Manley Labs 300B owner manual TOP View

Page 7

 

TOP VIEW

REGULATOR

RECTIFIER

0D3

5AR4

A

B

300 OHM - 4000 OHM

 

CAUTION! TUBES RUN HOT - DO NOT TOUCH TUBES

 

DO NOT OPEN CHASSIS - HIGH VOLTAGES !

 

 

REFER SERVICING TO QUALIFIED TECHNICIANS

HEADPHONE

0D3

POWER SEQUENCE : ALLOW SEVERAL MINUTES FOR WARM-UP

IMPEDANCE

TURN ON SOURCES FIRST, THEN PREAMP, THEN AMPLIFIERS

TURN OFF AMPLIFIERS FIRST, THEN PREAMP, THEN SOURCES

30 OHM - 400 OHM

(TO AMPS & SPEAKERS)

LINE OUTPUT

OUTPUT

MODE

HEADPHONES (MUTES LINE OP)

THE 300B PREAMPLIFIER

ALL TRIODE VACUUM TUBE AUDIO PATH

TUBE RECTIFICATION AND REGULATION

AUDIOPHILE 2dB STEPPED

ATTENUATORS

DESIGNED BY DAVID MANLEY

HANDCRAFTED IN CHINO, CALIFORNIA

5AR4

 

NOTE - PIN SIZE FOR

 

PROPER ORIENTATION

 

LINE

 

DRIVER

300B

300B

LEFT

RIGHT

PREAMP

6SL7GT6SL7GT

A - HEADPHONE IMPEDANCE - You should set this switch to best match your headphones. You may have to look at the specification sheet to get the value in ohms. If using two sets of phones divide that number in 2. If you don't have this info then pick the setting that sounds best - no harm will be done. If the phones are lower than the switch setting, slight loss of extreme highs may occur. Expect the 300 ohm - 4000 ohm setting to be louder. Electronically, we are simply either using the two transformer output windings in series or parallel.

B - OUTPUT MODE - Determines whether the output signals go to the back panel RCA output jacks or to the headphone jacks. In HEADPHONES mode the main outputs are muted - In LINE OUTPUT mode the headphones are muted.

TUBE LOCATIONS - See the diagram above for the proper tube locations. The 300B's are not installed during shipping to prevent damage to these tubes. Power should be unplugged and the tubes cool before handling them. We label the tubes and sockets to help and so that the calibration we do will be valid in your home. It is possible to put the 300B's in wrong. Note the two large pins and the two small pins on the base of the tube. The two large pins go into the two large holes in each tube socket.

Calibration ? Internally there is a trimmer for each channel to set gain. We set each channel for 18 dB of voltage gain (1V in = 8 Vout ). The trimmer adjusts feedback from 5 dB to 10 dB and ensures consistancy between channels and unit to unit. This amount of feedback can be considered minimal.

Image 7
Contents Manley Contents Thank YOU IntroductionBrown Live Mains ConnectionsConnecting Your Preamplifier AB C DEF TOP View Rear Panel C D E F G H I JOperational Notes Switching onSLO-BLO SpecificationsWarranty Warrantyregistration
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300B specifications

Manley Labs 300B is a high-fidelity tube amplifier that has gained a reputation among audiophiles for its exceptional sound quality and craftsmanship. This amplifier is named after its use of the 300B vacuum tube, a component famous for producing a warm, rich sound that is both detailed and engaging. The Manley Labs 300B amplifier has become a reference point for those who appreciate the artistic qualities of sound reproduction.

One of the key features of the Manley Labs 300B is its fully balanced design, which helps to minimize noise and distortion. This design approach allows for greater dynamic range and clarity in the audio signal. The use of premium components throughout the circuit further enhances performance, ensuring that every note is rendered accurately and with depth.

In terms of power, the Manley Labs 300B delivers 8 watts per channel in a class A operation, which is a hallmark of high-end audio equipment. While this may seem modest by modern standards, the quality of sound produced is often more important than sheer wattage. The 300B’s output stage offers a creamy and dynamic sound, excelling particularly with vocal and instrumental music, where it conveys subtle details with remarkable fidelity.

Another significant aspect of this amplifier is its flexibility in terms of speaker compatibility. It is designed to drive a variety of speakers, making it a versatile choice for different listening environments. The Manley 300B supports both 4 and 8-ohm output impedance settings, allowing users to match it to their favorite loudspeakers for optimal performance.

Additionally, the amplifier's construction is noteworthy. It features a robust chassis that not only reduces resonance but also adds to the overall durability of the unit. The hand-built nature of the Manley Labs 300B ensures that each piece is crafted with meticulous attention to detail and quality.

The Manley Labs 300B also comes equipped with a rich array of features, including an input selector, volume control, and high-quality binding posts for speaker connections. These components are not just functional; they also reflect Manley’s commitment to providing a user-friendly and high-performance experience.

In summary, the Manley Labs 300B is a sophisticated and beautifully crafted tube amplifier that offers a level of sonic performance that is hard to match. Its combination of high-quality components, thoughtful design, and powerful performance make it a standout choice for audiophiles seeking a true musical experience. Whether used in a dedicated listening room or as part of a larger audio setup, the Manley Labs 300B delivers a sound that is both engaging and lifelike.