Difference between Line-Out and Direct-Out

[Rockin Mike]

I guess in that case one should be careful to plug the shield cut side into the guitar so the other end can take noise to ground through the amps and pedals?

[bongomania]

Seems reasonable, but TBH I don't know the answer to that one. The instrument end is grounded too though--to the player, via the bridge and strings.

[Rockin Mike]

bongomania,

Thank you for helping me understand these things and your patience with my questions.

If the instrument grounds through the player, isn't the player vulnerable to dangerous electric shocks if he touches something and grounds out through it?

[HolmeBass]

Used to be that amp makes actually had different input impedances on their Active and Passive inputs. I think now most have a circuit on the input that matches the impedance, with varying degrees of success. It seems they do pretty well, usually there are only problems with extremely high output-impedance transducers like piezo pups without a buffer circuit. I much prefer a deliberate 10 dB pad button than the silly practice of "Active" vs "Passive" inputs differing only by a pad but actually being the same input impedance.

Line-out is useful for feeding any line-in affordance. There are two different "line" levels, -4dBu and +10dBu, it would be nice if line-outs and line-ins were labeled as to what level they actually run at. But I have found line-out to be useful to slave another bass amp's power section, if it has a "line-in" jack, or to drive an additional dedicated power amp. In a pinch you could run an effects loop of line-level "studio" style effects from your line-out and back in to your line-in jack. But for the sound board/PA, stick with direct out (balanced, usually XLR).

[bongomania]

Originally Posted by HolmeBass

Used to be that amp makes actually had different input impedances on their Active and Passive inputs. I think now most have a circuit on the input that matches the impedance, with varying degrees of success. It seems they do pretty well, usually there are only problems with extremely high output-impedance transducers like piezo pups without a buffer circuit. I much prefer a deliberate 10 dB pad button than the silly practice of "Active" vs "Passive" inputs differing only by a pad but actually being the same input impedance.

Errr... Here are the actual facts: the pad itself is a resistor network (often a single resistor). The added resistance lowers the input impedance significantly. It has always been this way--there has not been any change in how amp makers design the "active" input, no era of doing it one way and then another. If there are ANY amps with automatic impedance-matching circuits, I've never seen one.

For the finicky, yes there are a few instances where a preamp has been designed with a manually adjustable input impedance that isn't associated with an active-input pad. Summit TD-100 is an example. But there are very, very few exceptions like that.

[Calaverasgrande]

dont try those floated shield cables on old tube amps.
kinda tingly and flashy if you try to sing.

[Calaverasgrande]

Originally Posted by bongomania

Errr... Here are the actual facts: the pad itself is a resistor network (often a single resistor). The added resistance lowers the input impedance significantly. It has always been this way--there has not been any change in how amp makers design the "active" input, no era of doing it one way and then another. If there are ANY amps with automatic impedance-matching circuits, I've never seen one.

For the finicky, yes there are a few instances where a preamp has been designed with a manually adjustable input impedance that isn't associated with an active-input pad. Summit TD-100 is an example. But there are very, very few exceptions like that.

Summit 2ba221 as well. AWESOME DI for bass. Really amazing how some basses like a high impedance and others like lower impedance. It's not subtle at all.
Sweepable high pass doesnt hurt.

[krkozbassman]

The "noiseless" cables with 1 side of shield cut should have the cut end at the bass and connected side at the amp. This, in theory, uses the shield which is some type of braiding that surrounds the 2 inner +/- wires and acts like an "antenna" to capture the noise and take it to ground at the amp.

[chadds]

Originally Posted by Calaverasgrande

dont try those floated shield cables on old tube amps.
kinda tingly and flashy if you try to sing.

You mean right before the blue light that precedes the white light that we're supposed to go toward?

[B-string]

Originally Posted by chadds

You mean right before the blue light that precedes the white light that we're supposed to go toward?

The blue light goes to black first. Got in a hurry having to setup the PA and forgot to check the polarity on my old Sunn 2000S twice. Thought we were having a blackout? Didn't get to the white light

[chadds]

Originally Posted by B-string

The blue light goes to black first. Got in a hurry having to setup the PA and forgot to check the polarity on my old Sunn 2000S twice. Thought we were having a blackout? Didn't get to the white light

I dimmed the lights when I put the fuse back in my Marshall Major on Ampeg V4b cab without its fuse cap while touching the strings.....
Basically it felt like I was picked up suddenly by a helicopter by one arm......