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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: poorlyconditioned on February 23, 2006, 01:52:53 AM

Title: AD20 mods?
Post by: poorlyconditioned on February 23, 2006, 01:52:53 AM
So, I finally got my AD20.  (Thanks to AudBall for patiently waiting for me to mess with various Ebay transactions and third parties!)

OK, I tried it out tonight and I'm not totally happy with the sound.  Compared to my (poorlymodded) UA5, it seems pretty "lifeless".  It just seems muddy and not that clear.  So far, then my opinion is AD20 < (modded)UA5 < Presonus Firepod.  I'm not even sure this thing has a better line input than my MD, which is kind of dissapointing.

I opened it up and see what looks like a transistor input stage (good), but I see some pretty awful opamps there.  Some people have SSM2019, which doesn't look bad.  But I've got TLC2272 (CMOS!) opamps in there.  I'm wondering if I swap out something decent if this is going to sound OK.  Comments?

Also, if anyone has a DMIC20, *44.1k*, please let me know.  I'm considering trying one of these (hack it to output optical).

Thanks,
  Richard
Title: Re: AD20 mods?
Post by: udovdh on February 23, 2006, 04:08:36 AM
Is this a different device than the Inbox?
(which has optical)

44.1/48 is a matter of a crystal?
Title: Re: AD20 mods?
Post by: audBall on February 23, 2006, 07:23:31 AM
Is this a different device than the Inbox?
(which has optical)

44.1/48 is a matter of a crystal?

yes to optical.  This wasn't the Zefiro Inbox, rather the later one sold by Denecke.
Title: Re: AD20 mods?
Post by: udovdh on February 23, 2006, 07:46:06 AM
Is this a different device than the Inbox?
(which has optical)

44.1/48 is a matter of a crystal?

yes to optical.  This wasn't the Zefiro Inbox, rather the later one sold by Denecke.
I still have an Inbox and was just wondering if the ideas might apply.
Title: Re: AD20 mods?
Post by: audBall on February 23, 2006, 07:49:48 AM
Is this a different device than the Inbox?
(which has optical)

44.1/48 is a matter of a crystal?

yes to optical.  This wasn't the Zefiro Inbox, rather the later one sold by Denecke.
I still have an Inbox and was just wondering if the ideas might apply.

From what Richard posted, is it possible that Denecke rebranded them with lesser grade opamps?  I merely thought that Zefiro sold the remaining units and they were relabeled - just that.  guess not...

anyone know for sure?
Title: Re: AD20 mods?
Post by: JasonR on February 23, 2006, 10:40:14 AM
I purchased an InBox right when they came out, and Greg Hanssen gave me Mike Denecke's phone number to call with some tech questions.  Both Greg and Mike confirmed that the devices are identical save for the sticker on top that labels it a Denecke AD-20 or a Zefiro InBox.  From what I understood, Mike Denecke was responsible for the circuit design.

- Jason
Title: Re: AD20 mods?
Post by: spyder9 on February 24, 2006, 02:01:30 PM
Richard,

Did you run the 853s in front of the AD20 during your test?  The battery powered 853s can also add to your problem.  Phantom power improves dynamic range.
Title: Re: AD20 mods?
Post by: poorlyconditioned on February 24, 2006, 03:14:21 PM
Richard,

Did you run the 853s in front of the AD20 during your test?  The battery powered 853s can also add to your problem.  Phantom power improves dynamic range.

I ran my AKG CK91 "homebrew actives".  I know how they sound, so I can compare to MD (my own preamp and mic in), UA5 (my modified one), and Presonus Firepod.

It was not as good as my modded UA5.

I think this is a good solution for NJB3 or similar, but I was hoping for better.

BTW, the AD20 is forsale.  Any offers, say at $175?  I'm looking to sell and maybe something else.  Not sure yet though.

  Richard