Elekit TU-4523 & TU-4523VK 45/2A3 Single Ended Tube Amplifier kit

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Elekit, Japan, introduces the TU-4523 stereo single-ended kit, letting you experience the joys of low-powered, directly heated triodes, like the classic 45 and 2A3 valves. Both are renowned for their sound quality: the 2A3's natural tones and the 45's exquisite detail. With the resurgence of high-efficiency loudspeakers that need only a couple of watts to drive, and the reissue of these valves from the likes of Emission Labs, KR Audio, and Psvane, to name a few, Elekit has created this beautifully crafted amplifier.

The new kit follows the improved front-panel and chassis design of their 300B single-ended TU-8900.

45/2A3 output tube detection switch

The top-panel switch selects the output valve. The volume knob's background is illuminated green for the 2A3 and orange for the 45 valve.

Switch between NFB and NON-NFB

For the purists amongst you, you can switch out the negative feedback (NFB) by positioning a set of jumpers accordingly on the main printed circuit board. In NON-NFB mode, the gain increases by 8dB.

Matching headphone volume levels

Headphone efficiency varies significantly by model. You can adjust the headphone output level by removing the front panel and moving a short pin. The associated circuitry to the headphone output is all valve, not solid-state.

Speaker impedance selection switch

Switch the setting to match the impedance of the connected speakers and the output valves being used. For 45s, you have 6 to 16 ohms and for 2A3s you have 4 to 16 ohms.

Ample space for larger coupling capacitors

Coupling capacitors can significantly affect sound quality. For the TU-4523, we use high-quality conductive polymer electrolytic caps and polypropylene film caps. The maximum cap size to fit the space is 22mm in diameter x 44mm in length.

The kit is available in 2 versions. The TU-4523 uses the Elekit E & I output transformers, whereas the upgraded TU-4523VK uses the C-core LL3746 60mA Single-ended output transformer from Lundahl, a standard silicon-iron core.

Specifications:

Corresponding tubes

Voltage amplifying tube: 12AU7 (ECC82, 6189) x 2pcs
Output tube : 2 x 45 or 2 x 2A3
Circuit configurations: Stereo power amplifier
Output stage: Class A, Single-ended, Self-biasing
B-power: MOSFET ripple filter (Right and Left channel independent operation)
Max. output 2 x 2.5W (45 valve) or 2 x 4.5W (2A3 valve)
Output at 1% THD (8 ohm load, 1kHz) 2 x 1.5W (45 valve) or 2 x 3W (2A3 valve)
Rated input (with negative feedback) 660mV RMS (45 valve) or 800mV RMS (2A3 valve)
Voltage gain: 19dB (w/NFB) 27dB (w/NON-NFB) - (45 valve)
Voltage gain: 19dB (w/NFB) 26dB (w/NON-NFB) - (2A3 valve)
DF (8 ohm load, 1kHz) 6 (45 valve) or 8 (2A3 valve)
Frequency response (-3dB): 10 - 90000Hz
Input terminal: RCA jack, Stereo line no.1 (input resistance 50Kohm)
Speaker output: Binding terminal (Gold-plated, Banana plug compatible)
Headphone output: 3-pole standard jack (6.3mm)
Recommended speaker impedance: 6 -16 ohms (45 valve) or 4 to 16 ohm (2A3 valve)
Headphone impedance: 8-600ohm, unbalanced
Power voltage: 115Vac or 230Vac - select either upon asssembly)
Rated power consumption: 42W (45 valve) or 65W (2A3 valve)
Dimensions: W356 x H214 x D320mm (incl. projections)
Weight: Approx. 9.8Kg (assembled, excl. tubes and power cord)