Simple High Quality Splitters and Mixers

[cpsmusic]

Hi Folks,

I'm currently in the process of setting up a small music studio for recording demos and song writing.

I'm interested in making a couple of splitters and mixers which will help with signal routing and make the setup more flexible.

Specifically, I'm after the following:

1. A line level splitter for a mono input and two mono outputs.

2. A line level splitter for a stereo input and two stereo outputs.

3. A mixer that has two stereo inputs and one stereo output. Each of the stereo inputs has its own volume control.

As these devices are in the recording signal path I'd like for them to be low noise and low distortion.

I've come across various schematics (e.g. Jensen AS041 splitter, etc.) but I'm really unsure as to the quality.

I'm also aware that a small mixer can do these jobs however I'd like to learn something in the process.

Any help with this would be much appreciated.

Cheers,

Chris

 

[Andy Peters]

The splitters can be nothing more than simple Y cables.

You can make a micro-mixer out of an op-amp and the jacks and a power supply.

 

[Markus_Krippner]

I hope nobody kills me here, if I'd recommend this to you:

http://www.behringer.com/EN/Products/MX882.aspx

I had some of these units....these are very versatile....splitter, mixer, line driver ...whatever you want.
Quality is ok (maybe except the pots), I had them in a broadcast environment, but of course it's no highend audio ;-)

...markus

 

[cpsmusic]

The splitters can be nothing more than simple Y cables.

You can make a micro-mixer out of an op-amp and the jacks and a power supply.

Won't using a Y-cable affect the signal level? Also, what's the purpose of the schematic shown in Jensen's as041 design note? Why have three transformers and an op-amp when a Y-cable would suffice?

Also, which op-omps would you recommend?

 

[Andy Peters]

The splitters can be nothing more than simple Y cables.

You can make a micro-mixer out of an op-amp and the jacks and a power supply.

Won't using a Y-cable affect the signal level?

For standard bridging line-level signals, no -- low-Z drive (~100 ohms or less) into multiple 10k loads is not a problem.

Also, what's the purpose of the schematic shown in Jensen's as041 design note? Why have three transformers and an op-amp when a Y-cable would suffice?

Dunno, maybe they want to sell transformers? That circuit uses op-amps because it allows for trimming the gain.

The main reason to use a transformer is for isolation between source and load. If you have a driver on one mains circuit and your receiver is on another about 1,000' away and 30 VAC ground difference, a direct connection will damage something (exceeding the rails is bad). So you put a transformer in between and the two sides can float at whatever level they like without causing problems.

Also, which op-omps would you recommend?

Anything that can drive low-impedance loads. These days, most folks would use one of the THAT or TI balanced line-driver ICs and be done with it.

-a