Parallel Effects Mixer: The case of the missing downbeat

[Pushtone]

Parallel Effects Mixer

Like a lot of us I get very excited after reading JD's article on parallel effect mixing.
I looked at the few "blender" projects around but the excitement was diminished because they are predominantly single loop blenders.

There has been some excellent threads about mixers, so,
I set about making a layout for the project like JD describes when it occurred to me...
"what if I don't like mixing parallel effects?"
That would be a lot of work if I didn't.

I decided to quickly whip up a four-way buffer and throw in JD's simple mixer into a box.
I could quickly see if parallel mixing is as interesting as it sounds.
I did just that and no more. (no phase reverse).

I had a hard time deciding if it should be in one box or two.
I went with the one box design but two boxes might appeal to others.

The box has an in and out jack and bypass switch in case the mixing gets to mayhemenatic.
The hardwired loops work so much better than six phone jacks on a board IMHO.





GGG IC Buffer Project x 4 on one PCB.



GGG Simple Mixer on another PCB.
The output of buffer-1 is wired directly to mixer input-1 as a "clean" channel.
Buffers-2, 3 and 4 exit the enclosure via a terminal block and then back into the remaining three mixer channels.


JD's IC buffer is, as every knows, wonderful and the mixer works better than expected. Better as in low noise, high headroom, and the channels don't interact at all. I used 100k pots instead of the 10k in JD's schematic.
Other than the lack of a phase reverse circuit the system works well and in some cases the inverted phase may be a good thing.
See the Case of the Missing Downbeat below...



Well, I can say I LOVE parallel mixing.
There are thing so indescribably cool about it that it's tough not to get excited.
My guitar buddies give me the 1000 yard stare when I go on about it.
That tells me I on to something that will be "hot" in the near future. I remember that same stare from the 80s when my friends didn't understand why I wanted my guitar to sound like a barking dog (sampling).

To sum up, I am so glad I just pieced this together. It may not be elegant and lack the phase reverse but
now I'm intrigued to go on and build a second loop mixer with more bells.

That's much better than slaving over a PCB layout before ever knowing what it sounds like.


Couple more pics here.

[Pushtone]

Let me describe the cool thing from last night...




The case of two delays and the missing downbeat.

> BOSS DD-6 in one loop,
> GGG PT-80 delay in another loop.

With those two loops at an even level on the mixer I get 100% WET SOUND.
The dry, or direct, signal is 100% canceled!
I eliminated all other pedals and modeling amps to be sure.
I am able to repeat the effect simply by bringing each delay pedal to an equal level on the mixer.

OK, one of these pedals is inverting the direct signal (PT-80??),
but not the wet. Strange, Why not the wet?
The repeats are clear and when synced in time sum together 3dB louder.

Anyway it's a cool effect to control the wet level like on a recording console.
My mixer lets me blend in another signal in place of the direct.
As long as I keep the level of the two delays about the same I can set the level of the wet sound alone,
and dial in any direct sound from the third loop.

[Pushtone]

Please post any ideas for pedals to mix.

Here's what I've liked in just the last two weeks.

Blended Distortion with clean slapback auto-wah
LOOP-1: off
LOOP-2: Auto-wah -> Delay
LOOP-3: Distortion (HWY 89)
LOOP-4: Distortion (TS)
Love this for classic rock solos.


Dual Canceling Delays with Distortion (as described above)
LOOP-1: off
LOOP-2: Delay (PT-80)
LOOP-3: Delay (DD-6)
LOOP-4: Distortion
A practical application for phase cancellation


Distortion %^&*tail
LOOP-1: Clean
LOOP-2: Distortion 1
LOOP-3: Distortion 2
LOOP-4: Distortion 3
Much better than a series of distortion pedals


Pulsating Distortion (Cure sound?)
LOOP-1: Clean
LOOP-2: Distortion -> Delay
LOOP-3: Distortion -> Tremolo
LOOP-4: Distortion -> Flanger
Needs a deep tremolo carefully synced to the delay repeats produces pulsating chords.
The flanger brings it together and adds presence.

[gutsofgold]

Wow, that is so cool! I use parallel compression and reverb quite a bit when recording, it would be awesome to have that available for live use.

[Mark Hammer]

Welcome to the dark side, Dave.  Or maybe I should say the "enlightended side".  At Anderton's urging (in print, folks, not personally), I started dickering around with parallel processing in a rackmount unit I made for myself.  Can't say enough good things about it, and the mini-frac-rac thing I showed in the pictures thread a couple months back was intended to restore me to those glory days.  One of the truly sick and twisted things I made it possible to do was have "nested" splits and mixes.  Huh?  Let's say that splitter 1 send output A to a second splitter and output B to wherever.  Splitter 2's outputs are now processed in some way and blended back in some proportion by one mini-mixer (2-in-1-out), whose output is now fed to a 2nd mini-mixer that combines THAT blended pair of signals and whatever happened to the B output of the first splitter.  So, we have essentially three different possible versions of the signal happening, that can be blended in creative ways.

For the uninitiated, why is parallel processing so wonderful?  Well, think about the last recording you heard that had an amazingly well-recorded guitar or an extremely lush rhythm sound.  Part of what made it sound so great was that the engineer probably used several different amps and mics, and blended them together to nail a great full sound.  All of that multi-tracking we have grown so accustomed to is, at its heart, parallel processing.  Now, it often sounds one helluva lot richer in stereo, but even in mono, parallel processing can add a richer more animated quality to one's tone.  It's like the difference between watching a game when the arena/stadium stands are half full vs when the stands are packed.  Also, while you wouldn't think that making effects subtler ought to be the goal of a forum like this, arranging your blend so that there is lots bubbling just under the surface, but not so much as to distract from other aspects of the music that require their own little chunk of attention, IS a goal of soundmen, recording engineers, and producers.  And if you have recording or performing goals, it should be one of your objectives too.

Nice work Dave.

You wanted suggestions.  Stick a volume pedal and fuzz ahead of your wonder box, and run the outputs through multiple nonsynchronized choruses and a delay.  Now slam the most majestic chord you can think of, and gradually let that sucker fade in.  Wait until you get to work to do it, though, because you probably won't want to go into work once you try it.

[Ben N]

My reply to a long-ago thread about Neil Finn's guitar sound on Crowded House's "Don't Dream It's Over":

"I have no idea if this is correct, and I'm sure they didn't do it in the studio with pedals, but I play it with a chorus (CE-2) and a Flanger (Guyatone or Electric Mistress) in parallel, both going through a short delay (Dan-Echo or DD-3).  I use a Boss LS-2 to do the mixing.  Mixing the chorus and flanger gives a big, deep, 3-dimensional sound.  Try it."

If I were doing this today, I'd probably try running the EM and the CE-2 into both inputs on an Echo Park, and mix post-delay.
Mmm-hmm.

[andrew_k]

This thread has just decided what I'm doing with any spare time over the weekend! I've already got a pair of buff n' blend circuits and a dual TB loop box waiting to be combined, this just confirms that it's worth the time to do it properly.

Thanks to Pushtone and Mark for the info/inspiration 

[earthtonesaudio]

Definitely cool.  But careful around those cables.  With no protective grommets or anything, I'd be in constant fear of accidentally stepping on one and cutting through the insulation.

[RonaldB]

This is a really cool idea, i'm going to try this tonight.
Made a mixer real quick on the bread board.
I'm planning on doing 5 loops. 3 for overdrives and 2 for delay's.
I use quarter note delays and dotted eight note delay very much so i'm going to try putting the mix knobs in 2 expression pedals.
Then i can blend in how much quarter note or dotted eight note delay i want in the signal path.

great project

[Pushtone]

Welcome to the dark side, Dave. 

How deep does this rabbit hole go? 
Thanks Mark. Couldn't find the FracRac in the pictures thread. Sounds very interesting. Nested mixes and all.

There are so many things "routing-wise" you can do. Each builders loop mixer is likely unique.
The hard wired loops on mine for example. Works for me in the upper right hand corner of a board. May not work for others.
JD touches on HIS ideal design in the GGG article.



RonaldB: I like that take on it. Three distortions and two delays.
I picture it in a T1411 enclosure with five stomp switches to short the mixer channels to ground (channel mute).
A "mix strip".

Thanks for the comments

Dave

[Mark Hammer]

I cannot emphasize enough the coolness and utility of a "punch-in" switch for delay.  By this, I mean an arrangement in which a delay line of some type remains patched in to a mixer as an additional parallel signal, however the input path to the delay is set up as "on-demand".  When you get to a spot where you would like a riff or note or passage delayed and recirculated, you step on the momentary switch and your signal is routed to the delay.  Take your foot off the momentary switch and whatever is in the recirculation path continues for as long as you've arranged for, but nothing new is added to it.  It's like the "trails" function, but better and more effectively managed.

So imagine you have a song where you would like a particular riff to be treated as if it were like a couple of backup singers doing a call-and-response with the lead singer.  You set the delay for the required lag, turn down the recirculation, set the output to wet-only, and feed that into some additional processing to make it a little different (let's say an EQ).  So now you get to the part of the song where that needs to happen, and you step on the momentary switch.  The guitar signal is still going to the blend/mix node without interruption, but everything you play while stepping on the momentary, and ONLY that, will be delayed by the designated amount and mixing back in for that one time with a slightly different EQ.  Sorta like your own little arpeggiator...guitar style.  Meanwhile, you're off playing something different at that point.  You'd be surprised how handy that can be.

Dave,
As the above example illustrates, the rabbit hole goes as deep as you want it to.  I'd show you a picture of the Frac-Rac thing, but the filters at work prevent me from seeing anything on Photobucket, where I put the pictures.  If you have access to Photobucket, see my post here on the Canada Guitar Forum - http://www.guitarscanada.com/Board/showthread.php?t=152&page=19  That will probably be easier to find than digging through the "pictures" thread here, since it is several thousand posts shorter.  What I have almost built are several modules that each have a two-way splitter, and two-in-one-out mixer.  Naturally, you can patch the output and input points in the loop to wherever you want, including phase invertor stages, other splitter/blender modules, CMOS switches, filters, out-board effects, etc.  The intent is to have all the patching flexibility of a modular synth.  Incidentally, take a gander at the "Quad sequential switch" scan at my site for even more sick and twisted ideas.

[MadMac]

THIS is so cool!!

Ive been messing with parallel delays with splitter blend for a while with mixed results.

1/4 + triplet delays sounds so cool.

[earthtonesaudio]

I'm thinking this may be my next project...

[frank_p]

I got over that when I -finally- realized that rack gear is for the pa and pedals are for your axe. Be careful, next thing ya know your amp is a small PA system! 

OR



-------------------------
Mark Hammer ?
or
Moog Hammond ?
-------------------------
This is great and HUGE ! 

[frank_p]

Oh Mark!  Your "rack" reminded me of what pushed me to start soldering effects last year.  Maybe I should return to that kind of thingking too.  It makes me think also of R.G.'s FxBUS.

This is the system:


This is the link:
http://home.sprintmail.com/~daugard/synth.htm

You probably have already seen it.

[cheeb]

This sounds wonderful, and I'd like to try it since I've already built the mixer and it's just gathering dust. Color me ignorant, but I don't understand how you have it routed to your pedalboard. I can't wrap my head around how you have your effects set up, and how they function when the parallel mixer is bypassed.

[Pushtone]

To answer Cheep's question and anyone else interested...

There are really quite a few ways to arrange the signal flow into and through the paraMixer.
In JD's article he describes his ideal but there are alternatives.

Anyone embarking on a paraMix project has to decide first of all, one box or two?
If you put the splitter and mixer in one box the bypass options are easier to implement.

Here's what I'm working on based on JD's article.
A "one box" paraMixer with a couple of simple features.

1. Dual opamps are configured as buffer with polarity reverse.
One of the four buffers is also in the bypass path to buffer your signal all the time.
Layout for a T1411 enclosure is in the works.

2. The normalized jacks between splitter-1 and mixer channel-1 let the signal flow when nothing is plugged in.
Used like a "clean" channel to get the sound of pedal in front of the paraMixer.

3. Each splitter out has a mute (to gnd) switch. This is used when setting up a sound. It saves a lot of effort spinning the pot to hear the mix with and without effect on that channel. No so good for performance because there is a level drop when a channel is muted. But could be set up as a boost for solos. This switch could be a toggle or footswitch. Mine will include DPDT footswitches with an LED.

Block diagram.

[frank_p]

As said before,
I have to use this approach with my Danalectro Psychoflange,
This effects is three frangers in a box.
I will put in parallel a clean blend.
Then at the end, a high pass filter.

The Pscho. is like a pea soup, way too thick and bassy.
I now do that with a normal mixer, but a standalone would be great.

[joegagan]

great thread!
thanks for sharing this pushtone. and thanks as usual to mr hammer, great insights.

[Pushtone]

Here's a commercial pedal product that has an interesting take on a mixer for effect pedals.
www.herby.kielce.pl



Close examination shows the footswitch might toggle between two modes for the A and B outs.
Not totally sure how it works but it does give me an idea or two.


BTW: Heres how my next para-project is coming along.
I 've got a breadboard worked up using this schematic.




I have the first and second channels worked up.
The two channels sound very different.

I though I could save the parts and just use a buffer for channel one
but the other buffers with the pol rev sound different.

Not bad, just different.
I will have to make them all the same to have consistent tone on all four.

AFA the missing resistor values for the pol rev goes...
I tried to figure out the formulas but I'm not sure how to apply them and generally have math issues.
I tried many different values working up from low to higher.
When I close the rev switch the level either drops 3-6dB or I get no sound.
A little help figuring out the values for the pol rev (in red on the schematic) would be greatly appreciated.

I've found a couple of other pol rev schematics but they use a bi-polar PSU.
I will try them on the BB with 9V this weekend.
From this very good "mixer" thread:
http://www.diystompboxes.com/smfforum/index.php?topic=39182.msg279186#msg279186

Also I'm not sure how I will test the inversion after I have it working.
Software scope? Record a sine wave into ProTools and compare waveforms? Any suggestions?

Thanks all
Dave