Monitor 7 Refurb

kidglove13

I figured I would start a thread about my Monitor 7 refurb project
I paid $20 for the 7's and the cabs needed alot of work and there is a leaky cap in the crossovers.

I have started on the cabs and this is where I am to date
I am going to paint the cabs so everything has been stripped
Alot of putty, sand, putty sand and 6 coats of primer alot of sanding
1 cab is almost finished and prepped for paint.
I am not doing anything to the rear of the cabs I left the vinyl on there

I just received my Clarity PX and Dayton caps in the mail, I will posts pics of the crossovers when I get to those

Conradicles

Looking good. I will be doing the same thing soon to my Monitor 7's. Keep us posted and pictures rolling!

heiney9

Be sure to vigorously clean the electrolytic material off the pcb. Simple Green in a sonic cleaner with a toothbrush works really well. If you don't get every spec of that nasty fluid off the boards you will have issues.

H9

pitdogg2

heiney9 wrote: »

Be sure to vigorously clean the electrolytic material off the pcb. Simple Green in a sonic cleaner with a toothbrush works really well. If you don't get every spec of that nasty fluid off the boards you will have issues.

H9

Methyl Ethyl Ketone works much better.

kidglove13

Thanks for the tips on the old caps

It does not appear that the cap leaked onto the board, it is only showing signs of it at the end of the cap under the plastic coating
Almost like it was getting ready to let loose because it is bulged at the end

heiney9

pitdogg2 wrote: »

Methyl Ethyl Ketone works much better.

A lot nastier and harder to handle that what I suggested. But if he has the space outside of the house to use the stuff then it should be ok.

My way is easier on the nostrils and more environmentally friendly as well as user friendly.

H9

pitdogg2

I just put a little on a Q-tip and keep the lid on. MEK is what Steve Sank told me to use when I re-capped my Sony ES CD player. He does this stuff for a living at laughing Dog Transducer, Brock I've used Simple Green on many things but have never tried on boards.

weather or not you see anything on the board you should at least clean with one of the above or Acetone(nail polish remover) without lemon smell:) as sometimes it appears as if nothing got to the board but 6mo later you find out it did and now you're building traces.

That last sentence about the traces was more from what happened to myself. It would have to eat a LOT of copper to affect the XO board like it did my player board.


cheap insurance to clean.

heiney9

Ah yes, I was thinking soaking the entire board in a tub of that stuff. Perhaps that's not necessary in this case. The picture in my mind was of the Adcom amp pcb's and how they needed to be submerged as it leaked all over.

Yes, a Qtip might work if the electrolytic is not too invasive.

H9

Saftgeek

Great start! Keep posting and include the pics. When you're done your work will be there for others to admire. Way better then before/after pics.

Good luck!

-Saftgeek

kidglove13

Of course I had my first major screw up today.
I thought I got all sanding marks from the primer, but I did not and when I shot on the first coat of paint it looked horrible
Back to sanding again:mad:

These cabs are going to be far from perfect but will look good from about 5 feet away
But they will be way better than they were.

I just want a decent looking cab without it taking forever to do, its not a car nor will the finish be as such
They will not be a mirror type finish, to much work

jason32835

I wonder if you would have an easier time of it with a textured surface? Something like this: http://tinyurl.com/9y2jklh

Thanks for the post by the way, it is inspiring me..

kidglove13

I thought about that, and I still might do that

Problem is color choice with the textured paint like that.

Because of the paint schemes in my house I want to go with a Khaki type color/dark beige

I have one thin coat on the one cab now I will post a pic of it

I actually like the color, it is different than black or brown.

kidglove13

Pics of Color

jason32835

Oh nice, those look great. Very nice work. I look forward to seeing more pictures.

nspindel

Nice work, these are the kind of threads that make me love this place. I've got my CRS+'s stripped down to the pressboard right now, I've got some dings that I'm going to fix up with bondo, then planning to hang with my bro-in-law in his wood shop some time in October and veneer them in maple, and then oil them. Great job!

kidglove13

Thanks for the compliments
Getting that MDF smooth is real PITA
I wish that the cabs were not so banged up or else I would have probably gone the wood veneer route.
I had to slightly ease all of the edges because they were so banged up.
I got most of it fairly smooth but there are still imperfections to say the least, I have been working on the one cab for 2 weeks now
I got to a point where I said enough is enough
From 5 feet they look great but get alittle closer and you will see some of the imperfections, oh well
Plus I am definitely not a cabinet finisher nor do I have the patience for it, it is better than they were
Hopefully I can get some of the paint smoothed out after my screw up with some good wet sanding
We will see

The crossovers should be interesting considering I have never done one before
But I figured these would be good speakers to take a crack at it, the crossover is not overly complicated

TNHNDYMAN

Your project is looking great. I've redone a couple cabinets now and it definately takes patience and at some point you hit diminishing returns. All those imperfections that you see because you've been looking at them from 8" away while sanding....no one else will ever notice. Great job!

kidglove13

To grill or not?
I am not a big fan of grills
Should I redo the grills?

Also I am looking for soldering advice.
This will be my first set of crossovers that I will be doing on the 7's
Any helpful tips before I dive into the crossovers?

nspindel

If you have never soldered before, best advice is to go to Radio Shack, get a cheapo circuit board and some wire, and practice. You want to always remember to heat the joint, not the just the solder. You don't want to drip hot solder onto a cold joint. You want to heat the joint, and touch the tip of the solder to the iron so it melts over the hot joint, otherwise you can end up with loose connections and bad conductivity. Get plenty of practice before you go near your crossovers!

kidglove13

Thanks for the tips
That is a great idea about Radio Shack and getting a cheap board to practice on

Note to self: Do not try and paint on a breezy day

nspindel

Here's another tip for you. For about $10 at Radio Shack, get yourself a de-soldering iron. It's a soldering iron designed especially for disassembling solder joints like you will need to do with the old crossover components. The tip has a hole that leads up to a bulb that you squeeze and release. So when the iron gets hot, you squeeze the bulb, place the hole over the existing solder joint, and when the solder melts you release the bulb, which sucks all the old solder out of the joint and you can just pop the old resistors and caps right out. This will save you a lot of time and lead to a much cleaner job. Just be careful cleaning the old solder out of the de-soldering iron. The spent solder is inside, and when you squeeze the bulb again it can come spraying out. So after you remove solder from a joint, make sure the tip is facing away from you, and squeeze the bulb to shoot the solder out onto a safe surface. If you let the solder build up in there it can come dripping out on top of the next joint you're trying to undo, so clean it out frequently.

kidglove13

Cab #1 finished
Cab#2 now being started

11tsteve

nspindel wrote: »

Here's another tip for you. For about $10 at Radio Shack, get yourself a de-soldering iron. It's a soldering iron designed especially for disassembling solder joints like you will need to do with the old crossover components. The tip has a hole that leads up to a bulb that you squeeze and release. So when the iron gets hot, you squeeze the bulb, place the hole over the existing solder joint, and when the solder melts you release the bulb, which sucks all the old solder out of the joint and you can just pop the old resistors and caps right out. This will save you a lot of time and lead to a much cleaner job. Just be careful cleaning the old solder out of the de-soldering iron. The spent solder is inside, and when you squeeze the bulb again it can come spraying out. So after you remove solder from a joint, make sure the tip is facing away from you, and squeeze the bulb to shoot the solder out onto a safe surface. If you let the solder build up in there it can come dripping out on top of the next joint you're trying to undo, so clean it out frequently.

sorry to bust in, but i am following this thread as i have a pair of 5jrs i am going to be working on and i am interested in how the painting works out.
about the soldering iron, what do most here use, both tip type , gun or pencil(?), and wattage. just curious... i have a 15/30W i got at Radio Shack, and am not entirely happy with it, and before i get another, i thought i could help both Kidglove and me at the same time.

kidglove13

The painting is tough for an MDF cab.
If you are going for a perfect finish be prepared for alot of work.
I got to a point where enough was enough.
It is far from perfect and you can see imperfections up close and at certain angles in certain light, but it still looks good to me and most will not notice the other stuff.
Prepping the cabs is alot of work for paint, I used regular rattle can paint for the finish, so it is not completely smooth because of the orange peel effect
If you want a mirror finish the cab will have to be dead nuts perfect or else you will see everything and it will look like garbage
It has taken me about 2 weeks or so to do one cab with on again off again working on it.
Once I got the puttying done and sanded down I applied a good primer base of Bin's Shellac based primer and sanded again smooth and knocked down any high spot I could as best as I could then hit it with Bin's again then sanded smooth
Then I used Rusto Primer/Filler, this stuff is the bomb, and about 6 coats later and alot of wet sanding I applied my finish coats
It was a labor of love
If my cabs were not so beat up I probably would have gone the vinyl or wood veneer route

gimpod

nspindel wrote: »

If you have never soldered before, best advice is to go to Radio Shack, get a cheapo circuit board and some wire, and practice. You want to always remember to heat the joint, not the just the solder. You don't want to drip hot solder onto a cold joint. You want to heat the joint, and touch the tip of the solder to the iron so it melts over the hot joint, otherwise you can end up with loose connections and bad conductivity. Get plenty of practice before you go near your crossovers!

Sorry nspindel your close but no cigar. Actually doing it this way can cause cold solder joints and the iron can boil off the flux in the solder before it can do it's job, what you want to do do is heat the joint (ie. pad & lead) and touch the tip of the solder to the pad & lead not the tip of the iron, This way when the pad & lead are hot enough they will melt the solder making for good strong solder joint. Think of it this way, heat one side of the joint while applying solder to the opposite side. When done right you should end up with a nice shiny solder joint. If the joint look dull & gray that means your not getting the joint hot enough. One more thing use just enough solder to get the job done, in this case more is not better.

A few words about soldering irons, Most guys here use a pencil type Variable Temperature Solder Station something like this , personally I like to use a chisel type tip as it gives me better control, but use whatever works for you. Now wattage you really want one in the 30 - 40 watt range at least, That's what's nice about the adjustable ones you can turn them up or down depending on what your doing.

Happy Soldering. :biggrin:

kidglove13

Thanks

I like the chisel tip idea and I can see how that would work better

kidglove13

Decided to play with the soldering iron today at lunch and do one of the crossovers for the 7's

I used a Dayton 33uf for the lows and a Clarity PX 12uf for the highs

I will remove the double sided tape and use hot glue

Everything went fairly smooth.

StuartB

Looks good. Kind of fun, huh? I did my 5's earlier this summer. Are you replacing the resistor as well while you are upgrading? I did, and used Mills.

kidglove13

No resistors I am just replacing the leaking caps for now.

Maybe at some point I will replace the resistors but I do not see the need right now

TNHNDYMAN

coming along nicely kg- really like the painted cabs. Have a pair of 10's that need work and was considering doing a nice wood veneer, but now I just might paint them after seeing your work.

adb3da

That looks awesome. I wish I had some woodworking skills.