Reddish 500 EQ

[JMan]

I had a fascinating conversation with @nielsk this evening in which he regaled me with some history of the 500 format and API consoles. I learned quite a few things I didn't know!

I wanted to share a practical takeaway from the conversation with builders of the Reddish EQ. If you find that the unit produces lots of unwanted distortion (which is not what it should do), you may find that running a wire between the Audio GND and Power GND pins on the edge connector solves this issue. The short version is that this relates to how those ground connections are handled internally within your specific lunchbox/rack, and they are not all the same. There should be no negative effects of making this connection.

@creature.of.habit I am almost certain that this is what we were dealing with when you first plugged in your unit, and why swapping out the rack for a different model cured the issue.

 

[creature.of.habit]

@creature.of.habit I am almost certain that this is what we were dealing with when you first plugged in your unit, and why swapping out the rack for a different model cured the issue.

Very likely indeed. There were all sorts of problems with that rack, though, not just with the Redd. I was very glad to see it go.

 

[dmp]

The faceplates are a little wide (+0.02") for a 500 rack. When I have these in 11 modules will not fit. The spec is 1.5" but once painted they are more, so if you do another run, reduce the width.

 

[MidnightArrakis]

The faceplates are a little wide (+0.02") for a 500 rack. When I have these in 11 modules will not fit. The spec is 1.5" but once painted they are more, so if you do another run, reduce the width.

[The faceplates are a little wide (+0.02") for a 500 rack] -- >> ALL << of the "500-Series" panel-width dimensions that I see mentioned or shown here on this forum are basically incorrect!!! And, I keep on making mention within the various threads on this forum that using the stated -- 1.50" (38.10mm) -- panel-width is the wrong width dimension to use, but.....nobody on this forum ever listens to me!!!

With following the nominal and typical tolerance dimensions as used by your average run-of-the-mill "rack-equipment" standards, a "500-Series" panel-width dimension would be -- 1.47" (37.34mm) -- and your panels will work out to be just fine. This works out to be 0.030" less (actually, 0.015" X2) than the stated nominal panel-width (1.50" minus 0.015" X2 = 1.47").

And, once again, putting this tolerance into the EIA-310D "rack-standards" usage.....a 1U rack-panel height is stated to be 1.75" high. But, of course, if you actually made your rack-panel 1.75" high, it's -- NOT -- gonna fit!!! So, you reduce the panel-height by 0.030", so you end up with an -- ACTUAL PHYSICAL DIMENSION -- of 1.72" high (1.75" minus 0.015" X2) and ALL IS WELL!!! And, this same tolerance application applies to -- ALL -- rack-panels, no matter how many U's they may be.

And.....let me go ahead and mention this aspect of the "500-Series" panel-height one more time.....it should also follow the same tolerancing as the rack-panel do!!! Meaning, their stated height is of their being -- 5.25" (133.35mm) -- high. So.....you make your "500-Series" panel that high and it ain't gonna fit!!! However, by following the standard EIA-310D rack-panel standards, you would have your panel fabricated to be -- 5.22" (132.59mm) -- high (5.25" minus 0.015" X2 = 5.22") and then your panel will end-up fitting HUNKY-DORY!!!

Bottomline.....I have only been designing professional "rack-mount" equipment since 1975, so "WHAT THE F**K DO I KNOW" about panel designs and their tolerances??? Certainly nowhere nearly as much as the members on this GroupDIY forum apparently do!!!

https://groupdiy.com/threads/diy-rack-enclosure-extrusion.88722/post-1173708

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