What is a fader buffer?

[NYMorningstar]

When taking a direct out from a mixer's fader buffer is that pre or post fader?

 

[Massive Master]

Ideally, the direct out/tape out should be pre-fader. But I've seen both...

 

[oretez]

Not entirely sure about your terminology . . . a fader 'buffer' suggests some kind of digital desk (board console mixer control surface etc.)

but an out put (whether via single channel, whether line out or insert tap; or via a sub-group bus) reference as 'fader' with no prescript modifier (i.e. pre, post) suggests that it is post fader

otherwise, in terms of block diagram circuit logic there is no need to reference 'fader' at all, if you see what I'm saying

but real-world truth is that it all depends on the mixer (desk, board, console, control surface) Probably the more common configuration is for direct outs (or insert taps) to be pre-fader. On some boards this is easily 'switchable', on others you can open the board up and re-assign globally, on some re-assign channel by channel. And on some mixers you can mess with assignment at all without a soldering iron (& solder sucker)

a schematic, block diagram of mixer in question should let you determine its configuration

 

[bouldersoundguy]

Not entirely sure about your terminology . . . a fader 'buffer' suggests some kind of digital desk (board console mixer control surface etc.)

"Buffer" is a term also used to refer to a type of analog circuit, sort of an isolating stage.

 

[NYMorningstar]

I was reading this: "An impedance balanced DIRECT output is provided, fed from the output of the faderbuffer, which is therefore unaffected by the position of the ROUTING switches or PAN
control."

Now that I'm looking at it more I'm assuming since the output is unaffected by the pan it must be pre fader. Is that a good assumption? This is on a Spirit8 board.

By the way thanks for the replies, I appreciate it.

 

[bouldersoundguy]

I was reading this: "An impedance balanced DIRECT output is provided, fed from the output of the faderbuffer, which is therefore unaffected by the position of the ROUTING switches or PAN
control."

Now that I'm looking at it more I'm assuming since the output is unaffected by the pan it must be pre fader. Is that a good assumption? This is on a Spirit8 board.

By the way thanks for the replies, I appreciate it.

The direct outputs are set to post-fader from the factory, but you can switch them internally. See page 32 of the manual.

 

[NYMorningstar]

The direct outputs are set to post-fader from the factory, but you can switch them internally. See page 32 of the manual.

Thanks, that's just what I needed.

 

[oretez]

The direct outputs are set to post-fader from the factory, but you can switch them internally. See page 32 of the manual.

beat me to it by just 'that much' . . .


while if I never pick up a soldering iron again (except probably in hell) I'll be OK, am aware that there are analog buffer circuits . . . but original answer still stands in any type of elegant design one would not want pre-fader direct outs run through any fader circuits . . . but answer to question can only be resolved via schematic/block diagram (block in all cases, depending on how disingenuous mnfc is, might not resolve issue) for specific device

 

[Terra]

i'm confused on the concept of PFL...can anyone clarify? Some boards have a "pre-fade listen" I never understood.

Thanks, T

 

[oretez]

in the simplest sense it is pretty self explanatory it is a bus routing, that independent of other bus routings (e.g. main, aux, monitor, mono, etc.) lets you access signals 'pre-fader'

As to why it is a common feature and why you might what to use it, that is a slightly different response. But as one type of example, particularly in a live setting (even during sound check) you might use it for setting gain on a specific channel

 

[Terra]

ahhhhh. gotcha. thanks for the response brother.