The Qualiton 300B integrated amplifier runs 4x 300Bs in parallel single-ended Class A for a total of 25 Watts per channel.
The driver and preamp stages rely on a pair of 12AX7s and 2x 12AT7s per side. All tubes are from Electro-Harmonix. Inside reside custom power and output transformers designed and built in-house.
The Qualiton 300B amp employs an automatic bias system (so you don’t have to). From Qualiton:
This circuit continuously monitors the behavior of each tube and regulates the bias voltages accordingly, ensuring the smallest possible output voltage noise while guaranteeing the highest degree of linearity of the output stage. Additionally, it prevents the sensitive, high-permeability output transformer cores from saturating by precisely equalizing the quiescent currents of the power tubes.
The spartan front panel houses a multi-function knob for on/standby mode, input selection, and volume control along with a scratch-resistant smoked plexiglass display which shows power status, volume level, input, and display brightness level. The included remote offers these same functions as the multi-function knob and adds Mute and Display Brightness Level. The relay-controlled volume uses a 100-step relay-controlled stereo attenuator featuring 25 microprocessor-controlled signal relays that switch a total of 48 precision metal film resistors.
Around back reside a total of 5 inputs (1x XLR, 4x RCA), Sub Out, a pair of speaker outputs with 4 and 8 Ohms options, an IEC inlet, and power switch.
Here’s a bit more from Qualiton:
At Qualiton, we adhere to a pragmatic approach in tube amplifier design. We believe that a truly exceptional amplifier should:
- Be compatible with a wide range of loudspeakers.
- Exhibit a Total Harmonic Distortion (THD) of less than 0.5% across the entire power spectrum, from milliwatts to rated power, spanning 20 Hz to 20 kHz.
- Maintain a flat THD vs. Frequency plot when measured at a fixed output power.
- Deliver fast and controlled transients throughout the audio range, which goes hand in hand with the frequency response being wide and flat.
- Operate at low noise levels with an exceptional signal-to-noise ratio.
- Combine thoughtful design, robust technical parameters, and exceptional sound quality.
In the preamplifier and driver sections, the 12AX7 and 12AT7 tubes play a crucial role in achieving these goals. Furthermore, their DC-stabilized filament supply and circuits with low offset and stable DC operating points ensure resilience against parameter variations.
The rest of the bigger review picture includes some appropriate speakers coming in (and more)…stay tuned!
Qualiton 300B Integrated Amplifier
Price: $11,000
Company Website: Qualiton
US Distributor Website: Well Pleased A/V
Specifications
Electrical
Rated Output Power: 2 x 25 Watts @ 4 or 8 Ohms
Output Load Impedance: 4 or 8 Ohms
Number of Channels: 2
Frequency Response: 5 Hz – 85 kHz (-3 dB, 1 Watt) |15 Hz – 70 kHz (-3 dB, 25 Watts)
Total Harmonic Distortion: < 0.5 % across the entire power spectrum, from milliwatts to rated output, spanning 20 Hz to 20 kHz.
Rated Power Bandwidth: 20 Hz – 20 kHz
Signal-to-Noise Ratio: > 105 dB below rated output | 20 Hz – 22 kHz bandwidth, without weighting filter > 110 dB below rated output
with A-weighting filter
Number of Outputs: 2 Unbalanced POWER OUT, 1 Unbalanced SUB OUT
Number of Inputs: 4 Unbalanced STEREO IN, 1 Balanced STEREO IN
Input Sensitivity (for rated output): 0.65 Volts Unbalanced | 0.65 Volts Balanced
Input Impedance: 10 000 Ohms Unbalanced | 20 000 Ohms Balanced
Gain: +23.75 dB @ 4 Ohms | +26.75 dB @ 8 Ohms
General
Vacuum Tubes: 2 x 12AX7EH Gold, 4 x 12AT7EH Gol, 4 x 300B EH
Remote Control: Stand-By, Volume, Mute, Input Selection, Status Display Brightness
Power Requirement: 200 W idle | 460 W max | 1 W stand-by
Weight: 28 kg
Dimensions: 42.5 x 50 x 21 cm