audio mixer with tubes?

[unsolved]

Has anyone seen any diy project for an audiomixer somewhere? I´d like to get something like 2 mic channels and 2 line inputs, eq on mic channels and insert points in mic/line and mix bus...

I have no experience with building with tubes, but i have repaired some. It could be a nice way to learn about impedance matching, sum amp with tubes and so on....

And it would be nice if it is possible to expand to more inputs in a later stage (which means a lot to think about regarding power supply and so on i think )

Then, let's see if i will go for it and build, but it could be some nice reading :-)

[nigelwright7557]

I built a ECC83 2 stage valve mixer for my disco.
It has 2 inputs for CD players, one for a mic and one for line input from an IPOD.

The mic input used the first stage of the ECC83 and then all the line inputs went into the second stage. The mic input also doubles as an electric guiatr input too and gives a nice warm sound.

It was an interesting project having all sorts of problems with hum. In the end I used DC heater circuit grounded on one side.
I also had to put a bit of effort into the power supply to reduce noise.

Its probably not quite good enough for your purposes but I am sure someone will post something better.

[HollowState]

Here is some interesting reading.

http://www.tubecad.com/april_may2001/page22.html

Since you say you have no experience in building with tubes, you should definitely read "Building Valve Amplifiers" by Morgan Jones.

http://www.amazon.com/Building-Valve.../dp/0750656956

[m6tt]

I cannot stress enough how important lead dress, oversized resistors, good tubes, and a well done AC or DC heater supply is when it comes to microphones. Don't waste good watts on hiss . It took me a couple of builds and rebuilds before I got a good grip on those things, but I can tell you that carbon comp resistors are full of snakes, and that you should get a fairly high-powered soldering iron . Grounding is a big issue too, especially when it comes to microphones or other metal covered instruments, in regards to both safety and quietness. Don't use parts from radioshack. Good luck!