Need ideas for a mixing console enclosure

[sponzorb]

Hi folks, first post here, so sorry if this is the wrong section. I’m in the process of designing and eventually building a 16 channel mixing console - 8 mono channels and 4 stereo channels. Each channel will be input balanced via THAT 1206 chips, sent to a gain stage controlled by a 2520 type op amp, then to a high/low baxandall shelving filter in a 2520 type op amp, then to a summing section with switchable output stages / transformers for different coloration options. The transformers have been sourced and the options will be Neve style with the BA283 line driver to carnhill transformer (maybe switchable between the 2n3055 and a germanium power transistor), or API style with 2520 to a steel cinemag CMOB-2S transformer, or a 990 to a high nickel cinemag CMOB-1H transformer. There are 13 channels in total including the Mix Buss.

This is a lot of stuff obviously and I need an enclosure that can hold it all. I specifically would like a desktop unit so it can have faders and knobs for the pan, eqs, trim. I found a 20”x11” hammond enclosure that might be able to fit it all with 1.53” per channel, but there’s a minimum order of 10 units with milling and printing. I’m planning to just build one for myself and I wasn’t planning to start a business. I’m an electronics guy and don’t really know anything about the enclosure side of things. Does anyone have any ideas how to properly get a mixing console enclosure built, drilled, and printed? I’m totally open and in fact partial to having modular channels, but I wouldn’t know where to begin getting that metalwork done!

 

[ruffrecords]

Lime you, I am an electronics guy and I struggle with most things mechanical. I have been looking for ages for a decent off the shelf enclosure to use for basic mixers but there really seems to be nothing out there. Can you give the part number of the Hammond unit you found.

One crucial question you need to think about is how how you are going to access the electronics of each channel and how many things you might have to remove to gain access. This led me rapidly away from one piece front panels to a plug in modular approach. One solution to this is 500 series. No reason not to make your channel a 500 series compatible module. Most of the hard mechanical work has already been done for you.

Cheers

ian

 

[TwentyTrees]

Yes, I was thinking 500 series as well. The standard module pinout has a few pins that aren't generally used very often, which could potentially be repurposed as buses using a custom backplane - and if you were to get creative (think Wes Audio's additional connector for their bespoke chassis), you could add several more.

 

[ruffrecords]

Yes, I was thinking 500 series as well. The standard module pinout has a few pins that aren't generally used very often, which could potentially be repurposed as buses using a custom backplane - and if you were to get creative (think Wes Audio's additional connector for their bespoke chassis), you could add several more.

No reason why you could not do a double height unit as a complete channel strip and have two connectors/back-planes ,one of which would be dedicated to non 500 standard stuff like buses.

Cheers

ian

 

[gar381]

CAPI console 500 series erector set parts. I just don't know when Jeff will restock
tops and bottoms.

https://capi-gear.com/catalog/index.php?cPath=137_139
https://proxy.imagearchive.com/580/58033381f7c8dbfa9158b1351d7f0dc6.jpg
https://proxy.imagearchive.com/167/167926a3dfb0fe4503499e7b70ca3f54.jpg
https://proxy.imagearchive.com/b97/b9725587a543936b0b63b2870d80b591.jpg
cut Lowes / Home Depot 1/8" aluminum for side pieces for custom module front panel
length

Gary

 

[sponzorb]

Lime you, I am an electronics guy and I struggle with most things mechanical. I have been looking for ages for a decent off the shelf enclosure to use for basic mixers but there really seems to be nothing out there. Can you give the part number of the Hammond unit you found.

One crucial question you need to think about is how how you are going to access the electronics of each channel and how many things you might have to remove to gain access. This led me rapidly away from one piece front panels to a plug in modular approach. One solution to this is 500 series. No reason not to make your channel a 500 series compatible module. Most of the hard mechanical work has already been done for you.

Cheers

ian

That’s a great point - re: access to electronics. 500 would be a good way to go with this.

The hammond enclosure is 1456WL1WHBU.

After some more thought, I’m thinking I’ll make the frame out of wood and use aluminum for the metal work, nothing more than bending and drilling. Luckily my dad has access to a wood shop and metal shop so maybe it’ll be some good father son bonding to build the enclosure.

 

[Brian Roth]

IMHO, it is a GOOD idea to enclose the circuitry in some sort of metal enclosure. Olde School desks had a metal outer "shell" wrapping around everything. Neve took that to another level with a metal outer shell AND each audio module within its own "small" metal enclosure.

In these times, we live in an incredibly noisy environment. Cell phones, LED lighting, etc.

Bri

 

[sponzorb]

IMHO, it is a GOOD idea to enclose the circuitry in some sort of metal enclosure. Olde School desks had a metal outer "shell" wrapping around everything. Neve took that to another level with a metal outer shell AND each audio module within its own "small" metal enclosure.

In these times, we live in an incredibly noisy environment. Cell phones, LED lighting, etc.

Bri

What if I plated the wood case with aluminum sheets? Should that be a sufficient EMI deterrent?

 

[Brian Roth]

What if I plated the wood case with aluminum sheets? Should that be a sufficient EMI deterrent?

That sounds like a good plan! Kind of the reverse from how Olde desks were built. The wood was an outer "skin" surrounding the metal shell to make it look nice <g>.

Each of the inner aluminum pieces all need to be connected together to try and "emulate" a continuous metal shell. To connect the inner aluminum elements, I would suggest using strips of copper braid. Example:

https://www.surplussales.com/Antennas/Antennas-11.html
Bri

 

[sponzorb]

That sounds like a good plan! Kind of the reverse from how Olde desks were built. The wood was an outer "skin" surrounding the metal shell to make it look nice <g>.

Each of the inner aluminum pieces all need to be connected together to try and "emulate" a continuous metal shell. To connect the inner aluminum elements, I would suggest using strips of copper braid. Example:

https://www.surplussales.com/Antennas/Antennas-11.html
Bri

I actually meant aluminum on the inside wood on the outside like the old consoles but thinking the wood frame would allow me to have a sturdy structure to mount the metal onto. Seems like this is the way

 

[Brian Roth]

Maybe I didn't write my reply "clearly" <g>. Your concept and mine are the same. Hence my comment about ".....inner aluminum pieces...." Wooden outer structure with internal aluminum panels to try and reduce EMI.

Bri

 

[sponzorb]

Maybe I didn't write my reply "clearly" <g>. Your concept and mine are the same. Hence my comment about ".....inner aluminum pieces...." Wooden outer structure with internal aluminum panels to try and reduce EMI.

Bri

Maybe I didn't write my reply "clearly" <g>. Your concept and mine are the same. Hence my comment about ".....inner aluminum pieces...." Wooden outer structure with internal aluminum panels to try and reduce EMI.

Bri

haha duh! after reading again, i don’t know how i misinterpreted

 

[Brian Roth]

@sponzorb Thinking a bit further. I ASSume this is a very minimalistic mixer design. You didn't mention anything for aux sends or monitor controlling.

Like a few folks on this forum, I went down the "desk rabbit hole" myself!

http://brianroth.com/projects/m77/m77.html
NOT bragging or "showing off" .....just saying "been there, have the T-shirt" LOL

Another element to closely examine are the power supply requirements for your "gizmo" <g>

Bri

 

[Brian Roth]

Further comments. Before going off any deep end on enclosure design, you really need to define all of the items on the front panel.

Each channel:

1. What are the necessary user controls and switches per channel.
2. What brand/model control knobs and switches are specified for each. That will help define mechanical spacings. Ya gotta get your fingers to all those items! <g> Typically, the actual potentiometer or switch behind the panel will require less space than needed on the top plate for user access.

I suggest drawing it all out on a piece of paper/whatever in actual size and then set the selected knobs onto the paper to "get the feel" of the layout.

It doesn't matter if it's a single top panel or broken down into smaller "modules".

Bri

 

[sponzorb]

Further comments. Before going off any deep end on enclosure design, you really need to define all of the items on the front panel.

Each channel:

1. What are the necessary user controls and switches per channel.
2. What brand/model control knobs and switches are specified for each. That will help define mechanical spacings. Ya gotta get your fingers to all those items! <g> Typically, the actual potentiometer or switch behind the panel will require less space than needed on the top plate for user access.

I suggest drawing it all out on a piece of paper/whatever in actual size and then set the selected knobs onto the paper to "get the feel" of the layout.

It doesn't matter if it's a single top panel or broken down into smaller "modules".

Bri

great advice but i’ve done most of this! although not with paper directly with dimensions, but borrowing dimensions from spacing I already enjoy. I’m aiming for 1.5” channel width as this is what’s used in 500 series. And with that, each knob/switch would have 1.5” of space as well. Don’t want fingers to accidentally be shifting nearby knobs with the margins too tight.

The mixer will indeed be quite simple. Each channel will have the following:

Trim
High Shelf (concentric pot with switchable frequency)
Low Shelf (concentric pot with switchable frequency)
Mute
Pan
Attenuation Fader

There will only be one buss and no aux or inserts. This is mostly intended to be a summing mixer with an EQ per channel front end for a DAW. My aim is to do all signal processing in the analog domain and get away from the screen as much as possible. After building up a rack of analog gear, it’s safe to say there’s no way back.

ALSO WOW! YOUR CONSOLE IS FRICKING AWESOME!!!! I hope someday I can create something like that too. That has to be one of the nicest looking consoles I’ve seen.

 

[sponzorb]

@sponzorb Thinking a bit further. I ASSume this is a very minimalistic mixer design. You didn't mention anything for aux sends or monitor controlling.

Like a few folks on this forum, I went down the "desk rabbit hole" myself!

http://brianroth.com/projects/m77/m77.html
NOT bragging or "showing off" .....just saying "been there, have the T-shirt" LOL

Another element to closely examine are the power supply requirements for your "gizmo" <g>

Bri

Power supply is a tough one. I read somewhere once that transformers can increase the power requirements? That’s a big reason I’m going with the InGenius ICs for balancing the inputs. I’m not really sure how to determine the power requirements, so any advice there is super appreciated. I was considering just using an already existing power supply like the API L200 PSU since I have it already and the console will mostly be using 2520 type op amps. I’m not certain it will supply enough current though.

 

[Brian Roth]

Since I'm talking to myself here (lol) I'll recall my Very First mixer gizmo.

!974-ish. Tascam Model 10 desk, Ampex AG-440 1" 8 track bought by a (now RIP) friend for his small studio. We both had worked at a local studio with a MCI JH-416 desk.

The clever MCI desk design provided a signal flow which provided mic preamps. EQ, routing to the tape deck as WELL as signal paths for control room and cue mixing.

The Tascam 10 was just 16 ins into 4 outs. No monitor/cue mixing, no controls for CR speakers.

My contraption was built on a "X inches high" <now forgotten> 19" wide, stock aluminum rack panel I bought from a local supply house. Eight rows of pots, each horizontal row:

1. CR Level mix control.
2. CR pan pot.
3. Pre fade cue send.
4. Post fade echo send for CR and cue.

Lower side of the panel, stereo CR level pot with some simple switching to select CR mix, cue mix, tape playback and (forgotten) Partridges in a Pear Tree...lol.

Pots on the back side of the panel were those large (1.25" diameter??) Allen Bradley Type J "military" pots....chunky stainless steel items.

Put it all together....and the aluminum front panel had a very noticeable sag when in a flat /desk top 19" rack space. Took all the stuff off the aluminum 19" panel, drilled a new panel in a steel rack plate, reinstalled all the pots and switches. Friend/client used in that form for a few years until he had money to buy a MCI desk <g>.

Point being, mechanical design involves a bunch of aspects.

Bri

 

[sponzorb]

Since I'm talking to myself here (lol) I'll recall my Very First mixer gizmo.

!974-ish. Tascam Model 10 desk, Ampex AG-440 1" 8 track bought by a (now RIP) friend for his small studio. We both had worked at a local studio with a MCI JH-416 desk.

The clever MCI desk design provided a signal flow which provided mic preamps. EQ, routing to the tape deck as WELL as signal paths for control room and cue mixing.

The Tascam 10 was just 16 ins into 4 outs. No monitor/cue mixing, no controls for CR speakers.

My contraption was built on a "X inches high" <now forgotten> 19" wide, stock aluminum rack panel I bought from a local supply house. Eight rows of pots, each horizontal row:

1. CR Level mix control.
2. CR pan pot.
3. Pre fade cue send.
4. Post fade echo send for CR and cue.

Lower side of the panel, stereo CR level pot with some simple switching to select CR mix, cue mix, tape playback and (forgotten) Partridges in a Pear Tree...lol.

Pots on the back side of the panel were those large (1.25" diameter??) Allen Bradley Type J "military" pots....chunky stainless steel items.

Put it all together....and the aluminum front panel had a very noticeable sag when in a flat /desk top 19" rack space. Took all the stuff off the aluminum 19" panel, drilled a new panel in a steel rack plate, reinstalled all the pots and switches. Friend/client used in that form for a few years until he had money to buy a MCI desk <g>.

Point being, mechanical design involves a bunch of aspects.

Bri

Ah that’s interesting. So aluminum should probably be used on a per module basis rather than across several due to its elasticity that’ll cause it to sag. Loving hearing this wisdom and stories from when you had to create these things to get any audio at all!

 

[Brian Roth]

great advice but i’ve done most of this! although not with paper directly with dimensions, but borrowing dimensions from spacing I already enjoy. I’m aiming for 1.5” channel width as this is what’s used in 500 series. And with that, each knob/switch would have 1.5” of space as well. Don’t want fingers to accidentally be shifting nearby knobs with the margins too tight.

The mixer will indeed be quite simple. Each channel will have the following:

Trim
High Shelf (concentric pot with switchable frequency)
Low Shelf (concentric pot with switchable frequency)
Mute
Pan
Attenuation Fader

There will only be one buss and no aux or inserts. This is mostly intended to be a summing mixer with an EQ per channel front end for a DAW. My aim is to do all signal processing in the analog domain and get away from the screen as much as possible. After building up a rack of analog gear, it’s safe to say there’s no way back.

ALSO WOW! YOUR CONSOLE IS FRICKING AWESOME!!!! I hope someday I can create something like that too. That has to be one of the nicest looking consoles I’ve seen.

OK, cool...basically a summing unit used with a DAW,

Buy a stash of your chosen knobs ahead of time so you can lay them out in "realtime" on paper to suss out the feel (and maybe the look? lol...chicken head knobs vs. newer looks)

You raised an eyebrow with me on:

"High Shelf (concentric pot with switchable frequency)
Low Shelf (concentric pot with switchable frequency)"

Have you actually found a source for those? If, so....excellent. On my large desk I special ordered those stacked/dual concentric pots from Bourns....minimum order for each assembly was 100 pieces IIRC.

Thanks for your comment re. my "monster" <g>.

Bri

 

[Brian Roth]

Ah that’s interesting. So aluminum should probably be used on a per module basis rather than across several due to its elasticity that’ll cause it to sag. Loving hearing this wisdom and stories from when you had to create these things to get any audio at all!

The desk frame (#1) in the desk pix I posted had what the mechanical design shop said was "sturdy enough" for all the weight. Square steel tubing welded together. Alas, it had "frame sag" within a few years which caused problems with the mating connections into the motherboards down in the frame. Desk #2 (last one!) had an even sturdier welded steel frame. It didn't sag.

Nothing against a wide aluminum panel if it has some sort of "backing" behind the panel.. Maybe as easy as bolting a length of aluminum "L" or square tubing from left to right at the top and bottom of the panel to keep it from buckling.

Bri