all sound distorted.

There is a test report on the JSS97 here

http://www.diyhifi.org/forums/viewtopic.php?p=13118#13118

Cheers,

Jon
 
tubee

tubee

Member
Joined 2004
JonHarrison said:
Tubee,

Pedja told me that Philips did a run in 96/97 in the far east which were finished in France. I believe these JSS97 are from that run and are therefore genuine.




The chips are at work. I can check on Monday if the top and the bottom are the same.

My understanding was that the TDA1541 would run without the external DEM cap whilst the TDA1541A would not. When I removed the DEM cap my HSH93, HSH89 and JSS97 all sound distorted.

There is a test report on the JSS97 here

http://www.diyhifi.org/forums/viewtopic.php?p=13118#13118

Cheers,

Jon
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Hi Jon

Thanks for measurement link. The JSS97 looks not bad.

Leave the chip in the socket, and check if round dot on top has no sanded appearance compared to the whole flat upper surface. The dot is some lower, so not sanded off. I can also feel with my fingernail over the surface, the original feels different.
But it can also be my 4 chips are sanded, yours not. Still i find sanding peculiar, i don't like such. It's the same sugestion that you just bought a good wine, but in fact you bought K-mart wine with another label on it.
Btw, what is your source of the chips? And pricing?
 
sklimek

sklimek

Member
Joined 2004
stanklimekstudio.com
tubee said:

Btw, what is your source of the chips? And pricing?
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Hi tubee, Jon received the J's from me. About 8 months ago I was looking for quite a few A's to do a DAC project and was able to receive the ones I needed from doing trades in the trading post. Recently I decided to not do this particular project and decided to re-trade. Jon was interested but concerned and rightfully so about these two chips, I sent them before payment for testing. I can't remember who I traded with for these two particular chips. I have now sold all my TDA1541 A's.

Stan
 
J

JonHarrison

Member
Joined 2004
Hi Tubee,

I've had a closer look at the JSS97.

The centre circles are shinny whilst the surface of the chip is smooth. This is just like the other HSH89 and HSH93 chips I have. (I have seen some fakes where the centre circle is smooth)

The Philips logo isn't as sharp as the other chips.

The font is different.

The surface of the chip is smooth. The surface of the others has a slightly mottled appearance. If you run your finger over it you can feel the difference. This might indicate that it has been sanded ? Or perhaps the surface of the chip was cleaned in the factory so that the ink would adhere. If this chip was made in 97 perhaps the original stamps had worn out or had been thrown away so the chips had to be printed instead ?

There is one final thing. The white line at the left hand side of the chip goes down the sides of the indent. On the others it doesn.t This might be an indication that the chip has been printed rather than being stamped. This might also explain the fuzzyness of the logo.

I don't think that any of this clearly proves that the chip has been sanded and reprinted or is a fake though.

Cheers,

Jon
 
tubee

tubee

Member
Joined 2004
JonHarrison said:
Hi Tubee,

I've had a closer look at the JSS97.

The centre circles are shinny whilst the surface of the chip is smooth. This is just like the other HSH89 and HSH93 chips I have. (I have seen some fakes where the centre circle is smooth)

The Philips logo isn't as sharp as the other chips.

The font is different.

The surface of the chip is smooth. The surface of the others has a slightly mottled appearance. If you run your finger over it you can feel the difference. This might indicate that it has been sanded ? Or perhaps the surface of the chip was cleaned in the factory so that the ink would adhere. If this chip was made in 97 perhaps the original stamps had worn out or had been thrown away so the chips had to be printed instead ?

There is one final thing. The white line at the left hand side of the chip goes down the sides of the indent. On the others it doesn.t This might be an indication that the chip has been printed rather than being stamped. This might also explain the fuzzyness of the logo.

I don't think that any of this clearly proves that the chip has been sanded and reprinted or is a fake though.

Cheers,

Jon
Click to expand...

Yes i discovered too there are differences in letter types used.

The printing is usually done with a silicon rubber stamp, this is the same way to print dials of watches. The indention in the chip is then printed too, the soft rubber touches deeper area's also. The ink is drawn with the rubber tampon from an with typing etched plate.

The smooth surface could be indeed indicating sanding, because a (blacker) mottled surface is the original surface finish from the plastic mould of IC body.

When i have a camera post some very near difference pictures.

I should try one of the dacs in my modded CD304mk2, have there the original (1986) plain 1541,no A, with SAA7220A. Have an (better) SAA7220B too. But some others here claim the SAA7220B doesn't combine well with the TDA1541A, to much odd harmonics.
 
N

Nicowico

Member
Joined 2005
poynton said:
http://cgi.ebay.co.uk/TDA1541A-Twin...oryZ3272QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


This is the email he sent me :--



Hi Andy

I can give 100% guarantee of this chips authenticity. I realise what you mention regarding the S1 and double crown printing.

Between 1992 and 1998 I worked for Marantz UK as technical manager. I had involvement with the Special Edition (SE) models they were producing at the time, preparing the initial samples for review and supporting production.

If you recall the CD12/DA12 transport and separate D/A converter? A high-end unit. Ken Ishiwata (hope you've heard of him) devised an upgrade mod, one component of which was a double crown selected IC. I carried out all the work required as specified by Ken and it went off for review to Ken Kessler. Subsequently the mod was offered to existing owners of CD12/DA12 units. I carried out the first couple. I have two of these ICs which came from the same packaging tube as the ones we were fitting in this mod at the time. These were with Ken Ishiwatas blessing.

I always intended to build myself a double differential D/A based upon the CD94II output stage, but never quite got around to it.

I realise that this is a sought after device in double crown spec, didn't realise that someone might fake one... Please be assured that this is absolutely what it says it is.

Trust this explains its provenance.

Kind regards ...................................
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Hello Poynton,

do you still have the adress of that Marantz tech? And if so can you email it to me. I like to know all about the CD12/DA12 KI.
 
Franz Gysi

Franz Gysi

Member
Joined 2007
Unbelievable, how you want to decide: is this a fake or not?

The only way: measurements!

My actual story: Yesterday I purchased as Studer employee the rest of Studers TDA1541A S1 chips, and got double crowns.

Now, some people are accusing me to offer fake chips on eBay!

eBay ID's: 260461253069 ; 260461255070 ; 260461257963

It is impossible, that Studer has faked chips on stock!

Franz
 
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