Some things are hard to improve on and that is especially true of the 1930s 300B valve. *Directly Heated Triodes are considered by many to be the pinnacle of audio quality. At Icon Audio we have used all our skills in order to build an amplifier that gets the best out of this venerable tube. Warm, transparent, satisfying. With 30 + 30 Watts of power available from 20 Hz to 20kHz this amplifier is sure to please the most demanding listener.
Western Electric designed the 300B to give a high quality, good output in cinema sound. In doing so they created a valve which in audio quality has never been bettered. Although primitive by today’s standards it has very low distortion and has very linear, properties which make ideal for the finest amplifiers. Because of this more care is need in designing the associated circuitry in order to remain sympathetic to its genre (don’t expect to see 300Bs in a budget or guitar amp).
The all-important high definition drive circuit for the 300B output valve is achieved by using the superb 6SN7 valves in “Cascode” mode. 6SN7s date from 1940 so fit in well the overall sonics. We feel the 6SN7 (CV181) has a more relaxed presentation than their miniature cousins, these larger driver valves are the best in their class for their musical sound and longer life. Try our new David Shaw types or choose from TJ/Full Music, SG Treasure, Psvane, Vintage USA/Russian types.
Good sensitivity from the built in “passive” pre-amp ensures good results from virtually any type of input.
The “easy bias” meter enables simple checking that the 300Bs are at optimum performance, the meter also gives an indication of the output power. Very useful when you may need to know if you are likely approach the maximum available power.
Input sensitivity is varied by changing the feedback this enables use of the amplifier without any feedback or using low sensitivity ideal for use with a separate pre-amplifier.
Partnering loudspeakers and source equipment needs to be done carefully. If there is a down side to 300B amplifiers it is that they are more revealing and will not “mask” deficiencies as much as other amplifiers.
The standard valves give excellent performance. But for those who may wish to use “premium” or the new Western Electric 300Bs and want to maximise the life of these valves, therefore on request we can supply the amplifier with a lower HT which will give a maximum of 21w per channel output.
Comprehensive manual supplied
Remote control: HQ ALPS motorised volume pot
All hand wired point to point
Pure Class A CV181/6SN7 driver stage
Output power 30W 8Ω
Large Choke regulated power supply
4x 300B output valve (AC heated)
4x 6SN7 (CV181) double triode
Signal to noise level -85db
Freq resp 20 – 20kHz -0.2 to –0.5dB (8w 6.25dB FB)
THD typically less than 0.05% 1khz (1w)
THD typically less than 0.2% 1khz (8w)
4 & 8 ohm loudspeaker taps
Low feedback design (0, 6.25, 15.2dB)
Switchable gain control giving 140, 300, 790mV input sensitivity
SCR audiophile caps, Jensen upgrade option
Silver plated copper PTFE audio cable
Tertiary winding output transformers
Gold plated Input & speaker terminals
Channel balance typically within 0.2dB
117/235 Volts 150W – 235W
C E, ROHS WEEE, FCC
Size 380mm wide 330mm deep 230mm high
Unpacked weight 26 kg
Typical values @ 240v AC