DIY API 1604 inspired mixer (16x8x2)

[boji]

Been putting off posting about this project for too long. Figure some updates are better than none. Posts will not be in order of completion, since if I run across some older stuff, this is where it'll go. Suppose this will be the completion thread too....roughly estimated to be 6-10 months from now.

Original sourcing for project and 1604 schema transcription began here: Console signal flow, input cards, general discussion on API styled DIY mixer
(Thanks to members for uploading what you could)

A note on GDIY:
Thanks for everyone's help in seeing this thing to completion. A few of you took the time to look over my schematics, pointing out concerns or potential issues. The discussions on how to manage grounds was fantastic. There's been at least 100 other conversations since the beginning where I opened a thread up out of ignorance or confusion, only to receive generous and thoughtful responses that almost always amplified my knowledge around the topic, and often took paths that led to questions I didn't even know were in need of asking!

Truly, there's no place like gdiy.

-Boji

 

[boji]

Group / Aux VU (Thanks to JLM for VU buffer design improvements)
Prior to backfill and modutec ledger:

Using adafruit's neopixels for color segmentation and brightness. Plans in the future are to dim or brighten vu's that are solo'd or muted, as well as to 'color flash' as a peakmeter. That may require some A/D conversion. I say may because bufferboards include peakmeter, so it could simply be about assigning MC pins to sense dc --returning to it late game.

By the way... I don't see many people using blind tapped holes in their faceplate projects. Provided metal is thick enough, I can attest they are super helpful at mounting things on the back while making for a clean face, and they really don't cost much more than a standard hole, using FPE.

Backfilling:

VU panel backfilled and Main L/R meters complete:

Modutec Retrofit of sifam VU

Using sifam as template:

Dremel template cut:

Plaining the VU face to be as thin as the sifam (Whew boy, this took a lot of patience):

Completed:

Aux Group VU Metalwork :

Removing top and bottom mounting bars:

Cutting bottom flange to fit panel

Creating notch to leave room for vu

Notch closeup (fitted)

Notching out top

Getting top bar flush with panel

Success!

 

[boji]

Group faceplate, raw.  Custom powder coat color makes things a pita.  Trying out some color on my own, we'll see if it leaves enough gap in the engravings to hold backfill. If not, I may have to accept a standard color, and have FPE do the backfill (FPE only does RAL).

Channel faceplate evolution. Deceitful micrometer. Thanks to Frank at frontpanels.de for the color proto.
There's nearly a year of weekends in the below pict if you include PCB work.

Plenty more to follow, got metalwork to do right now.

 

[Fsharpminor]

This is so amazing. I hope you are able to keep us posted through to the end. This is a dream thread for me. FAN-TASTIC!

 

[Winston OBoogie]

Very cool Boji.
Regarding your wanting to use a custom paint colour,  can you have the panels painted the colour you want before having them engraved?
In the past I've done this before sending to FPE for the engraving and fill.  I used an under-coat and top-coat process and never had an issue with the FPE engraving chip any of the paint edges.
Anyway, happy building, thanks for posting

 

[Fuzz Face]

WOW this is impressive. I love the use of adafruit to control VU brightness/color

I can’t wait to see more!

 

[boji]

can you have the panels painted the colour you want before having them engraved?

I'm very glad you mentioned your positive experience, Winston.  I've had poor results trying this at home on my mini cnc,  with engraving edges chipping and flaking, but that could have been due to poor prep, as I didn't pre-etch aluminum at the time.  Also perhaps FPE has a particular endmill or S&F trick that keeps edges sharp.  I may very well try this, as it would allow the addition of a cool clear coat that is 'frosty' or ultra-matte, good for hiding scratches. Thanks!

Thanks for support FF and F#m

 

[ruffrecords]

I like the red square buttons, especially as they appear to have round fixing holes which are much cheaper than square ones. What type of switch are they?

Cheers

Ian

 

[Winston OBoogie]

I'm very glad you mentioned your positive experience, Winston...   
...I may very well try this, as it would allow the addition of a cool clear coat that is 'frosty' or ultra-matte, good for hiding scratches. 

When I first contacted FPE about them engraving an already painted panel they said that any guarantee of success depended on the paint application so I asked what would shift the odds towards a good result.  They said a well bonded prime coat and top coat would be best, which is obvious I suppose.  So that's what I told my painter to do and, as I said, I had no problems at all with chips.  Probably about 100 rack panels all told done that way. 
Good luck 
 

 

[boji]

Ian:

https://www.nkkswitches.com/wp-content/themes/impress-blank/search/inc/series.php?series=HB

Spec Sheet w/ part#'s
https://www.nkkswitches.com/pdf/hbilluminated.pdf

 

[john12ax7]

Looking good.  What are you using for meters,  is it Sifam or something else?

 

[boji]

Probably about 100 rack panels all told done that way.

 
Extra time in the phosphoric acid bath it is!  Thanks.

is it Sifam or something else?

Thanks 12ax. Big ones are sifam with modutec ledger.  Rest are modutec.
(added picts in first post to reflect this mod)

 

[boji]

Bought a roll of nomex last year and tried my hand at oldschool wire wrapping.
Turns out it's an artform that requires lots of practice. At least it's doing its job at wire management in the channel and group cards.


Can't even begin to express how relieved I am knowing the bulk of the PCB work is complete.  Mucho, mucho time. #hermit_life.

Here's a group assign card cracked open.  Passive HPF,  CAPI litzwire Tx's.  Dunno what I would have done without them,  along with the insane amount of OPA's needed to power the ship.  Then there's the 48+ 500 slots... >.<

 

[boji]

Aux Sends (3 x 2).  Just your basic 312 summing type amp. Heavy!

 

[boji]

Had an issue with backplane flex. While trying to push the cards down, the PCB was bending off the metalwork, even after secured with ~14 screws. There was also some flex from the lower plate even with the included right angle rails that secure the lower metal to the bucket sides (2 of 4 of those is what I'm working on now).

Solution was....hodgepodge, but effective.  I'm sure there's a better way to do it, but I used what I had around the shop.  Basically sandwiched the edge of the PCB with aluminum U-bends. Now, seating cards still requires pressure and a rocking back and forth to get the faceplates to sit flush in the bucket, but 90% of the backplane flex has been removed.

In the below pict, you can see the four U-shaped extrusions that give extra rigidity to PCB, while also setting the height at which the 100 pin edge connector passes into the metal notches for the backplane. They also serve as riser mounts to which an underside box 'cage' will be attached. This covering may also hold some ACA's and shield the bus bars.

 

[ruffrecords]

Now you understand why the Eurorack sytem uses a pair of extrusions to support back planes. Building a console is a tremendous learning experience. Keep at it!

Cheers

Ian

 

[Holger]

... Building a console is a tremendous learning experience...

Cheers

Ian

I second that.

Boji, excellent work and thanks for sharing.

 

[Winston OBoogie]

Wow, you've done tons of work.  Great job on all the pcb stuff.
I like the aluminium framework/side-cheeks etc.  Did you have them laser cut?

 

[Rocinante]

Boji! For the win man. Amazing work. Like spare no expense.  Those E-switch illumintaed switches are made in the burbs here in MPLS, did you order them from mouser or from E-switch?  I seem to recall that caps for them was an issue in how many were available, and IIRC there was a limit on how many switches were available of each color. It seeems you bought a ton, was there any difficulties?

 

[boji]

framework/side-cheeks etc.  Did you have them laser cut?

Thanks Wb. No, went the hard way.  Melanite template and a 1/2hp laminate router. 3-fin carbide flush cut with lower bearing guide, and yep!-- I went through a few of them.  Separation/mounting Bars are home depot, drill press and tapped. Brother offered his tig, but I think I'll keep to the bolt method for the 500-series backplanes. Pre-tapped faceplate mounts courtesy of CAPI.

Back XLR/Insert/Pwr
This was a frankenstein approach but it's turned out ok.  Took old wheatstone console channels and cut the backs off them and remounted to a hinged console back (more on this later as I get into wiring them).

Lid
This is my favorite accident (and the only thing that would carry forward if I started again):  Got a local AC ductwork guy to break some aluminum sheet 90 degrees, then I routed it down to mate with top VU bar. Roundover lip looks nice, like a preform mold or cast. Tops are in a vat of stripper as we speak, getting ready for a color change:

I seem to recall [cap color/qty] was an issue... any difficulties?

Thanks Roc,  Scooped them from the bay in bulk. Good price. Any color you want as long as it's red.
Been awhile since I made inquiry, but I believe Allied/Mouser carries a few of the insert color 'wafers',  and I've pulled the led's and replaced them. Way back when, Abby noted that in pressure situations we tend to forget button hold-time logic options, but I do need to differentiate pfl and afl, which at this point must be indicated with a bicolor led and solo button presstime logic. I'll add a lockout and panic button somewheres to be safe.