Topic: Denecke AD20>MT - clipping?

[yousef]

I'm sure this probably just betrays some fundamental misunderstanding on my part, but if someone could take the time to explain I'd be much obliged...

I was messing around with various bits of gear today and tried running my HLSC-1 mics into my AD20, which was plugged into the digital-in of my Microtrack.

I was just taping myself playing moderately loud acoustic guitar and found that when I turrned the gain up to full on the AD20, I was getting the red clip lights (and actual distortion) on the Microtrack - which itself was set to the absolute minimum gain.

But I don't understand - I thought that if I was using the MT as a bit-bucket, there was no possiblility of overloading it. So what have I misunderstood here?

I find it a bit bothersome as I picked up the AD20 to use with my DPA 4060s, which I suspect are somewhat hotter than the HLSCs and so am now wondering how useful the DPA>AD20>MT set up will be in the field...

[JasonSobel]

a few thoughts.

first, the AD-20 doesn't provide any sort of power for any type of microphone.  so I'm not sure what you are using to power your mics, maybe you just left that out of your description.

and as far as clipping.
when running digital in to the MT (or any other deck that accepts a digital input, for that matter), yes, you are bypassing any analog circuitry in the deck, so you don't have to worry about overloading the analog signal path of the deck.  BUT, 0dB is still 0dB.  digital clipping is still digital clipping.  none of that changes.  with the AD-20 > MT rig, because the AD-20 doesn't have any level meters of its own, you need to watch the meters on the MT and adjust the AD-20 accordingly (so you don't clip).

[yousef]

+t for explaining that in a way that even I could understand...

And yep, I forgot to mention the Soundpros 9v battery box in there.

Thamks again.

[DSatz]

Many recorders over the years have followed the convention that when three or more consecutive digital samples are at digital full-scale value (either positive or negative), the clip indicator lights up.

For mastering purposes it is preferable if the indicator responds to even a single full-scale sample; for that matter, Red Book CDs supposedly aren't allowed to use the last 15 codes in either direction, but I don't know of any software that checks for it.

Anyway, the recorder can very well let you know that the A/D has been overloaded.

--best regards

[willndmb]

clipping on the mt doesn't shock me
the ad20 has a min of 17db gain when all the way down (to the left)
i don't know how high the gain is turned up but if you had it turned all the way up you could clip easyyyyy i would suspect

[yousef]

Many recorders over the years have followed the convention that when three or more consecutive digital samples are at digital full-scale value (either positive or negative), the clip indicator lights up.

Interesting - thanks, I'll keep that in mind.

the ad20 has a min of 17db gain when all the way down (to the left)

I'd forgotten all about this - I now remember planning to put some sort of attenuation between mics and AD-20 but never getting around to it...

Is there a word for the (often disgracefully long) amount of time between buying new gear and actually using to record a show?