A-1500 300B SE Stereo
High power output 12.5w + 12.5w 300B SE stereo power amplifier.
Almost other 300B amplifiers are underdriven or distorted- driven by conventional
"Resister-Capacitor" circuit which gives only up to around 70V swing voltage with
high distortion. This means prior distorted sound to deep biased 300B grid.
Our powerful "Inductor Drive" circuit gives up to 150V swing voltage with very low distortion,(about 0.3%) that's why A-1500 has higher output 12.5w + 12.5w.
Real power drive.
Our choke inductor (100% nickel permalloy PC core) has very low power loss and infinitely high load impedance. The driver tube 6GV8 has strong power pentode, we use this power pentode to drive 300B via choke plate inductor. This is one of the ideal drive stagesfor 300B SE.
"Full Engagement" Output Transformers
Conventional output transformers use pre-set secondary windings to accommodate 4, 8 and 16 ohm loudspeaker loads. However, these conventional transformers utilize only one secondary winding at a time, while the other secondary windings remain "idle".
This approach has two adverse effects. First, the output transformers are not working at their maximum efficiency, reducing their output relative to their potential.
Second, the "idle" windings are not actually "idle" they are subject to parasitic oscillations, producing their own "signal". This undesirable electrical information is additive to the transformer's output, distorting the amplified signal going to the loudspeaker.
Allnic's "Full Engagement" transformers address these issues by having 4 independent, secondary windings which are always fully connected, never "idled".
This means that all secondary windings are always connected to your loudspeakers, regardless of which output switch position you use (4 ohms or 8 ohms or 8 ohms or 16 ohms, depending on the factory configuration you have selected). The result is that there is neither a loss of transformer output efficiency, nor the introduction into the output signal of distortion from parasitic oscillations of the secondary windings.
Nickel alloy output transformer.
We use a sophisticated ratio mixed nickel permally PB cored output transformers.
Due to its extremely high initial permeability, it allows us lower turns of primary winding with still higher 'open circuit inductance', which means very wide frequency range and low distorted bass response. This is another reason why our A-1500 excelsother 300B power amplifiers.
Long life and trouble-free operation.
We employ the 'Soft start circuit' to protect tubes and other parts.
It applys high B+ voltage only after tubes are fully warmed-up.
Fixed bias control grid.
We prefer low distortion and high output 'Fixed Bias' to high distortion and lower output
Self Bias' method. We can get rid of those hot cathode resisters.
Natural negative feedback.
We apply about -6dB, a natural negative feedback to upgrade 300B single ended to main amplifier from hobby D.I.Y or sub system, due to its' colorful and weak speaker driving force. With this natural feedback, we can get high 'Damping Factor', very low distortion, higher S/N ratio without losing single ended natural sound.
We can show you how beautifully 20KHz square wave response reproduced.
- Output Power : 12.5w + 12.5w (8Ω load, at 1KHz)
- Distortion : 0.3% at 1KHz, 2.83V
- Frequency Response : 20Hz - 20KHz Flat
- S/N Ratio : -76dB(CCIR, 1KHz)
- Damping Factor : 3 at 8Ω load at 1KHz
- Voltage gain : +24dB
- Input Impedance : 100KΩ(unbalanced)
- Input Sensitivity : 0.7V for rated power
- Tubes : 300B X 2, 6GV8 X 2
- Dimensions : 430mm X 330mm X 240mm(W.D.H)
- Weight : 20Kg net.