Manley Jumbo Shrimp Preamplifier with Remote Control

Manley Jumbo Shrimp Preamplifier with Remote Control

           The Jumbo is a special Manley product consisting of a two-channel, single-ended line-level control preamplifier, five stereo inputs, and two paralleled stereo line outputs. Through a five-position input selector switch, the signal is routed straight to the control grid of the first amplifier tube. Amplified signals are then sent via a specific White-Follower stage to drive the high-quality ALPS stereo variable attenuator, which is noted for its consistency, high durability, ease of maintaining, and exceptional inter-channel level tracking attributes.

At all signal-coupling points in the circuit, high-quality polypropylene dielectric film-and-foil capacitors have been used, as well as two extravagant 30 microfarads metalized monsters linking the output stage signals to the output RCA connectors. 

           The uncomplicated non-inverting signal route is the JUMBO SHRIMP's defining characteristic. Most simply and directly, this basic signal route technique is designed to bring unbalanced RCA-type line inputs to appropriate levels for the proper operation of downstream power amplifiers. This is achieved by employing just three active stages, as mentioned above, and careful use of vacuum tubes, whose purpose-designed utility in audio amplification is exploited to the fullest extent possible. The Jumbo Shrimp are single-ended by nature, with balanced I/O with extra circuitry, transformers, or I.C.s that would color the sound. 

Features of Manley Jumbo Shrimp

1. VERY SHORT SIGNAL PATH WITH POWER GAIN  

           The incoming signal source is loaded to a minimum of 100,000 ohms in each of the JUMBO SHRIMP's five input jacks, while the output can safely give over 3 volts into a test load of 600 ohms. Even if the VOLTAGE gain is kept to no more than 12 dB when the volume attenuator is at maximum, this suggests a POWER gain of greater than 22dB. The JUMBO SHRIMP's two sets of output connections have been hard-wired in parallel for ease of routing output signals for unique applications like bi/tri amplification. For maximum performance, the combined load on the outputs is kept to a minimum of 1500 ohms or higher, or above 5000 ohms total.  

2. VOLUME AND BALANCE ATTENUATORS 

           The volume attenuator has two standard logarithmic-taper resistance tracks, with the remarkable difference that their matching is very excellent across the control's rotating range. This appealing feature of the ALPS attenuator set results in outstanding level balancing between channels when the command is modified, which is often a hassle with cheap dual potentiometers. A White-Follower buffer stage exists before the volume and balance attenuators, a perennial favorite. This not only lowers the first stage's output impedance, making it easier to drive the remainder of the unit, but it also lowers distortion and improves headroom. The gain profile of the JUMBO SHRIMP's gain blocks has been purposefully constructed so that setting the volume attenuator to the "12 o'clock" position would result in unity voltage gain via the preamp as an extra measure of level matching assurance.

 When the balancing attenuator is set to the center-detent setting, it has a specific track with zero resistance on either side of the center. Because there is no parasitic balance-control resistance to overcome while driving the attenuator network, the voltage amplification load of the first gain stage is reduced. The use of these controls is self-explanatory, but caution is advised if it is found that extreme control settings are necessary when operating the JUMBO SHRIMP with associated signal sources and power amplifiers. Under normal conditions, the balance control should be very close or in the center-detent position. Setting the balance control below "10 o'clock" or above "2 o'clock" shows that the system has an issue to be addressed. As a result, the volume control may be used to lower the volume of louder sources, such as CD players, or to boost the volume of quieter sources, such as older tube tuners or tape decks. The White-follower output amplifier stage buffers them before directing the volume and balance attenuator output signals to the output connections. This lowers the preamp's output impedance and prevents output loads from responding unexpectedly with the attenuators. 

3. PUSH-BUTTON MUTE SWITCH AND MUTE INDICATOR  

           The always-useful output MUTE function may be accessed by a mainly lit push-button feature switch. During warm-up cycles and regular operation, the switch's built-in bulb indicates the condition of the mute circuit, and as we all know, BLUE LEDs make gear sound better. The mute circuit is in charge of the mute relay, which has contacts set up to quench signals at the preamp's output. A blinking bulb signifies the start of a 30-second warm-up delay, during which the mute relay is closed, and no sound from the preamp is heard. The manual mute circuit is activated when the bulb remains steady, cutting signals from the outputs (shorting them to the ground, more precisely). Press the MUTE button to unmute the preamp. The mute relay will relax, the mute bulb will dim, and the output signals will be restored. The MUTE button operates in an alternating toggle mode, or "press-on, press-off" mode. Note that unless the preamp has been disconnected from the mains for more than a few seconds, the complete 30-second warm-up cycle will not fully recycle.  

4. MANLEY REMORA REMOTE CONTROLLED VOLUME 

           The Remora is a radio-frequency-based remote control that permits indefinitely resolvable regulation of listening levels by commanding the silicon-free, high-quality motorized VOLUME attenuator set. The Jumbo Shrimp's attenuator can be controlled from another neighboring room through walls, floors, doors, even opaque closets or cabinets, so there's no need to "aim" the remote in any manner.

Features of the Remote Remora

• A crystal-clocked microcontroller controls the remote transmitter and receiver for optimal signal selectivity, flexibility, and system range. 

• The user can simply reconfigure the user-number component of the serial I.D. data stream from the distant system. This eliminates the risk of unintended behavior caused by remote command clashes. 

• When the transmitter is in operation, a multi-color LED indicates battery status and also two-digit user-number programming status when it is in program mode. 

• Internal antennas assist in a streamlined design look and prevent the risk of harm if exposed to the elements while still offering enough range. 

• The transmitter is powered by a 9V battery that is widely available. 

• For durability, the transmitter shell is composed of strong Lexan®. 

• For years of consistent operation, real compression-dome push buttons are employed rather than short-lived conductive silicone membrane pads. 

• A high-quality motorized attenuator is used for the essential audio channel, with excellent inter-channel matching. 

• When the button is held for half a second, the attenuator motor starts to run at a slower pace, and after a few seconds, it rotates at double speed.

• The keep-alive period on the remote transmitter keeps the Remora Remote awake for a few seconds AFTER either button is released, as shown by the LED bulb flickering DIM green or red. 

• The backup battery is unnecessary as the transmitter and receiver-CPUs decoder includes flash memory.  

• As a result of the clever system architecture and user-programming method, dip-switches are no longer required. 

• The Remora Remote uses relatively little power, resulting in extended battery life. 

• The preamplifier's audio route has less noise because of its electrically quiet operation. 

The Manley Jumbo Shrimp is a fantastic music machine that will gratify any audiophile looking for a great amplifier. The vocals and instruments, both electrical and acoustical, are convincing and recognizable, and the tone is rich and realistic. The tone clarity is startling, and the odd and even order contour harmonics add color to the listening enjoyment. The macro is Immanent, present, and overwhelming. The dynamic pressure and sound impact are at their maximum levels. For detail and naturalness of emission, the micro is invaluable. As a result, the technical specifications of this preamplifier imply a high degree of adaptability to any power amplifier, tube, or transistor.