We are happy to announce Rethm's highly anticipated website relaunch. Please have a look and learn more about these world class loudspeakers. www.rethm.com
Also stay tuned for updates to our growing dealer network.
The LISZT mono-block power amplifier (200W @ 8Ω) brings together apparently conflicting attributes like, operating speed, current drive capability, stability in any load, lowest distortion and ultra low noise to name but a few. A key ingredient in achieving this difficult task is the fully symmetric operation from input to output and the high speed signal processing. It is the fast transient ability and ultra wide bandwidth (1.2MHz unfiltered) approach that let you hear the room, the ambiance of the sound recording. Matching phase coherent speakers assumed, a pair of LISZT amplifiers will deliver a perfectly executed sound-stage.
Strictly balanced architecture
The LISZT features a completely balanced architecture, with no back and forth conversion. In consequence, two identical amplifiers are employed, one driving the speaker+ and one driving the speaker- terminal. While this doubles costs, it relieves the circuit ground from carrying the speaker return currents, resulting in a clean and unspoilt ground potential. The LISZT also offers a single-ended input, treated separately from the balanced input. A toggle switch located near the input jacks allows you to switch the amplifier between single-ended and balanced operation.
Ultra wideband design
The high quiescent current design of all preamp and driver stages enables a core speed close to 1.2MHz, slowed down only by input and output filtering to match real word requirements. With filters in place, the small signal as well as full power bandwidth (!) measures an impressive 400 kHz. The lower frequency limit is around 0.3 Hz. No coupling capacitors are used throughout.
Inherently low noise
High resolution audio is intrinsically tied to low noise and low distortion. System noise is the lower resolution limit of an analog system, because it determines the smallest signal not masked by a noise floor. Hence, low noise levels and thus a wide dynamic range are desirable. A-weighted output noise measures 40µV for the LISZT giving a SNR of 122dB or an equivalent to 20bit. 20 to 21 bits analog resolution is the realistic limit, dictated by the laws of physics.
Lateral MOSFET output stage
The lateral MOSFET transistor originally developed by Hitachi in the late 70’s is probably the only semiconductor power device solely made for audio use. Famous for its tube like characteristic and perfect bias stability under any load conditions, the LISZT uses a single pair of tandem devices in each output stage. The H-bridge output transistor array is energized by a heavy duty toroidal transformer running a bank of 120.000µF storage capacitors.
We had the distinct honor of hosting AV Showroom's Reviewers View at RMAF - enjoy!
• Proprietary hybrid 2-stage XMOS xCore XE216 + FPGA
• Fully-floating (isolated) USB decoding and clock generation by FPGA with proprietary code
• High quality, long life, low noise parts and modular design that distinguish aqua - acoustic quality equipment
• Sample rate in “Bit Perfect” up to 768 kHz PCM and quad rate DSD (DSD256)
• Latest version of customized XMOS X Core Driver on Windows OS (W7, W10)
• Native X Core Audio on Mac OS (Bit Perfect)
• USB Audio 2.0 operation on Linux (Bit Perfect)
This update has required significant optimization of code for the main FPGA of R2R ladder DAC which has improved sound quality.
The new hybrid USB XMOS xCore 200 (dual core) + FPGA circuitry enables the high-resolution file playback up to 768kHz PCM and up to DSD256 (Quad DSD)
Upgrading to xHD
The update for the Formula units of existing owners consists of the following hardware / firmware modifications:
1. new hybrid USB Board cod. A108 (high-resolution up to 768kHz PCM and DSD256 (Quad DSD)
2. hardware modification of board P1108 connected to USB board
3. new firmware of main FPGA (R2R ladder DAC) with optimization of the code
4. update of firmware of main microcontroller STM32
The TELEMANN supports all high resolution music formats including DXD (352.8kHz/24bit) as well as a DSD 64/128/256/512 stream. 5x digital inputs plus optionally 1x analogue input provides flexibility for the source connection, whereas the balanced and unbalanced analogue outputs directly drive a power amplifier. Volume is adjusted in the analogue domain featuring a relay - resistor network using gold contact relays. In comparison to his predecessors VIVACE 1 + 2, the TELEMANN has even lower noise, lower distortion, and superior accuracy.
Even with a standard 44.1kHz/16Bit source you will experience a crisp and clean sound never heard before. This is of particular importance because music from the major labels is obtainable in the CD format only. Higher data rates will give you more air and sparkle, while DSD showcases an even livelier and vibrant sound.
Femto master clock TJ < 0,0000000000001s
Digital to analogue conversion is carried out by the ESS9028 PRO chip, regarded as one of the finest silicon implementations in the industry. This chip incorporates innovative circuits delivering spectacular music free from annoying artifacts. The femto master clock with a clock accuracy of under 0.1ps clock jitter makes this approach feasible. 4x balanced 32-bit D/A converter per channel pass over audio to our proprietary discrete analogue circuits.
Galvanically isolated asynchronous USB transceiver
Any form of jitter in the incoming data-stream is compensated by a small buffer. The audio data is clocked by a local high precision quartz master clock, eliminating all timing related distortions. Furthermore the transceiver circuitry is galvanically isolated from the rest of the DAC. The coupling capacitance between the two sections is in the order of a few picofarads. This eliminates effectively the noise interference from the host PC.
Analogue volume control / pre-amp functionality
TELEMANN uses a highly sophisticated log. ladder network controlled by gold contact relays forming a constant impedance passive volume control preamp. Using this outstanding preamp functionality for an external analogue signal (e.g. phono stage) will make TELEMANN the last preamp you will ever need.
Digital filter with selectable characteristic
The user may select any from 7 filter options on the fly. Besides a standard PCM, high stop band rejection FIR filter giving the best performance on the bench, there are several other options to choose from.
Linear power supply
TELEMANN employs a full analogue, non switching noise free power supply. A switch mode power supply or even the tiny board level DC-DC converter work with high frequencies and high currents. In combination, both make up an excellent RF transmitter making it difficult if not impossible to control the noisy electrical fields. For this reason, TELEMANN does not use any of these circuits, not even for the LED-display.
Getting the most from a high quality audio component requires clean and uncontaminated power. For various reasons, our mains are polluted by high frequency noise, voltage spikes and asymmetry calling for some sort of filtering. If at all, a so called EMI filter is used. These filters are available of the shelf in different implementations. Although well designed for use in industrial applications and home appliances, these filters are inadequate for audio. Not one of these filters exhibits a smooth transition band. TELEMANN addresses the above problems with a low impedance, well controlled damping design, eliminating issues that sometimes audiophiles causes to reject mains filter at all.
Innuos has designed an exclusive 100 units Special Edition aimed to take your music to new heights.
With a new Triple-Linear PSU designed by Sean Jacobs, custom-wound toroidal transformer and a raft of improvements on EMI shielding and vibration isolation, the ZENith SE picks up the trademark PRaT (Pace, Rhythm and Timing) and neutrality of the ZENith and adds more body to the music, improving the depth and height of the soundstage.
Attention to detail that makes a difference
A number of improvements were added for this Special Edition:
• New oversize, custom-wound audiophile toroidal transformer with 3 independent outputs for each Linear Power Supply
• New Triple-Linear power supply designed by Sean Jacobs
using high-end Mundorf caps
• Three anti-vibration feet with asymmetrical positioning to better isolate vibration without a ecting dynamics
• Audiophile-grade silver-coated and shielded cabling for internal connections, hand-soldered directly to circuits to lower impedance from connectors.
Powered by innuOS
As all other ZEN MkII, the ZENith SE is powered by innuOS – Innuos’ own operating system developed in-house. It enables a complete computer-free operation for managing CD ripping, importing digital music and editing album data and cover art.
Recently added features on innuOS version 1.2 include the ability to playback music stored on an external NAS and the possibility of using it as Roon Core Server or Roon Player.
"It is a matrix-like gestalt. Takes two seconds once you find it," my notorious muse Herb Reichert once said to me (in a context I can no longer recall.) But these precise words came into focus as soon as I heard the system in the Well Pleased Audio Vida room. Throughout the entire show weekend, I had encountered many sonically and aesthetically pleasing rooms—with prices ranging from the affordable to the aspirational—that would have satisfied me for years on end. But this…this was something else. In the moment, and in thoughtful retrospect, this system was my favorite of the whole show...
"That's the Allegro in a nutshell: a thoroughly modern, properly engineered amp that's environmentally conscious, quiet like a tomb, utterly unfussy, of high resolution, low distortion and demonstrably potent drive to net very refined sonics. Listeners into deep space—shorthand for their enjoyment of maximally revealed venue ambiance aka recorded space—will find the Allegro twins their perfect tour guides. After VW's diesel engine debacle, made in Germany returns to its golden roots with LinnenberG's Allegro for honest engineering & class-leading performance."
Read the review here
Come out to visit us at this year's AXPONA Audio Expo in Chicago on April 21-23. We will be featuring a system comprised of the following components:
Rethm Bhaava loudspeakers
Linnenberg Maestro & Allegro amplifiers
aqua La Scala MKII Optologic DAC
Innuos Zenith Music Server
Room 504...we look forward to seeing you there!
"ALLEGRO delivers the superiority and authority of a linear class AB amplifier - even in demanding applications. It features high current capability and operating speed not to be found in IC-amplifiers aka “gain-clone” or any class D design."
Clever construction techniques enabled us to build an amplifier with high packing density, consequently making the signal and power paths extremely short. So, don’t be fooled by the tender look – it is part of the concept to get big sound. In fact, creating circuits with unrivalled speed and response time is amongst other things a matter of physical closeness of electronic parts. The higher the frequency, the more it is important to reduce every millimeter of board trace.
It is the fast transient ability and ultra wide band (1MHz unfiltered) approach that let you hear the room, the ambience of the sound recording. Matching phase coherent speakers assumed, a pair of ALLEGRO amplifiers will deliver a perfectly executed sound-stage. Furthermore, our concept has an order of magnitude lower distortion than competitors in the market. Distortion masks the integrity of the music, because it adds spectral components which weren’t there previously.
Lateral MOSFET output stage
The transistor originally developed by Hitachi in 1977 is probably the only semiconductor power device solely made for audio use. Famous for its tube like characteristic and perfect bias stability under any load conditions, the ALLEGRO uses just a single pair of tandem devices in the output stage in the so called “common source” arrangement.
Balanced signal path
Almost any LINNENBERG (past / future) product features true balanced circuits and connectivity. Historically, this may have a reason in our roots lying in professional audio. ALLEGRO is no exception: here, the circuit composes of a very low noise instrumentation amplifier such as used in high-precision measuring equipment. This approach ensures perfectly matched input conditions for the positive and negative signals and thereby allows the realization of high-performance balanced signal transmission.
Ultra wide band design
The high quiescent current design of all preamp and driver stages enables a core speed close to 1MHz, slowed down only by input and output filtering to match real word requirements. With filters in place, the small signal as well as full power bandwidth (!) measures an impressive 350 kHz. The lower frequency limit is around 0.3 Hz. No coupling capacitors are used throughout.
Inherently low noise
High resolution audio is intrinsically tied to low noise and distortion. System noise is the lower resolution limit of any analog systems, because it determines the smallest signal not masked by a noise floor. Hence, low noise levels are desirable. A-weighted output noise measures 25μV for the ALLEGRO giving a SNR of 120dB or an equivalent to 20 bit. 20 to 21 bits analog resolution is the realistic limit, restricted by the laws of physics (e.g., thermal white resistor noise)
The power supply consists of a 230VA toroidal mains transformer and a total of 60.000μF energy storage capacitors, enabling a stable output of 55W/90W at 8Ω/4Ω. Precision regulated supply voltages for preamp and driver stages. Microprocessor controlled – non intrusive protection circuits against over current, DC-offset or over temperature.
Input sensitivity: 1,5 V rms
Gain: 22,8 dB
Power output: 55W/8Ω, 90W/4Ω, 105W/2Ω
Peak output voltage: 68 V pp
Peak output current: +/- 20A continuous 1 : 10 cycle
Frequency range: 0 ... 350 kHz with filters, 0 ... 1MHz without filters
Full power bandwidth: 0 ... 300kHz
Rise time: 700ns
Damping factor: > 500
Signal to Noise ratio (SNR): 116dB linear BW = 30kHz 120 dB (A)
Distortion and noise (THD+N): 0,004%