OVERHAULING A MACKIE 32-8 MIXER week 3

[techristian]

So far, from this experience, I have learned that 98% of the problems on the channel boards ARE THE CONTACTS and SWITCHES.

 

The BUSS output board is another issue, probably some bad op amps.

 

So another one of the positive aspects of this cleaning and repair....Since I am already inside at the PCB level, I might as well do a few of the recommended mods from the Mackie instruction manual. This mod is to use the sliders for the "B" channels, rather than the knobs. A trace must be cut and a jumper put in place for all 32 channels. The wire is only Bell Telephone wire 1/16" long.

 

Dan

[Anderton]

It's always the mechanical stuff, isn't it?

[techristian]

It's always the mechanical stuff, isn't it?

 

YEP

 

The channel boards are 100% functional now, all 32 channels working.

 

Dan

[techristian]

The 8 BUSS OUTPUT BOARD IS COMING TO LIFE AS WELL !! (except for buss 5-6)

It forces you to really learn your mixer well when you have to operate it without the nice silk screened panel as a guide !!

 

Dan

 

MIXER TESTING IN LINK BELOW

 

http://clutterpop.com/joel.mp4

[Mike Rivers]

So far, from this experience, I have learned that 98% of the problems on the channel boards ARE THE CONTACTS and SWITCHES.

 

Add power supplies to that list and you'll be up to 99%.

[techristian]

 

Add power supplies to that list and you'll be up to 99%.

 

I thought of that. I'm only running 8 of the channels at a time right now. We'll see what happens when I plug in all 32 !

 

Dan

[Anderton]

Or add membrane switches, and bring it back down to 52%.

[Greg Mein]

I've always found mixers to be a major pain...every knob, switch and dial has to be removed to get them apart.

[Theo Verelst]

Hopefully the electrolytic capacitors are ok... Very decent distortion specs for such an old board, hard to get a similar new one for SH price. I don't know what the EQs sound like, and the frequency range seems most adapted for early digital work.

 

T

[Mike Rivers]

Hopefully the electrolytic capacitors are ok... Very decent distortion specs for such an old board, hard to get a similar new one for SH price. I don't know what the EQs sound like, and the frequency range seems most adapted for early digital work.

 

On the positive side, the Mackie 8-bus was a brilliant design and an ideal mate for the low-end studio with a TASCAM or Fostex 1/2" 8-track analog or Alesis or TASCAM 8-track modular digital multitrack recorder. With an 8-bus and three ADATs, you could have a fully functional and well thought out - both for tracking and mixing - studio with all the expected features, and decent sound.

 

An 8-bus that doesn't have ribbon cable problems by now will probably be fine in that respect, but like all electrolytic capacitors, it will take replacing all of the electrolytics used as coupling capacitors to bring it back to its original sonic performance. It's a tedious job, but one worth doing if you want to keep using the console. Switches and pots do indeed require cleaning but that's considered routine maintenance for any device that has them.

 

and

 

Or add membrane switches, and bring it [potential trouble points] back down to 52%

 

It seems that every manufacturer building low-mid priced hardware (and some building top tier hardware) somehow managed to use custom switches and pots in their manufacturing. Instead of using standard off-the-shelf parts and designing circuit boards and panels to accommodate them, they designed (primarily) panels to fit the features and functions into the space that Marketing told them couldn't be any bigger (gotta fit on the dining room table, you know), and had the mechanical parts built to those size constraints. Consequently, 30 years later, it's impossible to get exact replacements and, in most cases, darn near impossible to make substitutions for currently available parts.

[techristian]

So all 32 channels are working now and all the EQs . BUSS 5-6 are still a problem, but since then I have picked up 2 more Mackies cheap , a 32-4 and a 24-4 . Both look like they were kept in a garage, but the 32-4 seems to be working 100% with broken faders. So I'm grabbing some faders from the 24 channel unit and doing a complete cleaning. This will take up more space in the studio, but I will end up with, at least, 10 busses and a mixer closer to my drums.

 

The 32-4 is remarkably quiet and clean sounding.

 

Dan

http://clutterpop.com/mackie.jpg

[techristian]

So I need to explain how I got in this position.

 

I was on a Facebook group talking about my 32-8 and another user PMed me. He told me that he had a 32-8 and a 24-8 that he wanted to get rid of, that they were taking up space and that I could get them for CHEAP. I thought I could grab the output module from one of the units and make a quick fix on my mixer, and have a second to boot.

 

He lived 150 miles away and he never sent any photos. He was willing to part with the 24 channel for $75 or both for $200, but I could sense that he really wanted to get rid of both.

 

Well you can imagine the look on my face when I went to his house and saw the 2 FOUR BUSS systems (wrong mixers) sitting on the back porch.

 

When he saw that I was going to leave without the mixers, he was ready to give them to me for free. (I think he REALLY wanted to get rid of them to gain space)

 

I never went there to heckle with him. I was ready with $200 in pocket to buy a 24-8 and a 32-8.

 

Anyway after he offered to GIVE THEM to me ,because I came 150 miles, I paid him $100 and took them home, a bittersweet deal.

 

So that is the story behind this weird acquisition.

 

So I will end up with many more channels and less space in my studio.

 

MORAL OF THE STORY: ASK FOR PICTURES FIRST

 

Dan

[techristian]

Still waiting for PARTS for the 32-8. Re-assembling the 32-4.

 

I can tell you this. From a SERVICING standpoint, the 32-8 is WAY EASIER , because it has fewer surface mount parts and all the ribbon cables UNPLUG. The 32-4 has FLAT CONDUCTOR and soldered in ribbon cables which you must be very careful with.

 

Dan

[zeronyne]

I have two CR1604vlz mixers that need a going through...this is very inspiring...I'm starting to think I should just do it myself.

[techristian]

One down and one to go. Here is the Mackie 32-4 after much work and some frustration. Mounted on the wall.

 

LONG STORY TO FOLLOW.

 

http://clutterpop.com/Mackie32-4.jpg

[techristian]

In the meantime,anyone considering this project should watch these 4 videos.[video:youtube]

 

[video:youtube]

[video:youtube]

[video:youtube]

 

BTW THIS TAKES MORE THAN 8 HOURS. MUCH MORE !

 

DAN

[KuruPrionz]

I am impressed.

 

And, I am glad I don't own any large mixing boards!!!! I have a 12 channel Yamaha with 6 mic inputs that somebody gave me because they lost the power supply. I got another one.

It works. If it got messed up I'd get rid of it and maybe never miss it since it hardly every gets any use.

[techristian]

I am impressed.

 

And, I am glad I don't own any large mixing boards!!!! I have a 12 channel Yamaha with 6 mic inputs that somebody gave me because they lost the power supply. I got another one.

It works. If it got messed up I'd get rid of it and maybe never miss it since it hardly every gets any use.

 

I HEAR YA !!

 

So with the 32-4 I got this bright idea of partially assembling WHILE IT WAS ON THE WALL. It would be easier to lift (I figured... base/back plate is heavy gauge steel) . So the Power Supply had to be installed in the base and then screw the base to the wall. AND IT WOULD HAVE WORKED, except I made a small mistake when I plugged in the Power Supply. Because of the AWKWARDNESS of this, holding up the rest of the mixer WHILE, trying to attach the ground screw and PS CABLE , I plugged it in OFFSET by one pin.....WRONG WRONG, and didn't notice until the rest of it was assembled on the wall and when I turned on the power NOTHING NOTHING.

Pulling it down from the wall , it slipped out of my hand and I knocked 2 sliders off. So I had to take it apart again, unsolder the sliders, install 2 more sliders, , replace a cap on the power supply ,reassemble and set it up for re-hanging on the wall. I would hang it the way I did with my old 70's 16 channel Kelsey...with key like openings.(see attached) 13 of them to be precise, onto a 1/2" particle board back plate screwed into the joists. With this approx 40 lb mixer, I sweat BUCKETS, getting all 13 holes to line up with the screws, while I was hanging it.

 

 

Now I am re-assembling the heavier 32-8.

 

The 32-8 is like a puzzle. Not only must the right modules be in the right places with the right connections, but they must be installed in the RIGHT ORDER !!

 

To be continued...............................

[Mike Rivers]

OK, I'll show you mine since you've shown me yours. - a different but somewhat related Mackie 8-bus console, a Vintage d8b. This was Mackie's first digital console and really the only one that was completely finished before being discontinued.

 

The back story is that I've been using a Soundcraft 600 24x8x16 (mic, line, and tape return channels x buses x monitor returns) since I bought it new in 1985. It's tired, needs too many new pots, switches and faders (all unobtainable as new parts), and because of an imaginative internal grounding system, was fine for tape but not really quiet enough for digital work. I've been shopping for a new digital console for several years now and, while there are plenty of nice ones, they're all designed for live sound in mind rather than multitrack recording. Their common flaws are:

 

- Mic and Line Inputs on the same connector so you can't have everything plugged in at once

- No tape returns (not enough independent inputs for that)

- Frequently no direct outputs other than as USB to a flash memory card or recorder

 

 

The d8b was built as a recording console from the get-go, designed to mate with an 8-track up to 24-track analog recorder, have all the tape tracks available for a monitor mix (as well as mixdown, of course), and gee-whiz-it was digital. Plug-in I/O cards allowed a choice of analog or three flavors of inputs and outputs, EQ and dynamics are included for each channel, and a series of plug-ins running on optional DSP cards did all sorts of other stuff.

 

I work on the trailing edge of technology without need for much signal processing, so I decided I'd see what I could find in the way of a used d8b in reasonable shape. I ended up with one that's on loan with no time limit and no agreed buyout. There were a couple of things wrong with it which I was able to repair. Back then you could get good documentation from the manufacturers, so I was even able to track down one of the problems to a digital card, found a replacement, and it's now all working. It'll be ages before I learn all the automation tricks, but what the heck, I never used an automated console before, so why rush into it because it's there?

 

In addition to getting all the gozintas, gozoutas, and faders working, I needed to re-purpose many cables from the patchbay to the console because there were some holes to fill and some plugs that no longer had holes for their functions. There are still a bunch of loose cables back there ready to find homes.

 

Oh, and to the left of the d8b, you'll see the corner of a Mackie 1640VLZ3. That's for emergencies, remote work, and, since it has a Firewire interface to all the input and output channels, it's still hooked up to a computer so I can pretend to know how to record with a DAW if necessary.

 

Anyway, I thought I'd borrow this message thread and put up a couple of pictures.

 

 

Console in Natural Habitat

 

 

 

Back Side of the Console

 

 

https://imgur.com/e1pmvGo]

Just for kicks, back of the patchbay/rack

[techristian]

OK, I'll show you mine since you've shown me yours. - a different but somewhat related Mackie 8-bus console, a Vintage d8b. This was Mackie's first digital console and really the only one that was completely finished before being discontinued.

 

I like the duct tape on the the phono plugs. I use the same thing to to label cables.

 

These heavy beasts are hard on the back !!

 

Dan

[Mike Rivers]

I don't recall any duct tape on plugs, but there are a few 1/4" plugs labeled with a piece of "artist" or "console" (white paper) tape wrapped around the plug body. When I first made up the console cables (I had a plan, of course), I typed the cable labels on a computer, printed them with a sufficiently small font, and, before soldering the connector on the end, wrapped the label lengthwise around the cable, slipped a piece of clear heat shrink tubing over it, and shrunk it down. When a label became obsolete, I'd make a new one, wrap it over the heat shrink tubing, and secure it using clear packaging tape. The heat shrink labels last forever. The packaging tape starts to come unglued after about 10 years, so it's not hard to replace the label a second or third round.

 

The cables with the white paper labels on the plugs were intended to be temporary, usually an already-made cable, but you know how "temporary" goes.

 

Why were you working on your console when it was hung on the wall? In fact why was it hanging on the wall in the first place? Are you using it essentially as a router rather than an active mixer? That seems like an uncomfortable setup for real mixing. And, as you've discovered, you have gravity working against you when you start disassembling it. I understand why some ribbon cables need to be installed in a specific order because of cable lengths and that they end up being sort of in layers for things like the channel strips.

 

I needed to get to the underside of the d8b to troubleshoot the missing tape returns, and I was able to wrestle it off the table and into a close-to-vertical position using the table edge as a fulcrum and rolling it around on the corners. That way I never had to lift the full weight of the console while being able to flip it over on the opposite end when that got me closer to where I needed to work. That, too, had several circuit boards stacked layers and connected by ribbon cables. Those cables definitely had to be put back in their original places or you'd find yourself holding a few at the end that wouldn't reach between where they needed to be connected.

[Mike Rivers]

And here's how I propped the console up on end in preparation for the surgery: [$&*#$ the "only 2 file attachments" and lack of the ability (or my ability) to insert images in line]

 

I should add (and I did) that at this point in the resurrection the Soundcraft mixer was still in place with most of its cables still connected, and the d8b lived in front of it on a stack of 2 (on each end) milk crates. Not a particularly good position for mixing, but it allowed me to get access to all of the connectors and controls so I could see what was working and what was not.

 

When I decided that I needed to get to the underside of the d8b I propped it up as in this photo just to see if I could do it myself or if I would need to find a helpful neighbor. Knowing I could move it around bolstered my confidence. Sometimes you just need that!

[techristian]

Why were you working on your console when it was hung on the wall? In fact why was it hanging on the wall in the first place? Are you using it essentially as a router rather than an active mixer? That seems like an uncomfortable setup for real mixing. And, as you've discovered, you have gravity working against you when you start disassembling it. I understand why some ribbon cables need to be installed in a specific order because of cable lengths and that they end up being sort of in layers for things like the channel strips.

 

That mixer (the 32-4) on the wall is a NEW INSTALL. I have room for ONE MIXER on a table NOT TWO. It is on the wall to save space. It is next to my drums and will mostly be dedicated to the drum sub mix, acoustic instruments and Vocals. I won't need to adjust it too often. I still need to set up a TARP to cover it when not in use. Also that mixer is further from the Fairlight, which as you probably already know, MAKES LOTS OF FAN AND HARD DRIVE NOISE. So if my wife wants to sing, I can even have her microphone and headphones set up in the HALLWAY , more than 20 feet away from the Fairlight.

 

The other problem that this second mixer solved was that it got rid of MICROPHONE WIRES (some a bit tight) running all over the floor to the drums. As I said in an earlier post in this thread, I never had plans on having 2 mixers in this room. It just worked out that way, and may turn out to be a good thing!

 

The 32-8 will be on the table fairly close to the Fairlight but will be mixing mostly 4-6 sub-tracks for SYNTHs ,SAMPLERs and C64 with LINE IN cables.

 

I will put up a picture of the whole setup, once it is finished

 

The 32-8 is basically all together except for the underneath steel back, the meter bridge and the knobs.

 

Dan

 

http://clutterpop.com/mackieinside.jpg

http://clutterpop.com/mackieinside2.jpg

 

http://clutterpop.com/mackieoutside2.jpg