8 channel rack mount VU meter bridge

[JeromeMason]

They are 35 mm wide  10 should fit

Hey Bruce do you have the silk screen images for the board? Or a picture would be great.

Thanks!

 

[bruce0]

Pictures and a PDF of the board layout.

Note the attached PDF may be more useful, it has measurements provided for bolt holes and board dimensions.

Board you are getting is the wider one.

The little LED card can be used as an 8 level VU/PPM with or without Peak Hold, and also can be stacked to form linear arrays of 8,16,24,32 etc. LED's

The 10 Pin Header carries power and various reset lines and references if you make a "meter bridge" out of them.  This makes wiring them up easier with a ribbon cable.  Signal goes in on two header pins at the top right.

You are planning on using just the one board ( which has Receiver/Precision Rectifier/Meter drive)

Balanced Receiver and Rectifier Left

Balanced Receiver and Rectifier Right

 

[bruce0]

Well ... 8 would be nice, but a GDIY-500 Rack is 11, so I used those little cards to make an 11 PPM meter in 1U. Don't have a good front panel for it yet, but it meters 0dBFS, -6,-12,-18,-24,-30,-36 and -42dBFS.  0dBFS is a red clip indicator adjustable on a per channel basis ( to the overload level of the converter (which varies by converter) ).  Has a clip hold mode, and a common reset switch for all 11 channels.

Used Ian's DB25 summing cards to wire up 4 TASCAM inputs (2 input, 2 "through").  The first 8 channels are on 1 DB25, and they also are split 1-6, 7-11 the way my GDIY51X tascam cards split the whole 11.

It will run on a 24V dc wall wart, with a little breadboard rail splitter, with no ill effect observed thus far.

Needs a new front panel, but this is what is there now.  Switch has normal/peak hold/(reset)

 

[JohnWatkins]

That looks great!  I need something exactly like this for a routing box that I'm building and was hoping to add meters to.  Are these cards available for sale?  If so, I'd love a set of 10.  Thanks.

 

[bruce0]

John, I did a prototype set as part of another project, I think I have 10 extra sets.  I will PM you about the boards.

The meters are nice, but I should warn you that in order to get all the peak hold functionality they do not use the traditional LM391x but instead use two TL0074s, and 2 LM339's for the configuration shown.

 

[sodderboy]

Schweet build!

 

[dmp]

Wow Bruce, that looks great!