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Post by kcatthedog on Jan 27, 2018 11:30:29 GMT -6
Old hat for many of you, but as of this morning, this system I have been putting together since last year is pretty well operational. Using a real console is new to me. One initial question, I am using Logic's utility plug in by channel or stereo channels to send/receive the Delta's eq. The i/o is working fine on all 16 channels. I bought longer cabling than I have ended up needing as everything is closer together than I thought it would be: delta on top of two new floor racks I made last summer. I notice while using the delta inserts and logic utility i/o plug in that the levels leaving the daw and coming back in drop a fair bit -15-20 db ( see screenshot). I have copied the drum loop and am routing each one in pairs (3/4-5/6 etc), they go into the delta on two channels beside each other. I can adjust the levels in the logic plug in but do you think the level is dropping due to the cable run/resistance ? Does it matter if I can bring it up with the plug in ? Below I was soloing 5/6 ( yes 3/4 is soloed but muted). You can see how much lower the 5/6 signal is, returned to the daw, than the others or am I just misunderstanding something ? Thx !  |
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Post by stormymondays on Jan 27, 2018 13:01:14 GMT -6
What interface do you use? You need to find out how it's calibrated, both the inputs and the outputs. It might have different gain settings that you can set.
My advice is to pick a digital reference level for 0VU and calibrate your system. I wish there was a single article that explains it that I could refer you to, but I can't find one.
Let's say you pick 18 dBFS = 0 VU = +4 dBu, which is a common calibration, and the one I use. Here's a simple procedure:
1. Find out the gain/calibration of the converter's output in the specs. My RME offers several calibrations. I use the one for 0 dBFS = +19 dBu. This means my 0 VU in Logic = -15 dBFS. So, if I send a test signal at -15 dBFS it should measure 0 VU on analog equipment.
2. Get a test tone going with the Test Oscillator plugin. Set it to -15 dBFS (or the appropriate value for your interface) and send it to the desk through one of your converter's outputs.
3. With the desk at unity gain, the input signal should measure 0 VU = +4 dBu.
Now you need to do the same for the converter's input, which might have a different calibration/gain. Send the 0 VU signal and measure the input.
Now, for my particular case, because the RME is set for 0 VU = 15 dBFS and my analog reference level is 0 VU = +4dBU, there's a 3 dB difference that I need to compensate at the I/O plugin. So, I send signals out with +3 dB boost and I return them with -3dB. I also use a Focusrite Clarett Octopre that is calibrated differently, and it also has different gain for the outputs and inputs. For the Focusrite I need to set the plugin at +4dB output boost and +3dB input boost.
I hope I'm making sense here! Maybe not!!!
Once all that is done, I can send a -18 dBFS signal through any of my outputs, and return it through any of my inputs, measuring 0 VU on all analog equiment along the way.
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Post by matt@IAA on Jan 27, 2018 13:06:19 GMT -6
I don’t think a cable run is going to cause a 15 dB voltage drop...
Are you going out / in balanced?
Also, that’s good advice above.
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Post by kcatthedog on Jan 27, 2018 14:15:59 GMT -6
Thx, yes all new balanced cables , new symphony mkii and 3 new Samsung s patchbays.
Calibration sounds like a good idea.
The delta inputs are line and it’s really just going through the eq, so that large a drop doesn’t make sense to me ?
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Post by matt@IAA on Jan 27, 2018 14:23:02 GMT -6
Right but is the input point to the delta also balanced? And the output as well?
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Post by wiz on Jan 27, 2018 14:39:31 GMT -6
Set up the utility plug on the channel in logic pre the io plug. Leave the fader at unity.
Set it to -20 db. 1khz .
Set the delta channel fader to unity (0)
Adjust the gain on the delta channel until the meter in logic for the channel says -20db
Now you have a unity path
Cheers
Wiz
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Post by mulmany on Jan 27, 2018 15:29:35 GMT -6
The line input has like -10db attenuation available, so need to be set to 0.
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Post by drbill on Jan 27, 2018 15:37:29 GMT -6
I notice while using the delta inserts and logic utility i/o plug in that the levels leaving the daw and coming back in drop a fair bit -15-20 db ( see screenshot). do you think the level is dropping due to the cable run/resistance ? Does it matter if I can bring it up with the plug in ? Sounds like (quite possibly) you've got a -10 vs +4dB problem somewhere. Could also be an issue if your interface has active balanced i/o - the hardware may not like it. No way it's the wiring unless you've dropped the cold (-/negative) somewhere. You can bring it up with the plugin, but that's a bandaid. You're adding noise, and should figure out your problem and fix it. With that big of a difference, I seriously doubt it's a calibration problem with your interface, but you can go out your DA and straight back into your AD and check levels to rule out converter calibration. It should be within less than a dB. Theoretically it should be perfect, but..... THEN, you can check your console - make sure 0dB in is coming 0dB out. If that's all cool, it's an interfacing problem. Most likely active balanced i/o on your interface (but that's usually only around 6dB) or possible improperly wired cables. My money is still on the -10/+4 mismatch though. Is the console jumpered to be operating @ -10?. |
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Post by kcatthedog on Jan 29, 2018 5:01:16 GMT -6
Set up the utility plug on the channel in logic pre the io plug. Leave the fader at unity. Set it to -20 db. 1khz . Set the delta channel fader to unity (0) Adjust the gain on the delta channel until the meter in logic for the channel says -20db Now you have a unity path Cheers Wiz Like so ? Drum buss far right. we just use the pre to set unity, later, if you had a line signal for example it isn't touching the pre ?  |
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Post by kcatthedog on Jan 29, 2018 6:18:04 GMT -6
The line input has like -10db attenuation available, so need to be set to 0. Is this an internal setting on the delta or how do I confirm and re-set ? thx ! |
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ericn
Temp
Balance Engineer
Posts: 14,953 
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Post by ericn on Jan 29, 2018 8:45:11 GMT -6
The line input has like -10db attenuation available, so need to be set to 0. Is this an internal setting on the delta or how do I confirm and re-set ? thx ! Should be a jumper on each module check the manual on line! |
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Post by mulmany on Jan 29, 2018 10:17:28 GMT -6
The line input has like -10db attenuation available, so need to be set to 0. Is this an internal setting on the delta or how do I confirm and re-set ? thx ! It's just a setting of the gain pot. Send out your 0vu test tone, solo the channel with the fader set to 0db. Bring the line gain to 0 and check with the meters. Once each channel is set for 0vu you should not have to touch the gains again. Are you using the direct outs to get back into your AD. They are set for -2db output, if I read the schematic correct. |
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Post by schmalzy on Jan 29, 2018 11:08:27 GMT -6
I have a couple thoughts from fighting to get my console to a "sometimes mix through it" state:
Check your I/O balanced/unbalanced - that'll give you 6db there. My Allen & Heath GL4 has balanced line ins, balanced aux sends, balanced group sends, and unbalanced direct outs. Which means I was losing 6db per channel going through the direct outs. I'm mostly sending everything back through auxes and groups now.
Check your knobs and gain staging on the console. I had a pot where the knob was weird and it looked like it was at +/- 0db but really the knob was just pointing to the wrong spot. Double-checked and it was much happier on that channel.
Is your direct out padded? Mulmany may have caught that one.
Is the direct out pre/post fader? Some of those things are set up to be weird.
Are you sure you're plugged into the direct out and not the insert? The inserts on my console are unbalanced TRS y-style cables. If I accidentally plugged into that instead of my direct out I'd see a drop in level.
Does your interface have an input level adjustment on the line ins? I have a Focusrite Saffire Pro40 and the +/-0db for the line in is about 60% up the gain pot.
Here's the tests I'd do on each channel:
Run a cable straight from the out of the interface to the in of the interface. Are the levels identical within a db? No? Then do what you can until they are.
Run a direct loop through the patchbay (without hitting the console). Interface out -> patchbay ->interface in. That should yield a result very close or identical to the previous test. So far, we've not even introduced the console so if there's a problem it's in the interface settings, the cabling, the patchbay, or your computer settings.
Run a cable out of the interface straight to the console and straight back to the interface (bypassing the patchbay) using your preferred method of output from the console. What does that give you?
I've had so many problems where I assume it's one portion of the signal chain but it's actually another. At least now you'll know exactly where your problem is. You can get started sorting out from there, hopefully!
That's all I've got on this for now! I'll look at the Delta manual a little and see if there's anything that jumps out at me!
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Post by bradd on Jan 29, 2018 11:21:15 GMT -6
I'm a bit confused as to why you are using Logic's I/O for this purpose. Are you not monitoring through the console?
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Post by kcatthedog on Jan 29, 2018 11:38:35 GMT -6
Good test plan !
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Post by kcatthedog on Jan 29, 2018 11:45:58 GMT -6
I'm a bit confused as to why you are using Logic's I/O for this purpose. Are you not monitoring through the console? The original idea is to record in the daw (Logic), but while mixing use the logic utility i/o plug ins to send receive to the delta's 4 band eq and add OB comp(s) at the same time, if you want, then back to the daw to finish mix in the box. So, I was setting this up for the first time and checked monitoring in the delta and liked the sound quality a lot. So, did my first mix monitoring within the delta. But as the system is new to me, the calibration and unity setting described above, just seems like good studio management to me. As I have never used a real console before, nor with 3 patchbays and multiple OB, this is all new to me so I'll just ask the newbie questions , ah,, cus, I am good at that!  |
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Post by bradd on Jan 29, 2018 12:13:43 GMT -6
No problem. I'm no expert, but I use Logic and mix on a Soundcraft Ghost and incorporate outboard. Here's what I do. I send each track of Logic out D/A to individual channels on the Ghost. I then have all of my inserts wired to a bay where I can insert my compressors. Monitoring on the Ghost I can use the Ghost's EQ if I choose. I then record a final two track mix back into Logic. Doing this, I never have to mess with the I/O in Logic. Not saying it's the right way to do it, but it seems to work well. Best of luck.
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Post by matt@IAA on Jan 29, 2018 12:25:02 GMT -6
Yeah you kind of have a decision point there. Do you mix in the box and use the console as analog front end or mix on the console and use the DAW as tape?
API The Box supports the former with a unity gain button on each channel of their mixer.
I’m close to getting my space back and I’ll be integrating my little 1280b, so I’m kinda curious about what others think about this.
I’m not sure which way I fall.
During final mixdown, are you going to automate in the DAW?
Is your console basically acting as a collection of outboard gear or are you going to sum through it?
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Post by kcatthedog on Jan 29, 2018 12:25:33 GMT -6
Understood, so you are: - sending your session channels to the board's analog line inputs, - mixing in the board, (using eq, pan etc.), - using the inserts for your ob, - back to the board for mix down, and - you send the two channel mix back to logic and print it: right ? |
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Post by kcatthedog on Jan 29, 2018 12:28:41 GMT -6
"Is your console basically acting as a collection of outboard gear or are you going to sum through it?" Yesand maybe:I'm having fun, experimenting and creating a new work flow, so don't know yet ! |
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Post by bradd on Jan 29, 2018 14:01:00 GMT -6
You are correct about my workflow.
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Post by jimwilliams on Jan 29, 2018 15:39:58 GMT -6
Delta insert sends are -2 dbu. If you need +4 dbu use the direct out jack, but that will be unbalanced. The line in is balanced from -10 to +20 db.
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Post by kcatthedog on Feb 1, 2018 16:58:56 GMT -6
So far I have used Wiz’s suggestion above, so , of course ,levels are much more uniform. I will continue to test as there are a few gremlins: one channel of my Revive Audio dbx wasn’t working now it is, if I print my master outs: l/r are very different levels, my master faders and leds are reversed: left affects right led.
I dioxited all the i/o, put dioxit in clean glass jar and used q tip to paint jack then exercised, going to double check my patch cables as almost all are new but I am using a few older ones, wonder if they are all ok.
Will use logic’s 1k sine to send consistent signal to continue to diagnose,but the fun news is was remixing today in delta using its eq and all my ob comps by groups and it really is a revelation compared to plug ins.
I look on every session as a learning opportunity, same with buying gear, running in the delta, new bays and ob is very interesting, educational and a rewarding experience !!
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Post by jcoutu1 on Feb 1, 2018 18:48:17 GMT -6
Welcome to the world of hardware. Chasing problems is the name of the game.
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Post by kcatthedog on Feb 1, 2018 19:04:17 GMT -6
I no longer dream of clean recordings but of clean pcb’s
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