Compact desktop line mixer?

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
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
 
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!!!.....

/
 
Last edited:
@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
 
Last edited:
@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
 
Last edited:
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. :cool:

JR
 
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. :cool:

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?
 
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 :mad:

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
 
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
.
 
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
 
Last edited:
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.
 
Back
Top