Become a Site Supporter and Never see Ads again!

Author Topic: Analog input alignment  (Read 2553 times)

0 Members and 1 Guest are viewing this topic.

Offline balou2

  • Crippled, but still dancin'
  • Trade Count: (0)
  • Needs to get out more...
  • *****
  • Posts: 4443
  • Gender: Male
  • He was a friend of mine.
    • Little Mountain Sound Archive
Analog input alignment
« on: June 21, 2006, 03:03:11 AM »
Still on my learning quest....

How many folks out there do an actual analog input alignment?  For the all-in-one boxes (e.g. v3, ua5) I guess this would not be necessary, but for those running pre>ADC, who is actually doing this?  If I understand this right, the analog input levels need to be aligned using a 1 kHz sinewave fed from a +'X' dB balanced source.

A couple of questions:

  • How necessary is this procedure?
  • I don't have a digital peak meter.  Is there another way to calibrate this?
  • What are the possible ramifications of NOT aligning my analog outpu?

In my case, I'm running v3 > ad2K+, and hopefully looking to upgrade to v3 > mytek 192.  The Mytek has trim pots that are adjustable in 10-turn increments, running from mute to +4dB.  According to the Mytek technical specs, +4dB = -6dbFS, which is pretty sensitive.  Regardless, the trim pots allow for the manual alignment, but does anyone know how this would be done with the AD2K+?

I remember a couple years ago (seriously) there was a thread about calibrating ADCs to a pre.  I don't recall if it was the same thing, but I'm assuming it was probably close.

Thanks in advance for the dialog.

Mike
Socks are overrated.

Offline crunchy

  • Trade Count: (3)
  • Taperssection Member
  • ***
  • Posts: 400
  • Gender: Male
    • My List
Re: Analog input alignment
« Reply #1 on: June 24, 2006, 05:13:02 PM »
If I remember correctly there was some info about this on the sonicsense website. I remember glancing over it once or twice awuikle ago. I'm not sure if it's still there, I'll check and see.

Offline crunchy

  • Trade Count: (3)
  • Taperssection Member
  • ***
  • Posts: 400
  • Gender: Male
    • My List
Re: Analog input alignment
« Reply #2 on: June 24, 2006, 05:16:26 PM »
here is the page. I'm not sure if it is exactly waht your looking for but it might help
http://web.archive.org/web/20020815073321/sonicsense.com/calpage.htm

Offline balou2

  • Crippled, but still dancin'
  • Trade Count: (0)
  • Needs to get out more...
  • *****
  • Posts: 4443
  • Gender: Male
  • He was a friend of mine.
    • Little Mountain Sound Archive
Re: Analog input alignment
« Reply #3 on: June 25, 2006, 12:30:24 AM »
Yeh...that's the right info, but not for the AD2K.  I'm pretty sure I cannot do the analog input alignment without the gain pots.  I was just hoping someone knew a trick that I was not aware of.
Socks are overrated.

Offline Geoff G

  • Trade Count: (0)
  • Taperssection Regular
  • **
  • Posts: 152
  • Gender: Male
  • MMMmm...pretty colors. Pass the tea please.
Re: Analog input alignment
« Reply #4 on: June 25, 2006, 12:43:44 AM »
I believe the technique you're speaking of demands that the ADC have some sort of adjustable trim/gain...a la ADC-20, Mytek etc.  The AD2K cannot be "aligned" in this nature to the best of my knowledge.

As for the ramifications, they'll only be as severe as the equipment will dictate.  If you're running high-end equipment, you will notice little to no difference in the subtle db-variation resulting from NOT calibrating your analog input.  As long as the V3 stabalizes your mic inputs, you'll be fine.
(MK8/MK41/MK4V/MK2 -> KC5/CMC6) or (Neumann U89's)  -> AM Sorcerer -> 2 x Sonosax SX-M2 -> AM Sorcerer -> Mytek 192 -> 744t

Offline F.O.Bean

  • Team Schoeps Tapir that
  • Trade Count: (126)
  • Needs to get out more...
  • *****
  • Posts: 40689
  • Gender: Male
  • Taperus Maximus
Re: Analog input alignment
« Reply #5 on: June 25, 2006, 02:36:33 AM »
yeah, using that gear, i wouldnt worry about it, when i ran v3>modsbm1, i just calibrated the modsbm1 output to where the v3 would clip w/ the ansr on, so thatw ay instead of glancing at the modsbm1 all the time, i could just glance at the v3's peak hold and know the modsbm1 wasnt going over ;)
Recording Gear:
Schoeps MK 4 (MP) & MK 41V (MP) Capsules ->
Schoeps 250/0 KCY's X2 ->
Naiant +60v/Low Noise PFA's x2 ->
DarkTrain Right Angle Stubby XLR's x2 ->
Sound Devices MixPre-6 & MixPre-3 ->
SanDisk 128gb Extreme Pro & 64gb Ultra Plus

Portable Playback Gear:
Campfire Audio Andromeda & Dorado IEM's ->
Linum G2 SuperBax & Bax 3.5mm | FiiO LC 2.5c 2.5mm ->
Shanling Audio M5s | Sony NW-A35 DAP's

DAW:
Dell Inspiron 5570-5521 SLV Laptop
(Pentium i5/8gb RAM/256gb SSD)

http://www.archive.org/bookmarks/diskobean | http://www.archive.org/bookmarks/Bean420 | http://bt.etree.org/mytorrents.php

Offline Kyle

  • Made it back alive!
  • Trade Count: (2)
  • Needs to get out more...
  • *****
  • Posts: 2174
  • Gender: Male
  • Still loves his mic pre's
Re: Analog input alignment
« Reply #6 on: June 25, 2006, 03:37:30 AM »
According to the ad2k manual, "The “Input Level” switch should be set so that the AD2402-96 will clip 3 to 6 dB before the
microphone preamplifier.


I usually set it at +22 and  run the V2 pretty damn hot (a fair amount of red flashing, but not out of hand)  and use the trim pots, just a little, to fine tune the levels. The red lights on the V2 come on at +16 and it clips at +26 so I think what I am doing is pretty close to gain matching or input alignment.

Also, per manual, "For example, if your microphone preamp has a maximum output level
of +24 dBu, then set the switch to “+20”. This will reserve 4 dB of headroom in the preamplifier.
If too much headroom is allowed in the microphone preamplifier, noise from the preamp may
reduce the dynamic range of your recording. If no headroom is provided, the microphone
preamp may add distortion to your recording."


Hope that helps - if I am talking out of my ass someone please step up ;D
Schoeps CMC6/MK4  //  Nakamichi CM-300/CP-1/CP-2
E.A.A. PSP-2   // Grace Design Lunatec V2
Sonic AD2K+ 
Tascam HD-P2 (Oade BCM)  //  Sony TC-D5 PROII
 
Duncan - 12/84 > 8/8/05 - Miss you everyday

Offline balou2

  • Crippled, but still dancin'
  • Trade Count: (0)
  • Needs to get out more...
  • *****
  • Posts: 4443
  • Gender: Male
  • He was a friend of mine.
    • Little Mountain Sound Archive
Re: Analog input alignment
« Reply #7 on: June 25, 2006, 04:04:33 AM »
That's EXACTLY what I was looking for.  Much grass.
+t
Socks are overrated.

Offline dactylus

  • Site Supporter
  • Trade Count: (50)
  • Needs to get out more...
  • *
  • Posts: 5155
  • Gender: Male
  • Saint Paul, MN
Re: Analog input alignment
« Reply #8 on: May 29, 2019, 11:21:17 PM »

...blip...
hot licks > microphones > recorder



...ball of confusion, that's what the world is today, hey hey...

Offline jerryfreak

  • Trade Count: (23)
  • Needs to get out more...
  • *****
  • Posts: 2371
  • I'm a llama! (taboot)
Re: Analog input alignment
« Reply #9 on: May 30, 2019, 06:03:35 AM »
iirc
V3 is +25dB max output
V2 is +27dB max output

lowest sensitivity on AD2K is +24dB = 0dbFS, it should always be set to +24dB with these preamps

then you use the (excellent) meters on the AD2K

when the AD2K clips at 0dB (which of course you dont want to do, and really shouldnt ever need to, as it has great peak hold and lights at -5. -4. -3, -2 and -1), you still have 1 dB of headroom on a V3 or 3 dB of headroom on a V2

so really in *any* case its impossible to clip a grace pre before you clip an ad2k, but by setting it at +24 it allows you to run the hottest signal you possibly can into it for the best noise performance

the Ad2k is in the -110s and both the lunatecs are in the -120s on EIN.
« Last Edit: May 30, 2019, 06:11:19 AM by jerryfreak »
in:
small: MK4/4V > CMR > V3 or J.Williams Mod MicMan Jr or no pre at all >AD2K/R07/PCM-A10/Oade Warm 661/DR100-MKIII

smaller: 4061/4099 CORE or 4011/4018V> d:vice MMA



out:
home:Benchmark DAC1 HGC > Dynaudio BM15A active monitors
shop: Musical Fidelity VLink 192 Asynchronyous> coax> DAC1 > Rokit RP8 active monitors

Offline dactylus

  • Site Supporter
  • Trade Count: (50)
  • Needs to get out more...
  • *
  • Posts: 5155
  • Gender: Male
  • Saint Paul, MN
Re: Analog input alignment
« Reply #10 on: May 30, 2019, 09:18:13 AM »
iirc
V3 is +25dB max output
V2 is +27dB max output

lowest sensitivity on AD2K is +24dB = 0dbFS, it should always be set to +24dB with these preamps

then you use the (excellent) meters on the AD2K

when the AD2K clips at 0dB (which of course you dont want to do, and really shouldnt ever need to, as it has great peak hold and lights at -5. -4. -3, -2 and -1), you still have 1 dB of headroom on a V3 or 3 dB of headroom on a V2

so really in *any* case its impossible to clip a grace pre before you clip an ad2k, but by setting it at +24 it allows you to run the hottest signal you possibly can into it for the best noise performance

the Ad2k is in the -110s and both the lunatecs are in the -120s on EIN.

^
Thank you very much for the information!! 

 :coolguy:
« Last Edit: May 30, 2019, 09:57:28 AM by dactylus »
hot licks > microphones > recorder



...ball of confusion, that's what the world is today, hey hey...

 

RSS | Mobile
Page created in 0.185 seconds with 39 queries.
© 2002-2019 Taperssection.com
Powered by SMF