MANLEY LABORATORIES, INC. OWNER'S MANUAL THE 300B PREAMPLIFIER MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. 91710 TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley@netcom.com http://www.manleylabs.
CONTENTS SECTION PAGE INTRODUCTION 3 MAINS CONNECTIONS 4 CONNECTING YOUR PREAMPLIFIER 5 FIGURE 1 FRONTPANEL 6 FIGURE 2 TOP PANEL 7 FIGURE 3 BACK PANEL 8 OPERATIONAL NOTES 9 SPECIFICATIONS 10 WARRANTY 11 WARRANTY REGISTRATION 12
INTRODUCTION THANK YOU!... for choosing the Manley Laboratories "The 300B Preamplifier". Designed by David Manley, the 300B Preamplifier uses the best available parts with the shortest, cleanest, signal path possible. This Preamp features the 300B direct heated triode as the line and headphone driver. The 300B is typically used in low power amplifiers as the only power tube.
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 panel. Check that this complies with your local supply. Export units for certain markets have a moulded 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.
CONNECTING YOUR PREAMPLIFIER Setting up your preamplifier is rather easy. 1. Please refer to page 8 diagram 3 for an illustration of the back of the preamplifier. 2. There are two pairs of UNBALANCED RCA main outputs electically identical. Connect either (or both for bi-amping) of the RCA outputs to the input of your amplifier as required. 3. UNBALANCED inputs are found on RCA jack inputs and can be connected to any line level sources such as CD players, tuners or tape decks. 4.
INPUT SELECT VOLUME AUX HEADPHONES CD ON LINE OUTPUT TAPE TUNER OFF HEADPHONES VIDEO A B C D E F A - INPUT SELECT - 5 Position switch for input selection. Each input is electrically identical. The RECORD OUT directly follows this switch. There is no buffer amp to isolate the effects of loading and cable capacitance so we recommend disconnecting any interconnect cables from the RECORD OUT if you are not recording.
TOP VIEW REGULATOR RECTIFIER 0D3 5AR4 CAUTION! TUBES RUN HOT - DO NOT TOUCH TUBES DO NOT OPEN CHASSIS - HIGH VOLTAGES ! REFER SERVICING TO QUALIFIED TECHNICIANS 300 OHM - 4000 OHM A HEADPHONE IMPEDANCE 0D3 POWER SEQUENCE : ALLOW SEVERAL MINUTES FOR WARM-UP TURN ON SOURCES FIRST, THEN PREAMP, THEN AMPLIFIERS TURN OFF AMPLIFIERS FIRST, THEN PREAMP, THEN SOURCES 5AR4 NOTE - PIN SIZE FOR PROPER ORIENTATION 30 OHM - 400 OHM LINE DRIVER (TO AMPS & SPEAKERS) LINE OUTPUT B OUTPUT MODE 300B 300B LE
REAR PANEL A B C D E F G H I J A - MAINS FUSE - Replace with 2A SLO-BLO fuse only. B - IEC MAINS SOCKET - Standard IEC mains socket (120/240 VAC as indicated) C - LINE OUTPUTS - Main left and right outputs driven by 300B's. Connect these to your power amplifier inputs when the amps are off. These 2 pairs of outputs are electrically identical and a bi-amp set-up is one application. D - RECORD OUTPUT - Set at input line stage level. These normally are connected to a tape recorders inputs.
OPERATIONAL NOTES SWITCHING ON The power switch is located on the right hand corner of the front panel. Flip the switch up to turn on the preamplifier and down to turn off the preamplifier. RUNNING It is not recommended that you leave your preamplifier permanently switched on. This only wastes electricity and tube life. Your preamplifier has both tube and solid state rectification and reaches peak operating condition in approximately 30 minutes. TUBE LIFE As with all tubes, their quality degrades with age.
SPECIFICATIONS Vacuum Tubes: Lamp type Fuse type 120VAC operation: 220VAC operation: 2 x 300B, 2 x 6SL7GT 2 x 5AR4, 2 x OD3 1/4 X 1 1/4, 12 volt, .15 amp MDL2, 2 AMP / 250 Volt MDL1, 1 AMP / 250 Volt SLO-BLO Gain 18 dB at max Volume 1 volt in = 8 volts out Noise Floor Signal to noise typically -70 dB 1Hz - 100 kHz typically 105 dB A WGT 20-20K Frequency Response 5 Hz to 50 kHz @ +/- 1 dB Distortion THD+N = -80 dB (.
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 this form in to: 909-628-2482 Registration entitles you to product support, full warranty benefits, and notice of product enhancements and upgrades. You MUST complete and return the following to validate your warranty and registration. Thank you again for choosing Manley Laboratories.