\m/ My Stereo Analog Volume Indication Module for 500 Series…Sexy!?!?!

[jsteiger]

Hey guys,

I figured I would post some pics of a project I have been working on. The idea started with a desire to create a vintage looking VU sorta module that slightly resembled my console’s meter bridge. I spoke with Hairball Mike about meters and at that time, he had nothing with a window with the style and size that I wanted. I talked to all of the likely sources and decided to special order meters from Hoyt. The meters themselves are awesome and very solid and heavy. I am told these are the exact same meters they use when they build to order, true “VU” spec meters. I did not want to go down that road so I just ordered the DC meters and took the bridge rectifier into my own fat little hands.

I call the module “VI522”. VI is for volume indicator as it probably doesn’t meet all the required criteria to be a true VU but it’s about as close as you can get without breaking the piggy bank!

I have a 4558 that drives the meter. One half is a 100k Z, balanced circuit where 1.228V of AC will give you 0VU on the meter. The standard VPR pins 8 and 10 are used for this input and are also directly mult’ed to the module slot’s output. You can run a balanced signal thru this module and the original signal will never know the 4558 is hanging there.

The other half of the 4558 is feed an unbalanced signal from pin 9 of the card edge. This is fully VPR compliant, BTW. Pin 9 is easily accessible on my GDIY 508 backplane. This side of the IC has 6dB of additional gain. The idea is to feed it from just before an output transformer in the console. Selecting which side of the 4558 is driving the meter is done via a front panel switch. The signals are actually switched with a relay. This relay can also be controlled by a 0V signal being applied to pin 6 which is the DC pin according to VPR. Why do you ask? This way, one switch can flip multiple VI522 modules from say input channel metering to subgroup metering or what have you. Very important for the console build

When in “balanced”, mode the other front panel switch will toggle in a pad (more or less) for digital signals. This “digital” selection has it’s own trimmer so the user can set their dBFS to whatever they want. I have two ranges for this “pad” that are selected by a shunt jumper underneath the switch PCB. Basically, the first setting will give you a pad range of 2dB to 6dB and the second setting is 6dB to about 10dB. This way, I am not the one deciding what dBFS level = 0VU…you are!! Funny enough, I talked to 3 of my closest friends about this and got 3 different answers!

I also have a full wave peak detection circuit that hangs just before the typical 3k6 series R, which is just before the germanium diode bridge. This is a somewhat simple circuit that uses a 1458. This will illuminate the red LED that is just above the respective channel’s meter. The point where the LED fires follows the analog/digital switch. So, you can have one setting for your “digital” preset and a fully independent setting for your “analog” preset. Maybe you will have your analog peak LED light at +9dBu and your digital setting light at –2dBFS? No problem. These are front panel trimmed just to the left and right of the peak LED.

Down near the bottom, there are 3 more front panel trimmers for each channel. One is for the balanced digital setting, one is for the balanced analog setting and the last is for the unbalanced input.

This morning I ordered my second Rev of the 3 boards. I had a few minor things to tweak but nothing big. Anyhow, enough BS, here are some pics!

Peak LED set to +6dBu


Being fed a +4dB signal


I only built out one of the main boards for testing. I didn’t want to waste time since it will likely make it’s way into the circular file, Rev A.1 coming and so on…





Close look at the side


I call this the “cleavage” shot, looking down the shirt of…


The caboose


L-bracket side. Here you can see that the window of each meter is thru the faceplate. Actually, slight proud of the faceplate.


Light pink underbelly…


And lastly, I finally found the confounded germanium diode bridge!! 


Cheers for now, Jeff

 

[radiance]

Nice!

 

[Holger]

Nice!

... if not very nice 

 

[[silent:arts]]

cool 8) 8) 8)

since we know Jeff the added features are well thought after - like all of his products

PS: Holger, your actual post count of 500 is a bad sign, wrong alliance ;D

 

[jsteiger]

Thanks guys.

Yes, Volker, we try to think of everything but we know how that goes. Murphy creeps up and smacks us in the ass with his stupid law.  :-[

I forgot to post the pretty much settled upon artwork for the finished panels.



Cheers, Jeff

 

[JayDubrek]

As ever lovely stuff Jeff! I take it this will be part of the console project?

Cheers
Jay

 

[jsteiger]

As ever lovely stuff Jeff! I take it this will be part of the console project?

That was the original idea Jay but they will work just as well in a stand alone 500 or 51x rack. I don't think there is an analog module like this available right now in the 500 series main-stream. Even most of the other VU rack gear does not have the precision peak circuit. I tried to make it unique and as useful as possible. 

Cheers, Jeff

 

[gar381]

WOW Jeff

Just saw this.  Damn preaty my friend !! :-*

GARY

 

[dandeurloo]

wow, that looks very very cool!  Dang, again killer layout and design. 

 

[jsteiger]

Thanks guys. Nothing like a little bling in your rack 

 

[Ptownkid]

Hot damn Jeff...you are coming out with some really, really nice stuff man!

 

[JayDubrek]

Jeff the meters are sexy but I'd like to see em in the modular console fella! Haha...seriously though keep up the good work..

Jay

 

[boji]

Jeff I just want to say, these VU's are fantastic. Totally underrated stuff you got there.

The fact that you are allowing for VU signal insert points to be grouped across all channels is really, really nice!
And then to use relays as well for this? That's some Cadillac design!  =D

I can't seem to decide if including a modest pre/post VU option on my console is really beneficial.

I want to imagine I'd get a feel for the signal levels once familiar with how the desk responds to gear, and only reference pre/post if led peaking exists or, of course, distortion is audible.

But tell me, do you find yourself referencing back and forth a lot when you work?

Should I do the pre/post thing, even if it is just a spdt at the input card? Again, this comes back to my lack of experience on studio desks.

 

[jsteiger]

Thanks Boji.

For the new console project, I have added a pre/post feed for the metering. Mostly because all the signals were already there and super easily accessible. I just needed to add another relay per channel.

Unfortunately, my work has been not recording or using all this cool gear for a while now. I spend all of my time filling orders and working on new products and modules. I think some guys that are asses and elbows in the studio trenches would be better to ask. I bet though the opinions will vary just like anything.

Typically I think post fader is the most common point. By leaving out the meter relay on my input channels and adding a jumper, that's what you'd get. So the flexibility is there if one cares to use it.

That may not answer you question buy maybe some others will give some feedback.

Cheers, Jeff

 

[MarshallCS]

You know, the one thing that I'd truly TRULY love is a high quality headphone amp on it. That would be incredibly useful to me in a 5XX rack since I use it live. I've been wanting something like this I could put on my solo / cue outputs (which usually switch to outputting the stereo output when nothing is solo'd) and then monitor via cans as I need to, but with much better quality than the crappy headphone outputs on most consoles.

Please oh please oh please consider adding this in!!!!!

 

[fazer]

Looks great Jeff.  Well thought out.   
I also like the logo arrow trademark printed on the VU Meter scale.  That looks really cool.
Nicely done.

 

[Denyle Guitars]

You know, the one thing that I'd truly TRULY love is a high quality headphone amp on it. That would be incredibly useful to me in a 5XX rack since I use it live. I've been wanting something like this I could put on my solo / cue outputs (which usually switch to outputting the stereo output when nothing is solo'd) and then monitor via cans as I need to, but with much better quality than the crappy headphone outputs on most consoles.

Please oh please oh please consider adding this in!!!!!

I use a Purple Cans in my 51x racks, via patchbay with a 2nd stem feeding the adc or whatever. Works very well. There's no shortage of phones amp schematics on the net and I probably saved a dozen or so that use a bipolar psu on my old computer, thinking I'd want to build one at some point. That Cmoy one comes to mind and could be easily done, maybe with some DOA's.