BACKERT LABS RHUMBA 1.4 LINESTAGE TUBE PREAMPLIFIER
The Rhumba 1.4 is our most surprising tube preamplifier. Fully balanced input and output. Jaw-dropping sound.
“The Rhumba 1.3 is a fantastic preamplifier – period.”
”The most exciting aspect of the Rhumba is the lively, dynamic aspect of its sound.”
The Rhumba 1.4 has the following new features:
two fully-balanced XLR inputs, rather than just one.
two fully-balanced XLR outputs, rather than just one.
improved circuit developments in the regulator portion of the power supply, which provides a larger soundstage.
improved circuit design in the gain stage, which provides a higher-resolution, more 3-dimensional listening experience.
improved stock tubes, which are NOS American-made tubes that are bursting with resolution and dynamics.
a new 3-button remote control that now includes a “mute” button.
10 dB Gain
Features
Other features carried over from the Rhythm flagship include no use of negative feedback, pure Class A design, the luxurious and heavy remote volume control, mute switch, mono switch, balance control, REC OUT jacks, Home Theater Bypass jacks, custom-made toroidal transformer and Furutech IEC inlet to allow you to experiment with various power cords.
The Power Supply
One part of the Rhumba that furthers the achievement of Bob Backert’s mission by improving timing and dynamic accuracy is the power supply. Patented by Mr. Backert, GreenForce™ is the first completely new kind of power supply since switching supplies were invented in the 1950s. Contrary to other designers’ seemingly unending desire for larger capacitor values in the power supply, Bob Backert wanted to reduce capacitors to the greatest extent possible, because of their detrimental effects on timber, timing and dynamics. GreenForce allows the power supply to use almost nocapacitance, and therefore far higher quality capacitors (in the case of the Rhumba, high quality polypropylene capacitors drive the power supply).
The way the power supply works (described further here) is also key: it’s very different, because it actively pushes power into the amplifying circuit, instead of passively bleeding out power as the circuit demands it. That ‘push’ makes GreenForce more nimble in responding to power demands from musical recordings. This also improves the accuracy of rhythm and dynamics.
GreenForce gets its green “cred” by shunning typical power supply parts (electrolytic capacitors) that contain environmentally unfriendly chemicals, instead using environmentally neutral “film” capacitors.
Built in the U.S.
The Rhumba is designed by veteran circuit designer Bob Backert, and assembled in the U.S. under the close supervision of his son, Chief Operations Officer Gary Backert.
Tubes
Just two NOS 12au7-equivalent tubes are utilized for the gain stage, accessible by a convenient transparent access door that highlights the warm glow of the tubes through the top panel.
Gain Stage – “Dynamic Linearity” Circuit
As in the Rhythm, the gain stage features a unique tube support circuit that allows more accurate dynamics, lower distortion and very low output impedance (<80 ohms). These benefits are achieved without resorting to common tools such as negative feedback and cathode followers, which Mr. Backert feels are detrimental to sonic accuracy.
The Sound
The Rhumba sounds remarkably close to the company’s flagship, the Rhythm. Although it is less than half the price of the Rhythm we were able to bring the Rhumba’s dynamics, fun factor, overall musicality and punchy, involving timing extremely close to the Rhythm’s.
These sonic characteristics form part of the company’s mission. Bob Backert has said, “When you enter a club or restaurant, it’s usually pretty easy to tell whether the music is live, or being played on a stereo. I wanted to make it much harder to tell the difference.”
To do that, we focus on the accuracy of two things: dynamics and rhythm. Our technical innovations have brought us significantly closer to the goal of reproducing truly live sound.