Exposure 3510 Mono Power Amplifier Lab Report

Lab Report

While the stereo version of the 3510 power amp [HFN Nov '22] behaves almost exactly like the power stage from Exposure's 3510 integrated [HFN Nov '21], the newer, Mono version of this established chassis shows a distinct evolution. Not only has Exposure embraced a fully balanced input stage but this and the power output circuits are now fully DC-coupled, the latter governed by electronic thermal and over-current protection. As a result the 3510 Mono has a response that's flat to below 1Hz (the AC-coupled 3510 Stereo rolls off below 20Hz, reaching 4Hz/–3dB) while stretching out to 20kHz/–0.4dB and 100kHz/–6.3dB. Distortion is much reduced over the 3510 Stereo, achieving 0.0005-0.0028% over its rated 100W range while the 110W-rated Stereo model hovers between 0.0025-0.008%. Versus frequency, the 0.0016-0.018% distortion recorded for the 3510 Stereo (re. 10W, 20Hz-20kHz) falls to 0.0006-0.0055% with the 3510 Mono [see Graph 2, below], but it is the reduction in noise that marks out this new version. This is a phenomenally quiet amplifier that takes the 89dB A-wtd S/N ratio of the 3510 Stereo and pulverises it with a massive 100.0dB (both re. 0dBW).

But what of power? Again, there are differences, for while the Mono and Stereo (and Integrated) both deliver 135W/8ohm and 225W/4ohm, under dynamic conditions we see the impact of that new protection regime as the Stereo's 170W, 320W, 550W and 795W (28.2A) are traded for 160W, 305W, 530W and a reduced 310W (17.6A) into 8, 4, 2 and 1ohm loads, respectively [see Graph 1]. So while the Mono chassis is cleaner, quieter and reaches down deeper, it's the Stereo model that has the raw grunt to drive the very toughest of speaker loads. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 17.6A


Distortion vs. extended frequency (5Hz-40kHz; 1W/8ohm, black & 10W, pink) (20Hz-20kHz; 75W, red)

Power output (<1% THD, 8/4ohm) 135W / 225W
Dynamic power (<1% THD, 8/4/2/1ohm) 160W / 305W / 530W / 310W
Output imp. (20Hz–20kHz/100kHz) 0.013-0.020ohm / 0.126ohm
Freq. response (20Hz–20kHz/100kHz) +0.0dB to –0.4dB/–6.3dB
Input sensitivity (for 0dBW/100W) 177mV / 1777mV (balanced)
A-wtd S/N ratio (0dBW/100W) 100.0dB / 120.0dB
Distortion (20Hz-20kHz, 10W/8ohm) 0.0006-0.0055%
Power consumption (Idle/rated o/p) 14W / 179W (W standby)
Dimensions (WHD) / Weight 440x115x300mm / 12kg
Price £2990 (pair)

Exposure Electronics Ltd
Lancing, UK
Supplied by: Exposure Electronics Ltd
01273 423877