NCD - Marshall 2556A
- Thread starter fitz
- Start date
BFT Gibson
Ambassador of Originality
Very nice , thats fun stuff to do ! Saved these just in case one day.
OP
fitz
Ambassador of DIY
Picked up the speakers and mounted them up to try 'em out.
A little dusty, but they look mechanically in good order and read correct impedance on the meter.
Series wired them to 16 ohm, so the amp should be putting out about 50w.
Very noticeable difference from the four 10's, or the junk 70/80 & Frankenstein-ed G12 Vintage.
Might reconsider the series / parallel jacks, this amp is F-ing LOUD through a pair of decent 12's at 50w.
Not sure if I'll ever use the parallel wired 4 ohm for the full 100w, but why not have the firepower available.
Tracking still saying tomorrow on the goodies from Mojotone.
A little dusty, but they look mechanically in good order and read correct impedance on the meter.
Series wired them to 16 ohm, so the amp should be putting out about 50w.
Very noticeable difference from the four 10's, or the junk 70/80 & Frankenstein-ed G12 Vintage.
Might reconsider the series / parallel jacks, this amp is F-ing LOUD through a pair of decent 12's at 50w.
Not sure if I'll ever use the parallel wired 4 ohm for the full 100w, but why not have the firepower available.
Tracking still saying tomorrow on the goodies from Mojotone.
OP
fitz
Ambassador of DIY
Had the afternoon off, so I got started on the tolex while waiting on the Mojotone order to get here.
Here's a layout pic with the tolex cut to size and marked for where to place stuff after it's sticky.
Glue on and starting the wrap.
Corners cut on the back side.
Trimmed up with the corner guards and handle on.
Test fit with the chassis and chopped down logo panel.
Some gaps to close up after the new grill gets installed.
UPS just dropped off my Mojotone order.
Time for a dinner break - cab gets tolex next.
Here's a layout pic with the tolex cut to size and marked for where to place stuff after it's sticky.
Glue on and starting the wrap.
Corners cut on the back side.
Trimmed up with the corner guards and handle on.
Test fit with the chassis and chopped down logo panel.
Some gaps to close up after the new grill gets installed.
UPS just dropped off my Mojotone order.
Time for a dinner break - cab gets tolex next.
DirtySteve
Ambassador of Hold My Beer
Really cool seeing the progress. It's looking good!
OP
fitz
Ambassador of DIY
Cab pics:
The piece of green that I had was long enough to get from one side of the bottom around the top to the other side of the bottom.
Barely enough to cover past my bias splice jig.
Wrapped and both ends trimmed.
Had one scrap left that covered the bottom and cut in the double splice.
Cab tolex with all the corners cut and trimmed.
cut out the handle holes and foot cups.
The piece of green that I had was long enough to get from one side of the bottom around the top to the other side of the bottom.
Barely enough to cover past my bias splice jig.
Wrapped and both ends trimmed.
Had one scrap left that covered the bottom and cut in the double splice.
Cab tolex with all the corners cut and trimmed.
cut out the handle holes and foot cups.
OP
fitz
Ambassador of DIY
A few more pics:
Corners & feet,
Handles and foot cups.
Al the corners and head handle were leftovers from my AVT cabs I cosmetically altered to make big 112's for my Origin 50H.
They are all a matte finish, and even had the special top angle corners for the slant cab from the combo that was sacrificed for the O50 A cab.
Foot cups don't line up with the amp head feet, but that's not something I wanted to alter.
I've had a few 3210's and a 3203 come and go that would have fit this cab perfectly.
Also got the new 2-hole jack plate cut into the round hole in the back panel.
No tolex left to do the back panel, but I think the rattle can black will do just fine for something no one will ever see.
Thats a "wrap" for tonight.
Piping and grills tomorrow.
Corners & feet,
Handles and foot cups.
Al the corners and head handle were leftovers from my AVT cabs I cosmetically altered to make big 112's for my Origin 50H.
They are all a matte finish, and even had the special top angle corners for the slant cab from the combo that was sacrificed for the O50 A cab.
Foot cups don't line up with the amp head feet, but that's not something I wanted to alter.
I've had a few 3210's and a 3203 come and go that would have fit this cab perfectly.
Also got the new 2-hole jack plate cut into the round hole in the back panel.
No tolex left to do the back panel, but I think the rattle can black will do just fine for something no one will ever see.
Thats a "wrap" for tonight.
Piping and grills tomorrow.
OP
fitz
Ambassador of DIY
Front view.
And with the piping and grill in the head.
Now for some wiring shenanigans.
Palmer Cab Merger layout on the left - just substituted direct wiring to speakers for the cab jacks.
It's working...
Parallel jack for 4 ohm / 100w.
And series jack for 16 ohm / 50w.
And with the piping and grill in the head.
Now for some wiring shenanigans.
Palmer Cab Merger layout on the left - just substituted direct wiring to speakers for the cab jacks.
It's working...
Parallel jack for 4 ohm / 100w.
And series jack for 16 ohm / 50w.
ibmorjamn
Ambassador of Moar Jammin
@fitz
Tinkers Table , finally found this post.
I had posted elsewhere on mf( on my amp post)
Easier to comunnicate the whole thing in here. Maybe I should start my own post ?
I added some darn drawing app on my phone. It's not even close to a Auto Cad program but it's simpler.I could not make the lines intersect and the font size is off.
I am toying with a angle cab. It would be taller and about 5" deeper, still 24" wide
Tinkers Table , finally found this post.
I had posted elsewhere on mf( on my amp post)
Easier to comunnicate the whole thing in here. Maybe I should start my own post ?
I added some darn drawing app on my phone. It's not even close to a Auto Cad program but it's simpler.I could not make the lines intersect and the font size is off.
I am toying with a angle cab. It would be taller and about 5" deeper, still 24" wide
Last edited:
Amp Mad Scientist
Ambassador of Heresy
We bought some 70/80 speakers made in China.
The speakers have no excursion, the cone cannot move forward or back more than 2mm.
It appears to me that the voice coil / spider / cone was assembled wrong....and nobody in China caught the error?
Are these speakers built this way intentionally?
I have to call Celestion and find out what the cone excursion is supposed to be...
in the meantime, I remain befuddled.
ibmorjamn
Ambassador of Moar Jammin
I didn't even notice that had a angled top.
Interesting baffle and nice tool you made for the corners.
OP
fitz
Ambassador of DIY
The 2556A is 10" deep at the top, and 12" at the bottom.
The baffle is flat and at an angle on the inside.
There are triangle pieces on each side of the baffle with a cross piece in the middle to give the bend line for the half slant to the grill.