Specifications
Every published figure
Output, performance, power and physical specifications for the Selective range, as stated in the product’s own manual. Where the manual and the series datasheet disagree, the manual is what is printed here.
- Frequency response
- 20 Hz – 20 kHz
- THD+N
- Under 0.05 %
- Signal / noise
- Over 106 dB
SD125.4
Four channels at 125 W, or two 70/100 V lines at 250 W, in a half-rack 1U chassis.
| Channels | 4 × Lo-Z (4 Ω – 16 Ω) / 2 × Hi-Z (70V / 100V) |
|---|---|
| Output power @ 4 Ω / 8 Ω | 4 × 125 W |
| Output power @ 70V / 100V | 2 × 250 W |
| Power Share (up to) | 2 × 250 W, across each channel pair (Ch 1/2, Ch 3/4) |
| Total system power | 500 W |
| Output voltage | 70 Vp / 140 Vpp unloaded — bridged 140 Vp / 280 Vpp |
| Output circuitry | UMAC™1 Class D — full-bandwidth PWM modulator, ultra-low distortion |
| Signal-to-noise ratio | > 106 dB (A-weighted, 20 Hz – 20 kHz, 8 Ω) |
|---|---|
| THD+N (typical) | < 0.05% (20 Hz – 20 kHz, 8 Ω, 3 dB below rated power) |
| Frequency response | 20 Hz – 20 kHz (+0 / −0.8 dB, 8 Ω, 3 dB below rated power) |
| Input impedance | 20 kΩ balanced / 10 kΩ unbalanced |
| Power supply | UREC™2 universal switch-mode with PFC and standby converter |
|---|---|
| Operating voltage | Universal mains, 100–240 V, 50–60 Hz |
| Power consumption | 150 W |
| Standby consumption | < 0.6 W |
| Power ratings | 1% THD @ 120 Vac and 230 Vac |
| Protection | Short circuit, DC, undervoltage, temperature, overload |
| Dimensions | 44 × 220 × 319 mm (1.7 × 8.7 × 12.6 in) — half-rack 1U |
|---|---|
| Weight | 2.8 kg (6.2 lbs) |
| Operating temperature | 0 – 40 °C, indoor, below 2000 m |
| Cooling | Fan-cooled, temperature-controlled; fan off in standby |
| Ventilation | 80 mm clearance to the ventilated faces |
100V line mode operates @ −1 dB (≈ 90 V).
Mounting hardware
| Rack ears | 2 |
|---|---|
| ½ rack plate extension | 1 |
| ½ rack mounting plates | 2 |
| Rear supports | 2 |
Terms
-
UMAC™ — the manufacturer’s name for the output stage: a full-bandwidth PWM modulator with ultra-low distortion, quoted here as the manual states it.
Full-bandwidth is the part that can be checked: signal-to-noise, distortion and frequency response are all quoted across the whole 20 Hz – 20 kHz band into a real load, rather than at one convenient frequency.
-
UREC™ — the manufacturer’s name for the power supply: a universal mains switch-mode supply with Power Factor Correction and a separate standby converter.
Universal means one unit for any territory — 100 V to 240 V, 50 or 60 Hz. The standby converter is what holds standby draw under 0.6 W.
About these figures
Every figure on this page is taken from the amplifier’s own user manual at the firmware revision the site documents. Nothing is estimated, and nothing is carried over from a similar product.
Read the conditions column, not just the number. Signal-to-noise, distortion and frequency response are each quoted across the whole 20 Hz – 20 kHz band into a stated load, rather than at one convenient frequency, and the power ratings carry the distortion and the mains voltage they were measured at.
Specification sheets and installation documentation are in production. If you need a figure that is not published here — for a tender, a load calculation or a thermal budget — ask, and we will tell you whether it is measured or not yet stated.