Newbie question: Where to start on building audio splitter/selector

Greetings; first, I'd like to make it clear that I'm a complete newbie at audio projects. I recently graduated with a degree in electrical engineering, so I'm not a scrub with building/designing circuits, but audio projects are completely new to me.

My father is looking for a device with two stereo inputs and five outputs, which can each be independently set to either of the two inputs (or nothing). Such devices are commercially available, but prohibitively expensive. I've been looking for a new DIY project, and this sounded like a challenge, but as I dig into the research I realize that I lack a lot of the knowledge needed to build this thing well.

My questions are as follows:

1) The inputs will be coming from sources with their own amplification, so I don't feel the need to amplify the output any further; however, some volume control would be good. Which op amp chips would be the best quality/price tradeoff considering my father isn't a big audiophile?

2) I would like this to be wall-powered and not battery-powered; any suggestions for good power supplies for audio circuits?

Thanks
DBZ
 
I bought some switches, off ebay, that would work really well for this type application, search for 4p2t switches, then look for ON-OFF-ON type, these have a center off position. There are others which are ON-ON, with no center position, and (ON)-OFF-(ON) which are momentary on (spring loaded). Anyway, buffer BOTH inputs, then chain input one to one side of each of 5 switches, input two to the other side, then the center connection to the 5 outputs. This lets you switch signal and ground for each connection.

Tom.
 

matej8888

Member
2011-06-03 7:14 am
I have a similar project. I need an audio signal split in 5 times the input signal. I've read some posts on various forums, so the idea is to put in parallel to the input signal as many buffers as I like (seen some schematics on the net that should work) using
- transistor (JFET preffering due to its sound qualities) as voltage follower/buffer
- op-amp as buffer
The Gain of each buffer/voltage follower has to be 1.
The audio signal would mostly be comming from a laptop, Ipod, DAC, maybe thru an active crossover,....to various tube amplifiers.

Now, my question is which one should I use (J201, OPA27....just shooting versions, but I will consider any kind of high quality suggestion)?

I really do care about sound quality so what i'm looking for is high quality components.

Matej
 
One of Ben Duncan's pre-amps had a similarly complex input/output arrangement.
I think he did it with logic chips.

Rotary switches can achieve it simply, but require a lot of wiring. As the outputs quantity increases the wiring complexity increases.
Audiolab has 5 inputs and two outputs (record output is a different signal from audio output). I did similar about 20years earlier, without any buffers and crosstalk + hum were a problem.