Topic: ATU853 Mod

[scoper]

I recently got the ATU853 (cards and omni) from SoundPro. I elected NOT to get the 4.7K mod for lower sensitivity.

A stupid question: would putting an in-line attenuator between the mics and battery box (or attenuating at the battery box, which has a level control) serve the same purpose?

[taperwheeler]

No.  The reason for the mod is to prevent the overload distortion at the mic capsule level.  Your method attenuates after the mic receives it's signal.

[scoper]

No.  The reason for the mod is to prevent the overload distortion at the mic capsule level.  Your method attenuates after the mic receives it's signal.

If I understand correctly, the mod that Soundpro (and others) do puts the resistors in the stereo miniplug - how does that affect the capsules themselves?

[illconditioned]

No.  The reason for the mod is to prevent the overload distortion at the mic capsule level.  Your method attenuates after the mic receives it's signal.

If I understand correctly, the mod that Soundpro (and others) do puts the resistors in the stereo miniplug - how does that affect the capsules themselves?

Cool.  Yeah, you can put the mod in (well, behind, really) the capsules, or in the plug.  The advantage of putting it behind the capsule is that you only need to run two wires (signal plus shield).  The disadvantage is you have to take the capsule apart (not hard, but trivial either).  But most AT cables are three wires (red, yellow, shield) so you can *usually* do the mod at the plug anyway.

[geek mode on]
We say the "capsule" overloads.  What we really mean is the FET (transistor) behind the capsule overloads.  Different mics have different access to the FET.  In AT capsules the electret element screws off and the FET is in the body.  Other capsules, like AKG CK9x or the Neuman 140, 150 series have the condensor and FET inside the capsule housing.  Also to complicate things, some elements are electret and some require external polarization voltages.
[geek mode off]


  Richard

[scoper]

So Richard, am I right or wrong? Does post-mic attenuation solve the problem?

Chris Church's 9100 pre-amp has a switchable 4.7k resistor in the preamp, which is certainly past the mic stage. Or is the key the amount of power being fed to the mics as plug-in-power?

Just trying to understand, which with knowing nothing about electronics puts me at a disadvantage.

Scott

[illconditioned]

So Richard, am I right or wrong? Does post-mic attenuation solve the problem?

Chris Church's 9100 pre-amp has a switchable 4.7k resistor in the preamp, which is certainly past the mic stage. Or is the key the amount of power being fed to the mics as plug-in-power?

Just trying to understand, which with knowing nothing about electronics puts me at a disadvantage.

Scott

It is not easy to understand this stuff without electronics.

You cannot solve the problem by putting a mic pad on the preamp.

You *may* be able to use a 4.7k resistor in Chris's preamp, but to do that, you would have to run three wires per mic.  The mic input would be either two miniXLR or two miniplugs, not just a single miniplug.

I recommend everyone do the 4.7k mod.  This loses a bit of gain, but you can make that up by either: A (standard) preamp, or a decent mic input stage (minidisc or Sony PCMD50).

So, what I suggest you do is send your mics to Chris and have him insert 4.7k resistors into the miniplug for you.

  Richard

[Belexes]

I seem to remember that the discussion on the 853's was that they are less susceptible to distortion overload in comparison to the 943's.  Chris Church did some tests and I believe he does not recommend this mod for the 853 series, but YMMV.  I had the mod on some 943's I owned.

I did find that when I had the mod, I had to go +20 on the 9100 pre and when going line-in on the D50, I had to use a ton of gain...for a theater rock concert.  Perhaps this is a good mod for extremely high SPL stuff.

[Church-Audio]

I recently got the ATU853 (cards and omni) from SoundPro. I elected NOT to get the 4.7K mod for lower sensitivity.

A stupid question: would putting an in-line attenuator between the mics and battery box (or attenuating at the battery box, which has a level control) serve the same purpose?

You mean my mod right? lol.....

[Sunday Driver]

I'm finally going to try Chris' mod soon. I just got a hold of some 2.4k resistors, as I plan to run my mke40s mic in directly on my R-09HR. Then I'm going to torture test them at Tool in August and see how it comes out. It should be interesting to hear, as I don't think there are any modded Sennheiser > R-09HR tapes out there. If it works well, it would make an excellent budget low pro rig.

[fmaderjr]

I seem to remember that the discussion on the 853's was that they are less susceptible to distortion overload in comparison to the 943's.  Chris Church did some tests and I believe he does not recommend this mod for the 853 series, but YMMV.  I had the mod on some 943's I owned.

Chris recommends the mod for 853's and not 943's (although some here disagree with him and say the 943's benefit from the mod as well).

I made many recordings in the past with unmodded 853's and only rarely thought I heard distortion though. I never stack tape, but did think I heard distortion recording a few ear crushingly loud acts like Iggy Pop.

If you don't record extremely loud sources, you can probably take your time getting the 853's modded.

[illconditioned]

I seem to remember that the discussion on the 853's was that they are less susceptible to distortion overload in comparison to the 943's.  Chris Church did some tests and I believe he does not recommend this mod for the 853 series, but YMMV.  I had the mod on some 943's I owned.

Chris recommends the mod for 853's and not 943's (although some here disagree with him and ay the 943's benefit from the mod as well.

I made many recordings in the past with unmodded 853's and only rarely thought I heard distortion though. I never stack tape, but did think I heard distortion recording a few ear crushingly loud acts like Iggy Pop.

If you don't record extremely loud sources, you can probably take your time getting the 853's modded.

You don't always hear distortion right away.  In fact, I've recently noticed some (slight) compression only after looking at two different sources I made of the same show.  So, it pays to get the wiring right.  Recall that no "professional" mics are done without some kind of resistor on the source of the FET.  For example, if you look at the schematic of the AT8533x adapters, you'll see a 5.1k source resistor there!

  Richard

[taperwheeler]

I know that my rig sounds much better to me post mod.  With clean gain in an internal/external pre or combo of, just makes sense imo.