Gain - understanding it and getting it right

[Macca]

Good video this, worth a watch especially if you're a bit ropey on what gain staging is and what happens if it's done wrong:


https://www.youtube.com/watch?v=vu9lHR9o-Mc

[Barry]

An interesting video, but I'm not sure the average music lover would understand or even appreciate the difference between dB, dBu, dBFS, or even the fact that the electronics at the source end have to provide voltage gain, whereas the power amplifier needs to provide current gain.

And not all high quality audio gear has the gain stage versatility of Benchmark. Any prospective purchaser has to rely on the skill and ability of their local audio dealer to put together a system that works well.

My system has always been a mishmash of components from different manufacturers. In the early days it was largely from one manufacturer, so I assumed it would not be a problem; and it wasn't.
Now the audio components are from a variety of manufactures, but all have the provision to alter or adjust the gain: CD + DAC or CDP; MC cartridge transformers; preamps and power amps. This does mean having to make these adjustments internally for the various bits of kit (apart from the monoblock power amplifiers), but it can be done.

What I aim for is an arrangement where, regardless of source, the volume control of the preamp is midway through its range at about "12 o'clock", for my normal listening level. That way I can turn it down if need be or turn it up if I want to shake the floorboards. If no source is selected, but the volume control is at 12 o'clock, if I put my ear directly against the speaker grill I hear no noise, hiss or hum.

[Macca]

He does give a pretty clear demonstration of the different approaches to gain staging and what it entails. You don't need to understand dBu, dBFS or current gain to appreciate that.

My power amp has quite high gain (25dB) and the speakers are high sensitivity but I don't get noise.

Plenty of room to go up and down on the volume pot, usually it's between 9 and 11 o'clock depending on the recording - but you can adjust both analogue and digital input level on the pre-amp.