Turning budget CD player to audiophilic gear

Thrift stores are the good places to get some old electronic parts for projects.

A week ago I took my wife to a hair salon. Before taking her back, I had spare time to kill so I visited a thrift store nearby.  Minutes in the shop and I spot a very nice Philips CD player CD482.  I test it and it was nothing wrong except the tray belt. This machine has a CDM4/19 laser head and only the head itself is worth the price tag.

Here is the interior of the CD482 with the tray

There were several versions of CD482 with the same outlook but with different DAC configurations.  It is a standard CDM4 decoder with SAA7210 ( aka chip A) connecting to
1.  SAA7220 - TDA1541 (The best CD482, made in Netherlands)
2.  SAA7220 - TDA1543 (A cheaper version with over-sampling)
3.  NOS- TDA1543 (The cheapest solution in Non-oversampling configuration)

Remove the highlighted parts and install the sockets

The datasheet of SAA7210 stated that the SAA7210 can directly link to TDA1543 and provide the most economic solution,   My machine, having the code CD482 01R, is the most basic one and only has one TDA1543.  It was good since I had no burden to think about preserving the existing configure.  To me, TDA1543 is a so-so DAC chip.  But indeed, one Japanese Audio designer won  a competition by using a vintage TDA1543.  Amazing!


I do have the DF1 (TDA1307+ TDA1547) DAC board which can be used to convert this CD player. This is a very flexible DAC board which can provide 11.8688MHz system clock signal for SAA7210 so I can upgrade the clock as well.

Here is the work list:

1. Clean all parts and board
2. remove the TDA1543,  three LM833 (for IV conversion), install the IC sockets so the I2S signal can be taken out (pin1 to 3 and pin 4 of TDA1543 as I2S and digital ground)
3. remove the coupling  output capacitors, install the socket so the output can be connected back to the main board. 
4. remove the 11.8388MHz crystal and all related components, install the socket so the external clock signal can be injected to pin 19 of the SAA7210
5. install the transformer and the new DAC board


note: Don't remove the opamp for the headphone and the headphone on CD player is still functional.

It is not that difficult to modify this player since there is plenty of room in it.

I haven't changed any capacitors in this player right now and the caps in this player are pretty good in quality.  However, for the sake of safety, I will replace them  later.

Reading disc is quick and snappy showing that the laser is good.

The TDA1547 DAC board had been modified and the internal IV opamp had been bypassed and replaced by LM6172.    The design of this board was nothing fancy but following the suggested design from Philips, using two NE5534 in each channel.  Two OS-con caps were used for output coupling.

Let talk about the DAC board,  a MCU (micro-control unit) was needed to control the TDA1307 and not many manufacturers were using this chip with the TDA1547.The first Marantz Super Audio CD/CD player, the SA-1, is one of this.  TDA1307+1547 is the last ultimate High-end DAC from Philips. Sound is great, at least from the measurement.  Feeling is very subjective and some old chips with proper configuration can beat the new.  Who know?