200S Blueprints ?

[Greg_M]

That's right, my late '70 200S cab has the front-mounting grill - unlike my 1971 Sorado cabs, which have the grill cloth fastened to the baffle on the inside.

Greg M, if it's just a matter of measuring something from the front, I'll work from the above post and see what I can find based on my cab.

It might be that if you had a real thin ruler (6" machinist scale or something like it) you could slide it in between the grill and the edge of the cabinet. Or a very thin pin that you could slide in there and then mark the pin or hold your thumbnail on the pin and measure the pin.
I would hate to see anyone poke a hole in their grill just for this dimension

[CLD]

Shouldn't be a problem, especially since mine pops off. There's a little more room to maneuver around the grill.

[EdBass]

The dimension (I need) of "the red board" is how wide it is from front to back. I understand that it goes all the way from one side to the other and that it is made of 3/4" plywood, I just need to know that last dimension. The front to back dimension.

The center board you added in red is attached to the cabinet, and measures 5” wide. Unlike the ducting, it is made with the same .75” plywood as the rest of the cabinet.

 

.75” thick and 5” front to back. Am I missing something here?

I'm going to assume (which I hate to do) that the baffle boards are 1-1/4" from the very front of the cabinet. If the frame that the grill cloth is stapled to is 3/4" material that would leave a distance of 1/2" from the grill cloth to the very front of the cabinet (minus the velcro if used)

Using the "modified toothpick" method (I used a paper clip) I get 1.25" from baffle to front of cabinet.

The exterior dimensions of the box I have are 42" x 24" x 15" only 2" taller. What helps to make it look too tall is the extra thick plywood frame on the front. It measures 1-1/2" instead of 1-1/4" That extra 1/4" makes a lot of difference in the looks.
What Sunn did was to take and glue in an extra piece of 1/2" plywood around the front to make the walls look thicker. What who ever built this cabinet did was to use a some pieces of 3/4" plywood which accounts for the extra 1/4" of thickness. It throws off the ratio and it makes them look too fat

I think the too tall look is probably because it’s 2” too tall, which throws off the scale making it look skinny.

[Greg_M]

".75” thick and 5” front to back. Am I missing something here?"

No
I didn't see it nestled between the pictures

[HRobert]

The radius on the outside edges would be helpful.

Greg, Are you talking about the round over on the edges?  If so, I believe that the edge round over is 1/8" on all edges.  I don't believe that it's a full 1/4" like on a lot of other amps and speaker cabs.  It might be 3/16" at the most.

[Greg_M]

I went to Google and put in "Radius of Sunn Cabinets" and one of the hits was this place that sells corners and knobs and they had two radii of their corners......5/16" and 1/2"
Their descriptions suggested that Sunn (Ampeg, Polytone and others) used 5/16" radius (part #s 2801-Xnp & 2801-np)
Where as others (Fender and whatnot) used a 1/2" radius

https://www.vibroworld.com/parts/tech9.html

Here's an interesting post on corners on another forum (google result)
http://jam4jmessageboard.websitetoolbox.com/post?id=2721817

I built a lot of cabinets back in the 60s as I was too poor to buy the neat ones I wanted. The tighter radius (5/16) rings a bell because I remember Sunn having a smaller radius than the Fender cabinets I was always trying to duplicate. Never actually tried to build a Sunn before.

[HRobert]

I went to Google and put in "Radius of Sunn Cabinets" and one of the hits was this place that sells corners and knobs and they had two radii of their corners......5/16" and 1/2"
Their descriptions suggested that Sunn (Ampeg, Polytone and others) used 5/16" radius (part #s 2801-Xnp & 2801-np)
Where as others (Fender and whatnot) used a 1/2" radius

https://www.vibroworld.com/parts/tech9.html

Here's an interesting post on corners on another forum (google result)
http://jam4jmessageboard.websitetoolbox.com/post?id=2721817

I built a lot of cabinets back in the 60s as I was too poor to buy the neat ones I wanted. The tighter radius (5/16) rings a bell because I remember Sunn having a smaller radius than the Fender cabinets I was always trying to duplicate. Never actually tried to build a Sunn before.

Greg,  I believe that the 1/2" radius is too big.  That would be a 1" circle.  I used a 1/8" roundover bit in a router to do the edges of my cabs.  The corners had to be flattened a bit more with a rasp and then the OEM corners fit pretty well.  From this experience I think that a 3/16" would be perfect.

Have you tried to contact VibroWorld?  Last spring I tried several times to buy both the two and three legged corners, and every time the guy who runs the operation was off running sound for his band and I couldn't place an order.  Plus he either blocks his emails or doesn't return any messages. I tried several times to order the corners with no luck. I finally got tired of trying to deal with this guy and found out that you can get the OEM corners from Conrad.  I would suggest buying from him...great service and quick shipping.

Rob

[CLD]

Greg, I took some measurements this morning.

With the grill out, the distance from the baffle to the outside (front) edge of the cabinet is a full 1 inch. With the grill in place, there is 1/4 inch to the front edge.

The wooden frame itself is only half an inch thick but the cloth and early style faux velcro add a quarter-inch to the width.

I measured that center piece "red board" and mine is 5 1/8 inches front to back. I measured it three times to be sure; wouldn't be surprised by small variations like that being tolerated in Tualatin.

Getting back to the grill cloth discussions earlier, attached are two photos showing the "Conrad cloth" next to the original, 1971 cloth on my Sorado cabs.  One is absolutely original, never cleaned, and the other one is original but has been cleaned. As you can see, the Conrad cloth is very nice but slightly brighter. Not sure if it comes through in the photos but in person is has a slight (and very light) blue tint.

I hope these are helpful.

[Greg_M]

I dropped a note to Conrad to see what they are using now and if they sell any original corners.
An easy way to kind of measure the radius is to put a straight edge up the side of an original cabinet (sticking out the top) and then measure over to the end of the radius (with a ruler) as it goes across the top. That's not going to be perfect but it would give an approximate.

I've never tried to contact Vibroworld, I haven't built a speaker cabinet in a very long time. (but I'm getting the urge)

I have CNC mills (for metal) that I can jig up and make the cuts for the folded horns and what not. Might be fun to make one or two. I'm pretty sure they will spin fast enough to cut wood.

[Greg_M]

CLD
Yes probably there are slight variations on dimensions. Those variations are one of the things got me out of working wood and into metal working. 

The more measurements the better and we can average them out. I'll alter my speaker grill recess dimension to 1" and the red board to 5-1/8" probably won't matter much to the sound waves, but might as well

Thanks for the effort

[Greg_M]

Getting back to the grill cloth discussions earlier, attached are two photos showing the "Conrad cloth" next to the original, 1971 cloth on my Sorado cabs.  One is absolutely original, never cleaned, and the other one is original but has been cleaned. As you can see, the Conrad cloth is very nice but slightly brighter. Not sure if it comes through in the photos but in person is has a slight (and very light) blue tint.

I hope these are helpful.

The bluish look reminds me of the Fender "silver face" amp grill cloth as opposed to the "black face" amps.

Thanks for those comparison pictures!

[HRobert]

Greg,

Here are two sources for grill cloth.  Mojo Musical Supply. Black/White/Silver #6301005. 36" wide and is $21.75/ linear yd.   This is what I used on my Sentura II cabs.  Parts Express has a B/W/S grill cloth, 36" wide and is $15.90 / linear yd. I believe they are the same thing... I have some of both and can't tell the difference.  For some reason this cloth also shows a bluish tinge in pictures.  The blue comes from the camera flash.  But in person, it does not have the bluish tint...it's just as it says; B/W/S. I suggest buying 1 yd of each and comparing.  What the heck, you can always use the cloth for a small project.....monitors etc.

[Soundmasterg]

I went to Google and put in "Radius of Sunn Cabinets" and one of the hits was this place that sells corners and knobs and they had two radii of their corners......5/16" and 1/2"
Their descriptions suggested that Sunn (Ampeg, Polytone and others) used 5/16" radius (part #s 2801-Xnp & 2801-np)
Where as others (Fender and whatnot) used a 1/2" radius

https://www.vibroworld.com/parts/tech9.html

Here's an interesting post on corners on another forum (google result)
http://jam4jmessageboard.websitetoolbox.com/post?id=2721817

I built a lot of cabinets back in the 60s as I was too poor to buy the neat ones I wanted. The tighter radius (5/16) rings a bell because I remember Sunn having a smaller radius than the Fender cabinets I was always trying to duplicate. Never actually tried to build a Sunn before.

Greg,  I believe that the 1/2" radius is too big.  That would be a 1" circle.  I used a 1/8" roundover bit in a router to do the edges of my cabs.  The corners had to be flattened a bit more with a rasp and then the OEM corners fit perfect.  From this experience I think that a 3/16" would be perfect.

Have you tried to contact VibroWorld?  Last spring I tried several times to buy both the two and three legged corners, and every time the guy who runs the operation was off running sound for his band and I couldn't place an order.  Plus he either blocks his emails or doesn't return any messages. I tried several times to order the corners with no luck. I finally got tired of trying to deal with this guy and found out that you can get the OEM corners from Conrad.  I would suggest buying from him...great service and quick shipping.

Rob

The guy who runs Vibroworld (Zach) put the company on hiatus several years back to go be the amp tech for Robert Cray on a European tour, and as far as I know he hasn't started it back up again. I could be wrong though. He is across town from me and is a good guy, but is always very busy. I'd just go through Conrad for any and all questions regarding these cabinets and sourcing parts. He's a great guy and is very friendly and helpful.....not to mention he's the guy who designed it originally too. Just email him....

Greg

[Soundmasterg]

At some point velcro was added to the front of the cabinets to hold the grille cloth on. I've got a 2000S cabinet with the old style grille cloth and it has the velcro on it from day 1, so they probably added it pretty early. If I was making one of these cabinets, I would front load the speakers. It doesn't change the sound and makes the speakers much easier to remove if needed. Conrad likes to build them as front-loaders nowadays too.

Greg