Topic: Bad Recording (AT943's > Church Preamp > iRiver H100)

[Javier Cinakowski]

BELIEVE me, I have a preamp and a rockboxed iriver and overloaded the line-in but levels(levelmeter) were ok all the time.

I don't doubt you had problems, but it had nothing to do with the iRiver if the levels were ok.  BELIEVE the technical aspects of an intergrated preamp/adc, not me....

[ilduclo]

I gotta agree that a preamp is not needed for loud shows, but a BB is essential.

my set up for loud shows dpa4061's>spsb3>line in on d100

[Javier Cinakowski]

a new 9v battery is all you need.....

[prof_peabody]

a new 9v battery is all you need.....

If I had to put money money on an explanation it would be this, with slightly overloaded mics as a close second.  Sure the 943 can handle high SPLs, but will have trouble at some really loud shows.  Don't make me upload samples...

[Belexes]

I recorded Tool with DPA4061>STC-9100>M1 (line in) and I had the gain too high on the pre and even though the levels were fine, it completely distorted.  Tool was extremely loud, so I had no business turning up the gain on the 9100.  I should have had it at "unity" or less.

[Church-Audio]

AGC = crap recording.. Set your levels manually. AGC never works right people say it does but it does not. I think this was a case of the iriver being overloaded by my preamp. Also with the gain reduced like that there is no way you overloaded the front end on my preamp. I agree with what some people had to say in the way of a battery box when recording loud shows if you want to use my preamp as just a battery box run the input gain control at 11o'clock That is unity gain, Nothing boosted nothing attenuated. Just plug in power. When your recording a band like Rush they have drums out there ass... There is no AGC in the world that can deal with the dynamic range of a band like RUSH and produce a good quality recording. Don't be lazy use your manual gain settings

The original poster failed to explain he had RockBox AGC set to SAFETY, which is not your every day AGC, but a (fairly slow) routine that reduces gain when clipping risk is there (-3dB or -2dB, I keep forgetting). I also asked the original poster before and he said gain levels were the same after the show, so the algorithm never even kicked in.

What the recording does sound like is mics or pre overloading.

Now you know I have your cardoids + st9100 and I have to be really close to the PA to get something like this, and even in my case I am fairly sure it was the mics.

Which makes me point at the mics in this case as well.

So please, Chris, stop blaming Rockbox AGC Safety mode, you have to use it to understand that it is NOT TRADITIONAL AGC. Please.

And to prof_peabody: the reason I have the ST9100 was to be able to handle the louder shows because my previous pre was brickwalling.

Umm I have used it I have tested it I have owned many iriver h120's and the AGC sucks.... lol.

[som]

I put in a new 9v the day of the show.

I'm gonna do some testing and see if I can recreate the scenario. Hell, I'll even use a Rush CD!

[Javier Cinakowski]

Umm I have used it I have tested it I have owned many iriver h120's and the AGC sucks.... lol.

 

[prof_peabody]

I put in a new 9v the day of the show.

I'm gonna do some testing and see if I can recreate the scenario. Hell, I'll even use a Rush CD!

Maybe you had a bad 9V battery.  I know Moke has had this happen to him.

I agree with Chris, the AGC/ASAO feature is not great.  It's good for maybe the first couple times you run a rig, but once you get used to your rig you can dial in better on your own.  If you get unlucky and end up next to a screamer for a few seconds, the AGC will really crank down the gain permanently for the rest of the show... YMMV

[cgrooves]

The original poster failed to explain he had RockBox AGC set to SAFETY, which is not your every day AGC, but a (fairly slow) routine that reduces gain when clipping risk is there (-3dB or -2dB, I keep forgetting). I also asked the original poster before and he said gain levels were the same after the show, so the algorithm never even kicked in.

Petur-
I've come to accept that the Rockbox AGC Safety setting will never be thought of any differently than the standard AGC utilized on most recorders throughout the years.  I know when I first got my pcm-m1 and was learning about the settings, the use of AGC was always a bad thing.  There have been years of negative discussions about AGC use, and the Rockbox AGC Safety feature is often lumped in with 'typical AGC' in peoples minds.  Perhaps you developers could rename the feature as 'Clip preventer' or similar (j/k)    Whenever tapers hear the term 'AGC', it automatically brings negative connotations.  Probably always will.
+T

[Javier Cinakowski]

If you get unlucky and end up next to a screamer for a few seconds, the AGC will really crank down the gain permanently for the rest of the show

There is a setting that allows you to change the clip-time.  Set it its highest and this situation will not be as big of a problem.   

If the screemer does go crazy for an extended time, it will indeed reduce that gain.  However, there is no logical reason for someone to suggest the AGC safety clip caused the distortion in question.  Nor is there a logical reason to say that it sucks

[Roving Sign]

...and when I started recording the level came on at +20...

So - is this in addition to the gain from the preamp...?

 

[cgrooves]

...and when I started recording the level came on at +20...

So - is this in addition to the gain from the preamp...?

Hope I'm not speaking out of turn, but as I understand it.....Yes.

I have not run that rig before, but if I was going to I would try to leave the iRiver gain as low as possible (even at 0 if I could get away with it and get decent levels with the pre).

Edit:  I guess if you wanted to run 'AGC Safety', you would have to use some gain on the iRiver in order to see the benefits.  However, I would recommend trying the iRiver gain at a setting more like 10 than 20.

[Roving Sign]

...and when I started recording the level came on at +20...

So - is this in addition to the gain from the preamp...?

Hope I'm not speaking out of turn, but as I understand it.....Yes.

I have not run that rig before, but if I was going to I would try to leave the iRiver gain as low as possible (even at 0 if I could get away with it and get decent levels with the pre).

Edit:  I guess if you wanted to run 'AGC Safety', you would have to use some gain on the iRiver in order to see the benefits.  However, I would recommend trying the iRiver gain at a setting more like 10 than 20.

Is there a "no gain" or unity gain setting on the Iriver Line In...? If so - thats where you should be - It sounds like you are adding an additional 20db to your pre's signal - and likely overloading the Iriver Line Input. Try setting it to 0db and see if it still passes signal...(Im sure others more familiar with the device will chime in)

With the JB3 (for example) - you set it at "0db" - no gain added, no gain subtracted...just whatever the preamp will give...

[som]

Yep, that was 20 on the iRiver, in addition to the pre gain. When I turned it on it was at +20 and I was in a rush (no pun intended) and it did not appear to be clipping so I left it alone, thinking that the AGC (or whatever it *should* be called) would kick in if needed. I thought that was a lot of gain but it was not clipping, so....

One thing I've wondered is if the 1 second threshold on the AGC allowed some distortion to "slip through" without activating the AGC. The distortion is of pretty short duration, but is pretty pervasive throughout.