+ CTH-8550 MKII

No compromise « all in one » music machine
darTZeel is proud to introduce the new CTH-8550 full featured integrated amplifier. This new product combines in one casing most of the good things musical lovers found in our flagship NHB series.
The CTH-8550 features newly designed power output stages which include on board regulated power supplies for a very compact global layout. This new circuit brings outstanding transparency, speed, yet delicacy, giving a maximum listening pleasure.
With no less than nine inputs in total, the preamplifier section is dual-mono – one dedicated circuit per channel – with a minimal footprint which allows for very short signal paths.
No doubt that this newcomer is a true darTZeel machine.
Key features include:
    * A newly designed fluorescent display for user-friendly operation.
    * 7 standard inputs blended from a mix of Zeel, RCA and XLR sockets.
    * 2 additional, optional Phono inputs (1 MC, 1 MM), easy to implement at any time (factory upgrade only, though).
    * Full HT bypass function for all inputs.
    * 1 darT preamp output for driving an external NHB-108 power amplifier.
    * 1 RCA preamp output for driving any other optional power amplifier.
    * 1 RCA REC output, with independent record source selection.
    * A fully featured remote control, 100% darTZeel designed.
    * A new kind of approach in mechanical housing design thanks to state of the art Laser cutting & welding technologies, ensuring unprecedented high rigidity and easier assembly and maintenance procedures.
Detailed Insights
Output power stage
darTZeel designed a new circuit allowing cool running behaviour for less power consumption and more environmental friendly operation. Signal path has been carefully kept as simple as possible. The use of two paralleled output transistor pairs was chosen for hassle-free setup, whatever the kind of speaker used. The additional power gain provided by these two output pairs allowed us to reduce the number of silicon junctions in driver stages, thus keeping all speed and transparency we were looking for. There are now only three junctions in the power section, with an output power capability of 220 watts per channel under 8 Ohms, and a whopping 350 watts into 4 ohms!
Preamplification stage
All regulated power supplies involved in the analog section are located on the audio circuits, ensuring best possible ripple rejection and low noise floor. Optional phono sections are implemented on same circuits for very short signal paths from the input RCA connectors. Source selection and loudness level are controlled through very high performance, dedicated circuits. All DC drift is now entirely compensated by digital means, allowing the compensation to be completely kept outside of the signal path, a world premiere in audio!
Power supply transformers
Besides its unique, huge toroidal power transformer, the darTZeel CTH-8550 is a full dual-mono design. We chose to implement only one power transformer in order to minimize magnetic fields induced to low level signals, yet over sizing it enough to deliver all power needed under any demanding circumstance. A second, smaller transformer is in charge of the low level signal. So, the control panel allows for disabling the big power transformer in case of preamplifier usage only, bringing improved quietness and coolest operation.
Pleasure Control again
The new Pleasure Control optical encoder, custom-made for darTZeel by Elma, offers extreme feelings and high precision. The volume control electronics involves high quality semiconductor devices for best reproduction accuracy.
New display control panel
Extremely convenient and user friendly, the new display will allow you to fully operate your CTH-8550 in the most convenient way. Each parameter can be easily adjusted, such as source level, source name, default source balance, record source, illumination display, and so on…
Security and customization
Each CTH-8550 is delivered with its own dedicated USB key which contains all customer information: Owner’s name, Serial number, Firmware version and Voltage range settings. The provided USB key will also allow for eventually updating either CTH-8550’s firmware or software in the future.
Entirely designed with a dedicated 3D-CAD software, the new cabinet is made from high quality, 2mm thick, Swedish Grade Steel. Starting with a plain steel sheet, it is cut with a high precision Laser Beam, then all parts are laser-welded together, even hand welded in critical areas, then hand polished and finished before being painted in an industrial oven. The result is just breathtaking. Aluminium heat sinks are sandwiched inside the steel structure, allowing for optimal thermal dissipation and extremely high global rigidity. The front plate is CNC-machined from a plain, 15 mm thick, aluminium sheet, giving the darTZeel CTH-8550 its incomparable finishing.
The darTZeel CTH-8550 is available either in darTZeel standard color, or in full black dress.
Technical Specifications
Power output:                            220 watts RMS / 8 ohms
                                                   350 watts RMS / 4 ohms
Input gain, line:                          0 to +22 dB, user defined
Input gain, MM:                          24 to 44 dB, user defined
Input gain, MC:                          50 to 70 dB, user defined
Input sensitivity:                        Line 250 mV, Phono 0.5 mV
Frequency response:                 10 Hz to 100 kHz, +/- 0.5 dB
Total Harmonic Distortion:         < 1 % at any frequency
Temporal Distortion:                  None across full audio range
Crosstalk:                                  < -90 dB from 20 Hz to 20 kHz
Signal to noise ratio:                 > 100 dB (A), line, @ 2 volts output
                                                  > 70 dB (A), phono, @ 2 volts output
Power consumption:                  Idle: 45 watts, maximum 1000 watts.       
                                                  Standby: less than 5 watts.
Size in inches (WxDxH):             17.33 x 13.2 x 6.7; 16.35″ total depth with handles.
Net Weight:                               64 lbs.
Retail Price: $38000 (MC or MM Phono)