The transformer is manufactured at the Manley factory.
The phono stage is equipped with two MC inputs with impedance switching: 25, 50, 100, 200 and 400 ohms. The MM (Moving Magnet) pickup input also has impedance switching: 25, 50, 100, 200 Ohms and 47 kOhms. The capacitive load is switched between 0 and 1100 pF in 10 pF steps for all three inputs, MM and MC.
STEELHEAD is assembled on six tubes: 2 x 6922 plus 4 x 7044. The level of the output signal taken from the buffer stages on the tubes with low internal resistance can be fixed or adjustable. The output resistance is record low for tube devices that do not contain cathode repeaters (67 ohms). The gain is switched stepwise (without clicks in the speaker) in steps of 5 dB, the initial value is 50 dB. As a result, it is possible to use any MM and MC heads, which can have a significant difference in amplitude. By selecting the optimal R and C load for each head, it is not difficult to achieve equal characteristics of the signal amplification by the step-up transformer. In practice, the selection of input parameters can be reduced to the procedure of finding the positions of the switches at which the sound becomes the most pleasant and optimal in terms of volume level.
The gain factor of the phono-corrector is quite sufficient for MC heads with the lowest return. The device is equipped with a mute switch for quick mute. There is also a mute option ("Dim" switch), very useful when manipulating the tonearm. Another switch lets you switch from stereo to mono.
Stabilized power supply voltages are supplied from a massive external unit.
The "Retro" style is present both in the massive volume knob and in the engraved MANLEY STEELHEAD nameplate which is illuminated by a lamp. A row of blue LEDs brings us back to the present, reminding us that before us is a masterpiece of modern lamp technology.
The phono stage can be used as a high-quality tube preamplifier (there is an adjustable and non-adjustable output). It is equipped with a remote control.
Specifications
Tubes: 2 x 6922 SOVTEK (gain), 4 x 7044 or 5687 JAN NOS GE (output buffer);
Inputs: 5 x RCA;
Outputs: 2 x RCA
Gain factor: 18 dB;
Input resistance of the moving magnet pickup head: 25, 50, 100, 200 and 47,000 Ohms (switchable with a 5-step regulator);
Input resistance of the moving coil pickup head: 25, 50, 100, 200 and 400 Ohms (can be switched with a 5-step regulator)
Input inductance: adjustable in steps of 10 pF;
Gain factor: 50, 55, 60 and 65 dB (4-step regulator);
Deviation from the RIAA curve: <+0.5 dB / -0.3 dB (20 – 20,000 Hz at any gain setting), typically <+/- 1 dB (10 – 100,000 Hz);
Phase shift between channels: <4 ° (20 – 20,000 Hz at any gain setting);
Difference in gain between channels: <+/- 0.5 dB (20 – 20,000 Hz at any gain setting);
Dynamic range: 101 dB (1 kHz at 1% harmonic distortion);
Fixed output resistance: 150 Ohms (minimum load over 1,500 Ohms);
Adjustable output resistance: 75 Ohms (minimum load above 600 Ohms);
Harmonic distortion coefficient: 0.0042% (1,000 Hz);
Power: 100 W;
Dimensions (h x w x d): 89 x 483 x 394 mm (phono corrector), 114 x 343 x 289 mm (power supply unit);
Weight: 6.81 kg (phono corrector), 8.17 kg (power supply unit).
In the MM path, the input step-up transformer is not used.
Three connectors of the grounding wire allow you to ground the tonearm, the shaft of the record player to the body of the device, or to organize the grounding in such a way as to achieve a minimum background in each specific path.
The elements of the RIAA corrector are assembled on a separate printed circuit board.
Transient MultiCap capacitors in signal circuits.