Building my own live mixer

[rgand]

Looks good. Nice layout.

 

[Cagey]

Looks great! And if it ever gets stolen, it'll never sell  :laughing7:

 

[mayfly]

Thanks folks.  There are problems that I see - some of the holes are in the wrong place and I really need to do something with the output jacks - the board appears to be too wide.

But it's not bad.

 

[mayfly]

Update:  I've finalized the placement on the panel, so I printed out a full scale mockup and glued it to some 1/8" fiberboard.  The plan is to check the placement of the holes using the real boards.

 

[rgand]

Good progress, now. This is a really interesting project.

 

[mayfly]

Putting together another couple of line / instrument preamps.  I'm quite impressed with this circuit; it can handle instrument levels with no loss of tone all the way up to line level.  There appears to be a very high input impedance which suits the instruments and it has enough headroom to easily accommodate a +4db balanced signal.  I'm really pleased with it.

 

[mayfly]

More stuff.  Got around to drilling out the mockup top plate.  I used brad point bits and it went very well - a nice clean hole through the paper and out the back.

For at least the line / instrument preamps, everything lined up well.  Will check the others later.  However -  the switch holes were a little tight - might go up a bit in size in the final version.

Looks good from the back as well.

 

[Cagey]

You were right to design your own. I've Googled the hell out of mixers in all sorts of configurations from every manufacturer extant, and I can't find any that have "Trevor Guitar" or "Deanna Violin" inputs. At best, they give you channel numbers and maybe a little blank spot you can scribble on.

 

[mayfly]

Thanks Cagey!

For my next trick, I'm going to drill out those big holes along the top that are for the XLR connectors.  But there's a problem:  I don't have a brad point bit that big.

So I rummaged around and found my Greenlee knockout punch!  This relic from my Tube Amp days is for putting big ass holes in steel.  We're gonna find out how it works on particle board!!

 

[Logrinn]

Looks like a wrist protection strap for archers ...  :icon_scratch:

 

[mayfly]

It is not!  It is the case for a steel hole punch used by tradespeople around the world.  After a working life with an electrician, this punch was gifted to me and subsequently used to punch many many tube amp chassis (before I got smart and started having them made to my specifications).  It's a h*ll of a tool.

 

[mayfly]

so before I started punching, I had a look at the die of the size I wanted to use.  It was pretty beat up and rather dull.  I decided to whip out the straight cut file and sharpen it up a bit.  Glad that I did!  It cut a fairly clean hole, well relatively speaking, which to be honest really surprised me 

 

[Cagey]

It's a h*ll of a tool.

They also ain't cheap. I used to have one. That was a helluva gift.

 

[Logrinn]

Looks good. And now I can se the tool as well as the archer's wrist strap  :icon_biggrin:

 

[mayfly]

All holes punched!  I was a little nervous about the last two as they are quite close to eachother

But it turned out ok.  Good enough for a prototype in any case.

 

[mayfly]

It's a h*ll of a tool.

They also ain't cheap. I used to have one. That was a helluva gift.

That got me wondering how much this little punch is worth, so I checked out eBay on used greenlees.  Turns out $30 is about the norm for this punch set second hand

oh - and greenlee does not even make this exact set with the leather case anymore!  I now own a vintage punch set  :icon_jokercolor:

 

[BigSteve22]

Oooooooooo, vintage........ Greenlee punches are the best panel punches, but I'd bet the vintage set is even better! So jealous..........  :confused4:

 

[Logrinn]

And so it begins ...  :laughing7:

 

[mayfly]

Here's everything (well, almost) bolted to the mock-up top panel.  Still waiting on the PCBs for the stereo input and the new design of the summing mixer / power supply. 

I've got the prototype summing mixer in there now complete with crazy-assed heatsinks.  Here's how it looks from the bottom.  It passed the smoke test and the regulators didn't overheat.  More when I have some time to actually play through it 

 

[rgand]

That's really cool. You are making a fine mixer. What a fun project.