splitting a stereo line level signal - what should I buy?

Jonathanthomas83

I have a stereo signal at line level that I wish to send to my Cranbourne Audio headphone amp. But I also need to send it to my interface for times when I need to record it. 

It must be transparent and the ability to monitor via the headphone amp must still be optional even if I send the signal to the interface. 

The Radial MC3 looked good, but it's discontinued.

Any suggestions would be greatly appreciated.

octatonic

A small mixer is probably the best option.
You will find line splitters that cost all much the same for a much smaller feature set.
A mixer will probably give you extra features like EQ and aux sends.

A Mackie 1402VLZ would be ideal. Or the 1202 if you don't need faders.

uksaint7

Not sure about your particular application but I'd been eyeing up a Lehle P-Split Stereo for use on a pedalboard.

Musicwolf

Have you tried a simple splitter lead?

You may get away without any earth-loop issues, so worth a try before shelling out for a mixer or dedicated spliter box.

Jonathanthomas83

octatonic said:

A small mixer is probably the best option.
You will find line splitters that cost all much the same for a much smaller feature set.
A mixer will probably give you extra features like EQ and aux sends.

A Mackie 1402VLZ would be ideal. Or the 1202 if you don't need faders.

Thank you @octatonic , I value your opinion on things, given your work. 

It feels like a good option, but slightly more than I really need. I know there's a big price on the P-Split Stereo that @uksaint7 ;
recommends (thank you mate), but if I'm honest, the size and simplicity of it appeals. Do you have any experience of using a P-Split and is there any downsides to it?

Alternatively, something like this:

https://hosatech.com/products/analog-audio/patch-bays/mhb-350/?srsltid=AfmBOop8otHZdkrQqNaUw5RHpDzDnr0PLoddp9uvWiOJgNR3KjMO69jv in half normalled mode.

Would love your thoughts.

Musicwolf said:

Have you tried a simple splitter lead?

You may get away without any earth-loop issues, so worth a try before shelling out for a mixer or dedicated spliter box.

Just a bit anxious of it being detrimental to the audio signal, really, mate. It's line-level, so maybe it won't matter.

Musicwolf

Jonathanthomas83 said:

Alternatively, something like this:

https://hosatech.com/products/analog-audio/patch-bays/mhb-350/?srsltid=AfmBOop8otHZdkrQqNaUw5RHpDzDnr0PLoddp9uvWiOJgNR3KjMO69jv in half normalled mode.

Would love your thoughts.

Musicwolf said:

Have you tried a simple splitter lead?

You may get away without any earth-loop issues, so worth a try before shelling out for a mixer or dedicated spliter box.

Just a bit anxious of it being detrimental to the audio signal, really, mate. It's line-level, so maybe it won't matter.

Using a patchbay in half-normalised configuration (which is what you would do to split the signal to two sources) is actually the same as using a splitter lead.  As long as you don't create an earth loop then there should be no degradation to the signal.

Danny1969

The actual term line level can be a bit misleading to a certain extent, because the actual voltage level the receiving equipment gets on the input depends on the output impedance of the sending device and the input impedance of the receiving unit.

With professional audio Line Level is +4dBu which is 1.2V into (historically 600 Ohms ) but more realistically feeds into 10K or so now.  Outputs on pro audio +4dBu units will be very low impedance and happy to drive capacitive loads  (shielded cable) Consumer line level audio has a lower signal voltage and the output impedance could be a lot higher.

When you passively split a signal the output impedance of a device becomes more important, because what was a single input impedance now has another one in parallel with it. This lowers the total impedance and that means the unit sending the signal may struggle unless it's a very low impedance source. The extra loading combined with the RC low pass filter effect of shielded cable can degrade a signal.

So whether you get away with it depends on the impedance's of the devices and the length of cable. 

Jonathanthomas83

Danny1969 said:

The actual term line level can be a bit misleading to a certain extent, because the actual voltage level the receiving equipment gets on the input depends on the output impedance of the sending device and the input impedance of the receiving unit.

With professional audio Line Level is +4dBu which is 1.2V into (historically 600 Ohms ) but more realistically feeds into 10K or so now.  Outputs on pro audio +4dBu units will be very low impedance and happy to drive capacitive loads  (shielded cable) Consumer line level audio has a lower signal voltage and the output impedance could be a lot higher.

When you passively split a signal the output impedance of a device becomes more important, because what was a single input impedance now has another one in parallel with it. This lowers the total impedance and that means the unit sending the signal may struggle unless it's a very low impedance source. The extra loading combined with the RC low pass filter effect of shielded cable can degrade a signal.

So whether you get away with it depends on the impedance's of the devices and the length of cable. 

@Danny1969 would a buffer help with that, or two/stereo buffers, in my case?

Danny1969

@Jonathanthomas83

Could you not just use a monitor controller with 2 outputs, these are typically used to send a stereo signal from a DAW to 2 sets of active studio monitors, so audio integrity is generally high

Jonathanthomas83

@Danny1969 it's an option, yes. Do you have any recommendations?

octatonic

Jonathanthomas83 said:

octatonic said:

A small mixer is probably the best option.
You will find line splitters that cost all much the same for a much smaller feature set.
A mixer will probably give you extra features like EQ and aux sends.

A Mackie 1402VLZ would be ideal. Or the 1202 if you don't need faders.

Thank you @octatonic , I value your opinion on things, given your work. 

It feels like a good option, but slightly more than I really need. I know there's a big price on the P-Split Stereo that @uksaint7 ;
recommends (thank you mate), but if I'm honest, the size and simplicity of it appeals. Do you have any experience of using a P-Split and is there any downsides to it?

Alternatively, something like this:

https://hosatech.com/products/analog-audio/patch-bays/mhb-350/?srsltid=AfmBOop8otHZdkrQqNaUw5RHpDzDnr0PLoddp9uvWiOJgNR3KjMO69jv in half normalled mode.

Would love your thoughts.

I haven't used those products but everything Lehle do is wonderful and everything Hosa do is made to a price point.

The thing with a discrete box like this though is they are limited in function.
I have a load of single use things here when really a mixer can do so much more and for the same sort of money.

There are loads more of them about and they are easy to interface with.

If you are going to get a patchbay (every studio needs one) then I would get the Neutrik 1/4" ones at the budget end and the Audio Accessories bantam ones at the high end. Indeed, this is what I did.
Remember, outputs on the top, inputs on the bottom.
The number of times I see that reversed in studios, it is incredible.  
And wrong- you follow the signal flow.