BACKERT LABS

Rhumba Extreme™ 1.3

The Rhumba Extreme™ gives you a way to get a Rhythm (our flagship linestage preamp) at a lower cost. How? We put almost every bit of the Rhythm preamp inside the less-expensive Rhumba chassis. This is the Rhumba Extreme. On the outside, it’s identical to our $4,500 Rhumba. Except for two things: the volume knob, and the feet. We put a blue LED on the volume knob, similar to the Rhythm, so you always know where the volume is during late night sessions. The Rhumba Extreme also features solid brass hemispheres for feet. Because they are round, they will not harm your shelves.

On the inside, the Extreme is much closer to a Rhythm than it is to a Rhumba.

Rhumba Extreme vs. Rhumba

What are the goodies that make the Rhumba Extreme so extreme?

• A fully dual-mono power supply – so the Rhumba Extreme has two full GreenForce power supplies, one for the left channel, and one for the right channel. Each power supply gets its own discrete regulator.
• Our famous auto-bias circuit for the tubes, which keeps your tubes happy with the perfect bias level at all times. This will make your tubes last longer, and it will prevent tubes that have unusual bias requirements from sounding bad due to being deprived of the bias they want.
• A cool blue LED light on the edge of the volume knob, so you’ll always see the status of your volume.
• Solid brass feet, from edenSound.
• Beautiful mirror finish behind the main front plate, visible in the cutouts for Power and Mute switches.
• Higher quality Jantzen Silver capacitors for the power supply.

Rhythm™ 1.3

Specifications can be found here.

How is the Rhythm 1.3 improved over the Rhythm 1.1 and 1.2?

Fully balanced XLR inputs (2) and output (1): for those of you with long cable runs or who feel that balanced XLR just sounds better

Dual-mono power supply: left and right channels have their own power supplies and regulators for the ultimate in separation, imaging and accuracy

Improved output capacitors: The highly seductive V-Cap ODAMs now handle output duty

Improved power supply capacitors: the famously dominant V-Cap PTFE capacitors now drive our GreenForce power supply — with copper foil, an exotic capacitor that is unheard-of in any audio power supply – in any any power supply at all, actually

Improved circuit board: double the copper in each trace

Improved feet: the Rhythm 1.3 features the excellent Terracones, from edenSound

Improved stock tubes: the Gold Lion gold pin 12au7’s for maximum pace, inner detail and resolution

Our latest circuit: gain stage and power supply regulator designs benefit from our latest research

The Rhythm 1.3 is a line stage preamp that provides a new level of audio enjoyment by employing radically new technology.

Features

Designed, machined, and assembled in Pennsylvania, the Rhythm 1.3 utilizes two 12au7 tubes in its gain stage. In addition to its remote volume control, the Rhythm 1.1 has a balance control, mute switch, stereo/mono switch, five sets of inputs (3 RCA, 2 fully balanced XLR) and three sets of outputs (2 RCA, one fully balanced XLR) in addition to a Record Out output and a Home Theater Bypass input pair. Its handy tube access door allows tube changes with no tools, just the touch of a finger. And the pleasing glow of the volume knob’s LED indicator shows where volume is set.

Sound at a Glance

Acquire the Rhythm 1.3 if you want your music to come alive, if you want toe-tapping rhythm, and if you want your music to have all the clarity, accuracy, and beauty that is present on your source material.

More on sound quality here.

Technology At A Glance

The Rhythm 1.3 uses an amplification circuit (“gain stage”) unlike any other. The way it amplifies is extremely easy on your tubes, running at a constant current and a remarkably low voltage (150 volts) for the blackest backgrounds possible, as well as the longest tube life you will find anywhere.

Its internal parts are of the highest quality, including the best capacitors ever built into a power supply (V-Cap™ capacitors), a first in audio made possible by Bob Backert’s patented GreenForce™ power supply.

Amazingly low output impedance (75 ohms) means that the Rhythm 1.3 combines beautifully with any power amplifier. The transformer is toroidal and custom-made for us. The Furutech IEC connector allows you to experiment with various power cords. And the premium jacks on the rear panel are so sturdy and widely spaced, the Rhythm 1.3 can handle whatever interconnects you may select.

• More on technology here.

Rhumba™ 1.3

“The Rhumba 1.3 is a fantastic preamplifier – period.”

“… a solid contender among the big-name $10k preamplifiers.”

“The most exciting aspect of the Rhumba is the lively, dynamic aspect of its sound.”

–TONEAudio Magazine

At $4,500, the Rhumba 1.3 linestage preamp has the same basic circuit design as the $10,750 Rhythm 1.3, including fully balanced XLR input and output. That also includes the same power supply design — our patented GreenForce.™

All in a gorgeous chassis. Like the Rhythm, the Rhumba is designed, machined, and assembled in the U.S., with NO farming out of the aluminum chassis to other countries.

From its debut, the Rhumba has wowed listeners. See reviewer Terry London’s raving preview of the 1st-generation Rhumba 1.1 here including his stunning conclusion, “might be the best deal in high-end gear of the 21st century”.

His full writeup in Home Theater Review is found here.

Improvements from the Rhumba 1.2

The Rhumba has always featured a convenient tube access door to let you change tubes easily. The Rhumba 1.3 eliminates the detachable thumbscrews on the tube door, so it’s even easier now — there’s nothing to get away from you.

Other improvements:

circuit developments in the power supply and gain stage that provide a more 3-dimensional listening experience, with improved imaging

these changes also provide improvements to liveliness, warmth and immediacy

a new “mono/stereo” switch on the front panel, a feature taken from our flagship Rhythm preamp, which can be helpful to those who listen to mono records or CDs

improved stock tubes – we now use the smooth and sweet Mullard reissues

Features, Features . . . 

Other features carried over from the Rhythm flagship include fully balanced XLR input and output, no use of negative feedback, pure Class A design, a luxurious remote volume control, mute 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 Rhumba 1.3 has 9dB of gain.

The Sound

Rhumba 1.1 tube preamp

The original Rhumba 1.1, with remote

The Rhumba sounds remarkably close to the company’s flagship, the $10,750 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 impossible 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.

Compared to the Rhumba 1.1 and 1.2, the Rhumba 1.3 features progressively “bigger” sound with greater weight, more articulate midrange, and more precise imaging.

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 no capacitance, and therefore far higher quality capacitors (in the case of the Rhumba, high quality polypropylene capacitors).

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.

Like the Rhythm, 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

Two 12au7 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. The Rhumba comes with Mullard 12au7 tubes.

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 (just 75 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.

Colors

• The Rhumba is available with beautiful red or blue body color, shown below. Because company president Andy Tebbe thinks “literally every music lover in America should have a red or blue Rhumba,” we keep this affordable for our customers, adding only $300 for this option.