asynchronous USB digital input

Retrofittable digital input for the CD player. Whether playback from CD or other formats manages via the PC, you decide by pressing a button on only one device - now finally also for the analog converters TDA1540 or TDA1541.

The retrofittable USB input consists of a decoder module and a switching module, which changes the input source between CD and digital input on the analog board in the CD player. The 14-bit module has an additional board docked to provide the 14-bit simultaneous data mode.

USB input TDA1540

The USB input receives the data secured in asynchronous transmission, which means better quality compared to a simple adaptive data transmission. The formerly widespread S/PDIF transmission, whether electrically via an RCA cable or optically via Toslink, is ruled out because of its loss of quality. An asynchronous transfer driver to be installed is included, but Apple does not need it. For both sources, USB and CD, the connection to the analog converter is then done in non oversampling.

USB-in module, for TDA1540 14 Bit 258�buy

USB-in module, for TDA1541 16 Bit 198�buy

Installation example, Youtube Video (german language)

Streaming for 14 bit TDA1540

The 14-bit switching module is used on the analog board instead of the SAA7030 chip. On the switching module is a connection for a switch to change the playback between CD or USB and also a control input, which allows source selection via the remote control module.

USB input Revox B225

USB-in inside Revox B225

Streaming for 16 bit TDA1541

The 16-bit switching module is used on the analog board instead of the SAA7220 chip and is suitable for both the TDA1541 and TDA1541A. On the switching module is a connection for a switch to change the playback between CD or USB and also a control input, which allows source selection via the remote control module.

USB Eingang Philips CD304 MKII

USB-in inside Philips CD304 MKII

Hardware Installation 14 Bit

1. Desolder SAA7030 Digital filter in CD player
2. Isolate SAA7000 pin 16 and over 1k resistor to pin18
3. Solder switch module for source selection instead of SAA7030
4. Attach USB-in module and USB socket

source switch USB-IN

Source selection

The choice between CD and USB playback can be made using a simple switch. It is more comfortable with our remote control module. This is connected by cable to 3 places on the switch module (+5V, GND (-) and OUT). The module receives RC5 hand switches (Philips, Grundig, Marantz ...), or also universal remote controls. To switch the source, a key combination of first key 0 and then key 2 within 3 seconds is pre-programmed. This allows the playback source to be conveniently changed during operation. The miniature module can be easily attached to any air gap inside - often the back is enough.

infrared receiver

Remote receiver RC5 28�buy

If one of our remote control modules for CD player is already installed, this can also take over the switching function
This smart tiny device is also often used to switch other functions. The triggering remote control button can be changed in the software if desired.

Hardware Installation 16 Bit

1. Desolder SAA7220 Digital filter in CD player
2. Cable bridge Pin 9 > 10
3. Cable bridge Pin 11 > SAA7210 Pin 18 (SAA7310-QFP Pin 25)
4. Solder switch module for source selection instead of SAA7220
5. Attach USB-in module and USB socket

source switch USB-IN

Software Installation

dr-xmos (Windows)
Apple does not need a driver.

After the driver is installed, the CD player can be connected with a USB cable. The CD player is displayed in the Windows Device Manager as USB Audio Device.