RAKK dac K&K Audio RAKK dac Mark III Raleigh Audio I2S Interface Products Interface Specification and Installation Manual 3.
Kit version Use this manual with the following RAKK I2S interface products: • RAKK I2S Receive board version 3.1 (single input) • RAKK I2S Receive board version 4.1 (three input) • RAKK I2S Send board version 2.2 • RAKK I2S Interface Adapter for Juli@ version 1.1 Required Tools and Supplies 35 to 50 Watt soldering iron Diagonal cutting pliers Long-nose pliers Wire stripper Solder Warnings and Cautions Caution – Use only solder that is intended for electrical circuits.
Table of Contents Preface ........................................................................................................................................................................... 3 Introduction ................................................................................................................................................................... 4 Isolation and grounding .............................................................................................................
Preface For a digital interface to be defined, three aspects must be described: the logical, the electrical and the mechanical. The logical description tells how the data are encoded – for example, the number of signal and clock lines and how they relate. The electrical description outlines the structure – single ended or balanced – and the voltage, current and impedance of the circuit. The mechanical description covers the type of connector (if any) and how its pins are used.
Introduction The RAKK I2S Interface suite of products provides the capability to attach a component, such as a CD transport or computer, to the RAK dac Mark III using an external I2S interface. The various I2S boards contain circuitry to convert internal TTL level signals to external differential signals and vice versa. The RAKK I2S Interface suite of products consists of four PC boards: a Send board, a singleinput Receive board, a three-input Receive board and a daughter card for the ESI Juli@ PCI card.
The RAKK I2S Interface Adapter for Juli@, together with the Juli@ PCI card, provides an external I2S interface for a personal computer. The RAKK I2S Send board provides an external I2S interface for a generic CD transport. The circuitry in the CD transport could be anything and we have no way of knowing about it. Therefore it is up to you to determine how to connect the Send board to the I2S signals in that device.
The RAKK three-input Receive board allows for the attachment and selection of up to three external I2S interfaces. Each of the three inputs is identical to the input on the single-input Receive board, so any combination of PWT, Juli@ card or Send board may be used. Isolation and grounding For best performance, proper grounding practices must be followed in the system. This amounts to ensuring that ground references are provided where needed and that ground currents do not flow where they are not needed.
Now that the I2S interface Receive board and its power supply are completely isolated from the rest of the circuitry in the RAKK dac, the I2S circuitry is free to adopt the ground of the attaching device. This is fine and works well, however one problem remains. Since the I2S circuitry adopts the ground reference of the device that it is attached to, and does not have a ground reference of its own, the I2S circuitry is floating when it is not attached to another device.
Implementation Instructions PS Audio PWT Attachment • • Follow the Receive board installation instructions below. Connect the PWT to the RAKK dac enclosure using a standard HDMI cable. Generic CD Transport Attachment • • • Follow the Receive board installation instructions below. Follow the send board installation instructions below. Connect the CD transport to the RAKK dac enclosure using a standard HDMI cable.
I2S Interface Adapter Receive Board Installation Instructions The I2S Receive boards are designed to be mounted to the RAKK dac Mark III board. These instructions assume that the Receive board will be used with the RAKK dac Mark III. ———————————————————————————— 1. Complete the assembly of the RAKK dac Mark III. ———————————————————————————— 2. Mount the receive board on the RAKK dac such that the I2S interface pads are co-located. Use four standoffs and screws. ———————————————————————————— 3.
Skip the next two instructions if you have a single-input I2S Receive board. ———————————————————————————— 8. Install a wire from the +12V pad on the power supply that is providing power to the RAKK dac to the +12V pad on the three-input I2S Receive board. ———————————————————————————— 9. Install a twisted pair of wires from the input Select switch to the pads labeled “Input Select” 5 and 6 on the I2S Receive board. Observe the desired switch position for each wire.
I2S Interface Adapter Send Board Installation Instructions The Send board is designed to be mounted on the back panel on the CD transport with brackets holding the board. The brackets have been pre-assembled on the board to show how it should be mounted. ———————————————————————————— 1. Measure the board assembly with the brackets to determine a hole drilling pattern. ———————————————————————————— 2. Cut a hole in the back panel large enough to accept the HDMI connector. ———————————————————————————— 3.
I2S Interface Adapter for Juli@ Card Installation Instructions The I2S Interface Adapter for Juli@ card is designed to be mounted on the ESI Juli@ card in place of the analog card that is provided with the Juli@ card. ———————————————————————————— 1. Following the directions in the Juli@ User’s Guide, remove the four screws securing the audio daughter card. ———————————————————————————— 2. Detach the metal bracket from the card. ———————————————————————————— 3.
7. Place the metal bracket in its location on the cards. ———————————————————————————— 8. Install the four screws in the opposite order from which they were removed. ———————————————————————————— 9. Remove power from the PC or music server. ———————————————————————————— 10. Install the Juli@ card in the PC or music server.
I2S Interface Adapter Receive Board Interface Specifications Internal I2S interface The I2S interface is galvanically isolated from the circuitry and ground on the RAKK dac board. Therefore all six wires must be connected for proper operation. The interface is implemented with a standard 3.3V logic family and is designed to operate into standard 3.3V or 5V logic families. Electrical definition: Nominal output pulse amplitude = 3.
I2S Interface Adapter Send Board Interface Specifications Internal I2S interface The I2S signals are referenced to power ground. The interface is implemented with a standard 3.3V logic family and is designed to operate with standard 3.3V or 5V logic families. External I2S interface Electrical definition: The electrical interface is defined by the National Semiconductor DS090LV031 LVDS differential Line Driver.
I2S Interface Adapter for Juli@ Card Interface Specifications Internal I2S interface The I2S signals are referenced to power ground. The interface is implemented with a standard 3.3V logic family and is designed to operate with standard 3.3V or 5V logic families. External I2S interface Electrical definition: The electrical interface is defined by the National Semiconductor DS090LV031 LVDS differential Line Driver.
Parts List (Level B) Designator Part bracket with screws Description Qty mounted on Send board Document version history Document 1.0 Description Original document Intended to support parts version 1 Intended to support parts version 2, level A Document only update of power requirements. Include instructions for LED potentiometer. Document only update. Clarification for Extreme RAKK dac build. Document only update. Include instructions for grounding. Document only update.
