Compact desktop line mixer?

[Brian Roth]

PS...

Someone building this with woodworking skills (I totally lack) could built a nice "furniture wrapper" around the chassis.

That 1RU rack panel "below" the faders could hold the jacks for headphone out and "I-phone in". Keeps those plugs and cords away from the master panel surface.

Bri

 

[MidnightArrakis]

In fact, the height of the module panels doesn't have to be 2/3/4/5..... RU tall. This is a custom frame.

Rear panel with the connectors is a standard rack panel...2? 3? RU tall.

Bottom plate is another rack panel....however many RU tall, as required. Rubber feet to raise this contraption above the table.

The vertical front edge plate ("below" the faders) is a 1 RU panel.

How to attach those three rack panels to the side cheeks? While I've used standard rack rails (L-shaped steel with a bazillion holes drilled and tapped at proper rack spacing) inside custom wooden "furniture" racks, the short lengths required here probably don't exist. So, standard L-brackets from McMaster-Carr, Home Depot, Lowe's, etc.

If needed for additional cheek to cheek bracing (to avoid a chassis shape turning into a 3-D parallelogram! lol) something like this attached to the cheeks with L-brackets:

https://www.legrandav.com/products/...le_management/lbp_horizontal_lacer_bar/lbp-1a

The "joints " at the edge of top of the upper modules and the bottom edge of the fader module plate(s) where they intersect with the chassis is yet to be determined.

So, custom metal parts:

[In fact, the height of the module panels doesn't have to be 2/3/4/5..... RU tall. This is a custom frame] -- TRUE!!! But, the combining of "standardized" rack-mount components into a "somewhat variable customized" sheet-metal product does create some rather unique design challenges to be met.

[Rear panel with the connectors is a standard rack panel...2? 3? RU tall] -- As @Ian has previously indicated, the rear-panel works out to be a 3U (5.25") rack-panel.

[Bottom plate is another rack panel....however many RU tall, as required] -- The bottom-plate works out to be a 12U panel, which is 21.00" high/deep.

[The vertical front edge plate ("below" the faders) is a 1 RU panel] -- Ian had also indicated the front-panel is to be 2.00 high, but I guess a 1U panel (1.75") may work.

[How to attach those three rack panels to the side cheeks? While I've used standard rack rails (L-shaped steel with a bazillion holes drilled and tapped at proper rack spacing) inside custom wooden "furniture" racks, the short lengths required here probably don't exist. So, standard L-brackets from McMaster-Carr, Home Depot, Lowe's, etc.] -- As I am slowly coming up with my own "mental vision" of all of the various "Erector Set" pieces, my -- synaptic-ally connected brain-cells -- are telling me that the internal-bracing brackets are best suited as being "sheet-metal shop" fabricated.

>> And.....while on the one-hand I do see some possible advantages of using standardized rack-panels (of which I personally LOVE, anyway!!!), they don't really mathematically "fit" into the overall scheme of things mechanically because of their inherent height-reduced clearance tolerance. Meaning, the 12U bottom-panel is -- NOT REALLY -- 21.00" high, but instead is 20.97" high. The front-panel isn't 1U (1.75") high, but is actually 1.72" high. And, finally.....the rear-panel being 5.25" high is really 5.22" high!!!

So.....if you're thinking.....SO WHAT???.....it's only 30-thousandths!!! GET OVER IT!!! -- Accommodating and trying to "make-up" for that small difference usually requires a fair-amount of "mechanical design contortions and gymnastics" in order to have everything all fit together quite nicely!!! And, this is something that is always unseen by the end-user. But, for us "Creators", having to deal with all of these mechanical details is often quite headache-producing.

In the end, it requires one train-of-thought to use pre-existing "standardized" parts and making them fit within a custom-designed mechanical product. But, it ends up being a completely different train-of-thought to just go ahead and custom-design every detail and part for the same mechanical product on an "as needed" basis!!! In other words, you just go ahead and design everything to fit together as you wish for things to go together, instead of having to constantly come up with "work-arounds" to make an existing "standard" part fit within a custom-designed environment. Is any of this understandable to you??? It makes sense to me.

Meanwhile..... WATCH THIS SPACE >> -- -- -- -- -- << FOR FURTHER DEVELOPMENTS!!!.....

/

 

[Brian Roth]

@MidnightArrakis Hey, I'm "all ears". I've trying to keep the cost for just the metal parts as low as possible. If you can, make an estimate what the custom parts will cost. I know a one-off can be shockingly expensive.

The big hickey are the setup charges. If more than one set of parts are made, unit prices go down. But I'm not going to risk thousand of dollars of my own money for a pile of metal that may never sell to the folks here. <g>

The prices already found for the metal face panels are stunning. At this rate, we'll quickly be bumping a grand for metal. That is one reason why I'm seriously interested in the front panels being done from FR-4 so Gerbers can be sent to a PCB fab in China.

Meanwhile I'll "WATCH THIS SPACE >> -- -- -- -- -- << FOR FURTHER DEVELOPMENTS!!!....."

I am quite interested in ANY ideas to solve this Packaging Puzzle! Thanks!!!!

Bri

 

[ruffrecords]

@Brian Roth I like the idea of making the width 19 inches. It opens up so many possibilities of using mass produced panels ready punched for audio connectors.

@MidnightArrakis you are right about the small details of the mechanics being the hidden gotchas of mixer design. They are everywhere and often leap out to bite you in the bum when you least expect it and believe me I have the teeth marks to prove it. To mitigate this, one option is to use an off the shelf enclosure. I recently took delivery of a TAKACHI SLOPED CONTROL CASE part number CF45-28GS (see attached PDF). The front is 50mm high, the rear 99mm and it is 450mm wide and 280mm deep. It has plastic cheeks and extruded aluminium front and rear panels. It cost me £167. The only problem is the front panel would need to be just one or maybe two panels so modularity is compromised to an extent.

https://www.takachi-enclosure.com/assets/attachments/images/cf_catalog.pdf

Edit: Just a thought, how about 3D printed side cheeks?

Cheers

Ian

 

[JohnRoberts]

I could tell stories about end bell/end cheek designs I have used many ranging from cheap wood, to expensive wood, metal, to cheap injection molded plastic (not cheap to tool). Here's one perhaps amusing anecdote, but it was annoying to me at the time and still is painful for me to reflect upon.

Back when I was making big-dog 36x24 split consoles, we used massive (pretty) wood endbells. At Peavey I had access to the guitar shop so these endbells were NC machined from solid wood and painted rather spectacularly in the guitar paint shop. When painting guitars each one is a work of art so some variation from unit to unit is accepted. When it came to my console endbells the minor unit to unit variations were between subsequent endbells being manufactured in batches of say 25 lefts, then 25 rights. The batches of lefts and rights could be run days apart. Since the factory was strictly operated using MRPS (manufacturing resources planning system), I couldn't get the paint shop to paint them side by side in pairs, that way the slight unit to unit variations would be smaller and less noticeable. Instead I had to live with batch to batch variations. Then I had to deal with QA inspectors in the factory at final assembly who would reject endbells that did not color match closely. Try as hard as I could, I was not able to get them to paint them in pairs even though that would have elegantly resolved the issue.

Since I never got the factory to change how they ran these pieces, they probably had to deal with repainting lots of rejected endbells. I was stuck in the middle being pressured to make my QA inspectors accept endbells that didn't match, even thought these were routinely used by customers in low light environments and sometimes as much as 6' apart when mounted. That was a constant cause of tension between me and my QA people since I didn't want them to ever relax their standards for any other quality issues. In hindsight I could have specified a less attractive finish (like flat black), but these endbells were really attractive and a major selling hook.

This is what I meant by dejaPU, it upsets me again just thinking about this.

JR

 

[OneRoomStudio]

I could tell stories about end bell/end cheek designs I have used many ranging from cheap wood, to expensive wood, metal, to cheap injection molded plastic (not cheap to tool). Here's one perhaps amusing anecdote, but it was annoying to me at the time and still is painful for me to reflect upon.

Back when I was making big-dog 36x24 split consoles, we used massive (pretty) wood endbells. At Peavey I had access to the guitar shop so these endbells were NC machined from solid wood and painted rather spectacularly in the guitar paint shop. When painting guitars each one is a work of art so some variation from unit to unit is accepted. When it came to my console endbells the minor unit to unit variations were between subsequent endbells being manufactured in batches of say 25 lefts, then 25 rights. The batches of lefts and rights could be run days apart. Since the factory was strictly operated using MRPS (manufacturing resources planning system), I couldn't get the paint shop to paint them side by side in pairs, that way the slight unit to unit variations would be smaller and less noticeable. Instead I had to live with batch to batch variations. Then I had to deal with QA inspectors in the factory at final assembly who would reject endbells that did not color match closely. Try as hard as I could, I was not able to get them to paint them in pairs even though that would have elegantly resolved the issue.

Since I never got the factory to change how they ran these pieces, they probably had to deal with repainting lots of rejected endbells. I was stuck in the middle being pressured to make my QA inspectors accept endbells that didn't match, even thought these were routinely used by customers in low light environments and sometimes as much as 6' apart when mounted. That was a constant cause of tension between me and my QA people since I didn't want them to ever relax their standards for any other quality issues. In hindsight I could have specified a less attractive finish (like flat black), but these endbells were really attractive and a major selling hook.

This is what I meant by dejaPU, it upsets me again just thinking about this.

JR

Being stuck in the middle like that is never a fun place to be. I’ve found myself in similar situations between leadership/management and the “doers.” It plain sucks.

Out of curiosity, which console model was this? What kinds of volumes was Peavey doing on large consoles at the time?

 

[JohnRoberts]

Being stuck in the middle like that is never a fun place to be. I’ve found myself in similar situations between leadership/management and the “doers.” It plain sucks.

That's the "job" for middle/upper management to accomplish. Factory managers are trying to manage their personal pain but don't always (ever?) see the whole picture.

Here's another anecdote about one time when I apparently shared too much information with a plant manager. One time while I was over all mixers for Peavey I shared with the plant manager where mixer final assembly was being performed that I was working on the next generation mixer family. This was probably 9 months to a year away from full production but I decided to give him a heads up.

To my dismay he took this information the wrong way and gave my existing line of mixers weak production support. For several months I was in chronic backorder for very profitable small mixers. Nothing I could say to this plant manager could get him to properly support these very back ordered SKUs. I'd have sales reps and dealers beating on me because they couldn't get their orders filled. These mixers were in very competitive markets so these unfilled orders turned into massive lost sales, when customers instead bought some competitors mixers that they could get. Another anecdote that makes me angry. But I learned to not share too much information with people who don't understand the big picture.

Out of curiosity, which console model was this? What kinds of volumes was Peavey doing on large consoles at the time?

The consoles were the AMR Production series. There were 8 bus, 16 bus, and 24 bus models. These were effectively $20k split recording consoles being sold for about 1/2 price. Sadly right around then Mackie introduced their 8 bus inline console for $4k, with consumer level advertising support. I lobbied hard to get more advertising without success. I recall one meeting I had with the company controller trying to investigate my ad budget. He told me to get Hartley to stop giving big consoles away. There were a number of big name artists who were gifted free AMR consoles only to give them away to a studio tech or sell them. Hartley even gave one or two away to non-musicians (like one guy who manufactured guns/rifles) arghhhh

I don't know total production numbers but as I recall we had to build two soundproof final QA booths out on the factory floor so the QA technicians could test them fast enough. It took hours to test all the controls and audio paths in one console. IMO this was a good product at a great price, but inadequately marketed so out of favor with the market craving cheap inlines. I have more stories about marketing failures, but this is enough for now.

JR

 

[Brian Roth]

I was at an AES show when those were first introduced. I was pleasantly surprised at the price point, and the fact the desk seemed "out of the Peavey wheelhouse."

Serviced a few over the years. Most recently in 2016. Actually, that wasn't a service project, but an installation project. The desk sat idle for a number of years before the new owner purchased it. After wiring, I found almost zero problems with it...mostly some scratchy switches and pots that cleared up after some "push-push-push" and "twist-twist-twist".

Great (and under-appreciated) desks

Bri
.

 

[Estomagado]

There's one here with @JohnRoberts commenting, always helpful.

 

[gar381]

Just a quick note on 100mm faders.

https://www.audiomaintenance.com/acatalog/faders_carbon.html

Colin sells these at good prices.I don't know if he still has the audio taper
versions still but at 10 pounds each it might be worth an email.
Quick shipping to the USA.
Also check ebay for these.

The K series feel almost like P&G 8000 series.
I have used these before to replace faders on
my old Amek Angela desk.

GARY

 

[paulcheeba]

My rare Ocean Ark Malcolm was involved with has all the same knobs and buttons as his new little one. Mine is a line with customisation, POM went mad on the bus and it sounds great.

 

[JohnRoberts]

Just a quick note on 100mm faders.

https://www.audiomaintenance.com/acatalog/faders_carbon.html

Colin sells these at good prices.I don't know if he still has the audio taper
versions still but at 10 pounds each it might be worth an email.
Quick shipping to the USA.
Also check ebay for these.

The K series feel almost like P&G 8000 series.

Yes, the K Faders use the dual internal guide rods for good fader feel.

Alps developed those in response to the cheap Jung Poon sliders that used dual internal guide rods. The Jung Poon's felt OK but sadly they had fragile plastic sliders that broke if you looked at them crosseyed. I was saddled with a couple 10k of the Jung Poons in inventory before we started experiencing high rates of field failures due to slider breakage.

I originally designed in a different high quality Alps fader that was around 5x the cost of the K fader but I got over ruled by the guy whose name was on all the buildings. We were both rescued by Alps when they came out with the low cost dual drill rod K fader that didn't suck.

JR

PS: Yet another mixer story that is painful to recall. I had my factory people go through all the jung poon faders and bend the slider from side to side to see if they would break. I ended up rejecting a major percentage of them for breakage. But then my director of purchasing hung me out to dry and called a meeting between us and the Jung Poon importer to get him to accept all the rejects back. He took them all back but I was in the hot seat for thousands of dollars loss until he did.

I have used these before to replace faders on
my old Amek Angela desk.

GARY

 

[MidnightArrakis]

Yes, the K Faders use the dual internal guide rods for good fader feel.

Alps developed those in response to the cheap Jung Poon sliders that used dual internal guide rods. The Jung Poon's felt OK but sadly they had fragile plastic sliders that broke if you looked at them crosseyed. I was saddled with a couple 10k of the Jung Poons in inventory before we started experiencing high rates of field failures due to slider breakage.

I originally designed in a different high quality Alps fader that was around 5x the cost of the K fader but I got over ruled by the guy whose name was on all the buildings. We were both rescued by Alps when they came out with the low cost dual drill rod K fader that didn't suck.

JR

PS: Yet another mixer story that is painful to recall. I had my factory people go through all the jung poon faders and bend the slider from side to side to see if they would break. I ended up rejecting a major percentage of them for breakage. But then my director of purchasing hung me out to dry and called a meeting between us and the Jung Poon importer to get him to accept all the rejects back. He took them all back but I was in the hot seat for thousands of dollars loss until he did.

I think it would be a "fun read" if you wrote a small booklet about your mixer design experiences for everyone here to enjoy!!!

You could call it:

----------- Painful Recall -----------
The true behind-the-scenes life of
designing audio mixing consoles

/

 

[JohnRoberts]

I think it would be a "fun read" if you wrote a small booklet about your mixer design experiences for everyone here to enjoy!!!

You could call it:

----------- Painful Recall -----------
The true behind-the-scenes life of
designing audio mixing consoles

/

A fun read but a painful write to relive... I'm sure anybody who designed big dog consoles has similar experiences. Mine was a little more different because my consoles were a bit of a culture shift from value products manufactured by Peavey.
===
OK here's one you may appreciate. When we assembled the first prototype 36x24 split console, we didn't yet have the precision forming tool to accurately bend all the channel metal strips. Hand bending the channel strip metal even held to a few thousands of an inch tolerance per strip, added up across something like 70 strips wide. When it came time to assemble, we had to shoehorn the very last strip into the chassis. It was a very tight fit.

As I recall we worked late into the last night before the trade show when it was introduced (in Atlanta). After we forced the last strip in place, we had to first rush it over to the photo studio to get a last minute photograph for preparing the trade show literature, then load it into the van. As I recall James Brown and I drove the van over night with console loaded into the back, directly to the convention center in Atlanta without any sleep. We showed up the morning of the pre-show and carried it into the back of the room where the pre show meeting with reps and dealers was already going on. They thought we timed it that way on purpose to make a big splash, that's just how it played out.

As I recall I couldn't check into my hotel room until mid afternoon so I was wandering around in zombie mode for several hours.

JR

 

[MidnightArrakis]

I recently took delivery of a TAKACHI SLOPED CONTROL CASE part number CF45-28GS (see attached PDF). The front is 50mm high, the rear 99mm and it is 450mm wide and 280mm deep. It has plastic cheeks and extruded aluminium front and rear panels. It cost me £167. The only problem is the front panel would need to be just one or maybe two panels so modularity is compromised to an extent.

https://www.takachi-enclosure.com/assets/attachments/images/cf_catalog.pdf

Edit: Just a thought, how about 3D printed side cheeks?

[I recently took delivery of a TAKACHI SLOPED CONTROL CASE part number CF45-28GS] -- And, HERE YA GO!!!.....



[how about 3D printed side cheeks?] -- And, HERE YA GO!!!.....(maybe).....

>> LEFT-CHEEK:
(See attached -- STL -- file):


>> RIGHT-CHEEK:
(See attached -- STL -- file):



>> FYI: I have no idea "how well" or even -- if -- the attached "STL" files will actually work or not. I first, of course, had to import the entire enclosure CAD-file to start with. Then, I had to individually delete every separate component item from the file, leaving just a side-cheek. And, I had to go through this process -- twice -- because it was necessary to also delete the "opposite" cheek of the one that was desired to have, leaving only the desired cheek left in the CAD-file itself at all. WHEW!!!.....

Within the attached ZIP-file, I have also included individual -- STEP -- files of each cheek that will, hopefully, be able to be imported into your FreeCAD program. Interestingly.....the downloaded -- STP -- file of the CF45-28GS from the TAKACHI website DID NOT IMPORT into my SolidWorks program. Of all of the -- STP -- files that I have downloaded from the TAKACHI website, this is the first CAD-file that didn't work!!! In fact, NONE of my other CAD-programs were able to import this -- STP -- file at all. So, I contacted TAKACHI Enclosures directly myself last night and this morning they had sent me an -- IGS -- CAD-file instead. Fortunately, that file imported with no problems whatsoever and the included -- STL -- files are the results from that file.

I am also including the TAKACHI -- STP -- file so you can find out if you are able to import it into your CAD-programs. Let me know if you are successful or not, OK? THANKS!!!

/

 

[Brian Roth]

Well, with plastic side cheeks we are totally starting over. That is absolutely unsuitable for things like the Eurorack rails attaching to the cheeks (the rails also contribute to the mechanical stability/strength of the enclosure).

Bri

 

[ruffrecords]

Well, with plastic side cheeks we are totally starting over.

Not necessarily. We don't really have a mechnaical design as such just yet except for perhaps a general acceptance of extruded rails held apart by cheeks.

That is absolutely unsuitable for things like the Eurorack rails attaching to the cheeks (the rails also contribute to the mechanical stability/strength of the enclosure).

Bri

Again, not necessarily. Many of the enclosure made by the synth boys have wood cheeks and I think I have even seen plastic ones.

Having said that, it may turn out the 3D printed cheeks are not strong enough but it is a great way to get small quantities of non-standard shapes so I think it is worth considering.

Cheers

Ian

 

[OneRoomStudio]

Hmm, that is interesting....and even more so if we don't need the rail system at all. If we used a single top panel for everything, but then kept the boards modular, we might not need them. Using @Brian Roth's initial "strip" pcbs for the faders, channel cards for the channels, and 2-3 pcbs for the master section (one for FX sends/returns, one for mix summing and mix insert, and maybe one more for monitor/headphone controls), it could still be "semi-modular." Still serviceable and customizable to some degree.

The only custom panels would be the top and the rear i/o...which would bring the price down significantly. For someone who hates metal work, that sure is a tempting direction to go in!

 

[Brian Roth]

As I mentioned before, I don't have any dogs in this hunt! <g> I have no plans to build one.

I've been trying to come up with packaging that is at least somewhat professional and sturdy and attractive without costing a small fortune.

The package can be built out of plywood and nails to really save money. When I was in Jr. and High Screwall I ran a pirate radio station from my bedroom. I made a mixer from scrap lumber in the my family's garage. Even the top panel was 1/4" plywood. I used my Boy Scout knife on the back of the panel to scrape out enough wood so the bushing of the pots could barely make it through the wood. Side panels were 2x4 boards. No powered tools.

Bri

 

[Brian Roth]

As I mentioned before, I don't have any dogs in this hunt! <g> I have no plans to build one.

I've been trying to come up with packaging that is at least somewhat professional and sturdy and attractive without costing a small fortune.

The package can be built out of plywood and nails to really save money. When I was in Jr. and High Screwall I ran a pirate radio station from my bedroom. I made a mixer from scrap lumber in the my family's garage. Even the top panel was 1/4" plywood. I used my Boy Scout knife on the back of the panel to scrape out enough wood so the bushing of the pots could barely make it through the wood. Side panels were 2x4 boards. No powered tools.

Bri

I clicked something wrong and can't delete my reply to myself! LOL

Bri