Simple active summing mixer.

[radiance]

Lorlin

 

[syn]

thnx.they don't look like Lorlin(CK).where do you get those? :guinness:

 

[radiance]

now you mention it, they are not lorlin...

Got them from > http://www.banzaieffects.com/Rotary-Switches-c-275.html

scroll down a bit....

 

[syn]

thanks.

 

[radiance]

Ok, got some more work done. I wired all 20 channels to the master bus and it all works. Here some pics of my progress:

There will be another fronpanel that fits over this one....

Imagine punching 48 holes for xlr's  ???

Still have to wire the insert switching and some knobs...


I plugged the master output (with fader/pot on max) straight into my DAW.
With all 20 channels assigned to the master bus (that's 10 channels per bus) I got this reading on a spectrum analyzer.
What does that say? Is the PSU hum below 120db? I dont really have a clue about meassuring noise.
Also, I don't hear this with both master and headphone volume cranked up full so I guess I'm fine...

 

[dagoose]

wow! That is sum (whehe) serious DIYing upthere! You should change the subject to: Re: Serious active summing mixer.  ;D Are these the boards you showed me some time ago?
Turned it to be a real professional summer to me! How does it sound? I'm also seriously thinking of getting rid of my mixer and go for summing.

 

[radiance]

Yes, those are the boards I showed you. About the sound, well, hard to say. I've not done extensive listening test yet.
As you can see it has very low noise. I can hardly hear it's on, even with the headphones cranked up full...

 

[livingnote]

Wow, now that's a reading. Congratulations!

 

[radiance]

Thanks Livingnote!

I did some experimenting with the grounding..... thicker & shorter groundwires did reduce the the hum to less then 125dB...
I guess this is not something to worry about.

 

[tv]

(OT)
-125dB noise floor ... nice!

radiance, is this your own metering equipment?

 

[radiance]

(OT)
-125dB noise floor ... nice!

radiance, is this your own metering equipment?

It's a pectrum analyzer plugin from elemental audio.

 

[radiance]

Got a lot of pm's with questions about the progress of this project.
I think it would be best to ask them here...

Right now I'm waiting for some John Hardy 990 DOA's to arrive.

 

[livingnote]

How did you get that case together? I remember Ruiari had a Great River Pre with a similar thing on the sides, nice and sturdy metal profile on the left and right...

 

[radiance]

well, actually, it's a Schroff Multipac case without the fronpanel.
I made the second frontpanel (the one that holds the switches and such) myself.
The Schroff frontpanel will go over of that.

Here an idea of how the frontpanel will look like......(on a bad photo day)

 

[creal]

Hello radiance!

Congratulation, very nice work

 

[dagoose]

Looks great! Are these the switches from TU?

 

[radiance]

Looks great! Are these the switches from TU?

Thanks Mate!

Those are EAO series 01 switches, taken from an old Neumann switchbox. I think TU sells these but so far I've only bought lenses for these switches from them.

 

[josh]

Why do I get excited when I see 990 opamps?
or
really old Alva boards?  Man, my first board was an Alva mini.

 

[radiance]

Mine was a Gator....that's before he went wacko alright

 

[JAY X]

Hi Radiance!

After seeing your project, if i ever want to build a mixer with preamps for input and output gain, and mute, sends, etc. it seems that an active summing network is the way to go. ¿ is this true?

all the best ,

JAY X