How to Build a DIY Analog Passive Summing Box

[@kellyraysmith7697]

Hi Peterson, I know it's asking a lot, but could you please take the time to do an A/B shootout between this summing box and in-the-box summing. I would be very interested to hear the results, and I think a lot of other viewers would too. Thanks for your videos, -Kelly

[@MattOttewill]

Nice video and project. Thanks. It would be nice to have a clear explanation of what the resistors are for and how to calculate their values for a given number of summed signals. This knowledge is assumed in the video. Perhaps I've missed an explanation on the site / posts page?

[@djgalawak]

ola, here it help : www.diyrecordingequipment.com/blogs/news/tagged/how-tos

[@Pyrocrig]

Thank you so much for posting this! This is EXACTLY what I need for my studio. I have a bunch of line-level modules and keyboards that plug into a mixer, flat flat flat - no eq, unity levels for everything, etc. (that is noisy as... well, you know) and then out to an amp and monitors. I can bypass all that mess! Never even thought about this option. PERFECT!

[@ckjjclan]

Holy shit. I just found your company and these videos, thank goodness, as I was about to drop some serious $ on other gear. This video alone showed me what I suspected all along, that the “summing” part of expensive boxes, is a pretty cheap and simple circuit.... THANK YOU!

[@Wizardofgosz]

Other boxes have different circuits. If it's an expensive summing box I can assure you it's a much more sophisticated design. A favorite of mine uses op-amps on each output, and transformers on each channel.

[@corystevenponzo7007]

If you run the sleeve to pin 1 the ring to 3 and the tip to 2, it should still be balanced. Also ground the pin chassis to pin 3. Assuming you send it a balanced signal. And output to a balanced in. It should all be balanced throughout the summing, although I'm not sure if phase would flip as you add each signal to the buss. Do amplitudes and larger voltages on peaks flip phase? I wonder if low tolerance resistors will benefit.

[@shiftdrummer1991]

I know this video is really old but how would you go about adding a pan pot to each channel? As simple as wiring the signal input to the input of the pan pot and then wiring one signal to the left side bus wire and wire the other signal to the right side bus wire?

[@stevezafeiriou]

i love you

[@SilentNote]

Hi... about an ANALOG SUMMING CABLE... 16 channel TRS Male to 2 TRS Male... Does DIY Recording Equipments post a VIDEO showing how to do it ? Kind Regards

[@PetersonGoodwyn]

Since the output is microphone level, you would need some sort of amplifier to get it to line-level before sending it to your headphones or power amp. What are you looking to achieve?

[@ROCKNROLLMODS]

This is just to put all of the individual tracks in a recording session down to a stereo track for cd or whatever medium. Sounds better to do it in the analog realm, rather than stacking up a bunch of ones and zeros in your recording software. It's not for any sort of playback or monitoring etc.

[@ShadovvV]

Very interesting, with the exception that there aren't any capacitors or IC chips being used. What would be the difference?

[@brocknbrollrecords]

Hi, I want to do one of these for summing some synths to a single stereo output. I only need 3 stereo inputs. So 6 inputs and 2 outputs. How would this effect the choice of resistors? How do I know what output impedance I want? The stereo output would go into DI box and then into a PA system. Cheers.

[@gurindersingh7933]

can u please make a side by side video for how to use these project . i appreciate ur videos and efforts .

[@DMSBrian24]

If you use this for line level devices (e.g. interface and turntable preamp outputs), won't they backfeed into each other's outputs, potentially causing damage?

[@PetersonGoodwyn]

Nope! The resistors prevent that.

[@aaronarakawa6398]

is this just a wood textured adhesive veneer on metal face plate? where did you get it?

[@Jaime_Estevez]

be easier to send group from the box right through an analog output of the "DAW", process out of the box and return it to the box?

[@waterdropmusic]

I like this project and I have some questions: I mainly use Outboard gear (think Stereo Synths and I have 1 mono input from my Mic Pre-Amp (Avalon) and couple of mono synths. The reason I want this is I want to capture the clean uncolored sound from these instruments into my sound card (Aurora 8)... Right now they all go into an Allen and Heath GL2400 analog active mixer then into Aurora 8 and then into DAW to cpature... I don't care about panning or gain and I can control the volume of all from the instruments themselves. MY question is do I have to use all channels at once or I can just plug in just 4 stereo tracks (4 synths) into the 8 stereo (16 channel version of the mixer) ... What about if I shut off one synth and theres only 3 playing? would that make a better or worse difference in sound quality level? I understand you don't want to mix balanced or unbalanced signals.. What about if one of the mono synths is an older one with 1 unbalanced TRS output? Any help would be appreciated. Thanks Much!!! :)

[@esaugalindo4733]

peterson, could you show a video of how to hook up your sb2 to a interface?

[@albundie3]

could you replace any of the resistors with potentiometers? I'm new to all this and I want to make a synthesizer with a patch bay on it for mixing various oscillators at different pitches in and out. is this mixer a good route for that? I guess it's a two part question but yeah. thanks for the video very informative

[@playstorepj2788]

MrAnagmate i have a quick question cant we use a diode in place of the resistor (i mean diodes pass electricity in one direction only right?)

[@alexandreoliveira6110]

Hi, I really appreciated that... I´d like to know if is possible to create mono i/o too.. Thanks, and congratulation for your job..

[@mikobaku]

Can you use some of the inputs when you don't need all 16 or should you always try to use all inputs? Just curious if you could use only 8 inputs instead of 16 if you don't need all 16 (but want to have them sometimes). Or should you build two boxes, one for 8 and one for 16?

[@clydejabrahimi7729]

You can use as many as you want.From 1 to 16

[@3ds12Game]

Ok but I would have liked some more explanation about how it worked or seen some schematics. And since the video quality is not the best, i'm still not sure how it works.

[@jackrussell9809]

Wondering what transformers and power supply you recommend if I plan on creating a version with a balanced output and built-in preamp.

[@russellwilson9740]

Jack Russell -I was thinking along these lines. If I'm not mistaken, it would require input and output X-formers, op-amps -a complete preamp.

[@LivingwithoutAir912]

online it seems to be a steel rackmount and its only 1u tall. did you custom make this wooden one thats 2u? if so, mind telling how cause i would prefer this.

[@borabecker5834]

Can we listen to a comparison audio? i mean, a mix before and after passing throw the summing box... Please! build it worth?

[@roykasika870]

I came here for this

[@AMusicalPsychosis]

Can this handle stereo subgroups with panned instruments, or is it mono only?

[@MyCadaverDog]

stumbled across this...somehow, haha, and decided to buid one a few hours later...really cool idea. btw, love the website. any more videos brewing?

[@ericBcreator]

I build mine this weekend. It is working but it sounds a bit like an old AM-radio that is not tuned well: compressed and noisy, almost like it's clipping. Also there is a continous whining sound, even when no inputs are connected, which has the same volume, regardless of the volume setting of the preamp. Anybody an idea what could be causing this? Maybe the grounding or some kind of radio interference? BTW: I have no other problems like that in my home studio.

[@MrNEWDY]

I'm not an expert but from my recent restoration of an old shure mixer and getting similar issues, my best guess is that your impedance resistors are not the right value. This old mixer has variable impedance per channel and when I increase the impedance to a high value my signal gets mega crushed and distorted and also loud. It could also be the signal fed into the summing box. Line level is higher than instrument level which explains why I got a cleaner signal sending my guitar through a channel on my repaired mixer vs sending tracks from my dad through it at line level.

[@djgalawak]

you fix it ? what was the problem noise ? cheers

[@EL34tube]

Thanks! Will be my first DIY project. I don't understand the calculation for the output resistors that i have on a schematic: (20K/N)200 / (20K/N) - 200 WHERE N = NUMBER OF INPUTS I will have 3 Left + 3 right inputs, six total So i found this for each one of the two resistors (left and right): (20000/3) x 200 / (20000/3) - 200 = 0.2k Is this ok? Thanks!

[@ferranleal]

Hi!! If I wanted to mount one of 20 mono channels / 10 stereo channels, what resistance should I use? Thank you so much, your videos are really inspiring.

[@PetersonGoodwyn]

10k resistance with a 150R shunt resistor will work just fine.

[@ferranleal]

Thank you so much!! I’ve made it my own and works just fine!! Magnific video and a diy project! 😘

[@corystevenponzo7007]

Look up OEP and VTX Transformers around 10 a pop. Add 18 of these plus two for output pre post amp, four discreet opamps with output faders now you are in the high end world. Build it all for $300 including Penny and Giles faders and sweet VU meters with a buffer or fed possibly off the unused primary on the master output. Power supplies are found in equipment at your local thrift store for pennies.... Pun intended Or use a few 9v until you can coble one together.

[@djgalawak]

a tuto for summing box with transformer will be great, to understand circuit and built it .. ;) cheers

[@Jbdoster]

So neat and tidy, fantastic job man cheers!

[@itsme5900]

i want to listen to the audio output of this unit, can you do that ?

[@jacobbraun4916]

Do you guys still sell this? I can't find it on your site.

[@zapz2101]

Hello what if a want to do exactly the opposite? 1 in and 8 or 6 out?

[@rocketsauce5067]

Transformers would be your best bet. They make splitting transformers in multiple ratios and secondary windings.

[@SomeplaceWonderful]

I need to sum 8 mono inputs into 1 mono output. Is that as easy as I think it might be? looking at the still pics it seems it would essentially be half the circuit.

[@PetersonGoodwyn]

Exactly! You could think of this as two 8-to-1 mixers next to each other.

[@SomeplaceWonderful]

@@PetersonGoodwyn Thanks for confirming!

[@BairdonBassNS]

Could you leave a message explaining the point of this? To me it seems like it's a mixer with no gain, no eq and fixed faders (resistors). Its a really neat project but I'm not sure what the applications would be. How do you use this in your setup? Thanks BTW, nice job on your clean and tidy work!

[@PetersonGoodwyn]

Hi, there are a couple reasons someone might want a device like this. A) Some people believe that analog summing sounds better than the algorithmic summing that's done in your audio mixing software. I'm not so convinced of this. B) A passive summing box is a great tool in a workflow that involves a digital recording medium with some "outboard" analog processing gear. For example, I like to use Reaper as my mixer, but mix "live" through my analog compressors & EQs into this box, which then goes to some nice preamps for makeup gain and back into Reaper as a 2-track mix.

[@artissonbeats3057]

@@PetersonGoodwyn right

[@CaptRadar101]

How would you do a 32 Channel one

[@willyderwilde4763]

Great Video!

[@dealio82]

Can I replace the XLR connectors with normal 1/4" jacks?

[@TimMer1981]

Yes, no problem. :)

[@homeestudiolf1395]

oi bom?, o que gasto pra fazer uma desta?

[@sdfasgagfafgvav]

I might build one but with faders and just run my busses out of my daw and then back into my daw.

[@MusicTechHelpGuy]

Thanks so much for this video. I took your concept and added stereo pots for each pair of channels and it turned out great. I actually did a back to back of summing in Pro Tools and summing analog, and the coloration of the wiring and resistors alone (although subtle) is worth it for my kind of music. soundcloud.com/joshua-d-carney/digital-vs-analog-summing-with-diy-summing-box

[@mindseyerobot]

+MusicTechHelpGuy im convinced, can definitely hear the improvement.

[@mikep6967]

I hear a more robust mix in the second version? Is the second w/ the summing unit?

[@ROCKNROLLMODS]

It's certainly louder. So hard to tell on this stuff. Kinda like how buying a new putter makes your golf game better. I know analog summing makes me feel like superman, so I'm more into the mix down process. Which whether or not the gear is actually doing it, you get a better final product.

[@itsme5900]

i just mean to say how this unit sounds like ? it will be nice if you can route some audio through it, record and let everybody listen ;-)

[@PetersonGoodwyn]

@MyCadaverDog Thanks! Yeah, got one brewing right now on the anatomy of a dymanic microphone.

[@Senj1n]

this is soooooo fucking great man!! very appreciated

[@gabetachell5791]

If you are sending line level outputs from your daw to this thing does the output still end up being mic level? If so why?

[@artissonbeats3057]

Dope

[@americanryan]

Add transformers and this would be cool!

[@evish2155]

so sexy :)) but how does it sounds? are summing boxes that simple?

[@Exaltation-heliacal]

Penn rules. Nc. Penn Jersey Ga. Better musicians.

[@mixmz4917]

I need someone to build me one for about $250 to my specs. 20-channel, 2 xlr, 3 d-sub's (with 4 unused channels, because you don't want more than 20 on a passive unit). All connections are on the back. Rack-mountable, 3U or less. Sell it to me or trade me for a free mix that I'll do using your box.