Advice and ideas for a mixing console build

[efinque]

I'm taking the same direction with pre's, mostly to option tx's in signal path.

Have you looked over the "green pre"?
https://groupdiy.com/index.php?topic=5839.880

Or poured through the THAT pages?
Pre:
http://www.thatcorp.com/datashts/dn140.pdf
Comp ideas:
http://www.thatcorp.com/Design_Notes.shtml

I assume you are wanting to keep things simple and avoid tx's.

I used to search for information and go through schematics.. I still do at times but I think I understand the basic concepts, the rest is details, most often use-specific.

If there was a reasonable-size "open-source" mic/line pre or a published commercial design with readily-available components and documentation all you'd find is a few stranded wires and a bunch of Vishay technical papers.. even so people wouldn't be content with it because everyone would use one in their projects.

 

[Hideki]

I think I understand the basic concepts, the rest is details

Looking at your "unconventional" designs, I don't think you understand much beyond the very basic concepts.

I would focus on learning more electronics before you set out to design your large format device.  Copy subcircuits that are known to work. Copy how others draw their schematics.

For example, potentiometers have three connections, so show how _all three_ connect. You often draw pots that are supposedly connected as rheostats (variable resistors) with only two connections. I understand what you want, but the drawings do not make that clear. If something is connected to the wiper, then DRAW that connection too.

- Explain how a simple one pole highpass and lowpass suddenly turn into shelving high and low filters.
- Explain why you need to switch both ground and signal to enable/bypass your filters.
- Explain why your insert point does not have both send and receive connections.

 

[efinque]

- Explain how a simple one pole highpass and lowpass suddenly turn into shelving high and low filters.

I've noticed passive filters are load-dependant.. their characteristic changes when you drive them.

- Explain why you need to switch both ground and signal to enable/bypass your filters.

I see no reason why not.. besides a DPDT switch is more robust.

- Explain why your insert point does not have both send and receive connections.

If you mean TRS; I was thinking about it the other day. But I believe I have no use for such feature.

 

[iampoor1]

Not trying to be a meaniepants, but I would recommend learning more following a more ahem...tried and true path with the circuit design. It doesnt really look like you have even the slightest clue of how to design a decent circuit. This isnt a huge deal when building 1 or 2 channels of something, but investing all of this effort into a design when a Mackie 1642 will be miles ahead and probably sound better? Well, that to me seems like a fools errand. Douglas Self has written practically half a book on this, Steve Dove has written an entire set of articles, and Rod Elliot (ESP) has a full set of plans too.

I admire your passion and desire to build things, but building such poor performing circuits is well...painful to watch. There is a reason the DJ mixer thread hasnt had any replies in months other than your updates......

 

[Hideki]

I've noticed passive filters are load-dependant.. their characteristic changes when you drive them.

It is true that they will change a bit, but they will not magically (unless you are Harry Potter) turn into a shelving filter. Most such filters use some form of the Baxandall circuit configuration, which gives you both boost and cut -- and yes, it can also be passive if you say that it must be.

I see no reason why not.. besides a DPDT switch is more robust.

And that is the real problem here. You don't see why.

If you mean TRS; I was thinking about it the other day. But I believe I have no use for such feature.

An insert point actually lets you insert something at that point in the chain. It breaks the connection and sends the signal somewhere else for processing. You then return the processed signal right after the break. If you have no need for this, then do whatever you like, but expect people be confused when you still call it an insert. While it's common and cost/space efficient for unbalanced systems to use a single TRS jack (with a switch), it can also be done with two separate connectors.

iampoor1 is right. It's hard to respond to your posts when it seems like you live in a parallel universe where all those years of developments in audio engineering never happened.

 

[Moby]

I would think twice about choosing all wood enclosure.  No shield, no grounding ... 

 

[Whoops]

I would think twice about choosing all wood enclosure.  No shield, no grounding ... 

YES, the wood enclosure is a bad start, like others have said, you should get the geometry and space you need after, but above all you need an enclosure that shields the console circuits, and there's no shielding in wood.
Normally wood is only used for aesthetics and only in the side panels (still there's metal underneath it)

 

[JohnRoberts]

YES, the wood enclosure is a bad start, like others have said, you should get the geometry and space you need after, but above all you need an enclosure that shields the console circuits, and there's no shielding in wood.
Normally wood is only used for aesthetics and only in the side panels (still there's metal underneath it)

I put painted wooden end bells on my big consoles. I had the luxury of a guitar paint shop in house to make truly pretty wood details, BUT (there's always a but) the guitar paint shop was run like a factory (because it was). They would paint the left end bells one day, and right end bells in a different batch sometimes on a different day.  Painted guitars don't have to color match perfectly, actually a little variation is desirable,  but my console QA people were in constant conflict with the guitar paint shop to make the end bells match.  I even tried to get them to paint them in sets or pairs which would logically resolve the color match, but I was unsuccessful getting the factory bureaucrats to bend even that little.

JR

PS: Of course the innards were completely encased in a grounded metal chassis.

 

[boji]

You then return the processed signal right after the break. If you have no need for this, then do whatever you like

If you're only providing an output point (no return) and it does NOT break the signal path in the channel then call it a 'mult' as it is a normalled send.
If patching into it breaks the channel signal path but has no ability to return on the same jack, perhaps call it 'direct' or 'option out'.

 

[boji]

If you mean TRS; I was thinking about it the other day. But I believe I have no use for such feature.

Do you ever plan on using outboard gear? Would you ever consider injecting a guitar pedal, vocoder, spring reverb or arduino nutty fx machine into a channel during recording or mixing?  Sure you can use an aux, but you'll run out of auxes fast if you're trying to get creative or want to set up a cue mix for your performers. Inserts in these examples become indispensable.

Let's back up for a moment: Draft out for us your real-world signal flow scenario all the way from inputs to mix down.  Leave nothing out.  8)

Btw, where's the insert point into your aux in the circuit?  Only one aux per channel?  I can tell you under tons of advice around here from VERY established engineers and creatives that you can never have enough auxes...

 

[Whoops]

PS: Of course the innards were completely encased in a grounded metal chassis.

 

[efinque]

Do you ever plan on using outboard gear? Would you ever consider injecting a guitar pedal, vocoder, spring reverb or arduino nutty fx machine into a channel during recording or mixing?  Sure you can use an aux, but you'll run out of auxes fast if you're trying to get creative or want to set up a cue mix for your performers. Inserts in these examples become indispensable.

I'm aiming to mix tracks from a sequencer into the mixer.. but while I'm at it why not make it record-ready too? I'll probably put inserts in the plate of few channel modules for fast access.. a patch bay would effectively solve this and I'll probably make/buy one but as you can see there's a lot of work before that.

Btw, where's the insert point into your aux in the circuit?  Only one aux per channel?  I can tell you under tons of advice around here from VERY established engineers and creatives that you can never have enough auxes...

I think wiring auxes uses a ton of cable.. I'm probably going with a 16:2 configuration for now.

 

[boji]

I'm just trying to understand where your head's at. If I'm not helping, just say so ok? So...

I think wiring auxes uses a ton of cable..

My take is that Auxs as fx inserts actually reduce the need for cable. The bulk of wiring is going to be permanently fixed at the patch panel, and auxes let you send fx inputs from multiple channels without having to create a rat's nest at the patch or around the mixer.

I'm probably going with a 16:2 configuration for now.

When you say 16:2 do you mean 2 auxs per channel or two auxs are at the stereo bus?

 

[efinque]

My take is that Auxs as fx inserts actually reduce the need for cable. The bulk of wiring is going to be permanently fixed at the patch panel, and auxes let you send fx inputs from multiple channels without having to create a rat's nest at the patch or around the mixer.

I mean, every aux needs a separate output wiring from a channel strip (3 wires, L/R & ground times the number of channels, per one aux) to a separate summing bus.. doesn't seem much at first but think 4 or 6 (edit : that's 6 output connectors for 2 auxes, 12 for 4, 18 for 6 etc)

When you say 16:2 do you mean 2 auxs per channel or two auxs are at the stereo bus?

16 channels, 2 aux buses. Leaves some room for expansion too I guess.

 

[ruffrecords]

I mean, every aux needs a separate output wiring from a channel strip (3 wires, L/R & ground times the number of channels, per one aux) to a separate summing bus.. doesn't seem much at first but think 4 or 6 (edit : that's 6 output connectors for 2 auxes, 12 for 4, 18 for 6 etc)

Does this mean all your channels are stereo channels?

In your very first post you said you would need AUX buses. Why have you changed your mind?

Cheer

Ian

 

[Newmarket]

I think wiring auxes uses a ton of cable.. I'm probably going with a 16:2 configuration for now.

Having decided on the major task of building a not very small mixing desk then I wouldn't worry about the amount of connections needed for the AUX buses.
You will end up wanting them (well - ever heard anybody say that their desk didn't need all the auxes it has ?).
Then, of course, you need to decide whether they are pre/post x fader/eq and fixed / configureable (eg jumper) / switched. Happy Days
& as others advise - don't start with the shell and even if you do not a wooden shell.
Good Luck .

 

[pucho812]

I had some ideas that I have been sketching for a console.

I love the idea of a removable mic pre/eq module like on the old Neve's and trident desks. While it does up the cost a bit it does make it plausible to run those modules separate from the consoles for remote recording.

SoI  sketched ideas for that. Right now I have a separate aux, buss, panpot, solo/cut switch, section and then separate mic pre eq modules in mind. 

We should do a gdiy console project. I plan on 24 buss and 8 auxes because I still have that desire and need to a degree.  Plus it's becoming more rare to do.  If anyone wants to trade ideas around maybe we can get to doing it.

 

[ruffrecords]

I had some ideas that I have been sketching for a console.

I love the idea of a removable mic pre/eq module like on the old Neve's and trident desks. While it does up the cost a bit it does make it plausible to run those modules separate from the consoles for remote recording.

SoI  sketched ideas for that. Right now I have a separate aux, buss, panpot, solo/cut switch, section and then separate mic pre eq modules in mind. 

We should do a gdiy console project. I plan on 24 buss and 8 auxes because I still have that desire and need to a degree.  Plus it's becoming more rare to do.  If anyone wants to trade ideas around maybe we can get to doing it.

I think it is a great idea. My first piece of advice would be to sort out the basic module mechanics first because this defines where and how you can mount the various controls you will need and also the electro-mechanical interface between them and the rest of the mixer and the outside world. My second piece would be that 3U high 500 series modules are too small for this.

Cheers

Ian

 

[efinque]

Does this mean all your channels are stereo channels?

In your very first post you said you would need AUX buses. Why have you changed your mind?

Cheer

Ian

No, but for panning you need two channels into summing (plus ground)

I think the aux channels could be used as stereo channels too (without pan control).. like for when one needs to run backing tracks. Another thing is pre/post send switch, which I'll probably implement (I made the schematic for reference and to clear things up)

 

[pucho812]

I think it is a great idea. My first piece of advice would be to sort out the basic module mechanics first because this defines where and how you can mount the various controls you will need and also the electro-mechanical interface between them and the rest of the mixer and the outside world. My second piece would be that 3U high 500 series modules are too small for this.

Cheers

Ian

of course. I already have some sketches as for that as far as mechanicals.  But it's very preliminary.