Soundstream Technologies Class A 5.0 owner manual LSE.Q THEORY AND USE continued, Design Features

FIG. 5 Limited Excursion

DESIGN FEATURES

∙Pure Class A Output Topology for the utmost in musicality and definitive power output. Soundstream's unique design allows the Class A amplifiers to deliver incomparable sonics or, when operated at lower impedances, to provide phenomenal amounts of power.

∙Uncompromising Design and Construction including mil-spec glass epoxy circuit boards and high current custom gold-plated solid brass connections that will accept up to 4 gauge power/ground wire.

∙Quad Factor™ Circuitry - Soundstream’s newest power supply design allows the Class A amplifiers to make four times the power when going from a 4 ohm stereo load to a 2 ohm stereo load, and again when going from a 2 ohm stereo to a 1/2 ohm stereo load!

∙Coherent StereoTM/Mixed Mono selection for either “pure” stereo operation or mixed mono for simultaneous stereo and mono.

∙ChassisinkTM Darlington Power Array - Soundstream’s “overbuilding” of the output section incorporates multiple output transistors instead of a few

for faster, stronger power delivery. The transistors are sandwiched between the circuit board and the heatsink in a design called ChassisinkTM to ensure cool, efficient amplifier operation.

∙PowerGrid Power Supply Design - All power supply components are located near one another, connected by thick, wide PCB traces, which ensures rapid, high current delivery. The entire power supply is isolated on one side of the circuit board while the audio stage is located opposite it, guaranteeing minimal noise.

∙Ultra-Low ESR Capacitance Bank - Multiple small input power capacitors are used to provide a lower ESR (Equivalent Series Resistance), which means more power in and out faster.

∙Smart Thermal Rollback - Most amplifiers shut off when they get too hot. In the unlikely event the REFERENCE Class A amplifier reaches 85° C, it will gradually roll back its average power (without affecting the dynamics). Once the amplifier has cooled off, it returns to full power output. If overheating should continue, a second thermal sensing protection circuit will shut off the amplifier if the heatsink reaches 95° C.

∙Fault Monitor LED on the top panel notifies you of blown power supply fuses.

∙1/4 ohm Drive Ability - The REFERENCE Class A amplifiers are designed to drive virtually any load— all the way down to 1/4 ohm stereo (1/2 ohm mono).

∙Dual Discrete Class A Drive Stages - Over six times the drive current of

LSE.Q THEORY AND USE (continued)

This is	due		to	the	loss	of	any	8.0
								7.0
appreciable		resistive			air mass.		At	6.0
frequencies		below resonance,					the	5.0
								Xd
woofer starts to behave as if it were								(mM) 4.0
mounted in “free-air”.					If we wish to			3.0
								2.0
improve	the		performance			of	a	1.0
								0.010 Frequency (Hz)
vented system,				we should		remove			50	100	200

these unwanted signals from our system. These can be removed by

adding a subsonic filter. Figure 5 shows the effectiveness of LSE.Q on woofer excursion. Woofer travel is 7.5 mm at 10 Hz, with LSE.Q properly adjusted, this excursion can be

reduced to less than 1 mm. This is of great benefit to lowering woofer distortion and increasing output.

Adjustment

An easy method of optimizing your existing subwoofer enclosure with LSE.Q's “Hz” control is as follows.

1 Adjust frequency and boost control to full	FIG. 6 LSE.Q Setting
CCW position. (See figure 6)

2 While listening to music with strong bass content at a moderate level, slowly adjust frequency control clockwise. Listen for a reduction of

			bass response.		Now,	rotate
10			f r e q u e n c y	c o n t r o l		s l i g h t l y
5			backwards. This serves the purpose
0
			of removing	the	“subsonic” bass
-5
dB			energy.
-10
-15			Soundstream’s LSE.Q contains the
-20
			same type of circuit with the added
-25
-3010 Frequency (Hz)	50	100	200 benefit of infinite adjustability. Our
FIG. 7 Various Settings			“Q” and “Hz” controlcan provide

virtually any combination of boost

NOTE: The LSE.Q circuit on the Class A 10.0 can be defeated for flat operation down to 20 Hz by placing the LSE.Q switch in the "OUT" position. You may wish to use this option to achieve a higher S/N Ratio when using ultra-high efficiency speakers, such as compression

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