Topic: Is a preamp always necessary?

[hexyjones]

if, running mic in (or line in, I believe) on a d7/d8, you need to turn your level knob below 5 in order to not have digital overs, the mic pre IS going to clip/brickwall unless it's been modified (oade mod, etc.) to get past this problem. 

Huh? Whether you get digital overs has really nothing to do with where the level knob is...


and digital overs really have nothing to do with Mic Preamp headroom - any mic pre can be brickwalled...modded or not...brickwalling is an analog issue...

Are you saying the D7/8 pre is going to brickwall with any signal?

[dnsacks]

yep -- my understanding is that if the signal being fed to a d7/d8 (mic in or line in) is hot enough to require you to turn the volume knob below 4 (threw in 5 to be safe), to avoid digital overs, it's too hot for the d7/d8's analog circuitry to handle and will cause the analog circutry to brickwall.

This was the reason that the oades started modding d7/d8 analog inputs.

[hexyjones]

I think the Oade mod is for the Sony Mic Pre (mic in) only...


From Oade

Here is a little information on a problem with Sony D7/8/100/PCM-M1's known as "brickwalling" . Many of you know that to record thru the D7/8/100/M-1 mic inputs and go over the -6 level on the level meter is bad news. Here is why, the mic preamp overloads. It is NOT possible to fully utilize the dynamic range of these digital recorders thru the mic inputs. The stock D7/8 mic preamp overloads with a -15 db input level when set on the low sensitivity setting. They overload at -35 db when set on the high sensitivity setting. The D100/M1 mic input overloads at -20db with the pad on and -40db with it off (i.e. set to 0 db). No matter which mics you use or what the signal source is, this is true. It takes a -10 db input signal to get to 0 db on the D7/8's meter using the line level inputs even with the record level knob at its highest setting. It takes a -5db input signal to get to 0db on the D100/M1. As you can see there is a 5 to 15db "hole" in the gain structure of this design. The upgrade rebuilds the mic preamplifier completely in the D7/8 and the D100/M-1.