[mgalusha]

Randy & Tom,

I was also wondering where you bought the display plastic from?
I can get some smoked acrylic from mcmaster.

I just used the original display plastic from the SB2. Nothing fancy. When I built the Burson/Preamp I did use some smoked acrylic that I had on hand. It came from an old CD tower front cover.

In this case the front panel is .1875 thick (3/16" inch). I machined the recess in the back .100" deep, leaving .087 as the lip. Obviously the plastic isn't flush. And as Tom mentioned, the machined AL is visible since the panel is pre-anodized. I just use a black marker on the lip where it's machined. Not a perfect match but close enough given the size. Plus, since the machine are is at a 90* angle to the face plate, the color difference is much less noticeable. If you did want to flush the plastic it would certainly be more work. Get something like .250" thick smoked acrylic and machine the acrylic to fit inside the recess with a portion sitting inside the recess to make it flush with the front panel. For me this wasn't worth the effort but could be done. If one were to make the front panel from hardwood it wouldn't be nearly as difficult since to make a nice opening you would need a router with a guide bushing and a template. You could use the template and guide bushing setup to cut the acrylic as well though I'm not sure how well acrylic reacts to a 20,000 rpm cutter. It may be hard to keep it from melting.

When I cut the opening I measured the original lens and then subtracted .100 from each side of the width and .125 from the length for the opening size. The recess is cut to the lens size although I shortened it very slightly. I believe The final dimensions were 1.000" for the opening width and 1.200" for the recess width. I think (not at home, no drawing here) that the length was 7.5" but it might be a little shorter. The reason I did this was there are four small circular molding marks in the lens corners and I didn't want them to show. The SB2 case corner radius normally hides these but since I used a .250" diameter end mill the .125" radius wouldn't cover it.

As for securing it, just a couple small (really small) drops of hot glue in the recess.

Hope this helps.

Mike

[randytsuch]

Randy & Tom,

I just used the original display plastic from the SB2. Nothing fancy. When I built the Burson/Preamp I did use some smoked acrylic that I had on hand. It came from an old CD tower front cover.

In this case the front panel is .1875 thick (3/16" inch). I machined the recess in the back .100" deep, leaving .087 as the lip. Obviously the plastic isn't flush. And as Tom mentioned, the machined AL is visible since the panel is pre-anodized. I just use a black marker on the lip where it's machined. Not a perfect match but close enough given the size. Plus, since the machine are is at a 90* angle to the face plate, the color difference is much less noticeable. If you did want to flush the plastic it would certainly be more work. Get something like .250" thick smoked acrylic and machine the acrylic to fit inside the recess with a portion sitting inside the recess to make it flush with the front panel. For me this wasn't worth the effort but could be done. If one were to make the front panel from hardwood it wouldn't be nearly as difficult since to make a nice opening you would need a router with a guide bushing and a template. You could use the template and guide bushing setup to cut the acrylic as well though I'm not sure how well acrylic reacts to a 20,000 rpm cutter. It may be hard to keep it from melting.

When I cut the opening I measured the original lens and then subtracted .100 from each side of the width and .125 from the length for the opening size. The recess is cut to the lens size although I shortened it very slightly. I believe The final dimensions were 1.000" for the opening width and 1.200" for the recess width. I think (not at home, no drawing here) that the length was 7.5" but it might be a little shorter. The reason I did this was there are four small circular molding marks in the lens corners and I didn't want them to show. The SB2 case corner radius normally hides these but since I used a .250" diameter end mill the .125" radius wouldn't cover it.

As for securing it, just a couple small (really small) drops of hot glue in the recess.

Hope this helps.

Mike

Hi Mike
Thanks for all the details on your display cover.

So, your front panel is 3/16 thick?  I thought the fronts from par were 1/8.  It matters because I can find 1/8 thick smoked acrylic, like this
http://www.estreetplastics.com/1_8_Thick_Grey_Smoked_Transparent_Plexiglass_2064_s/81.htm

So, I can have FPE machine a cavity, with a depth of maybe 0.100, and have 0.0875 of metal left.
And I think the 1/8 acrylic is around 0.117 thick, saw that somewhere.  So, it is 0.017 above flush.

And, FPE offers perspex as a material type.  This is a trade name for acrylic/plexiglass, so they do machine the stuff. 
I have a feeling they don't do it at 20,000 rpm  .

So, my plan is to send FPE the front panel, and a piece of smoked acrylic.  They can cut a cavity in the middle of the front, and also machine the acrylic to size.  Should cost less then $50 for them to do this, since it's my material.

One other option is to attempt to do something like this
http://www.diyaudio.com/forums/showthread.php?postid=386045#post386045

I obviously can't build something as nice as Peter can, but this seems pretty simple to do.  I think I would just need to glue a piece of angle to the acrylic front, to bolt it to the rest of the chassis.

Randy

[mgalusha]

Randy,

I just measured the original front panel that was on the case and it is 1/8", actually it's .121". Since we were reusing an existing case he ordered a new front panel. Par-Metal offers them in .182" aluminum and this is what Jerry ordered. At least I'm 99% sure of that. The last 1% is because the piece is 50 miles away and I can't measure it.

So, you can have your choice. I looked on the eStreetPlastics site and they offer 3/16" as well. They have 1/4" too, so you might be able to have FPE machine some 1/4" to match the thickness of the panel so it would be flush and still leave a lip to mount it with. Hmm, thinking about it this is likely what I'll do when I build the next one.

As for Peter's stuff, yeah it's in a different league altogether.   

Mike

[randytsuch]

Randy,

So, you can have your choice. I looked on the eStreetPlastics site and they offer 3/16" as well. They have 1/4" too, so you might be able to have FPE machine some 1/4" to match the thickness of the panel so it would be flush and still leave a lip to mount it with. Hmm, thinking about it this is likely what I'll do when I build the next one.

As for Peter's stuff, yeah it's in a different league altogether.   

Mike

Hi Mike
Not sure what you mean, seems like you are talking about 1/4" front and 1/4" thick window, but then there would be nothing left for a lip?  I was thinking 1/8" window, so even flush with 3/16" front, I would have a 1/16 lip.

But, right now, I am leaning more towards copying Peter.
I found this place that has the material Peter said he used
http://www.tapplastics.com/shop/product.php?pid=341&
Only thing, I am not sure what color Peter used, and exactly what color these guys sell.  The color description for grey does not match anything on the color chart, so I may give them a call, and see what they have.  They also say they can cut to size, which would make it easier.  I would just have to drill a few holes, and attach a couple angles.  I would probably put tapped holes in the angles, instead of using press nuts.  Another thing we do at work, for Al, is to add thread inserts (helicoils).  But, I have never tried that. 

I was also thinking about painted the back of the acrylic piece black, except for the window.  All in all, seems like somethink I could do, and I just finished my sub.  I would like to finish one more project, a dynco 70 rebuild for Curcio boards, but that is 80% complete, and I can start buying stuff for this now.

Randy

[randytsuch]

So I called Tap this morning, and the color is 103-2/2064
http://www.tapplastics.com/info/acrylic.php?#GP
From this link under Acylite GP, find “Transparent Colors”
and click on "smoke gray (103-2)", and it will show you the color.

They will also cut to size, at no extra charge.

A 2x4x1/4 inch sheet of this is $80, enough for at least two front panels.

I think I will probably go this way.

Any comments Tom?

Looking at a Par Metal chassis now.
One of these
BENCH TOP CASES (anodized)   B,C   Anodize or painted with masking
MODEL                1 to 5   6 to 19   20 to 49   50 up   
20-12124B   74.00    66.60    59.90    53.90    12W x 12D x 4H
20-16124B   80.00    72.00    64.80    58.30    16W x 12D x 4H
20-16164B   85.00    76.50    68.90    62.00    16W x 16D x 4H
20-12125B   80.50    72.50    65.30    58.80    12W x 12D x 5H
20-16125B   86.00    77.40    69.70    62.70    16W x 12D x 5H
20-16125B   86.00    77.40    69.70    62.70    16W x 12D x 5H
20-16165B   89.50    80.60    72.50    65.30    16W x 16D x 5H

I need to go measure things, and figure out how big a chassis I need, then I can order it.  I probably won't order the acrylic until after I get the chassis, and take a look at the front of it.

Randy

[TomS]

Randy,

I'm probably going to go big on the case, maybe 16x16x4.  Might as well save some room for other goodies.  Are you going to have FPE punch the rear panel for AC, fuse, various I/O's too?  I was thinking of re-using the XLR from the PS as a power output on the re-case so I could connect another SB3 if necessary.  Also, connect the SB2 analog direct out to a set of RCA's as well as to the inputs of the Burson Buffer which would have it's own set of outputs.  Then, maybe have a 75ohm BNC for the digital output.  Just trying to cover all the bases 

Tom

[randytsuch]

Randy,

I'm probably going to go big on the case, maybe 16x16x4.  Might as well save some room for other goodies.  Are you going to have FPE punch the rear panel for AC, fuse, various I/O's too?  I was thinking of re-using the XLR from the PS as a power output on the re-case so I could connect another SB3 if necessary.  Also, connect the SB2 analog direct out to a set of RCA's as well as to the inputs of the Burson Buffer which would have it's own set of outputs.  Then, maybe have a 75ohm BNC for the digital output.  Just trying to cover all the bases 

Tom

Hi Tom
I am planning on putting in a Felica balanced power generator, as well as a large transformer for the SB3 PS (I bought it from Apex Jr a while ago), so I need a large case as well, at least 4" tall, and probably 16" wide.  I was going to look at that soon.

For the rear panel, you can have par punch stuff out.  I guess I need to figure out what I am going to have in my rear panel, and then see what the cost would be for Par or FPE to do it.  I was thinking I could do that part myself, since it is in the back, and no one sees it.  Holes are easy, the IEC is a harder, but I have done them before with a drill and a nibbler.  Not bad if you are working on Al. 

I was also thinking about putting a DAC in here, I have a twisted pair dac I built a little while ago, that I might try, to see how it compares to the analog out of the SB3.

I am also planning on building at least one jung regulator for this.  I have a few, but I need to assemble them.
Btw, I was going to post this on it's own, but you can buy jung boards here
http://at-view.co.uk/alwsr.htm, for a pretty reasonable price.  I bought this same board a while back, from a diyaudio group buy.  I am sure Mike's regulator is good, but I would be surprised if it could better a jung.  (No offense Mike  )

Randy