Eroica Almighty-55
¥ 59,000 (around the mid 1960 s?)
Commentary
Eroica bulb integrated amplifier.
Aiming for the world's highest frequency characteristics, we have achieved total pre-main characteristics of 10 Hz to 50 kHz ± 1 dB.
Five 12AX7s are used in the preamplifier section, all of which is composed of an NF loop. Even if an input of 30 dB or more is input to the phono terminal or the like, the output of the preamplifier has the same distortion as when the rated input is input.
Except for the output tube 6L6GC, printed circuit boards are used for all products to eliminate unevenness.
NF-type tone control has been adopted, and the previous stage is 2-stage NF-type and the input impedance is high and the output impedance is low.
The equalizer uses a CR type to keep the distortion constant from low to high frequencies.
A 2-stage NF circuit is installed in front of the CR equalizer and the output impedance is lowered to obtain sufficient output voltage.
All five vacuum tubes of the preamplifier section are DC ignited by four silicon diodes to prevent heater hum.
In addition, a shield plate is used to prevent guide hum.
The transformer was designed jointly with tamura.
Power amplifier and control amplifier can be used independently.
It is equipped with headphone terminal and tape monitor circuit.
Model Rating
| Type | Integrated amplifier |
| Undistorted maximum output | 27W+27W |
| Frequency characteristic | 10 Hz to 50 kHz ± 1 dB |
| Input sensitivity | phono:3mV tape head:1.7mV Aux, tuner : 100 mV |
| Distortion factor | 0.35% or Less (at 10W) |
| Signal-to-noise ratio | 94dB |
| Output impedance | 4 Ω, 8 Ω, 16 Ω |
| Tone control | 50 Hz : + 13 dB to -15dB 10 kHz : + 12 dB to -15dB |
| Accessory circuit | Tape monitor DIN terminal Headphone jack Tuner level set Body earth terminal Tape equalizer switching (19cm/s, 9.5cm/s) |
| Vacuum tube used | 12AX7 : 5 pieces 12AT7 : 3 Pieces 6L6GC : 4 pcs DS-1M : 2 FR-1P : 4 |
| External dimensions | Width 460x Height 170x Depth 300 mm |
| Weight | 14kg |