Input trim

[ChrisIRL]

On amps that have the feature does anyone know what exactly it does? Is it basically a volume adjustment to have all inputs at the same level or does it alter the input sensivity? I ask because increasing it seems to enhance detail at lower listening volumes in a way that simply increasing the volume doesn't seem to do. Could be a trick of the mind.

 

[Vladimir]

It's to adjust for the input sensitivity of the amp. You are hearing more details because you turned it up louder. The input trimer is linear, unlike the logarhitmic pot used as a main volume control, so turning it up should feel more immediate, as you've noticed.

 

[ChrisIRL]

I think I'd prefer linear adjustment, why not just have this anyway? Thanks.

 

[keeper of the quays]

It's to adjust for the input sensitivity of the amp. You are hearing more details because you turned it up louder. The input trimer is linear, unlike the logarhitmic pot used as a main volume control, so turning it up should feel more immediate, as you've noticed.

if i fitted one if these retrospectively to my wind up 78 player do you think ill notice a improvement? I see its linear? My 78 player sits on a flat table.

 

[abacus]

I think I'd prefer linear adjustment, why not just have this anyway? Thanks.

The reason is because the ear follows a logarithmic law, not a linear law. (This is the reason why you need 10 times the power (10db) to double the volume, rather than just double the power)

Hope this helps

Bill

 

[TrevC]

On amps that have the feature does anyone know what exactly it does? Is it basically a volume adjustment to have all inputs at the same level or does it alter the input sensivity? I ask because increasing it seems to enhance detail at lower listening volumes in a way that simply increasing the volume doesn't seem to do. Could be a trick of the mind.

It's exactly the same thing as turning the violume up and down, the idea is to equalize the volume of different sources.