MANLEY LABORATORIES, INC. OWNER'S MANUAL MANLEY LABS MONO & DUAL MONO MICROPHONE PREAMPLIFIERS MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. USA TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley@netcom.com http://www.manleylabs.com REV.
CONTENTS SECTION PAGE INTRODUCTION 3 MAINS CONNECTIONS 4 BASICS 5 CONNECTING YOUR PREAMPLIFIER 6 OPERATION NOTES 8 FRONT PANEL 9 REAR PANEL 10 SPECIFICATIONS 11 TUBE AND PARTS LAYOUT 12 TROUBLESHOOTING 13 WARRANTY 15 WARRANTY REGISTRATION 16 APPENDIX 1 : TEMPLATE for STORING SETTINGS (17) APPENDIX 2 : WIRING YOUR OWN CABLES (18) 2
INTRODUCTION THANK YOU!... for choosing the Manley Laboratories Microphone Preamplifier. We use this manual for both the MONO and DUAL MONO versions. They are identical except the DUAL has two of everything. These are all-tube Microphone Preamplifiers chock full of nice audiophile parts that combine flat frequency response, very high headroom, low noise, and low distortion with a big rich beefy sound. We wind the input and output transformers right here at Manley Labs.
MAINS CONNECTIONS Your preamplifier has been factory set to the correct mains voltage for your country. The voltage setting is marked on the serial badge, located on the rear or side panel. Check that this complies with your local mains supply. Export units for certain markets have a molded mains plug fitted to comply with local requirements. If your unit does not have a plug fitted the coloured wires should be connected to the appropriate plug terminals in accordance with the following code.
BASICS This Microphone Preamp, like most mic preamps, is pretty easy to use. First we can discuss why outboard mic pre's have become "a must have item" in almost every studio even though your console probably has a bunch of them and that manufacturer claims that they are really great and you don't need outboard mic pre's. Then, why is everybody buying them, using them, and why are most people going back to tubes? Good question.
CONNECTING YOUR PREAMPLIFIER There are two inputs and two outputs for each channel on the Mic Preamplifier. You generally only have to use one input and one output per channel. On the back panel are female XLR's labelled MIC INPUT A and MIC INPUT B. The signal from the MICROPHONES get plugged in here. There are a few warnings and suggestions. These connectors also "send" PHANTOM POWER to the mics. Some mics can be damaged by the 48 volts of phantom power.
This Mic Pre also has two outputs for each channel. One is balanced and one unbalanced. The XLR is a true transformer balanced output. The 1/4" mono (tip -sleeve) jack is unbalanced and gets its signal before the transformer.
OPERATIONAL NOTES SWITCHING ON Allow this unit a few minutes for the tubes to warm up before use. It is not recommended that you leave your preamplifier permanently switched on. This only wastes electricity and tube life. Your preamplifier has solid state rectification and reaches peak operating condition in approximately 30 minutes. TUBE LIFE As with all tubes, their quality degrades with age. This is due to cathode emission, a natural process found in all tubes.
FRONT PANEL 40 CHANNEL A 48V ON • 45 • 50 CHANNEL B IN DIRECT DIRECT PHANTOM INPUT ATTENUATE A B C MANLEY IN 180º 180º PHANTOM POWER 48V ON 0º 0º INPUT ATTENUATE D E F G H I J DUAL MONO MICROPHONE PREAMPLIFIER DESIGNED BY DAVID MANLEY HANDCRAFTED IN CHINO, CALIFORNIA K L M A LED PHANTOM INDICATOR Illuminates when 48V phantom power switch is activated on channel A. B PHANTOM SWITCH PULL TO SWITCH.
REAR PANEL FUSE 1 AMP SLO-BLO CIRCUIT UNBALANCED OUTPUT B UNBALANCED OUTPUT A CHASSIS A B C D E F G H A IEC MAINS SOCKET Standard IEC mains socket (120/240 VAC) B FUSE HOLDER C I Replace with 1A SLO-BLO fuse only. GROUND TERMINALS Separate CIRCUIT GROUND AND CHASSIS GROUND normally joined together. Used for finding and fixing hum.
SPECIFICATIONS Vacuum Tubes: 1 x 12AX7LPS, 1 x 6414 per channel Frequency Response 20 Hz - 60 KHz ( +/- 1 dB) THD .05% Signal to Noise Ratio 80 dB or better typical depends on settings and tubes Maximum Output +32 dBv ( 70 volts RMS ! ) +15 dBm into 600 Ω Maximum Input 450 mV with maximum gain settings. The Input Attenuator is before the tubes so normal maximum input is much higher.
TROUBLE-SHOOTING NO POWER, NO INDICATORS, NADA - Probably something to do with AC power. Is it plugged in? Murphy's Law. Check the fuse on the back panel. A blown fuse often looks blackened inside or the little wire inside looks broken. A very blackened fuse is a big hint that a short occured. Try replacing the fuse with a good one of the same value and size. If it blows too then prepare to send the unit back to the dealer or factory for repair.
HUM - Let's assume it knows the words. Once again - several possibilities - several cures. Most likely it is a ground loop. The two most common procedures are: try a 3 pin to 2 pin AC adapter (about a dollar at the hardware store) which is better than messing up the power cable by bending the ground pin until it breaks off. Method two - cutting the shield on one side of the cable (PIN 1). This is done by some studios at every female XLR to "break" all loops. You may get a loop simply from the rack.
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 warranty is available to the original purchaser upon proper registration of ownership within 30 days of date of first purchase.
WARRANTY REGISTRATION We ask that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO CA, 91710 or you may FAX IT to (909) 628-2482 There is also on-line registration in the Tech Support Section of our website www.manleylabs.com Registration entitles you to product support, full warranty benefits, and notice of product enhancements and upgrades.