MANLEY LABORATORIES, INC. OWNER'S MANUAL MANLEY STEELHEAD Version 2 MM/MC GRAMOPHONE CARTRIDGE PREAMPLIFIER MANLEY LABORATORIES, INC 13880 MAGNOLIA AVE. CHINO, CA. 91710 TEL: (909) 627-4256 FAX: (909) 628-2482 emanley@manleylabs.com http://www.manleylabs.com Rev.
CONTENTS SECTION PAGE INTRODUCTION 3 INSTALLATION PRECAUTIONS 4 FEATURES AND APPLICATIONS 5 OPERATIONAL NOTES 9 TROUBLESHOOTING 12 SPECIFICATIONS 14 WARRANTY 15 WARRANTY REGISTRATION 16
INTRODUCTION THANK YOU!... ...for choosing The MANLEY STEELHEAD phono preamplifier. Please read over this manual carefully as it contains information essential to the proper operation and maximum enjoyment of this fabulous instrument. The MANLEY STEELHEAD is designed to provide that rare combination of maximized sonic performance coupled with a generous ability to adapt to any moving magnet, moving coil or iron vane phono cartridge you may wish to use.
INSTALLATION PRECAUTIONS a) Avoid locating the preamp where it will be exposed to direct sunlight, excessive humidity, dust or moisture. Extreme environments may temporarily or permanently degrade preamp performance. b) Keep the preamp housing away from sources of strong magnetic field radiation, such as large video display CRTs, large power lines or power/audio transformers in nearby equipment. Extra measures have been taken to shield the magnetically sensitive bits inside the preamp housing.
FEATURES AND APPLICATIONS 1. HIGH PERFORMANCE FRONT END The STEELHEAD preamplifier makes the best use of active and passive component and circuit developments generated over the past half-century. The hybrid cascode gain blocks simultaneously deliver wide-band high-gain, low noise and low distortion performance without having to resort to heavy-handed amounts of negative feedback. Or overly complex circuit topology.
3. SWITCH-SELECTABLE CARTRIDGE LOAD IMPEDANCE An effective means of varying the load seen by the MC cartridge has been included in the form of a 5-position rotary switch. This switch selects various taps on a specially manufactured dual-primary bi-filar wound, high-bandwidth low-resistance and multiple-shielded nickel-core step-up autoformer.
Each cartridge manufacturer’s product will work best in a laboratory sense when terminated (loaded) with a certain amount of resistance and capacitance. By lab sense it is meant that the signal developed by the cartridge is at maximum power transfer into the pre-amp, with minimum overshoot and ringing, flattest frequency response and gentle roll-off characteristics. But it is those settings that create the most musically satisfying results for you that are of uppermost importance.
7. LINE INPUT SELECT BUTTON The LINE switch routes external line level signals to the top of the feature switch stack, and through the VOLUME control. In this way, an external signal source may be manipulated by the SUM, DIM and MUTE switches, along with the volume control, before transmission to any downstream power amplifiers. Notice here that the Steelhead’s VARIable internal line driver does not have any voltage gain, but does have power gain by virtue of its low output impedance.
OPERATIONAL NOTES VOLUME U M M M INPUT TE C M D MANLEY STEELHEAD 1 IM C M 2 GAIN dB 9 0 10 25 50 55 60 65 1 7 3 8 2 6 8 2 1 9 0 10 100 LOAD CAP pF x100 20 0 4 5 x10 4 6 7 3 1 9 0 10 5 6 7 3 8 2 E N LI 7 3 5 M 50 4 SU x10 6 400 5 MC LOAD Z, ohms LOAD CAP pF x100 4 8 2 1 9 0 10 SLEEP PREPARATION FOR INSTALLATION Budget a suitable space in which to place the preamplifier, power supply and associated interconnect cable.
The winking MUTE lamp indicates the beginning of a 30 second warm-up mute delay, during which time the muting relay is engaged; no output will be heard from the preamp. DURING OPERATION Once audio is heard from the STEELHEAD the exploration for the ideal control settings can begin. However it would be best to allow about 15 minutes of warm-up time for the system to reach thermal equilibrium.
Let the preamp tube(s) cool down, if necessary, before handling. Tube heater filaments are somewhat more suceptable to damage when warm or hot. Each tube should require only moderate force for removal and replacement. Gently rock the tube back and forth a bit during removal or replacement. Avoid bending the circuit board. Notice that the heaters of the 6922s are connected in series, and neither channel will function if one of the filaments is open or burned out, or unless both of the 6922s are installed.
TROUBLESHOOTING The STEELHEAD’s system architecture is designed with a variety of features so as to allow flexibility in accommodating as many cartridges and as much downstream gear as possible. Access to these capabilities rest on the assumption that all STEELHEAD systems are functioning properly. If trouble is encountered please review the following short list of symptoms and corrective remedies before contacting your dealer or us. Symptom Possible Cause Corrective Action NO lights, power.
Symptom Possible Cause Lights ON, no output either channel after warm up delay times out. Open 6922 filament, either channel. 6922 unplugged. Check for glowing 6922 filaments. Replace if necessary. Output MUTE function activated. UnMUTE the preamp. Input connectors are nonshorting. Avoid unused inputs; install shorting plugs. Hum heard on unused MM or MC inputs. Corrective Action, cont’d Hum heard on active inputs. Ground link between CHASSYS and CIRCUIT open.
SPECIFICATIONS Vacuum tube compliment: 6922 x 2 (gain) plus 7044 x 4 (output buffers) Fuse type and ratings: 117 VAC: 1.5 Amp 3AG slow-blow main 0.5 Amp 3AG slow-blow logic 234 VAC: 0.75 Amp 3AG slow-blow main 0.25 Amp 3AG slow-blow logic Moving Magnet input impedance: 5-step user adjustable via fixed low-noise resistors. 25, 50, 100, 200 and 47000 ohms. Moving Coil input impedance: 5-step user adjustable via multi-tap autoformer: 25, 50, 100, 200 and 400 ohms.
WARRANTY All Manley Laboratories equipment is covered by a limited warranty against defects in materials and workmanship for a period of 90 days from date of purchase to the original purchaser only. A further optional limited 5 year transferrable warranty is available upon proper registration of ownership within 30 days of date of first purchase.
WARRANTY REGISTRATION We ask, grovel and beg that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO, CA. 91710 USA Or you may FAX this form in to: +1 (909) 628-2482 or you may fill in the online warranty registration form found in the Tech Support section of our website www.manleylabs.
