ytsestef

Not really much to say here.. Just the fact that I was going for the "Bus-Bar" thing that a lot of people do around here do, using some (tinned?)copper wires that stretch them across some chassis-mounted connectors (I don't know what they're called). But I couldn't do it right, it was really messy and I decided to go with a veroboard. The type that has parallel lines of copper. I couldn't find a smaller case that had the same faceplate with the other stuff I have built, so I got the same one and wasted a lot of space, but whatever!

It has 16 inputs and 2 outputs (duh!), as usually, they're stereo pairs (1-2,3-4,5-6 etc) only the last four inputs are routed to both output channels. I did this because I don't want to waste stereo buses to put some things dead-centre (bass,kick,snare,vox), plus this way they're summed OTB, so I think this is great economy, since once I am done with the "mono" stuff I have 6 Stereo Groups to do the rest. I have made quite a few mixes in which 2 or 4 channels remain unused, so for busy projects this suits me just fine.





And this is how it fits with the others:



So I have a completely analog summing and master bus, which sounds very very good and includes summing, preamp and compressor. So, yeah, I really want add an EQ too. A Nite EQ would be kick-ass!!  8)

...What am I doing??  :o NO..! NO!! ...MUST... STOP... BUILDING... HARDWARE.... AAARGHH!!!

Does it qualify for the "finished projects" META?
« Last Edit: October 22, 2009, 06:42:09 PM by ytsestef »
Stefanos.


Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #1 on: October 22, 2009, 07:41:15 PM »
Nice summing box. Great job! I've been meaning to make one of these too. I don't understand how you routed the last 4 i/p's to both L and R out. Doesn't that affect the gain structure? the voltage would be halved, right? And the idea of a summing box is to sum instruments into a stereo group (so drums, gtrs, vocals, etc.). why would you want to have a separate i/p for kick?

ytsestef

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #2 on: October 22, 2009, 07:56:35 PM »
Nice summing box. Great job! I've been meaning to make one of these too. I don't understand how you routed the last 4 i/p's to both L and R out. Doesn't that affect the gain structure? the voltage would be halved, right? And the idea of a summing box is to sum instruments into a stereo group (so drums, gtrs, vocals, etc.). why would you want to have a separate i/p for kick?

Thanks a lot! The gain structure isn't affected if you use different values for the resistors in those channels.
The idea of a summing box is to have a better summing than the crappy algorithm most DAWs have. You can route through it anything you want clear with better definition and seperation. Instead of having the kick, snare, toms and OHs summed but the DAW isn't it better to have transient types of instruments into individual channels? The difference was breathtaking the first time I tried it. The way I built it, I think of it more like a console, but with controls in my DAW  ;) If I want, say, a guitar solo (not likely, but for the sake of the example) to cut through the mix without boosting its gain, maintain its spectral content psychoacoustically regardless of what the other instruments are playing, and make it really seperable from the rest, I might as well route it through a bus by itself. Like I said, this is a pretty fictional scenario, but you can imagine how good will that be for the vocal track, the transient stuff (kick,snare), and the god-awful bass hot notes. They all feel way less washed-out. Sometimes I even route my reverb by itself though a bus (helps retain the tail A LOT)
Stefanos.

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #3 on: October 23, 2009, 03:16:19 AM »
I see. That's interesting. Not sure it would work for me since a lead vocal would most definitely be a stereo track (as would a kick and snare in many cases). What would you do if you have, for example, a stereo reverb and delay on that fictional guitar solo you spoke about? I'll have to experiment once I have my own one built!

ytsestef

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #4 on: October 23, 2009, 07:50:48 AM »
OK, here's how I do things in modern rock mixes:

1    Kick
2    Snare
3    Bass
4    Lead Vocal
5/6  Drums. Sometimes including snare and kick, but with a compressor on this bus, so the whole set gets pumped, but the kick and snare is in parallel compression because in 1 and 2 the transients are maintained. This way kick and snare are still stereo, I am just helping them stand out and maintain clarity.
7/8  Guitars
9/10 Keyboards
11/12 FX (All reverbs delays etc)
13/14 Unused or sometimes my Lexicon reverb.
15/16 Unused or backing vocals. Sometimes where I have double-tracked vocals I ditch bus 4 and route them here.

Besides the benefits mentioned before, this way tracks can be treated individually using hardware compressors/eq's before getting into the summing box. That's a huge benefit of having some important mono tracks on their own bus. Compressing the kick is different than compressing the drums. Same thing goes for vox. ;)

Of course other genres of music would be differently approached in terms of mix, but I find this system quite versatile.
Stefanos.

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #5 on: October 23, 2009, 06:10:25 PM »
I see. That's a cool approach. You should try grouping stereo instruments with their FX sends (lead vocal too if it has stereo FX), print a mix (or "bounce") and then try your way with a separate FX group. And listen to the difference. It might be interesting  :)

ytsestef

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #6 on: October 23, 2009, 07:13:58 PM »
Hmm "printing" stuff is against my philosophy on mixing. I like to have real-time control over everything and be able to go back if I need to. Bouncing groups to free up channels reminds me of the way The Beatles were doing it back in the days  :D YMMV, of course!!

One of these days I am going to record a minimal song with 2 acoustic guitars, one vocal track, one track acoustic bass, one track electric guitar, a stereo-miked 3-piece string trio and 4 tracks of drums (room stereo-miked, kick,snare) and route each instrument in a different bus. I would do this one way or another, it's not something that I'll do for the sake of it...
Stefanos.

pucho812

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #7 on: October 23, 2009, 07:36:41 PM »
very nice. However I reject the use of the word summing mixer as it is redundant.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

ytsestef

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #8 on: October 23, 2009, 07:42:18 PM »
very nice. However I reject the use of the word summing mixer as it is redundant.

Heh, now that I think about it, you're right!! English is not my first language, anyway...  :-[ :-[
Stefanos.

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #9 on: October 23, 2009, 08:40:42 PM »
Hmm "printing" stuff is against my philosophy on mixing. I like to have real-time control over everything and be able to go back if I need to. Bouncing groups to free up channels reminds me of the way The Beatles were doing it back in the days  :D YMMV, of course!!


perhaps you misunderstood. all i meant was make 2 different mixes and compare the differences.

P.S. what's wrong with the way The Beatles recorded? Their recordings remain amongst the most sought-after of all-time. People try to recreate the wonderfully musical characteristics of those recordings and fail miserably! Bouncing tracks is a good idea as it forces the engineer to use his brain and think on his feet. There is no "it's ok if it sounds crappy, we can fix it later". Listen to the White Stripes "Elephant". all recorded on a 4 track.


ytsestef

Re: [BUILD] "Unison Design" Passive Summing Mixer Complete!! Pics Inside!!
« Reply #10 on: October 23, 2009, 09:33:39 PM »
Yeah, I misunderstood! I've already done this, there is not a huge difference. The basic improve comes with not having everything summed ITB in my opinion . Which a lot of people doubt, too. Others say it's not better, just different. Well, i prefer it anyway. Generally all of these stuff are nit-picking. They're details. But it's the detail makes the difference after all.

I love The Beatles, don't get me wrong. I try to get a sound as close as the want I want during the recording process. This is the first and last irreversible thing I do. I put compression and eq (lots of them if needed). During the mixing I like to have more control, and I prefer to have realtime effects over some more free buses on my summing box. YMMV...
Stefanos.

rednex

Hi All!
Help meee!
values for the resistors(monocs) please:) & wiring network
thx

red

Have you used the search function?  Have you read through the Meta-Meta? 

Start here.
http://www.groupdiy.com/index.php?topic=2779

rednex

The topic or board you are looking for appears to be either missing or off limits to you. :-\

or link not aviabile

ytsestef

If anyone wishes to replicate this, this is the schematic:

Stefanos.

Rockitdog


If anyone wishes to replicate this, this is the schematic:



Hi there

I know this is an old post but it seems to be a good thread on summing mixers. I want to build one of these but am a little wet behind the ears when it comes to modifications. I would like to include an input level pot on each channel.

My question is, where would I insert the pot on the schemo and what value should I use? Do I replace the resistors that are already there?

Thanks for a great forum.

Cheers


sodderboy

Looks great.  Do you have the board insulated from the chassis?  It looks like it is bolted right up against the painted metal.  Make sure there is enough spacing or proper insulation away from the metal.

And those burgundy 1/4" cables are sweet!
Mike

JohnRoberts

Those pix are a few years old...

To add some simple input pads, add dual pots, with the Rs tied to each wiper could add a variable pad to each mono input..

The stereo inputs could alternately use the dual pots in a variant on a H pad to trim the stereo levels.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.


 

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