The Personal Hi-Fi Blog: January 2019

~~Sharp IM-MT880/IM-MT899~~

Portable NetMD Recorder

In 2000, Sony announced MDLP (MiniDisc Long Play), which added new recording modes based on a new codec called ATRAC3. In addition to the standard, high-quality mode, now called SP, MDLP adds LP2 mode, which allows twice as much recording time (160 minutes on an 80 minute disc) of good-quality stereo sound, and LP4, which allows four times more recording time (320 minutes on an 80 minute disc) of medium-quality stereo sound. The bitrate of the standard SP mode is 292 kbit/s, and it uses separate stereo coding with discrete left and right channels. LP2 mode uses a bitrate of 132 kbit/s and also uses separate stereo coding. The last mode, LP4 has a bitrate of 66 kbit/s and uses joint stereo coding. The sound quality is noticeably poorer than the first two modes but is sufficient for many users. Tracks recorded in LP2 or LP4 mode playback as silence on non-MDLP players. Sony announced they would cease development of MD devices, with the last of the players sold by March 2013. NetMD recorders allow music files to be transferred from a computer to a recorder (but not in the other direction) over a USB connection. In LP4 mode, speeds of up to 32× real-time are possible and three Sony NetMD recorders (MZ-N10, MZ-N910, and MZ-N920) are capable of speeds up to 64× real-time. NetMD recorders all support MDLP. NetMD is a proprietary protocol, and it is currently impossible to use it without proprietary software, such as SonicStage. Thus, it cannot be used with non-Windows machines.{wikipedia}

Introduction

"Sharp Corporation will release the "IM-MT880" (IM-MT899) portable MD recorder compatible with "Net MD" on December 17, 2001. The price is an open price, and the expected shop front price is expected to be 45,000 yen (approx $400). Products include "2 lines display remote control" and "charging stand" that can be charged simply by placing it.

*The "IM-MT880" (IM-MT899) is a portable MD recorder compatible with "Net MD" that can transfer ATRAC/ ATRAC3 music data at high speed from PC.

Interface with PC is USB, "OpenMG Jukebox Ver.2.2 for SHARP" is included as transfer software, the corresponding OS is Windows 98/98 SE /Me /2000 /XP. In this software, WMA /MP3 /WAVE data can also be converted to ATRAC /ATRAC3.

Sharp Jukebox is SonicStage Software for transferring songs to PC

*Moreover, the LED is arranged around the USB terminal of the MD main unit, and the "7 color light navigation" function which shines the transfer status in seven colors is also carried.
Furthermore, in addition to high-speed transfer with "Net MD", you can also edit the MD already recorded from the PC and enter the title.

*It corresponds to MDLP, and the ATRAC part adopts "24-bit calculation method". Analyze the bit allocation at compression and its result in the compression algorithm and execute bit allocation again. It also carries a time axis direction/frequency axis direction/amplitude direction adaptive bit allocation algorithm, realizing highly efficient compression.

*Amplifier circuit adopts "+/- power supply audio circuit" without an output capacitor. Bass enhancement functions "X-BASS" and LP "A sound skipping guard memory" corresponding to 160 seconds are also equipped.

*The playback-related function is equipped with "MDLP group mode" that manages music information divided into 99 groups at maximum. In addition to that, you can also perform "intro play" function which automatically plays each song for about 5 seconds, random play, random repeat, all songs/repeat play of 1 song.

*As a recording-related function, it incorporates a "sampling rate converter" and "digital recording level control" that allows you to adjust the recording level even when recording a digital sound source. It also features a "microphone sync function" that automatically records in response to sounds and voices, pauses for 3 seconds or more of silence and pauses, "automatic microphone sync function", automatic indexing at fixed intervals (3 minutes/5 minutes/10 minutes) "Time auto mark function" which records it in the same way, and "double speed quick play listening function" which can listen to the disc of double monophonic recording at double speed". (Sharp's press release 2001)