Author Topic: Looking for Signal Splitter Circuit for Recording Purpose.  (Read 6567 times)

nguitar12

Looking for Signal Splitter Circuit for Recording Purpose.
« on: October 20, 2015, 04:53:00 AM »
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

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #1 on: October 20, 2015, 05:31:37 AM »
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 ?

« Last Edit: October 20, 2015, 05:42:15 AM by nguitar12 »

Kipper4

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #2 on: October 20, 2015, 07:27:12 AM »
Why not take an aux out from pa to recorder ?
I ain't no muff builder boi.
Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
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bluebunny

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #3 on: October 20, 2015, 08:26:03 AM »
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).
Ohm's Law - much like Coles Law, but with less cabbage...

alexanderbrevig

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Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #4 on: October 20, 2015, 08:40:15 AM »
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

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #5 on: October 20, 2015, 09:11:20 AM »
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

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #6 on: October 20, 2015, 09:13:33 AM »
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

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #7 on: October 20, 2015, 09:44:42 AM »
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
I ain't no muff builder boi.
Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Granny Gremlin

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #8 on: October 20, 2015, 09:57:47 AM »
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.
my (mostly) audio/DIY blog: http://grannygremlinaudio.tumblr.com/

Kipper4

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #9 on: October 20, 2015, 10:08:19 AM »
Klipper ? Lol
I was indeed mate talking about the Paul in the lab schematic
I ain't no muff builder boi.
Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

alexanderbrevig

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Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #10 on: October 20, 2015, 02:39:14 PM »
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.

« Last Edit: October 20, 2015, 09:01:31 PM by alexanderbrevig »

Granny Gremlin

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #11 on: October 20, 2015, 03:16:30 PM »
You will learn that I am the king of typos.  Sometimes they are rather apt or hilarious, but this is rarely intentional.
my (mostly) audio/DIY blog: http://grannygremlinaudio.tumblr.com/

PRR

Re: Looking for Signal Splitter Circuit for Recording Purpose.
« Reply #12 on: October 20, 2015, 03:31:06 PM »
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.)