Faulty TDA1541A?

[slav]

Hello
I have just finished tube DAC based on CS8412 and TDA1541A -Adagio schematic.
Problem is that voltage on TDA1541 pins Vdd and -Vdd2 are -0.7V(???) and -3V respectively.When disconnected from chip and shorted with resistors to simulate correct current as on datasheet ,voltage is as should be :Vdd=+5V and -Vdd2=-15V
other pins of CS8412 and TDA1541 are OK Vd=5V Va=5V and -Vdd1=-5V.
I wonder if there is problem with TDA1541?

[guido]

Maybe a fake. Post a picture.

[slav]

Bought another one , this time from UK seller .
I have one more question , I have made 3 separate PSU's for analog supplies and 1 for digital.All analog grounds tied together and going underneath of TDA1541A, then decoupling caps plus agdn connected to this ground .
Digital Ground going underneath of CS8412 , dgnd and agnd from chip tied together also dgnd to chassis .Any suggestions ?

[slav]

[attach]177912[/attach

[slav]

Picture of chip I bought:
TDA1541A.jpg

Real one?

[guido]

There are quite a few threads here on the subject. Search through them and compare pictures.

But HSH indicates holland and 03 would be 2003. Seems fishy. And since it's not working..

[studiostevus]

HSH = Kaohsiung Taiwan

Should have the 'line' on the left reading 'Tai wan', and no production in 2003. What I don't understand is why, if one wants to make a fake chip, would you print an impossible year/week/location combination on the chip?

Anyway, still fishy.

[guido]

Shure? Seems you've changed your mind:

Genuine TDA 1541A ?

Most of the HSH pictures seen here don't have taiwan on the left (apart from one). RSH always says taiwan.

Always thought HSH is nijmegen, could be wrong though.

[slav]

Finally got hold of new TDA1541A.
After connection I realised that CS8412 is in wrong mode , after changing mode to:
M1=1
M0=0
M2=0
M3=0
SEL=1
music played for a few seconds and faded away , now I am getting hell a lot of noise and some sound very very deep in the background .
If I put finger on RCA ground noise dissapears but still there is no music coming out of DAC.
I have checked voltage on TDA1541A and compared with Lesha's web:

28 +4.91V
27 +4.91V
26 -5.11V
25 -53.3mV
24-3.50V
23 -3.91V
22 -3.94V
21 -5.23V
20 -5.48V
19 -7.53V
18 -7.43V
17 -10.88V
16 -10.87V
15 -15.17V
5 0V
6 -53.3mV
7 -3.49V
8 -3.89V
9 -3.93V
10 -5.20V
11 -5.45V
12 -7.46V
13 -7.36V
14 0V


only difference are pins 6 and 25 as I have used 47ohm I/V resistor
Any help?/?

[jean-paul]

Hi Slav, I am shamelessly promoting my TDA1541A here. If you need original and good measuring/sounding TDA chips please send me a PM.

BTW no chips were made in Taiwan in 2003 AFAIK. The whole RSH/HSH issue is confusing as I have chips with HSH with the Taiwan logo and chips with HSH and no Taiwan logo. There were some batches made in Taiwan in 1997/98. Most recent chip I have is a version with laser engraved (modern!) markings and that one is from 2004. I was told the chip has been produced again because there is enough demand for it but since I can not track it down I don't want to burn my fingers on it. I file it under "suspicious"

Originally Posted by guido

RSH always says taiwan.

Always thought HSH is nijmegen, could be wrong though.

Wrong, I had a box full with original Taiwan chips with HSH code.