The RAAL 1995 Immanis with the Ribbon Current-Drive Interface, which doubles as a headphone stand.
RAAL brings exciting transducer tech to Upscale
We've just welcomed Serbian high-end brand, RAAL 1995, to Upscale Audio. It brings with it a transducer technology not yet seen in our headphone lineup. True ribbons are in the same general space as planar magnetics and electrostats in that all three use extremely thin, flat drivers that vibrate in a magnetic or electrical field. But there are some big differences.
The Three Planar Technologies
Electrostatics use a charged film that sits between two high-voltage stators that carry the signal and cause the film to vibrate. Electrostats are extremely responsive and intricately detailed, but it's hard to get a large excursion, so they can be lighter in impact. The bias voltage and high signal voltages of electrostats require specialized amplifiers.
Planar magnetics use a plastic film diaphragm with conductive traces on the surface. The structure is suspended in a magnetic field, and the traces carry the signal. These bonded traces interact with the magnetic field, causing the entire film to vibrate. Planar magnetics work with conventional headphone amps but favor those with strong current delivery and low output impedance. Because the traces have to move the diaphragm, planar magnetics are relatively less responsive, at least within this category of headphone technology.
A true ribbon uses folded aluminum strips that conduct the audio signal while suspended in a magnetic field. This means the entire diaphragm is moved by electromotive force, resulting in swift, precise transducer behavior. The downside is that because the entire diaphragm is the conductor, impedance is extremely low. So low, in fact, that ribbon headphones practically present a short circuit to traditional amplifiers. The RAAL Immanis, for example, has an impedance of 0.057 ohms, rising to just 0.29 ohms with the cable attached.
The Ribbon Current-Drive Interface allows regular headphone amps to drive the extremely low impedance ribbons.
The Interface
The low impedance of ribbons is where the RAAL Ribbon Current-Drive Interface comes in. The RCDI uses a transformer to allow a conventional amplifier to drive the extremely low-impedance ribbon load. The voltage-drive output of the amp is converted into the high-current drive required by the ribbon, with the RCDI presenting a low, but manageable, 32 ohms. In addition, the RAAL RCDI doubles as a headphone stand, putting all that mass to good use.
The Two RAALs
RAAL 1995 currently offers two headphone models, the Magna ($6,370) and Immanis ($10,200). The Magna has 2.6 sq. in. of driver surface area, while the Immanis offers 3.9 sq. in. Both have 4 mm of excursion, which is huge for a ribbon headphone. What this means is you get the delicacy and detail of planars, with the weight and bass impact of a dynamic driver.
Currently, RAAL headphones will ship directly from RAAL. We'll let you know as soon as we have in-store demos.