Tascam DR70d implementation of dual level recording is very limited (no pun intended):

This function cannot be enabled if more than two channels are selected for recording or if the two selected channels prevent the recording of a stereo pair (for example, CH1 and CH3).

Seriously getting annoying to have features that don't use the whole device, (4 channels etc). So many stupid limitations to remember.

What is nice about MixPre is that the limiter works flawlessly on all 4 channels. Simple to remember. Especially in stressful onset situations, we need gear we can just turn on - press record - and get usable material from.

So your view is that the MixPre's analog limiter isn't that exciting? Better to go with Zoom F4/8? (I'm kind of over the Tascam for a few 'firmware' related reasons.

I know that the DR100MKii has an analog limiter, and I loved using that device, especially unmanned for performance audio. So personally an analog limiter is very reassuring that the quality of the audio will be maintained in a bad situation.

So on that level the MixPre would be very useful for me, as I do lots of productions like that. MixPre looks like the best of both worlds (analog and digital) until digital limiters are designed correctly as you pointed out VK.

Also the volume knobs on the DR70d are digital as well, so you can't simply change volume during recording as it will cause audible changes in volume (volume terracing) which I am assuming as the MixPre is analog volume then that would not be the case.

Once again, this probably and should work well on a digital system, but its just not implemented in a way that is 'analog'. Pity. 99% of everything I do audio wise is digital (in DAW) just don't understand why that can't work on portable device?

Looks like you can also connect Keyboard to MixPre and log metadata. Could be useful onset for more complex productions (from manual):

The use of standard USB computer keyboards is supported. When using the MixPre-6 in situations requiring extensive metadata entry, titling and wired remote control capability, a USB keyboard may be desirable.

http://cdn.sounddevices.com/download/guides/MixPre6-UG_en.pdf

@alcomposer

When using safety track record feature the unit will only be able to use half its inputs. So the f8 gets reduced to 4 input etc. So if you are using this "feature" there is little difference between the specs of the f8 and mix pre 6.

We always use Tascam safety track feature on exhibitions. Very useful thing.

@Grimor

Depends on content.

@alcomposer

Sometimes if levels where way off or just one guy periodically talks very loud you can be forced to use all backup file, just faster. If you are not recording in studio or quiet place no one will even notice.

Good news @Vitaliy_Kiselev, looks like from this video Gain is digital. (Suppose it should be ok if it is smooth transition between volume levels?)

Checkout beginning of video and gain value setting.

More info about knobs and settings, Sound-devices has already saved a life:

Already bugs in firmware, SD will fix (stated by SD):

Yeah, I have had that issue before, (with actors actually). Sometimes even -12db can be distorted, if only mildly. Use a repair software if it is - like RX6. There is an 'De-Clip' function, the only one I have found that actually makes the audio usable afterwards, its magic.

I haven't looked at the pmd661 @Grimor. File encryption? Must be good for police / military usage?

Sometimes even -12db can be distorted, if only mildly. Use a repair software if it is - like RX6. There is an 'De-Clip' function, the only one I have found that actually makes the audio usable afterwards, its magic.

Example can be Canon C200 interview audio from CG, source had not large but many clippings even at safe track.

@Grimor ah. Yeah I only mentioned it as when I looked it up that was a "major feature". I don't quite know when that would be useful, but for police interviews yes it probably would.

@Vitaliy_Kiselev I believe that the Zoom F8 allows setting independent gain for safe tracks. So user can set level much lower than -12. Or in another situation one could use safe dual gain to "cheat" and record soft material at same time as loud material. (As long as they are not happening at same time obviously) for example if an actor had dialogue that went from whispering to yelling.

Do Zaxcom have exclusive 32bit WAV license? (I never thought I would one day need 32bit, but here we are) :-$

24 bit should allow 144db dynamic range. ( 24 bit * 6 db) Limiting factor is analog side. However with "safe track" if the zoom f8 actually does use a seperate analog stage for recording, should give better result than 32 bit, as that one 32 bit AD will still be sampling the same analog gain stage.

(Obviously if equipment becomes 32 but it may actually have more DR anyway due to having better analog side)

Problem is just like camera sensors. 120db is from clipping to noise floor. Just because we have 120db doesn't mean we can use all that range.

Now, MixPre does have 32 bit AD, but dithers to 24. Considering many 24 bit AD's are not even real 24bit- (more like 20 bit) that could be interesting itself.

So with a zoom f8 you get a bit of the clips less audio recorder tech (dual ADC) then we simply need software to make a HDR file out of two audio files. (Like in photography)