Bram Jacobse

Tinkering CD Players & Digital Audio

8 x Over Sampling TDA1541a – CXD 1244 ?

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See also Staggered DAC

Today I received the PCB for my new experiment

Quickly poke some parts , and check SMD check footprints

 

Idea based on grundig cd9009.

 

SMD placed

Some IC-sockets

Check power 5v, 3v,

Missed GND ;-(

sop/ssop Soldered by hand 🙂

We have  27 MHz

Quick test  in  philips CD 360

input signalen to  CXD 1244

  • Yellow  – Bitclock
  • Purple – L /R clock
  • Bue – Data

Audio to cxd-1244

Digital Silence  to CXD – 1244

PL1708 changed by  PL1707 and placed  S/Pdif transmitter to see if it will work

Recieved CXD-1244  and working in the Philips  CD 360

FFT spectrum of a  Multi-tone 4 x OS uit CXD 1244.

 

Staggered 8xOS by 2 times 4xOS time  shifted  and uses  inverted Wordclock for 1 of the i2s

Information from Sony leaflet

 

 

 

 

 

  • Groen – Wordclock
  • Blue  -Data even samples,
  • Yellow – Data un even samples uit CXD-1244

 

More Sony Mode instead off i2s

Stopped clock in CD 104 with TDA1540

  • Yellow  – Stopped Clock
  • Blue – Audio data
  • Green – Latch

Again t CXD 1244 in Sony mode .

Building TDA1541(A) with double i2s input

 

PCB arrived  🙂

Testing with  TDA1541a , working 🙂

Testing with 2  TDA’s 1541a , Works well but 6 dB more output

2 TDA1541a Parallel 0 dBfs to much for i/v converter

after modding   I/V OpAmp, level is now 0dBfs is  2 Volt , Multitone

 

Oeps mistake , 2 SMD condenstator not solderen

Resoldered , we have nice THD+n numbers:-)

1 kHz FFT 20-20kHz

  • Rood =  Grundig CD9009 2 x TDA1541a S1
  • Blauw = Philips CD360   2 x TDA 1541a with CXD 1244 mod

1 kHz FFT 20-96kHz

  • Rood =  CD9009 2 x TDA1541a S1
  • Blauw = CD360   2 x TDA 1541a

Is it real  8 x oversampled , “meten is weten” , measured on  i/v opamp output

SAA7220a + TDA1541 , 20 kHz 4 x oversampled

CXD1244 + 2 x TDA1541A  2x   4x oversampled staggered

Building Proto 2

 

 

 

 

 

 

See also Staggered DAC

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