Al,
What can you decipher from the following specs?
Power amplifier
Output Configuration: Push Pull, advanced Pentode Mode, Grid 2 Voltage 300 V, Idle Current
Tubes 28 mA - BIAS Low, 34 mA - BIAS High. Negative Grid Voltage separately adjustable for
each Tube. Range: -16 to -40 V, 3 turn precision regulators.
Wideband Output Transformers using Silicon steel PMZ Core, single Impedance Output.
Optimum Load Impedance 3 - 16 ohms Nominal Speaker Impedance. Efficiency greater than 83
dB. Amplifier remains stable with No Load and Output short-circuited.
Output 2 x 70 W @ 4 ohms
Frequency response 20 Hz - 70 kHz @ 40 W -1 / - 3 dB
5 Hz - 70 kHz @ 10 W - 0 / - 2 dB
THD 0.1% at 10W @ 4 ohms
Signal-to-noise ratio -100 dB / 40 W
Output Noise less than 300μV
Optimal load impedance 3 - 16 ohms
Minimum load impedance 2 ohms
Gain 38 dB
NFB 10 dB
Tube set 4 x 6550 C
Quiescent current; output tubes 28 mA - BIAS Low, 34 mA - BIAS High
Preamplifier
Input sensitivity 180 mV Line Level Inputs
Input Impedance 50 k ohms
Crosstalk input to input - 105 dB
Output Impedance Pre Out 240 ohms
Channel Balance 0.5 dB to - 70 dB on volume control
Channel Separation 55 dB
Max. Level Pre Out 5 V RMS
Tube set 1 x ECC 83, 2 x ECC 81
A FAQ about Octave amp in general:
5. What is the significance of loudspeaker impedance and efficiency?
The impedance and efficiency of modern loudspeakers is not an issue for OCTAVE amplifiers.
The often-quoted damping factor is not normally a guarantee that an amplifier will exert tight
control over the loudspeakers. In practice, speakers of 85 dB efficiency and above are suitable
for use with tube amplifiers. The high stability of the OCTAVE power amplifier technology even
allows the use of speakers whose impedance dips as low as 2 ohms.
Ciao,
Audioquest4life