Author Topic: Attenuation vs. 'Gain Control'  (Read 1812 times)

Offline Morne Coetzee

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Re: Attenuation vs. 'Gain Control'
« Reply #15 on: May 09, 2018, 02:55:29 PM »
Very interesting read, thank you. I have always wondered about this. I do have a question though.  I noticed that I can set the output voltage of my digital source via dipswitch, the manual reads: "Maximum Output Voltage:
Can be adjusted via internal switches from 0.3V to 4.25V to match system sensitivity." This source is connected via balanced cable to my preamp.

Getting to my preamp (fully balanced dual monoaural) I can again adjust the gain manually between +/- 0-18dB for each channel (supposedly to level match different components) manual reads: " Fully balanced instrumentation amplifiers are used in the gain stages, and each input can be separately adjusted for 0 - 18dB of gain. This allows the volume control to work in its optimum range even with sources of substantially different output levels."Volume control: "The attenuator modules are constructed on their own four-layer Arlon boards, where local power-supply regulation and bypass capacitors make for clean power and optimum isolation. An array of precision resistors provides attenuation in 0.1dB steps down to -57.0dB, at which point the steps increase to 1.0dB. In total, this hardware provides for more than 65,000 steps, allowing the"stepped attenuator" to act—and sound—like a continuously variable control."

My preamp in turn, is connected via balanced cable to my monoblock amplifiers with the following specifications: Rated continuous-power outputs: 150W into 8 ohms (21.8dBW), 300W into 4 ohms (21.8dBW), 600W into 2 ohms (21.8dBW), 1200W into 1 ohm (21.8dBW). Frequency response: 20Hz-20kHz, <0.5% THD. S/N ratio: better than 80dB (ref. 1W), better than 105dB (ref. full output). Input impedance: 100k ohms balanced, 50k ohms unbalanced. Output impedance: <0.05 ohms, 20Hz-20kHz. Damping factor: greater than 800 at 20Hz. Input sensitivity: 130mV for 2.83V output, 1.59V for full-rated output. Voltage gain: 26.8dB. Typical power consumption: 540W ±5% at idle, 210W ±5% in standby. Mains voltages: 100V, 120V, 200V, 210V, 220V, 230V, or 240V AC mains operation at 50 or 60Hz, set at factory.

My question is this, given that I can adjust these settings and having the specs what should my optimum output voltage setting be as well as gain setting for the stated amplification? Should I adjust these settings or just leave it at factory default? I can adjust my volume with 0.1dB resolution, so volume "range" has never really been an issue.

Thanks I appreciate your input  :thinking:
« Last Edit: May 09, 2018, 03:13:51 PM by Morne Coetzee »
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