Unparalleled transparency
All-vacuum tube buffer preamplifier
All tube buffered preamplifier with 4x gain, low output impedance and very high transparency. 4 selectable inputs, relay-switched volume control with individual resistors, very well balanced. The PRE14B has a fully balanced configuration with two RCA phono inputs, two balanced XLR inputs, one RCA phono output, and one balanced XLR output. All amplifier stages are 100% vacuum tube configuration and OTL (output transformerless) design. No semiconductor components, transformers, or chokes are used in the audio chain.
Volume and input selection can be controlled by remote control.
Advanced stabilized power supplies (for anodes and heaters) provide very low levels of hum and noise.
The amplifier consists of three PCBs and the chassis is made of 10 mm aluminum, providing excellent mechanical stability and completely eliminating noise caused by vibration.
The PRE14 works very well with the PA3, PA12, and PA34 OTL power amplifiers, especially as the low distortion characteristics of the PA12 and PA34 require high demands on the preamplifier; the PRE14 achieves its goal and does not affect the clear sound of the PA12 or PA34. Of course, it is also the best choice for other applications where a very transparent preamp is needed.
The PRE14 uses Q-tron Audio's proprietary 64-step attenuator instead of a typical potentiometer for highly accurate and reliable volume control. While there are some good quality potentiometers on the market, our attenuator eliminates the channel-to-channel imbalance that potentiometers cause and provides better performance than any potentiometer.
This attenuator has 64 positions and allows adjustment in 1 dB steps. Each step is precisely switched using relays with gold-plated contacts, and the channel balance is accurate to within ±0.05 dB at any volume setting. It also boasts an extremely high accuracy of up to 0.02 dB, maximizing audio transparency and dynamics. This design allows for smooth and precise volume control, greatly enhancing the quality of the audio experience, making Q-tron Audio's 64-step attenuator the perfect choice for audiophiles seeking a level of precision and sound quality unattainable with conventional products.
Vacuum Tube | 6N6Pi x4, ECC82 x2 |
---|---|
Gain | 12dB (4x) |
Channel Balance | ±0.05dB |
Input impedance | 40kΩ |
Output impedance | 300Ω |
Harmonic distortion (THD) | < 0.001% at 1kHz, 1V output |
Frequency response | 5Hz ~ 100kHz (-1dB) |
Hum and Noise | < -100dBA at 1V output |
Volume control | 64 steps |
Input terminals | 2 gold-plated phono, 2 balanced XLR |
Output terminals | 1 gold-plated phono, 1 balanced XLR |
Dimensions | 430 x 110 x 370 mm, (W x H x D) |
Weight | 11.5 kg |
The preamplifier has a rather elaborate design, with the front panel consisting of a power switch on the left, a narrow-tipped knob in the middle and a small display window on the right. This custom-made knob is shared by the volume and input switch. The volume is a 64-step attenuator, and input switching is done by pushing in the knob to select one of the four inputs in sequence. In both cases, the selected input or volume level is displayed on the panel next to the knob. There are two balanced and two unbalanced inputs. Both unbalanced and balanced outputs are also provided. It is difficult to describe the sound quality of the preamplifiers, but the sound is firm, and even during fortissimo, the upper side of the sound is not suppressed at all. Even with complex sounds, each note was stable without any wavering, and I thought it had enough performance to be a high-end amplifier. It taught me that there are still things in the world that I do not know. *See "Radio Technology