COPLAND CTA504
¥ 380,000 (around 1994)
Commentary
XENA AUDIO tube type stereo power amplifier.
The power supply circuits are classified into seven systems, each of which is protected by high-quality film capacitors, and which suppress mutual interference even in the ultra-high frequency band.
The power supply section is equipped with a specially designed toroidal transformer of a lorry cage and a capacitor with sufficient pressure resistance margin.
To drive the output tube 6550A, a push-pull phase inversion circuit using two bi-triodes is adopted.
It uses a 4-mm gold-plated output terminal that can be used with banana plugs, and provides dedicated outputs for 4 Ω and 8 Ω speakers respectively.
A gold-plated RCA pin jack is used for the input terminal.
The output transformer uses an EI core made of directionally rolled super silicon steel sheet.
Especially, the coupling density between the primary and secondary windings is high, and a balance between characteristics and efficiency is maintained.
With a knob on the front panel of the hairline finish, you can switch between the A-class pentod connection and the triode connection.
The power cord uses a Verden shield type thick cord.
Model Rating
Type | Bulb-tube power amplifier |
Effective power | Pentod connected : 50W + 50W Triode connection : 26W + 26W |
Total harmonic distortion factor | 0.08% (1kHz/1W) or Less 1% (1kHz/50W) or less |
Frequency characteristic | 5 hz to 65 khz -3dB |
Output bandwidth | 8 Hz to 45 kHz -3dB |
Signal-to-noise ratio | 100 dB (IHF / Input Short) |
Input sensitivity | 1.5V |
Input impedance | 250k Ω |
Output impedance | 4 Ω or 8 Ω (Common Minus, Switched Plus Connection) |
Negative feedback | 16dB |
Input-output phase | Orthophase |
Vacuum tube used | Voltage Amplification and Phase Inversion : E83CCx5 pcs Power Amplifier : 6550WAx2 Set |
Power consumption | 185W (Electrical Appliance and Material Control Law) |
External dimensions | Width 430x Height 175x Depth 375 |
Weight | 25kg |