Search this site

Labels

4-channel ACCUPHASE ACOUSTIC ENERGY ADC ADCOM ADS ADVENT AIFAI AIWA AKAI AKG Alchemist ALIANTE ALLISON ALTEC LANSING AMPEX amplifier AMPLIFON ANCIENT AUDIO AR ARCAM ARISTON ARMONIA AUDIA AUDIO ACADEMY AUDIO ANALOGUE AUDIO DYNAMICS AUDIO INNOVATIONS AUDIO NOTE AUDIO RESEARCH AUDIO-TECHNICA AUDIOLAB Audiostatic AUGUSTA AVALON AVID AXIOM B-I-C Bang & Olufsen BASF BASSOCONTINUO Bell Belt-Drive BEVERIDGE BEYER-DYNAMIC BOSE BOSTON BOWERS-WILKINS BOZAK BRAUN BRIONVEGA BSR California Audio Labs CAMBRIDGE CANTON cartridge CARVER CASTLE CD Player CD Transport CEC CELESTION CEMARK Centrex CERWIN-VEGA CHARIO CHARTWELL CIZEK CLARION CONRAD-JOHNSON COPLAND CORAL CORAL ELECTRONIC CREEK CROWN CYBERNET CYRUS DAC DAHLQUIST DALI DAT DBX DECIBEL DENON DIAPASON direct-drive Ditton DOKORDER DOMA DUAL DYNACO DYNAUDIO DYNAVECTOR EISA ELAC ELECTRO-VOICE EMPIRE EMT EPI EPICURE EPOS ES Series ESB Esotec ESOTERIC ESS EUMIG FAIRCHILD FOSTEX GALACTRON GALE GARRARD GENELEC GENESIS GIUSSANI RESEARCH GOLDENOTE GOODMANS GRAAF GRUNDIG H.H. SCOTT HAFLER HARBETH HARMAN/KARDON headphones HEATHKIT HECO HIRTEL HITACHI HPM idler INDIANA LINE INFINITY italian JAMO JANSZEN JBL JEFF ROWLAND JENSEN JMLAB JVC KEF KENWOOD KLH KLIPSCH KOSS KRELL KYOCERA LAE Lafayette lathe LEAK LECTOR LENCO LESA linear LINN loudspeaker LOWTHER LUXMAN LYNGDORF MAGNEPLANAR MARANTZ MARK LEVINSON MARTEL MARTINLOGAN MARUNI MASH MAXELL MBL McIntosh McLAREN MERIDIAN MERITON MICRO SEIKI MICRO-ACOUSTICS MIRAGE MISSION MITSUBISHI MONITOR AUDIO MONRIO MORDAUNT-SHORT MUSICAL FIDELITY MYRYAD NAD NAGRA NAKAMICHI NHT NIKKO NORESCO NOVA ONKYO OPERA OPTONICA ORTOFON PANASONIC PARADIGM PATHOS PEARL PHASE LINEAR PHILIPS PICKERING pioneer POLK AUDIO Power-amplifier Pre-amplifier Pre-phono Pro-Ject PSB QUAD quadraphonic RADFORD RCF receiver Reel to Reel REK-O-KUT REVOX ROGERS ROKSAN ROTEL ROYD RUARK SACD SAE sansui SANYO SENNHEISER SHARP SHERWOOD SHURE SIARE SIGNET SME SOMA SONAB SONUS FABER SONY SOTA Soundcraftsmen SPECTRAL Spica STANTON STAX Stereo 8 STILE ITALIANO STRUSS SUGDEN SUPERSCOPE Synthesis TAC TAD TAMON TANDBERG tangential TANNOY TASCAM TDK TDL TEAC TECHNICS THE FISHER THIEL THORENS tonearm TOSHIBA TRANSCRIPTOR TRIO tuner turntable ULIX Uni-Q UNISON RESEARCH unitra UREI UTAH VANDERSTEEN VOCE DIVINA VPI WADIA WHARFEDALE XAVIAN YAMAHA ZENITH ZINGALI

What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Akai CD-D1 cd player


The CD player Akai CD-D1 -

Incorporates a large number of well designed ergonomic features. One feature that  particularly liked is that the disc holder is manually closed rather than electronically closed; this relies on the natural response of most users to "push the darn thing closed" and not to look for another switch with which to close it. In the centre of the panel is the display module which is divided into four horizontal layers. The top layer provides mode information, telling you whether the unit is in standby, pause or play mode. The second level of the digital display tells you the number of the selection that is actually playing. If the unit is not playing a zero is displayed. The third row provides the elapsed playing time in minutes and seconds. The programming keys on the right hand side of the panel also tell you the time in minutes and seconds at which the start of a cycle or sequence should commence. The bottom section is a quasi -analogue display which shows the position of the recording head using an array of light emitting diodes. The control switches consist of one double sized 'play' button with its own self indicating LED. four buttons for 'Stop - Eject', 'Pause', 'Fast Forward' and 'Fast Rewind' and two buttons labelled 'PLS' for automatic location of either the previous selection or next selection on the disc.

 


On the right hand side of the console are ten keys for keying in numerical data, a 'set' switch, a 'cancel' switch and six elongated keys. The top elongated key is for the selection of 'phrase', a term commonly used by all the manufacturers meaning the selection of the time or section in seconds.

The 'index control' is used on those compact discs that have the display IN:DEX. These discs, which are not currently available, will allow you to select the music sequence number and select a particular segment within that sequence. This is achieved by selectively pressing the 'index' key then pressing the sequence number. As none of the discs that I was playing had the IN:DEX display I could not check this function. The 'time' switch tells you the residual playing time on the disc, the 'memo call' allows you to check what you have stored as memory instructions, the 'repeat' switch allows you to repeat one sequence over and over again and the 'total time' switch tells you the total time on the disc. On the back of the unit is a volume control with which you can adjust the player's output level to match your amplifier's auxiliary input requirements. This unit also has a pair of gold plated phono sockets which is a common feature on all the CD players reviewed.

The performance characteristics of the Akaí player are excellent. The frequency response is ±0.2 dB from 20 Hz to 20 kHz and the replay linearity is almost perfect from 0 dB to -60 dB, 0.5 dB high at -80 dB and 1.4 dB high at -90 dB. The A -weighted signal-to-noise ratio both with and without emphasis is 106,4 dB  which is significantly better than claimed for the unit by Akai.  The channel separation from right to left is better than 103,9 dB at 100 Hz, better than -95 dB at 1 kHz, better than -89 dB at 10 kHz and better than  -92 dB at 20 kHz.

 


The distortion levels at 0 dB are 0,0034% at 100 Hz, 0,0021% at 1 kHz and 0,0027% at 10 kHz.

The distortion level increases as the signal level decreases, so that at -80 dB (reference 0 dB level) the distortion level is 12%. This was just about the highest level of distortion recorded from any machine, although I must make it clear that these distortion levels would be totally inaudible and during the subjective testing we could not detect them. Functionally, the performance of the Akai CD -D1 could not be faulted and I really liked the neat control format and the multiple design features. The best demonstration discs produced a scintillating sound which impressed everybody who heard it.

 


Specifications

Disc :

Scanning Velocity:  1,2 - 1,4 m/s

Revolution:  Counterclockwise (viewed from pick-up side)

Track Pitch:  1,6 microns

Disc Diameter/Thickness:  120 mm / 1,2 mm

Signal Format:

Quantization:  16 bit linear/channel (2's Complement )

Sampling Frequency:  44,1 kHz

Channel Modulation Code:  E.F.M.

Channel Bit Rate:  4,3218 Mb/s

Error Correction:  CIRC

Frequency Response:  20 Hz - 20 kHz ±0,5 bd

Signal-to-Noise Ratio: more than 90 dB

Dynamic Range:  more than 90 dB

Channel Separation:  more than 90 dB

Harmonic Distortion:  less than 0,005%

Wow and Flutter:  Quartz Accuracy

Output Level:  2,0 V RMS (100% mod.)

Play / Start Time:  approx. 2 seconds

F.FWD / F. REW Time:  approx. 4 seconds

Random Access Time:  average 3 seconds

Power Requirements:  120 V, 220 - 240 V 50/60 Hz

Dimenisons (W x H x D):  440 x 145 x 320 mm (17,3" x 5,7" x 12,6")

Weight:  7,4 kg (16,3 lbs)

Nessun commento:

Posta un commento