MASCO MAP 15 - need help install 3 prong ac cord

[sig]

MASCO MAP 15 Grill Mesh with G Clef

Started working on the cosmetics for the MASCO MAP 15. I had to strip off old paint off the original vinyl covering, it took several hours to do it without damaging the vinyl. I used a Dollar Store Product called "AWESOME" which worked very well and I highly recommend it as a cleaner and to remove water based paint.

As a temporary measure, I'm going to use some vintage looking grill cloth I picked up off ebay for $5. The attached pic is the original grill that a previous owner painted. The amp was really ugly, but it's starting to look better now. Should be able to post a pic of it back together tomorrow.

1. I've looked all over the net for a replica of this kind of grill mesh, no joy. Is there someone out there that does this kind of work? The mess is like a screen material, firm and solid. What's left of the original G CLEF feels like think FELT material.

2. Tested the original Jensen Speaker today, it works well!

3. Although the amp sounds good!!! I'd appreciate recommendations on how to get the noise floor down a bit. My POTs and all resistors are 65 years old, jacks as well. I cleaned the pots and they work OK, but I've read that some recommend replacing them as they can be noisey. I replaced the Filter CAPS with original value CAPs 16uF 450vs and 8uF 450V, 'm thinking higher value Filter Caps might help, if you agree, appreciate recommending values for me.

Some additional photos of the chassis and the amp before reassembly are here if you are interested:

http://www.facebook.com/#!/media/set...495.1444914471


Paul

[Jazz P Bass]

That looks like "jute"cloth.
It is a woven fabric.
You could try something like Mesa Boogie.
Here is a link to a seller:Mesa/Marshall Style Tan Jute (Small Weave Cane) 36" | SteamcoMusic dot Com

[sig]

That looks like "jute"cloth.
It is a woven fabric.
You could try something like Mesa Boogie.
Here is a link to a seller:Mesa/Marshall Style Tan Jute (Small Weave Cane) 36" | SteamcoMusic dot Com

Not bad, looks a bit like what I bought off Ebay. Thanks!

[sig]

MASCO MAP 15 Grill Mesh with G Clef (VIDEO of Amp after Refurb Completed)

Again everyone, I humbly and gratefully appreciate all the help everyone gave me. This was a great project for me, it gave me a lot of satisfaction in finally getting the amp back to it's original glory. It's a really, really, cool amp.

I posted a Youtube Video of the amp with me playing my Gibson ES-330 if you are interested in checking it out. Here's the link:

YouTube - ‪M4H02479‬‏

Thanks again! Highest regards for the people on this forum.

I'm in Bowling Green, VA, and if you're in my area, stop by for a visit and play some music. sigmon@sysmatrix.net

Paul Sigmon

[Amp]

Hello.
Bumping an old thread because this is the amp I have and the conversation here seems good.

How to I take out the chassis to clean the pots?
Also, is this an OK job for a beginner to learn recapping?

I have an interest in vintage radios too and am just overly-confident enough to jump in, screw everything up and eventually have to send it off to someone to do it right... I've never done it before, but ya gotta start somewhere.

Any help appreciated.
THanks.

[sig]

Hello.
Bumping an old thread because this is the amp I have and the conversation here seems good.

How to I take out the chassis to clean the pots?
Also, is this an OK job for a beginner to learn recapping?

I have an interest in vintage radios too and am just overly-confident enough to jump in, screw everything up and eventually have to send it off to someone to do it right... I've never done it before, but ya gotta start somewhere.

Any help appreciated.
THanks.

Hi. I'm a novice but I did it with the help of forum members. I think I probably over did what was necessary. I've read a lot and learned a lot and I've now successfully rebuilt 4 vintage amps I've bought that didn't work. With the Masco, I suggest you merely replace the filter caps first which might be all you need. Whereas, I replaced every cap in the amp on my Masco and probably didn't need to. Some of the old signal caps (paper/oil) types are known to sound better. So, first, I'd just replace the large filter caps, I'm sure they need to be replaced, easy job. Regarding the pots, I'd first attempt to leave them in the amp and get some "Contact Cleaner" from your local hardware store or Radio Shack. Take the knobs off and spray the front of the pot good and turn the control back and forth a lot. This should clean up the pot. Then, after the filter caps are changed and the Pots are cleaned, if you still have problems, then consider replacing the pots. My POTs work fine. After completing my amp, I think all I really had to do was: Clean Pots, Replace Filter caps, replace tubes. I had a bit of cosmetic work as well to clean up the cabinet. But now, I'm really pround of the amp because I fixed it myself. My direct email is sigmon@sysmatrix.net if you need anything. All the best! Paul

[Dave Curtis, dB AudioTech]

"Regarding the pots, I'd first attempt to leave them in the amp and get some "Contact Cleaner" from your local hardware store or Radio Shack. Take the knobs off and spray the front of the pot good and turn the control back and forth a lot. This should clean up the pot."

That just *might* clean the shaft, and it also might strip any lube the shaft had. That's not how to properly clean a pot. The following is an old usenet post regarding "scratchy" pots:

Lord Valve Speaketh:

Once you have the chassis out of the cabinet, you have to eyeball the
pots and see if they are accessible. If they are, like in old
Fenders and Marshalls, it's a piece of cake. You'll need two
type of Caig Labs chemicals...D5S-6, and MCL100LS-2. Put about
a half-second shot of the D5 (red formula) into the pot, and
rotate it vigorously 10-20 times. Let it sit for a couple of
minutes, and finish it off with two shots from the MCL (blue
formula) can, again rotating the pot vigorously 10-20 times.
The MCL100LS-2 can emits a 1/4-second timed burst when you push
down the sprayhead, unlike the D5 can, which will spray as long
as you hold the valve down. The red formula takes care of
corrosion and other nasties on the metal contact surfaces, and
dissolves other crud so that it can run out of the pot. The
blue formula is good for the carbon track, and also replaces any
lubricating grease the red stuff dissolved, making the pot feel
nice and smooth again. HEADS-UP: Do *NOT* put the red stuff
into your console faders. It's damn near impossible to make 'em
feel right again after you put any cleaning solution which includes
a solvent vehicle (like D5S-6) into them. There is a 100% formula
(no solvent) for the red variety, called D100-2. Use that instead
of the D5, and follow the above procedure. Also excellent on EQ
sliders and rotary switches.

Here's the weenie: If you find that you're looking at the solder
side of a PC board where the pots ought to be, you'll have to
pull the PCB out to clean the pots. This type of construction is
very common (reissue Fenders, Crates, etc.) these days, so if you
have a newer amp it'll be a pain in the ass. You'll need to pull
all the knobs off the pots, take all the bushing nuts off, maybe
unplug some ribbon cables and remove some screws which go through
the PCBs into chassis-mounted standoffs. If you have LEDs on the
front panel, you'll need to be especially careful not to bend the
leads for them out of place while you have the PCB out. You may
also need to make yourself a "gozinta." A "gozinta" is a device
which makes sure the doctor juice "gozinta" the pot, instead of
all over the place. (Maybe in your eye, nose, or mouth, if you're
not careful. Trust me, D-5 tastes like utter shit. ;-) Since
the slot where the contacts enter the pot body will probably be
sandwiched between the pot and the board where it's damn hard to
spray into, you'll have to take the red plastic tube that sticks
out of the spraycan and bend it. (I have a whole shitload of these,
bent to various angles, for reaching into specific amps and mixers.)
This is easily done by heating the tube *carefully* with a lighter
(or propane torch throttled *way* back) where you want to bend it.
Once it's hot, you can push it against your workbench to bend it
to the angle you need. If you screw up and collapse the tube or
melt it too much, just snip the bad part off and start over.
Use the same procedure I outlined above, and then re-install the
PCB.

Be aware that there are circuit conditions which can cause a pot
to become noisy; you won't be able to tell the difference unless
you know your tech shit. DC on the pot is the most common one.
If you have a pot that's still scratchy after you've treated it
in the way I recommend, it's either a bad pot or you can suspect
a circuit malfunction. 90% of the time, a scratchy pot just needs
to be cleaned. 5% of the time the pot is defective, and 5% of the
time something's gone south in the circuitry. That's a 9/1 crapshoot,
with the odds in your favor. Go ahead and clean 'em.

Lord Valve