Sound Devices MixPre 10-II tip

 

 

Late 2021 I took the leap and ordered a Sound Devices MixPre 10-II I was motivated by a number of factors, first was a desire to record 32bit 192kHz with multiple microphones. My old SD 788T is still a rock solid performer, but its hardware limits it to only capturing 4 channels of 192kHz audio. So I mainly use it for AMB recording where 96kHz is fine, and for that it is brilliant. I had upgraded the HD to an 500GB SSD and with NP1 battery I can do long runtime recordings eg yesterday I used it to record 5 channels of 24/96 capturing over 10 hours of real-time recording, swapping batteries every few hours.

I still have my other SD recorders – two 722 and a 744. So I can combine them with C.LINK to do six channel 192kHz recording, but it is not ideal to be powering and monitoring three seperate recorders.

The other feature of the MixPre10 is the Musician plugin. This directly suits a few music projects I am working on. But I will document that once I am further down the track and have some experience with it.

So the new Mix Pre 10 arrived, I ordered a NP1 battery cap for it and have it all up & running, and it is fantastic. But there was one aspect of the MixPre that I could not understand. I read the manual before it arrived and again after I’d used it for a bit and still I could not understand it.

This is so basic, every one of my other SD recorders provides it by default, but the one thing I wanted:

Direct access to the input gain of every channel!

As an example, if I plug a mic into my 722, power it up and hit record. The gain knob on the front of the 722 gives me direct access to instantly control the input gain of the mic. This is essential. Every time I record something the first thing I do is gauge the extremes of volume and set the gain, to cleanly record without clipping.

But for some bizarre reason, this is not how the MixPre is set up, by default. The MixPre has three modes.

1. Basic
This is fixed at 48kHz, I will never use Basic mode.

2. Advanced Mode
I set up a project as 32 bit 192kHz recording. I enabled phantom power for each mic and armed the record tracks. BUT The gain knob on the front of the MixPre does not control input gain! It controls post-record level, for creating a LR guide mix! Now I do appreciate why this is useful: it is essential for every production sound recordist. Delivering a guide mix to the director and to camera is as important as recording the iso tracks. But for me: I never record a guide mix. The LR bus is only of use for monitoring. I work at a fixed monitor level & solo to check mics etc…
With the MixPre in Advanced mode, the only way to access the input gain of each channel takes 3 steps: first select mic input 1 with a click, then click select input gain, and then use the fiddly little knob beside the headphone jack to set the gain. Then do the same for mic 2. Then do the same for mic 3. Then do the same for 4. Then do the same for 5. Then do the same for 6. Then do the same for 7. Then do the same for 8. Even reading that was a pain!

3. Custom Mode
I was getting frustrated by this point. There must be a way!? I read the manual and found Custom Mode, which mentioned one feature that still did not make sense:

Gain
Allows advanced operation of channel gain, including dual gain stage (gain and fader) and Remix.

Huh? What fader?
In frustration, I asked on the MixPre FB Users Group and some lovely helpful people replied!

First thanks to Robert Keilbar, who replied with a handy photo:
“Hey Tim, try custom mode and in the submenu set Gain Basic, that should solve the problem”

Bingo! Problem solved.
But as I said I have used SD recorders for many years. I had read the manual and I was stumped. I don’t consider myself an idiot, but why was this so difficult to discover? Why is there not a default MixPre set up for this, its always been a default?

It seems like Sound Devices decided that production sound takes priority, and everyone else should have to manually set up a custom mode to get it to work, the way their recorders have always worked.

Now someone else commented (thanks Bernard Ulrich!) saying the old MixPre 10 manual was better. They provided a link and I checked. And he is right, the old manual clearly explains it on page 24.

“CUSTOM MODE
By setting the Channel Custom Setup to Advanced and the Gain Custom Setup to Basic, you can use all the Advanced Channel Input features while retaining single gain stage control using the physical channel knobs. This allows you to use the channel knobs to adjust the level going to the ISO tracks.”

Why was this removed from the new MixPre manual?
I would have found that instantly and had zero confusion.

Now someone else joined the discussion at this point, and his comments were very helpful in understanding how the MixPre differs from previous recorders (but it still does not explain that omission from the manual)

Thanks to Dmitry Chernov:
“Even in the advanced mode the knobs do not control Input gain. They are after ADC and control at what level the digital signal is recorded into ISO tracks of a poly WAV file either in 32 bit or 24 bit mode. There is no analog input gain control at all neither in MixPre II series nor in Zoom F6. The only option to choose different levels prior to ADC is switch between Mic and Line level sensitivity.

The preamp has a fixed gain and then the signal goes to the ADC that consists of three 24 bit converters receiving the analog signal at 3 different levels to cover the wider dynamic range. The processor then combines the outputs of the 3 ADC converters to get the best signal-to-noise ratio and prevent digital clipping.”

That is very useful insight. It explains how the MixPre achieves its great results, but it still doesn’t explain the default allocation of knob useage.

I have contacted Sound Devices and provided my feedback. I hope they improve the manual, because I should have solved this myself instantly when reading the manual. Had I read the old manual, I would have solved it!

And it’s not just me. Someone else commented: “Thank you all for this enlightment! I thought there was no way to use the front knobs to adjust gain.”

Please improve your MixPre manual, Sound Devices!