Technical Service Bulletin

July 25, 2024

CD11, CD11 Tribute, CD11MKII, CD14, CD14MKII, RCD-1572, RCD-1572MKII, DT-6000

In above Rotel CD players, a random order algorithm issue has been identified in earlier developed software versions.

When the system completes the TOC reading and is ready to play, pushing the [RANDOM] button on IR remote enables random playback mode. The begins playback starting on the 1st track of CD album every time as below and not the first track in the random list.

Original Random Playback Order

Corrected Random Playback Order

This issue has been resolved in the latest released main software versions as listed below.  New production starting with the serial numbers in the list already have the updated software installed at the time of production.  Should you require this update in a CD player please contact an authorized Rotel dealer or authorized Service Center.  

Affected unit models include: CD11, CD11 Tribute, CD11MKII, CD14, CD14MKII, RCD-1572, RCD-1572MKII, DT-6000

Most of Rotel products provide one 3.5mm mini-jack to receive command codes from industry-standard infrared receivers via hard-wired connections. This feature could prove useful when the unit is installed in a cabinet and the front-panel sensor is blocked.

Q: Where is the 3.5mm mini-jack on the unit?

The 3.5mm mini-jack is located on the EXT REM port of the rear panel.

Q: What’s the IR protocol used for Rotel products?

Most current Rotel products use NEC Hex codes as their standard IR library, the base hex library used for most receivers, preamps and integrated amps is NEC 8311, and current Rotel CD players is NEC 8312.

Q: What’s the NEC Protocol?

The NEC IR transmission protocol uses pulse distance encoding of the message bits. Each pulse burst is 560µs in length, at a carrier frequency of 38k Hz. A logical "1" takes 2.25ms to transmit, while a logical "0" is only 1.12ms.

Q: What’s the carrier frequency of the external IR receiver can be used for Rotel products?

Carrier frequency of external IR receiver that works with 38k Hz.

Q: How to connect the Rotel External IR Remote Control?

For standard Rotel products with IR Remote Input require power to the IR Receiver then convert the wireless IR signal to a wired data stream connected to the IR Remote Input on the device. 

Below picture shows that External remote connection needs Power Adapter, Connecting Block (IR remote transceiver), IR Receiver (3 pins for power, ground and receiving IR) and one piece of 3.5 mm Plug Shield Cord.

Q: How to choose a Plug Shield Cord?

A 3.5 mm Plug Shield Cord 2-pin or 3-pin cable is required for connection to the Rotel unit for external IR remote connection.

The pass-through feature allows the audio signal from a Surround Receiver or Processor to pass through a separate stereo preamplifier without any signal modification. This is useful if you have a high-end two-channel system but want to watch video with surround sound on occasion.

To use the Bypass mode on the RC-1580, plug the front channel output of the surround sound processor into the Tape 2 inputs. When the Tape 2 input is selected, the signal from the processor is sent directly through the preamplifier and by-passes the tone and volume functions. Once the unit is in bypass mode, the BYPASS indicator on the front panel is turned on.

Setting a system up this way provides a way to integrate a stereo amplifier to be used as the front channels of a surround sound system. Only the Tape 2 input can provide the bypass function. It requires no additional setup, making it easy to switch between normal stereo mode and surround sound mode by using the input selector.

Technical Service Bulletin

June 16, 2023 

Michi Bluetooth 5.1 aptX™ HD Module 

The latest Apple iOS version (including OS V15.7.2) may cause the APPLE MUSIC app to stop playing audio when manually jumping between tracks in a playlist.  The Bluetooth connection is maintained but there is no audio output and no playback information (sample frequency and/or bit rate) displayed.  A hard power cycle of the unit remedies this issue. 

Earlier versions of iOS do not appear to have the same issue.  Other iOS Apps (i.e. iTunes, Spotify, Tidal, etc.) are NOT affected by this use case.

If this is reported, please contact Rotel at sales@rotelglobal.com to order a new Bluetooth 5.1 module (Rotel Part Number: 093E-BTM0002-D-3) with updated firmware V1.04 (or newer) that resolves this iOS compatibility issue.  

Note: All new delivered spare parts will be programmed by new firmware V1.04 (or newer) before package and shipment from now on, either of below two methods can help to identify this change.

   

   

Bluetooth module replacement requires removal of the top cover and replacing the Bluetooth module in the socket (no special tools or soldering is required) as shown below.

Affected unit models include: X3, X5, P5, X3 Series 2, X5, Series 2, P5 Series 2

Release Type

X3 Series 2

X5 Series 2

P5 Series 2

● Part Number of New Bluetooth Module 5.1 is 093E-BTM0002-D-3

● New Bluetooth module 5.1 built Qualcomm IC as below photo.

The Instruction use Michi X5 Bluetooth Dongle Replacement as example

b. Remove the Bluetooth 5.1 dongle from the socket. 

c. Prepare the new ordered Bluetooth dongle (with firmware V1.04 or higher installed)

     

d. Install the new Bluetooth 5.1 dongle in the socket. Pay CAREFUL attention to pin alignment to avoid damage to the dongle and the unit.

e. Reassembly the unit and top cover.

f. Test to verify the new Bluetooth module works properly.

 

PDF file download please click below:

Technical Service Bulletin - Michi Bluetooth 5.1 aptX™ HD Module