EK JAPAN CO., LTD
15th Anniversary of Foundation
Limited Model / NOV 2009
* 參考資料 : 日本KIT SET定價為88,200日元、砌機收費26,250日元，需時30日，不包括運費。
限量成品，即日接受預定，2009年11月份推出。TU-875 / 879 / 882AS / 884CD / 881CD 等已登記行貨用家優先發貨。
300B SINGLE STEREO POWER AMPLIFIER"TU-LAB"
A single stereo power amplifier with 300B tubes, the most popular tube, which is designed so that tube amplifier fans can work over it on their own after assembly.
Find your favorite combination of tubes, output transformers (OPT), volumes, etc, and enjoy this experimental TU-LAB!
Experimental amplifier for audiophiles !!
Triode connection of pentode also available!
Triode-connected pentode and beam tube have equal qualification and attraction as 300B. In this TU-LAB, 8 pin sockets are equipped, which enables triode connection of such tubes as KT88(6550), KT66, EL34(6CA7), 6L6GC, etc, without any modifications to the amplifier.
Try different OPT and volumes!
A slide universal bracket, or in other words "magical bracket" , that enables various kinds of OPTs in various shapes to be installed, is developed for TU-LAB so that most of commercially-available OPTs for 300B single amplifier can be used.
Full of ingenuity for high quality sound, stability, safety, and energy-saving
["Constant current circuit, self-bias + fixed bias" method]
Constant current circuit is adopted instead of cathode resistors of self-bias method so that a constant plate current flows no matter what tubes in our assumption are used. (rated currency value can be fine-adjusted.
[Power shut-down circuit for OPT upon over-current]
If over-current occurs in either of the OPTs even for one second, the B power supply is shut down and LED indicator at the troubled side shows that there took place a malfuction.
[FET ripple filer]
FET ripple filter, time-proven in the performance of the reduction of ham noise is adopted for the B power supply.
[All tubes heated by AC]
From ecological point of view, all tubes are heated by AC power so that the power loss in the rectifying circuit is improved and heating is moderated.
World-wide power transformer
Upon request for se under 200V environment or oversea countries, a multi power transformer that can be used under 4 different power voltage environments, such as 100V, 115V, 200V, and 230V (Select the setting location of the corresponding connector upon assembly.
Max. output: 8W+8W (by default, with 300B tubes and 8Ω of load applied)
Frequency response(-3dB): 15Hz~40kHz
Residual noise (IEC filtering): 0.5mV (0.1,V when KT88 installed)
Input sensitibity: 200mV (DF：6.3 Speaker: 4~16Ω)
Output terminal : Gold-plated, binding post (bare wires up to Φ5mm can be inserted, and banana plugs can also be used.)
Input terminal : Gold-plated RCA jack, single stereo line (at the back)
Power input : 3P inlet (IEC320)
Power voltage : 220V ~ 240V 50/60Hz available. Change the soldering location of the connector for power transformer as shown in the photo below.
Power consumption: 80W by standard (70W~95W as ip is fine-adjustable.)
Dimension: W400xH213xD250 mm (Chassis with the punched metal cover, protrusion not included.)
Weight: 10.8kg (fully assembled, without a power cable)
ip adjustment range: Approx. 50~80mA (L,R independently adjusted) Ham balancer function equipped A microcomputer is adopted for TU-LAB, for the first time to our TU series amplifier (warming-up timer , cathode voltage monitoring, automatic shut down of B power supply upon malfunction)
OPTs (Output Transformers):