[ [ [ About the stock of OP21A and OP21E ] ] ]
We are very sorry but the OP21A and OP21E products are out of stock.
The next sale of OP21A and OP21E is scheduled for the end of August.
We appreciate your patience and understanding.
[ [ [ Precautions when ordering ] ] ]
Our recommended external DC power supply (LTPW01P) and DC cable for connection are sold separately from the main unit.
Please use the option set sale.
The AC power cable is not included in the set order with the external DC power supply "LTPW01P".
You can prepare the AC cable yourself or order an additional AC cable on another page.
We will ship your order approximately 12-15 days after your order is confirmed.
[ Product Overview ]
A master clock for high-end audio that brings together the technology and experience of cyber shafts.
Equipped with the same ultra-high precision OCXO as OP21E -1 by making it a single output, the price is kept down while maintaining high performance. In addition to the external DC power supply, it is equipped with an ultra-low noise and ultra-high PSRR regulator circuit equipped with three next-generation linear regulator LT3045s.
Designed with a luxurious cast front panel.
*The chassis surface treatment has been changed from alumite to metallic silver paint. (11-May-2022)
[ Features ]
This product uses a brand new OCXO, and a unit with outstanding stability is selected and mounted by long-term calibration.
In addition to the OCXO unit, a robust heat insulating case composed of a magnetic shield plate and a heat shield board is added to maintain an environment where the performance of OCXO can be maximized.
The front panel is combined with a transparent cast material with a thickness of 4 mm to enhance the design.
The bottom of the chassis is made of 2 mm thick aluminum material + 8.4 mm thick laminated iron material, and has a robust vibration damping structure with a total of 10.4 mm thick plate. In addition, a strong magnetic shield using a 5.2 mm thick laminated iron material is configured around the board.
Uses aluminum die-cast 3-point support feet that can be stable on any installation surface. It can be replaced with an optional spike insulator with a 4 mm screw.
The output can be set to an impedance of 50Ω or 75Ω. (Registered utility model)
The function to insulate the GND side of the clock output from the GND of the main unit is the best way to protect against external noise. In most cases, insulating the GND will provide a noise-free connection and good results.
You can set whether to connect the output GND potential to the main unit's GND or to isolate it. It can flexibly handle complicated GND processing that differs for each audio system. (Registered utility model)
The DC supplied from the external DC power supply regulates the LT3045 with ultra-low noise and ultra-high PSRR inside this unit with a three-unit structure under the best conditions. Very clean DC is supplied to OCXO.
For the internal substrate, a copper foil substrate with a thickness of 70 μm, which is twice the normal thickness, is used. The internal layout, which has been verified many times, is in the best condition.
Equipped with an LED monitor that allows the oven circuit to operate normally and control the OCXO unit temperature.
Strictly measure characteristics using a highly accurate calibrated measuring instrument. The clock quality is guaranteed by plotting the phase noise and allan Deviation in the output section for each unit.
It comes with a 2-year free repair warranty.
[ Output GND insulation / enclosure GND selection function ]
The output GND potential can be switched between "insulated from the chassis GND" and "housing GND". If the output GND of this unit is grounded in common, the GND potential difference between this unit and the connected device will flow through the GND of the connection cable, causing noise called a GND loop. Therefore, it is usually better to insulate the GND of each output for better noise resistance. Depending on the system you are using, the GND of each device may be firmly grounded. If there is no GND potential difference between these devices, it may be better to have the output GND grounded to the chassis GND to obtain better results against noise.
Since the environment of the audio system is various, you can choose the most suitable method according to your own environment. The bottom plate of this machine is equipped with a housing GND terminal.
[ External DC power supply ]
This unit is designed to operate only with an external DC power supply. Be sure to prepare an external DC power supply. We recommend our dedicated power supply (LTPW01P), but you can operate it with your favorite linear power supply if the specifications are met.
The specifications of the external DC are 13.5V to 16V 1A. The recommended voltage is 14V. The LT3045 can sufficiently eliminate noise even if the input / output voltage difference is 1V. The smaller the input / output voltage difference is within the specified range, the more the LT3045's capabilities can be demonstrated. Therefore, a good DC power supply with very no noise can operate from 13.5V.
The external DC plug standard is 2.1 mm / 5.5 mm. You can use a normal DC plug, but we recommend the [RS product 487-820] plug because it uses a screwable jack.
(RS products are easily available all over the world. [RS WORLD WIDE])
[ OCXO characteristics selection value ]
The OCXO mounted on this product uses a stable OCXO unit that has been calibrated for several months. In order to perform the optimum selection as an audio clock, we are conducting a comprehensive evaluation of the phase noise characteristics and the short-term stability (Alan Deviation) that allows more detailed examination.
The product cannot be evaluated by measuring only the output characteristics of the built-in OCXO unit. The measurement of our calibration is not the output of OCXO unit directly, but is measured from the output terminal of this product in order to evaluate all the performance including the buffer circuit.
[ Selection characteristic value ]
|OP GRADE||Phase Noise @offset 1Hz/10Hz||Allan Deviation tau=1s|
|OP21A(-D/-1)||> -121 dBc/Hz / -140 dBc/Hz||> 1.60E-13 (0.000160ppb/s)|
|OP21E(-D/-1) ||> -121 dBc/Hz / -140 dBc/Hz||> 1.95E-13 (0.000195ppb/s)|
|OP21E(-D/-1) ||> -120 dBc/Hz / -140 dBc/Hz||> 1.60E-13 (0.000160ppb/s)|
|OP20A(-D/-1)||> -120 dBc/Hz / -140 dBc/Hz||> 1.95E-13 (0.000195ppb/s)|
* We have changed the previously announced reference value for each grade to the selection value actually used by us and released it. All products already sold are shipped with the OP selection values in this table.
-OP21E (The characteristics are the same as OP21A) products have the same performance standards as OP21A.
-The OP21E(-D/-1) specifications are positioned as intermediate characteristics between OP21A and OP20A.
As in  and , either PN or ADEV meets the OP21A specification value.
The overall characteristics are almost the same for both  and .  or  cannot be specified.
[ OP grade guarantee card ]
An "OP grade certificate" with hologram is always attached to each OP grade product.
A tamperproof sticker is attached in the center. A hologram is printed on the right edge. In addition, a hologram sheet with the serial number described in the option grade certificate will be attached to the OCXO unit inside the main unit. Please be sure to check when purchasing for second use.
[ Compatible audio products ]
ESOTERIC Grandioso K1X、K1、P1X、P1X、P1、D1X、D1、K-01XD、K-01Xs、K-01X、K-01、K-03XD、K-03Xs、K-03X、K-03、K-05Xs、K-05X、K-05、K-07Xs、K-07X、K-07、D-02X、D-02、D-05X、D-07X、P-021、P-02X、、N-01XD、N-01、N-03T、N-05、G-0、G-0s、G-0Rb、G-02、G-03X、G-25U、TASCAM CG1000 / dCS Vivaldi clock、Paganini clock、Scarlatti Clock / MUTEC iCLOCK、MC-3+、MC-3+USB / Antelope Audio Isochrone OCX HD、OCX-V、OCX、TRINITY、PURE2、ZODIAC PLATINUM / BRAINSTORM DCD-8 / Phaseteck HD-7A / Phasemation HD-7A192 / SFORZATO DSP-Vera、DSP-Dorado、DSP-Pavo、DSC-Vera、DSC-Drado、DSC-Grus、DSP-01、DST-01、DSP-03、DSP-05 / TEAC UD-503、UD-505、NT-503、NT-505 / SPEC RMP-X1 / Sound Warrior SWD-CL10 / TechDAS D-7、D7i / RATOC RAL-DSDHA2 / M2TECH EVO DAC TWO PLUS、HIFACE EVO TWO / CH Precision C1,D1 / aurender W20/ soulnote D-2、S-3 / SOtM sMS-200ultra、tX-USBultra、SOtM sNH-10G (require master clock input function) /SHENZHENAUDIO GUSTARD U16、Singher SU-2 / iFi Audio Pro iDSD / UpTone Audio EtherREGEN / Audio Gd DI-20HE、DI-20、R-7HE (version 2020)、R-7 (version 2020) /VMV SMSL D3
Other, master clock generator with 10MHz clock input, CDP, DDC, DAC, Audio HUB, etc.
*If you are uncertain about the specifications of the device you are using, please contact us with the model name.
[ Specification ]
Accessories: instruction manual, test report, and phase noise/Alan Deviation characteristic graph
( BNC and AC power cable is not included. )
Output: 10 MHz x 1 lines, sine wave
Output level: 1.5 Vp-p ( with 50 ohm setting)
Output impedance: 50 ohms/75 ohms Each system is individually switchable
Output GND potential: Main body GND/insulation can be switched (each system can be switched independently)
Body size: W141mm x D210mm x H90mm (including protrusions) Optional use H100mm
Weight approx. 3 kg
External DC power supply: DC 13.5V-16V 1A recommended voltage 14V
External DC plug standard: 2.1 mm/5.5 mm screwable
○ 2-year free repair guarantee
*Design and specifications are subject to change without notice for improvement.