Is this a real TDA1541A?

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H

HtP

Member
Joined 2004
jean-paul said:
A development sample from 1997 !? SAA7321 and/or SAA7350 ( or others, forgot the count with 1 bit chips really ) were in development then, isn't it ?

If I look at the pictures in post #1 and post #2 I see they are marked exactly the same except for the datecode which is 10 years later and the A, hence my suspicion about the datecode and genuinity. Also font and ink seems different. The same chip in post #2 in the lower right corner, what about that one ? Is that a development sample from 1987 then ? ( I suppose the 4182 code says it all ).
Click to expand...

As far as I know, the last developement of the TDA1541A was the TDA1541A version N3X which was never released. A pitty because it was the best one I have seen. Batch number was 7784 with week number 8714. Therefore I agree with Jean-Paul about the error in the weeknumber. The Philips logo was added about that time and the print style changed. I have TDA1541 with weeknumber 8631 without logo which is without any doubt a Philips part. The logo was added because of copyright issues. Also on the ic masks, a logo was added.

Question to Bernhard: why are you so sure that is must be fake?

regards,
 
Bernhard

Bernhard

Member
Joined 2002
HtP said:
Question to Bernhard: why are you so sure that is must be fake?
Click to expand...

Henk,

I was just kidding, note the ;) in my post, because Jean-Paul likes to suspect fakes ;)

But now as you ask...

I have 1541 with 3944 batch and 8718 date code.
Also I have 1541A with 10795 batch and 8801 date code.
This chip is 4184 batch and 9727 date code, so could be 8727 date code and printing error.

But all my 1541 including S1 have 5Y beside date code while my 1541 A has 2Y and my 1541A S1 without silvercrown from CD880 and S1 silvercrown bought in shop have 2 without Y.

But this chip got 5Y and pretends to be an A.

Also all my 1541A have Philips logo.

Is it a new perception that 1541A S1 have no Y ?

So if there is the Y, it is a fake ???



Question to you as you seem to be an expert:

What you think about using passive I/V conversion with floating ground for the TDA, driven by the TDA's output voltage, buffered with opamp ???
 
H

HtP

Member
Joined 2004
Bernhard said:


Henk,

I was just kidding, note the ;) in my post, because Jean-Paul likes to suspect fakes ;)

But now as you ask...

I have 1541 with 3944 batch and 8718 date code.
Also I have 1541A with 10795 batch and 8801 date code.
This chip is 4184 batch and 9727 date code, so could be 8727 date code and printing error.

But all my 1541 including S1 have 5Y beside date code while my 1541 A has 2Y and my 1541A S1 without silvercrown from CD880 and S1 silvercrown bought in shop have 2 without Y.

But this chip got 5Y and pretends to be an A.

Also all my 1541A have Philips logo.

Is it a new perception that 1541A S1 have no Y ?

So if there is the Y, it is a fake ???



Question to you as you seem to be an expert:

What you think about using passive I/V conversion with floating ground for the TDA, driven by the TDA's output voltage, buffered with opamp ???
Click to expand...

Data sheets for released parts were printed on white paper. Data sheets for development parts were initially printed on yellow paper, later on white also. The Y indicates that it was a development part. I do not know if it is still used that way but certainly the Y does not indicate that it is fake.

Aswer to your question:

1. It is active I/V conversion, not passive conversion.

2. At the analog output very difficult, at least more difficult than normal active I/V conversion.

3. It will introduce signal dependent delay for the digital data, including the BCK. This will give frequency modulation to the spectrum. How much depends on the rise time of the digital signal, and the amplitude of the analog signal.

4. It will sound very interesting but I do not think that you will like it.

regards,
 
jean-paul

jean-paul

Disabled Account
Joined 2002
Bernhard said:


I was just kidding, note the ;) in my post, because Jean-Paul likes to suspect fakes ;)

Click to expand...

Ahum, I said remarked with which Henk seems to agree. Just as suspicious as the markings on the S1's you showed ( especially after the explanation of HtP ).

Bernhard, it is economically not interesting to produce fakes so you won't likely find such chips. Remarking gives profit without much costs. They are around these days driven by the hype/facts about TDA1541A.
 
R

rfbrw

Member
Joined 2001
Perhaps someone could shed some light on the background to this fake/not fake saga and where this thread in general is heading.
Are you i.e. the accusers suggesting there is some kind of backdoor operation going at TSMC after hours or perhaps some questionable east European types are breaking into the Infineon or Atmel fabs at the weekend and knocking off a few TDA1541AS1's? Afterall, semiconductor fabrication plants are not the sort of thing to be found in a hobbyist's garage.

ray.
 
jean-paul

jean-paul

Disabled Account
Joined 2002
Some people remark old but NOS TDA1541 chips with the marking TDA1541A-S1 to gain higher profits ( TDA1541 = 3 to 6 euro, TDA1541A-S1 = 40 to 50 euro ). Not such a strange phenomenon when you think of rebranded 2SA1302, rebranded Intel & AMD CPU's and others.

A bit like the chip in post #1.
 
G

gio_b

Member
Joined 2004
tda1541 to 1541a

i have a cd 960 philips with a tda1541 non philps.can i replace it with a good philips tda1541A?does it plays better???
and more....
in 960 there are 4 op 5534d jrc 6216 for analog signal,can i replace with other equivalent...opa627 ad860 ad826 are good??
ciao ciao
 
jean-paul

jean-paul

Disabled Account
Joined 2002
Re: tda1541 to 1541a

gio_b said:
I have a cd 960 philips with a TDA1541 non Philips. Can I replace it with a good Philips TDA1541A ? Does it play better ???
Click to expand...

Please use the Search for that info, it has been discussed more than once:

http://www.diyaudio.com/forums/search.php?s=

OPA627 is an excellent choice but remove the compensation caps ( 22 pF in general ) from pin 1 to 8 as OPA627 is compensated internally.
 
Bernhard

Bernhard

Member
Joined 2002
Re: tda1541 to 1541a

gio_b said:
i have a cd 960 philips with a tda1541 non philps.can i replace it with a good philips tda1541A?does it plays better???
and more....
in 960 there are 4 op 5534d jrc 6216 for analog signal,can i replace with other equivalent...opa627 ad860 ad826 are good??
ciao ciao
Click to expand...

Do you have a picture ???

TDA1541 without A ???
 
G

gio_b

Member
Joined 2004
thanks jean_paul and bernard

because of raptus i remove all conponents(cards) from my cd960..
(for a better maintenence,spring belt..etc...etc...).
i ll try to remount all with new(4) op by jean_paul and i tell you how it sonds(if it).
so,if i replace the tda1541,this is the version i have, with tda1541a sounds better?
i also have saa7220p/a
84080
csg8644m2 (?)
 
G

gio_b

Member
Joined 2004
hi

hi jean_paul
so, my i replace my old 4 op 5534d with 4 new opa627,take care of capacitor to be removed as you told me,and nothig more?
is 5534d 1 op or 2 op?
and opa627 is 1 or 2 ? is full equivalent...?
opa627 is 24€ each....
so i prefer to be scure.
thanks
 
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