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The Power Supply and Misc. Measurements

I must gripe about the giant wall wart. It's...giant. You will have to give it a solitary spot on your strip or use a cheap $1.99 extension cord if power strip space is at a premium. The second gripe is that under heavy load, it gets so hot that you could burn yourself if leaning up against it. Actually, a more realistic possibility is what it might heat up forgotten on the floor behind a desk of some sort. Be careful where you put this thing.

As we figured out, the unit is rated at 14.4 watts. After that, any stronger current requirements decrease the output voltage, increase the hiss and distortion. A larger filter capacitor would solve this dilemma. As I did not attempt a two-tone test (i.e. 100Hz and 1 KHz), the power supply table reflects only two of the three output channels fully driven. The house AC input measured 119 Volts.

DC Voltage
Load
Description
16.80
None
not plugged into sub
16.10
Idle
plugged into sub w/no music
14.86
1 channel
3.67 watt, 1 channel draw
14.83
2 channels
6.52 watt, 2 channel draw

With both sat channels at maximum, the total current draw exceeds 1 amp and the wart is seriously stressed. Adding the power hungry sub to the equation could easily have the current near the 3 amp mark. Current limiting is heard as the familiar "pumping and breathing" or just flat out distortion.

The signal to noise ratio, or the amount of hiss that emits from the speakers was a very high 79dBC at max volume measured from the satellite outputs. No appreciable hiss or hum was heard at any volume setting.

The analog volume control fits in your hand nicely. It has a twofold purpose: loudness and input impedance. Rather than the ubiquitous hashy sounding digital volume control (they all have distortion), Labtec has a volume "pickle." Similar to those game show hand-held buttons, this one is very small and sports a side mounted potentiometer that operates smoothly and precisely. It feels more expensive than it should.

Input Z (impedance) is the resistance that the position of the volume control sends back to the amplifiers. Effectively controlling loudness, if the Z is too low, it will load down the music source, in this example the sound card. The measured input Z was 5.35Kohms. This figure will keep noise figures lower than if a 10Kohm pot was used, but it could load cheap sound cards. Nominally, if the input impedance is at least 10 times the output impedance of your sound card, less than 1dB of sound will be lost and very little high frequency loss will occur. Many cards in the $10-$20 range have output impedances of 1KHz or more, which could cause problems with these Edge 418's. The Sound Blaster Live! card I used for testing has a much lower output impedance and was a great match for the volume control.

Speaking of the SBLive!, it's usually known as a high quality, high output card. So when I had to boost the device mixer input to max as well as the master volume, I was inclined to check the amplifier input requirements. I found that a high-ish 240mV was needed to drive the 418's to full output. Some sound cards definitely will not meet this requirement.

Miscellaneous Pictures

Accessories
Directions
Monitor Mount
Table Mount





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