Auditor Headphone Monitoring Amplifier
The Auditor is our interpretation of a high-end headphone amplifier. We strictly followed a purist approach to achieve the highest sound quality.
The basis for such high-end developments is our proved 120 volts reference technology. Core elements are the handmade SPL SUPRA op-amps running on 120 volts – it corresponds to approximately twice that of most modern analog audio semiconductor technologies. Through such 120 volts circuitry and processing we reach performance levels far beyond conventional designs in dynamic range and distortion levels, and such technical specifications exceed all known analog or digital standards. In other words: simply sounds.
There is more than meets the eye in working with headphones. For example the modern audio production is often a decentralized process, maybe recording and track laying in one studio and mixing in another and as a result a production often take place in acoustically questionable rooms. In such circumstances, a mix might occur in an acoustically deficient ambiance (for example, in an extremely modal room), and employing headphones then begins to make sense when a successful mix would otherwise turn out to be impossible. Another fact is that many musicians or producers might wish to – or be able to – mix at home (to say nothing of having to). Then the headphone becomes a clear must, enabling an evening or late night session that can only take place thanks to its being unhindered by the local acoustic environment.
But also when working with full range monitors in the studio, headphone monitoring is an extremely important alternative to loudspeaker monitoring: analytical monitoring via headphones offers a very high precision to observe details. Headphone monitoring is like working with an acoustic magnifier, excluding external room influences. Working with the magnifier effect of headphones has the advantage of safely hearing clicks or similar defects and helps in fine tuning crossfades or to judge tonal problems in individual tracks.
The End of Ear Fatigue
With headphones, ear fatigue can begin relatively soon, and there are several causes. First, some cans themselves may not be that comfortable to wear...
Moreover, a standard headphone amplifier is often an additional important reason for premature ear fatigue. Almost without exception, present-day headphone amplifiers employ comparatively undemanding IC’s. In the best cases they might work with symmetrical voltages of +/-15 V to +/-18 V, and in less favorable cases, with only a simple supply of 9 or 12 V from cheaper external “wall-wart“ power supplies. But the voltage level acts in circuitry much like the cubic inch capacity to the productive power of a combustion engine: Cubic inch capacity is replaceable with nothing but more cubic inch capacity – and in the productive power of electronics, voltage level functions similarly.
For some years, now, SPL has addressed this issue in all of its mastering product series through its own specifically developed 120 volt technology. Consoles and signal processors of the SPL Mastering Series appear as central elements in installations of today’s most renowned mastering houses (e. g. Bob Ludwig’s Gateway Mastering & DVD in the USA, Simon Heyworth’s Super Audio Mastering in Great Britain or the Galaxy Studios in Belgium). This 120 volt technology is based on discrete operation amplifiers from SPL’s own production, developed and perfected over many years by SPL’s co-founder and chief developer, Wolfgang Neumann. The SUPRA OPs have a signal to noise ratio of 116 dB and offer a 34 dB headroom – that yields an unequalled 150 dB dynamic range.
The musical result is not to be mistaken: Regardless of the monitoring means, regardless of how loud you monitor – the Auditor always remains a distant, impartial factor unaffected when used to capacity and beyond being overloaded. The phase stability is always perfect, its THD next to immeasurable. The SUPRA OPs cannot be stressed in the most stressful circumstances, and for precisely this reason its musical sound is always relaxed and spacious. All frequencies are reproduced in balance, basses are stable and tight, mids are clear and differentiated and highs remain transparent and soft.
Such supreme and heretofore unreachable neutrality in audio reproduction is the direct consequence of our technical approach and basis in 120 volt technology: Possible disturbances from such as noise or distortion are so slight that we even arrive at the boundaries of the best measuring equipment, and what remains is quite simply unaltered musical sound.
Specifications Model 2910
Audio Frequency Response: ‹5 Hz to ›200 kHz (-3 dB)
CMR:-80 dBu (@1 kHz, 0 dBu input level and unity gain)
Crosstalk: -84 dB (@1kHz)
THD: 0,001 % (@ 1kHz, 0 dBu input level and unity gain)
Noise: -97 dBu (A-weighted)
Dynamic Range: 129 dB (@ 600 Ohms Impedance)
(XLR connections, electronically balanced)
Impedance: ca. 20 Ohms balanced/ca. 10 Ohms unbalanced
Maximum Input Level: +24dBu
XLR Connections: Input thru, electronically balanced
Headphone Output: 6,3 mm stereo TRS connection
Pin Wiring Tip = left, Ring = right, Shaft = GND, Impedance: 9 Ohms
Max. Output Performance:
1,7W (+32,2dBm) @ 1 kHz and 600 Ohms connection
360mW (+25,6dBm) @ 1 kHz and 30 Ohms connection
Voltages: 230V AC, 50Hz/120V AC, 60Hz
Power Consumption:max. 5,6 W/7,9 VA/0,03 A
Fuses (slow blow): 200-240 V AC: 200 mA/100-120 V AC: 400 mA
Dimensions & Weight
Height x width x depth: 95 x 210 x 315 mm
Height with lifted feet: 127 mm
Depth with volume knob: 335 mm
Weight: 2.65 kg