Greg

Behringer Meters on SSL Comp
« Reply #20 on: June 16, 2004, 06:20:44 PM »
I think I just confused myself. Assuming the value I need is 12k, do I replace the 2k resistor on the board with a 12k or am I shunting the meter with a 12k?

I think replacing the 2k, but just want to be sure.
Greg Stein
New Orleans, LA


Ghengis

Behringer Meters on SSL Comp
« Reply #21 on: June 16, 2004, 07:04:01 PM »
Just to address a few things...

The behringer meter that I ordered does have a linear scale below the "VU" scale going from 0-20.  when I tested it however, it seemed quite linear to half way (pointing straight up - which corresponds to 5dB (10dB scale) or 10db (20dB scale)) but after that it tightened up, meaning that 10db reduction (on a ten db scale) ended up being around the "0dBVU) point, with -15dB at the end.  As Gyraf said, they are a little homebrew, but providing you are using the top half (bottom half??!) of the scale I found it quite ok... I am going to use it across the bus, probably only pulling 4-6dB max anyway so for me, 10db scale works well with the linearity ok around my working range.[/i]

Ian MacGregor

    Echo Park, Los Angeles, CA, USA
  • Posts: 280
Behringer Meters on SSL Comp
« Reply #22 on: June 16, 2004, 07:24:57 PM »
Greg,
You are replacing the 2k with the 12k.

As far as how accurate the meter is, I guess I'm just a bit more relaxed about it. I just sorta use it to gauge "approximate" levels of compression. We even had our prototype SSL without a meter for a couple months and actually liked having to really listen for the GR. I think I will still test it and see how close it really is.

Ian
www.blackwatchsound.com
www.standard-audio.com
 ------------------------------

Greg

Behringer Meters on SSL Comp
« Reply #23 on: June 22, 2004, 08:13:13 PM »
I just finished testing and coming up with a scale and resistor value for my Behringer meter. Since the scale that came with the B* meter has 12 divisions on it, I decided to make each division theoretically represent -1dB of GR. As a result, the -6dB point is striaght up... this was the point to which I calibrated my meter.  With no GR, my output with a 1k input signal was 1VAC (RMS since I am using my Fluke 111).  Then I went through each division and recorded the voltage... then calculated the amount of dB by using the formula 20log(VwithGR/VnoGR).

As previously stated, this is not a linear meter, but the results do provide me with a very good idea where the meter is accurate and where it is not.

I'll provide results in both output voltage and dB.

Tick 1: 0.859VAC, -1.32dB
Tick 2: 0.748VAC, -2.52dB
Tick 3: 0.675VAC, -3.41dB
Tick 4: 0.697VAC, -4.34dB
Tick 5: 0.548VAC, -5.22dB
Tick 6: 0.499VAC, -6.04dB
Tick 7: 0.445VAC, -7.03dB
Tick 8: 0.390VAC, -8.18dB
Tick 9: 0.333VAC, -9.55dB
Tick 10: 0.270VAC, -11.37dB
Tick 11: 0.217VAC, -13.27dB
Tick 12: 0.161VAC, -15.86dB

From these results, you can see where the meter behaves most linearly and where it is closest to the actual theoretical values. Notice that once the meter deflects to tick 9+, it's very non-linear. It appears to be most linear between ticks 3 and 8, and most accurate between ticks 5 and 8, which is where I will probably use the meter most of the time.

So the value of the resistor for a 12dB scale (theoretical), with 6dB GR accurately deflecting at 50%, is 3.3k. I had the 2k in the Main PCB, and a pot trimmed to 1.3k in series with the meters V-.

I hope this is useful and might clear up some confusion.
Greg Stein
New Orleans, LA

Ghengis

Behringer Meters on SSL Comp
« Reply #24 on: June 23, 2004, 01:26:03 AM »
I guess similar results to me!!! I decided to use the "half scale" ie straight up (pointing to the "10") was to be 5dB of reduction - with a resistor of 2.4k... so I guess we are in close proximity which is good to hear!! After testing it a little more, I found that I used it around 4dB of reduction which means the resistor is better for me at 2.4K...

Next question... anyone fired up the lamps on these things??!! what voltages??  don't want to switch it on and go POOF!

Ghengis

robomatique

Behringer Meters on SSL Comp
« Reply #25 on: June 23, 2004, 08:27:00 AM »
GREAT THANKS!!!

Now I have to make a new scale to fit the new scale, the nrg scale is 0-20dB reduction isn't it? Anyone knows the resistor value for this scale? Or am I asking for to much now  :roll:

Robert
"Trying is the first step towards failure."
-H. Simpson

Greg

Behringer Meters on SSL Comp
« Reply #26 on: June 23, 2004, 09:25:11 AM »
Quote from: "Ghengis"
Next question... anyone fired up the lamps on these things??!! what voltages??  don't want to switch it on and go POOF!


Yes, I used my bench supply to fire up the lamp. I had up to 12VDC on it and it didn't go POOF and didn't seem to be burning overly bright. So I'm thinking about putting 12VDC (possibly with limiting resistors as well) on mine. I just need to determine where I'm going to pull it from. I know that there is 12VDC on the threshold pot, but I'm not sure if that'd be a good idea. I guess I still need to think about it.
Greg Stein
New Orleans, LA

Greg

Behringer Meters on SSL Comp
« Reply #27 on: June 23, 2004, 09:38:20 AM »
Quote from: "robomatique"
Now I have to make a new scale to fit the new scale, the nrg scale is 0-20dB reduction isn't it? Anyone knows the resistor value for this scale? Or am I asking for to much now  :roll:


Well I think you need to decide what amount of GR you want to be most accurate. Since it's non-linear, the point you calibrate to will be the most accurate. From my results, my last tick should have had -12dB reduction, instead it had almost -16dB. In general, it seems that the between 0-25% and 75%-100% are the most inaccurate, non-linear parts of the meter. So if you set 50% to be -10dB, I'd suspect that fully deflected will be alot more than -20dB.

It's a very simple process to calibrate the meter, do you have function generator and a multimeter... and a pot of course.

Last night, I took my trim pot out, measured the value, the put in a resistor, and heat shrunk the ends. So I'd rather not have to undo that to get another scale. I'm still using the scale that came with the meter. I'm just disregarding the numbers. I'm considering building a new scale in Adobe Photoshop that corresponds to my measurements (from 0dB to 16dB), and if so I'll post it for all.
Greg Stein
New Orleans, LA

SSLtech

Behringer Meters on SSL Comp
« Reply #28 on: June 23, 2004, 11:09:32 AM »
...I have three SSL comps in my workshop at the moment. One uses 2181's, one uses 2001's, and the third uses 202XTs.

I'm doing comparisons on them at the moment, but two use Behtinger meters, and they are most definately far from linear. Set to indicate 20dB at full-scale (checked with a Neutrik A2), they indicate half-scale deflection at about 7-point-something dB, so almost 13dB on the right half, and a little over half that on the left part of the scale. -The Sifam is definately linear... the Behringer is there as a clue, not an accurate measure at all.

Results later...

Keith
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

Greg

Behringer Meters on SSL Comp
« Reply #29 on: June 24, 2004, 09:27:02 AM »
The VERY last thing I need to do on my SSL is get the meter lamp working, but I have a couple questions:

1) Should I use a DC unregulated voltage, ie rectified but not regulated? I measured 22VDC after the rectifier.

2) Assuming that is where I should take the voltage from, can I just use a simple voltage divider to drop the voltage? Or can I just use a resistor in series?

Thanks.
Greg Stein
New Orleans, LA


kvintus

Behringer Meters on SSL Comp
« Reply #30 on: June 30, 2004, 10:09:22 AM »
Where can I buy a SSL compressor B-ringer meter in europe?

/Anders
...not perfect, but close enough for rock 'n' roll...

tubejay

Behringer Meters on SSL Comp
« Reply #31 on: August 11, 2004, 08:57:32 AM »
When wiring the Behringer meter up, do I hook the actual GR Meter controls up to the inner connections, the one that has the + sign next to it?  Is the light for the outer two connectors?  

Also, what's supposed to happen when I power up the compressor?  Is the meter supposed to jump up to around zero?  So far, the only thing that appears to happen to the meter, is when I power down it will sometimes jump up for minute.  Any ideas what I'm doing wrong?  I never changed the value of the resistor, but I thought that for basic testing to see if it was working, that might not matter.  Help!!  :shock:  :shock:

gyraf

Behringer Meters on SSL Comp
« Reply #32 on: August 11, 2004, 09:10:12 AM »
Check with an ohmmeter which connectors are for the meter - it will move when ohmed.

The SSL GR-meter is a linear scale, dB/V meter - meaning that it will indicate GR by moving upwards from zreo, not downwards from 0VU like the 1176.

So with no compression, the meter will rest at zero, at the left end of the scale.

The "jumping" you see when powering down is normal - it's just the opamps freaking out a bit when powersupply voltage and references are going.

Jakob E.
..note to self: don't let Harman run your company..

tubejay

Behringer Meters on SSL Comp
« Reply #33 on: August 11, 2004, 05:38:34 PM »
Thanks Gyraf!  The meter works fine...if only it compressed now...

Behringer Meters on SSL Comp
« Reply #34 on: October 24, 2004, 10:29:03 AM »
Quote from: "JayDee"
Hi,

Frank did some experiences with the Behringer VU. A new scale as well. Looks like the sifam. You can get it here :

http://www.nrgrecording.de/html/vumeter.html

What do you think doing all these posts in one official SSL thread ?


that link contains a PDF for reprinting the scale of the sifam meter.  i opened my meters up and the scale that's in it is a piece of metal.  have any of you guys replaced the scales?

and what did you use?  thick card stock?

nrgrecording

Behringer Meters on SSL Comp
« Reply #35 on: October 24, 2004, 11:05:24 AM »
You can use photopaper which is glossy and has more thicknes than standard paper. I used the two original screws to attach the scale to the meter. Works fine.
You could also try to glue the paper to the metal scale. A Pritt glue stick could work good here.  :wink:
Frank Röllen. www.energyrecording.de [FORUM · DIY WEBSITE · STUDIO]°°°° www.frontpanels.de [Engraved Frontpanels]°°°°

Behringer Meters on SSL Comp
« Reply #36 on: October 28, 2004, 05:27:33 PM »
the origianl sifam display goes from 0 to 7, has anyone come up with a resistor value (instead of 1k for 10db) that would correspond to the stock display values?

i guess that would make it a 7 db range.

Ian MacGregor

    Echo Park, Los Angeles, CA, USA
  • Posts: 280
Behringer Meters on SSL Comp
« Reply #37 on: October 28, 2004, 06:04:17 PM »
Well.. If 2k gives a 20dB range and 1k gives a 10dB range, I would hazard a guess that 700 ohms would give a 7dB range.

Try it!

Ian
www.blackwatchsound.com
www.standard-audio.com
 ------------------------------

Behringer Meters on SSL Comp
« Reply #38 on: February 07, 2005, 10:48:18 PM »
So just to confirm, if I go with the Sifam Director meter and I want 20db Full scale, I should use the 2K resistor?

moqtev

Behringer Meters on SSL Comp
« Reply #39 on: February 08, 2005, 03:09:40 AM »
What behringer meter is it you are using?...I've got a couple of BE-45 will they work?

Morten


 

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