Need Advicce for Microphone line splitter

[Olegarich]

Dear Diy family.

I need your advice in something new for me. I've checked other posts about that, but want to check details.

I need microphone signal splitter which I'm gonna to use on live shows. Signal from microphones will go to that splitter and then to our small format console which gonna be used as monitoring and second signal will go to the FOH. So it's gonna be 2-way splitter.
So here questions i need help with.

1. Which is better Active or Passive. Transformer based or transformerless?
2. How it works with condenser mics? I mean if it transformer based how I'm gonna feed  +48 phantom power??
3. Which transformer to choose? What specifics do i have to look for?
4. What else do i have to care about? Do I need something like buffer?
5. Maybe you know some good schematics for that??

Thank you a lot guys, you allways helping me a lot and I'm learning from all that.
Have a nice evening!!

 

[Andy Peters]

Dear Diy family.

I need your advice in something new for me. I've checked other posts about that, but want to check details.

I need microphone signal splitter which I'm gonna to use on live shows. Signal from microphones will go to that splitter and then to our small format console which gonna be used as monitoring and second signal will go to the FOH. So it's gonna be 2-way splitter.
So here questions i need help with.

1. Which is better Active or Passive. Transformer based or transformerless?
2. How it works with condenser mics? I mean if it transformer based how I'm gonna feed  +48 phantom power??
3. Which transformer to choose? What specifics do i have to look for?
4. What else do i have to care about? Do I need something like buffer?
5. Maybe you know some good schematics for that??

The big boys commonly use non-isolated (transformerless) passive splitters with no ill effects. They work perfectly fine with phantom power; generally one console is considered the P48 "master" and supplies all phantom, but in general having the phantom enabled on both consoles for a given channel shouldn't cause problems. If you have your recording rig and your FOH rig all on the same mains power, there's no need for transformers. (If you were feeding a recording truck outside, you might wish to have transformers.)

Multichannel splitters are available from several sources, including Radial, Whirlwind, EWI, and others.

-a

 

[Olegarich]

But if I want to make isolated - with transformers, what spec to look?

 

[sahib]

Oleg,

I have ( about 80 ) 1 in 3 out microphone splitter transformer  which handles signals up to +22dBu. Will do your job perfectly. There are two ways of applying the +48V.

One is that you include it in the splitter box and incorporate it to the primary of the splitter as you would do on a micpre input.  So the mic goes into the splitter primary and you have three isolated outputs. One goes to FOH and the other two for recording/monitoring etc.

The other one is that the mic goes into the splitter primary and at the same time  to the FOH console. In other words the mic goes straight into the FOH console and you tap onto the signal. In this way the mic gets the +48V from the FOH and again you have three isolated outputs for recording/monitoring etc.

 

[JohnRoberts]

But if I want to make isolated - with transformers, what spec to look?

First check your bank acct.

A 1x2 transformer split can maintain the bridging termination with  1:.707 step down ration that will step up the loading 2:1. The few dB of signal loss while more than from a passive split is not significant.

In general hard wire splits are preferred because of lower cost. Good quality mic transformers are not cheap. So only used when you anticipate serious ground issues between widely separated power drops.

The obvious spec for transformer audio quality is LF max signal handling vs distortion.

JR

 

[0dbfs]

Common transformer based splitters consist of a 1x3 in to out system where there is one direct out (paralleled to in so phantom passes), and two isolated outs.

MON, FOH, BROADCAST with Mon taking the direct out and supplying 48V with FOH and Broadcast using the ISO out's...

Each channel uses a transformer with one PRI and two SEC's...

If you need more splits you can design/spec trafo's with additional secondary windings, or daisy chain another "standard" 1x3 splitter from the direct out so you maintain a path for phantom.

Most trafo mfgr's have transformers designed for this.

Hope that helps!
Best Regards,
jonathan

 

[gridcurrent]

So it's gonna be 2-way splitter.
1. Which is better Active or Passive. Transformer based or transformerless?

a transformer is less ultimate hassle.

2. How it works with condenser mics? I mean if it transformer based how I'm gonna feed  +48 phantom power??

any/all outputs can be configured creatively to supply phantom.  one phantom configured output is the most practical.

3. Which transformer to choose? What specifics do i have to look for?

suggesting a 1:1 with split windings, wired 2:1.  short list includes UTC A-20, Triad A-67j, Hammond 804, UTC LS-30, there are many others.

4. What else do i have to care about? Do I need something like buffer?

concerns include galvanic isolation, microphone loading, source impedance for the following preamps.

5. Maybe you know some good schematics for that??

not sure about the "good" but attaching one.

I've used the industry standard 1:1:1 isolated splits for years, from several of the well regarded manufacturers: to my ears they sound like AM radio.
Thus the submitted  design.

 

[Andy Peters]

But if I want to make isolated - with transformers, what spec to look?

For live use, in your situation, with a split for FOH and monitors, just save yourself a boatload of money and forget about the transformers. You don't need them.

-a