This product is a hybrid preamplifier combining vacuum tubes and operational amplifiers.
The operational amplifier in the pre-amplifier stage adjusts volume and tone, while the vacuum tube in the post-amplifier stage adds harmonic components. By utilizing the strengths of both vacuum tubes and operational amplifiers, you can enjoy the unique sound of vacuum tubes without unpleasant distortion, even at maximum volume.
Furthermore, while incorporating highly regarded audio-grade components throughout, it is offered at an affordable price, making it suitable for serious audio applications.
Renewed to the 4th production lot from December 11, 2024:
* Input/output coupling capacitors changed to TDK EPCOS MKT capacitors.
These capacitors are characterized by their high-resolution sound quality, offering a gentle and warm tone without the harshness that can lead to listening fatigue, thus enhancing the sound quality of the vacuum tubes.
* Other minor component changes.
There are no changes to the main board circuit in this update.
[How to Use]
Please use this product between the output of your audio playback device (such as a CD player, DAC, or silicon player) and your power amplifier. INPUT: Connects to analog output terminals of CD players, DACs, etc.
OUTPUT: Connects to analog input terminals of power amplifiers, main amplifiers, etc.
【Product Features】
■6K4 Vacuum Tube as Standard Included
While the TUBE-03J used the 6J1 military-grade vacuum tube as its included tube, the 6J1 is now difficult to obtain, so the TUBE-03J+ uses the 6K4 as standard.
The design itself is based on the 6J1 and has been adjusted to work without problems with the 6K4, but to experience its full potential, we recommend the 6J1 (sold separately).
This doesn't mean the 6K4 is bad; it's just a difference in sound characteristics, so trying out your preferred vacuum tube is one of the joys of the TUBE-03J+.
■Hybrid Preamplifier with Vacuum Tubes and Op-Amps
The pre-stage buffer and tone control sections utilize the Texas Instruments audio-grade op-amp "NE5532" (DIP socket type), which has a reputation for excellent sound quality!
The subsequent stage features a hybrid configuration of vacuum tube and operational amplifier circuits, leveraging the strengths of both to deliver high-resolution sound quality with depth and richness.
■ Tone Control Function (Tone Direct Function)
■ Gain Setting Function
Two-stage gain setting (High/Low) is possible via the DIP switch on the back of the unit.
■ Power Transistor Active Filter Circuit
■ Carefully Selected Components
■ Improved Characteristics Through Revised Artwork
■ Full-fledged Operation Even with DC12V, and Complete Noise Reduction Through Voltage Boost
【Caution】
*AC adapter sold separately. Please purchase the recommended AC adapter at the same time.
*This unit is a preamplifier. A separate power amplifier is required to connect to passive type speakers (without built-in amplifiers).
【Product Specifications】 Brand: FX-AUDIO-
Product Warranty Period: 6 months from the date of purchase
Input Terminal: Stereo RCA terminal
Output Terminal: Stereo RCA terminal
Functions: Tone control function (BASS/TREBLE), Gain setting function (High/Low), Tone direct function
Power Supply: Rated voltage DC12V, Power capacity 1A or more (AC adapter sold separately)
Power Connector: DC jack, outer diameter 5.5mm, inner diameter 2.1mm (center positive)
Accessories: Instruction manual, 2 x 6K4 vacuum tubes (types will be one of the following pairs: Shuguang, Beijing, or Shanghai; selection is not possible)
Dimensions: Height 33mm (maximum 76mm including vacuum tubes) x Width 98mm x Depth 118mm (excluding protrusions)
Weight: 318g (with included vacuum tubes installed)
*Specifications and design may change without notice due to improvements, etc.
Op-amp & vacuum tube hybrid preamplifier
Uses a 6K4 vacuum tube as standard, with a two-stage gain setting function (High/Low)
Tone control function (Tone Direct function)
Equipped with a power transistor-based active filter circuit
AC adapter required (sold separately) DC12V/1A DC jack 5.5mm x 2.1mm (center positive)