Looking for Signal Splitter Circuit for Recording Purpose.

[nguitar12]

Hi everyone I am current looking for a signal splitter circuit for microphone. I want to split the signal for both the PA and my recorder (mic input) . I find one circuit from but I am not quite sure whether it is what I looking for.





http://www.paulinthelab.com/2012/04/buffered-y-splitter-veroboard.html

Can someone please tell me if this circuit works and if there any other better circuit

Thanks.

[nguitar12]

Sorry forgot to mention. The signal is balanced so is it mean that I simply need to duplicate the above circuit for both the "hot" and "cold" signal or if there other approach to do this ?

[Kipper4]

Why not take an aux out from pa to recorder ?

[bluebunny]

Or if it's just the mic you want to record, and the mixer has one, steal a feed from the insert jack on the mic channel (it will be at line level by that point, and you don't need to deal with balanced hot/cold).

[alexanderbrevig]

In a studio/recording setting I'd prefer not to go through an opamp if I didn't have to.

I'd first try to do a simple parallel (you will probably need to drive your mic harder, or up the preamp):


If that's no good I'd do something like:

Which is a much better solution that only works with dynamic microphones as is. If you need phantom power you need to add a DC offset to the Input side of the transformer. There's probably schematics for it, if not (and you're building this) let me know

[nguitar12]

Why not take an aux out from pa to recorder ?

It is not my place so I won't be able to access into the control room to deal with the PA/Mixer

[nguitar12]

In a studio/recording setting I'd prefer not to go through an opamp if I didn't have to.

I'd first try to do a simple parallel (you will probably need to drive your mic harder, or up the preamp):


If that's no good I'd do something like:

Which is a much better solution that only works with dynamic microphones as is. If you need phantom power you need to add a DC offset to the Input side of the transformer. There's probably schematics for it, if not (and you're building this) let me know

Any chance the simple parallel will make the mic dull or increase the noise level?
Will my schematic work? Your schematic contain a transformer which I don't believe I can get easily here.

[Kipper4]

I wouldn't have thought your schematic will work well.
It's a high impedance input and your gonna need a much lower input impedance for a mic.
Besides its not a very good design. There's much better out there with noiseless biasing.
And a better performing op amps maybe.
If it where me I'd have a word with the front of house engineer, recording engineer and politely ask what he can do for you.
I've never turned down a nice polite request yet that I haven't been able to fulfill as an engineer.
Rich

[Granny Gremlin]

Do not use the Y cable.  Depending on the mic and preamp it can do different things.  It could be negligible, but it also could raise noise floor a lot and cause weird frequency response effects.

The transformer is the best solution, though that diagram above is a little overly complicated.  You only need a 1:1 transformer (cheaper and easier to source) not a 1:1:1, because you can take the direct out to the mixer (mic + and - to primary; primary + and - is also direct out as in the diagram) and then the isolated out from the secondary to your recorder.  You don't need any of the caps/resistors in that diagram, they are more for robustness and more flexibility (ground lifts etc).  Do keep those leads twisted as described tho - common mode rejection is your friend.

An easy Phantom power solution if you're using a condensor is to split the output of a preamp that has phantom vs the mic signal (mic split with a transformer = same setup for pro line level).  If that's not going to happen, then an array of 9 volt batteries and a couple XLR jacks will give you the cleanest most stable phantom you've ever had (phantom is rarely ever a full 48V  - some things give as low as 18-24; 36 is a good target, but 48 won't hurt anything, it's just an an aweful lot of batteries)

I must assume that Kiipper is talking about the active solution up top.

[Kipper4]

Klipper ? Lol
I was indeed mate talking about the Paul in the lab schematic

[alexanderbrevig]

Kiipper

Klipper

It's not easy getting it right. (I meant this humorously)

nguitar12 I think the best tip so far is to ask the engineer to help you out.

[Granny Gremlin]

You will learn that I am the king of typos.  Sometimes they are rather apt or hilarious, but this is rarely intentional.

[PRR]

The op-amp plan is for Line level.

Mikes need a much lower hiss level, are often balanced, often have 48V Phantom Power on them.

The TL072 self-hiss level is 2X to 10X the self-hiss of a microphone. This may be tolerable micing a rampaging Fender Twin, but soft vocal work will be annoying.

There's other problems with this plan, especially for this use.

97% of ALL Pro mike-splits are done passive. For small gigs, just Y the mike cable. Mike impedance and mixer(s) impedance are different enough that no harm is done. (Granny's opinion differs; strange stuff happens.) You really should not even need to "up the preamp"; the loss is around 1dB and there will be 3dB-6dB differences between takes due to mood and vocal fatigue. (Fix that in the mix-down.)

Where the stage is deep inside a cow-palace and the recorder is in a truck way out in the parking lot, on a different power feed, Jensen's transformer is invaluable to break ground loops. For a session all on the same floor, it is usually overkill. (The studio operator has already cleaned-up power/ground issues so he may take unbalanced lines from amps into mixer.)

> I don't believe I can get easily here.

It may help to say where "here" is. And I think Jensen will ship nearly any place. Maybe someone near you knows a good place to buy or even borrow connections. (Yes, the Jensen transformer is awful expensive for occasional use; the equivalents are also expensive.)