Topic: Zoom F3

[Ozpeter]

At risk of (a) getting it wrong or (b) confusing the issue further, it seems to me that the F3 preamps can't be adjusted by the user.  What can be adjusted by the user is the position of the comparitively narrow ribbon of subsequently digitised audio within the wide ribbon of 32 bit float data. 

I imagine seeing a DAW track, whose height represents the 1500dB (?) of 32 bit float data.  The audio data would be seen as a quite thin waveform ribbon running along that DAW track. 

In the F3, when recording the user can choose whether to position that thin waveform ribbon higher or lower within the imaginary broad DAW track height.  You can't change how wide the ribbon of recorded data is within the DAW track, only how high or low within the track it is placed.  But at the end of the day, it doesn't matter where it's positioned - it will sound the same after the D/A stage, if appropriate analog replay gain or attenuation is applied (so you don't explode your speakers, or have to press the speakers to your ears).

If someone tells me that's completely wrong I will happily delete this post!

[daspyknows]

Looking for advice on the phone app.  I have had it crap out on me twice.  No biggie considering levels don't matter but what I am wondering is if the hold is not engaged on the recorder but only the phone app, will the hold still apply?  I am not going to experiment during the show.  It all seems to run fine despite the app losing connectivity and also wondering if reconnecting will blow the recording.

[Chanher]

I just took my F3 for it's maiden voyage a few nights ago. I appreciate everyone's input on the confusing "magnification settings". The fact of the matter is 32FP is still very new, a bit complicated and thus slightly confusing. Here are my initial thoughts:

-32FP IS AWESOME. IT IS WORTH THE INITIAL CONFUSION. I had a soundguy who was nice enough to offer use of his table right next to the soundboard. It was really crowded in the booth and with the crowd surrounding it so to be able to hit record, engage the hold button and just walk away was AWESOME. I didn't have to bother him or fend off other people to access the table and set my levels and so I wandered the venue for the entire show without worry. Reeaallly cool.

-It was a medium sized theater and a medium loud rock band. I decided to set the "magnification level" to x2 according to what I read here. Looking at the resulting wav file that I just transferred to my computer, I thought it was a bit low, BUT I ran my at853Rx's and I think the output of those is a bit low. Next time for a similar venue/band I will try x4 and report my findings. There is a free classical concert in the park this evening that I'd like to try my CM4's > F3 and I plan on trying magnification level x8. I will also report my findings if I'm able to get out there tonight.

-Thank you to Voltronic for looking at the actual manual and reporting the BLOCK DIAGRAM puts the magnification setting AFTER THE ADC's. I believe this confirms we are NOT affecting the actual gain stages before the (2) ADC's. WHATEVER the magnification settings are, we are not affecting the gain before the analog signal hits the ADC's.

-Now, the nerd/ scientist in me (and I'm guessing most of us) are wondering if the magnfication settings are affecting the 1's and 0's COMING OUT of the ADC. Is it the equivalent of (digital) gain being added to the file and thus changing the 1's and 0's? I honestly don't know and I still want to figure that out. But I think I can safely agree with what others have already said in that it's not a huge deal. I just performed the following test in my living room:

Using my F3, I recorded the exact same song in my living room but each time at different magnification settings. I started at x1, then x2, x4, x8, x16 etc etc all the way up to x1024! (it keeps doubling each time, for a total of 11 different magnification settings). After the 11th recording (at x1024) I cranked the volume of my stereo and recorded a 12th file (still at x1024) to really get those wav peaks flattened out to what we NORMALLY would consider clipping. I transferred all 12 different recordings of the exact same song, and placed them in Reaper. Below is a pic of the different wav files in a multi track setting. You can't see all 12 but you can clearly see how they actually get louder, confirming what others have said about it affecting how the final waveform APPEARS in a software setting.

Now listening to that 12th and final track, that APPEARS to be clipping, the track meters in Reaper are showing the red (actually pink) clipping indicators. Reaper was actually AUTOMUTING the track because it's technically so far over 0dB that it's engaging the AUTOMUTE feature to protect your speakers. What I could hear before the AUTOMUTE feature engaged did NOT sound like clipping. Then I opened that 12th track in Audacity and reduced the gain -20dB and reopened it in Reaper. It looked normal (see the 2nd pic below), and surprisingly sounded normal. There was ZERO distortion, clicks/pops or any negative audible artifacts that I could hear in playback. It is my initial belief this is because of the 1500dB (? plz correct) range of 32FP data (or gain range, plz correct) available that others have talked about. I still don't completely understand this but am simply accepting it for now, haha.

This tells me you cannot ruin a recording by mis-applying the magnification settings. With that being said, obviously don't test this by recording an important concert at x1024. I think we should all post our experiences with the magnification setting for the type of concert and how close it was to ideal "levels" and perhaps just accept the results haha. We'll then let the true audio engineers worry about the details.

[Chanher]

Update: I did make it to the free classical concert at the park and ran CM4's > F3 with a magnification level of x8. I just copied the files into Reaper and at x8 I still think they're too low. It is worth mentioning that I showed up late and ended up pretty far back by the "soundboard" and it was a good 80-100 ft back from the stage and it was pretty darn quiet. Shoutout to the old lady who finally turned around and shushed the volunteers who wouldn't stop yapping.

But while I was enjoying the concert, I was thinking about the magnification settings and what I believe is the truth: it still truly doesn't affect the final sound of your recording. No matter what, some type of gain is going to have to be applied. If I was using a normal 24-bit recorder, I would have applied analog gain to get the peaks around -10dB to -5dB. If I had set the magnification to x16 (which I would do if I could go back) then I believe Zoom's post-ADC digital gain (correct me if wrong) would have boosted the sound levels. But with my x8 recording, I ended up adding digital gain in Reaper to get the stereo file to an acceptable listening level.

I'm only thinking out loud here and welcome corrections, thoughts and feedback. If what I'm thinking is generally true, then we can at least have the argument about which gain is better: an analog preamp, Zoom's post-ADC digital gain (if that's what's happening, I'm still open to being wrong about this) or your DAW software gain/normalization. I can't help but remember reading a really old TS post about preamp gain affecting "soundstage".

Ultimately I hope everyone goes out and tapes more using these super cool devices and reports back. Comps are even better. If anyone in Denver with CM4's wants to comp an F3 and an Oade Warm Mod 661, that could be useful.

[fguidry]

...
Now listening to that 12th and final track, that APPEARS to be clipping, the track meters in Reaper are showing the red (actually pink) clipping indicators. Reaper was actually AUTOMUTING the track because it's technically so far over 0dB that it's engaging the AUTOMUTE feature to protect your speakers. What I could hear before the AUTOMUTE feature engaged did NOT sound like clipping. Then I opened that 12th track in Audacity and reduced the gain -20dB and reopened it in Reaper. It looked normal (see the 2nd pic below), and surprisingly sounded normal....

No need to go into Audacity. In REAPER without playing the track, hit F2 (Media Item Properties) and adjust the level. You can see the change in the track levels each time you hit Apply.

Fran

[Chanher]

No need to go into Audacity. In REAPER without playing the track, hit F2 (Media Item Properties) and adjust the level. You can see the change in the track levels each time you hit Apply.

Fran

ahhh nice 👍

[Gutbucket]

I'm only thinking out loud here and welcome corrections, thoughts and feedback. If what I'm thinking is generally true, then we can at least have the argument about which gain is better: an analog preamp, Zoom's post-ADC digital gain (if that's what's happening, I'm still open to being wrong about this) or your DAW software gain/normalization. I can't help but remember reading a really old TS post about preamp gain affecting "soundstage".

The primarily job of a preamp is amplification, and in that regard it is pretty safe to say you'll have no need to use one with the F3. 

Technically, as with any analog circuit there are potential situations where the voltage levels of an input signal exceed the usable dynamic range of the F3's analog input stage - either so low level that the signal becomes swamped in the analog input stage's noise floor, or so high that it overloads it to the point of distortion or clipping.  To make a good recording using the F3 in that kind of unusual situation (say recording the footsteps of small bugs, or a rocket launch at close proximity), you'd need to amplify or attenuate the signal ahead of the recorder, and could use an external preamp which exceeds the specs of the analog input stage of the F3 do that.  Its just shifting signal level to comfortably fit within the real-world analog input dynamic range capability of the F3, which is quite large [edit- but minuscule in comparison to the ridiculously large dynamic range of the 32bit floating point format], large enough that you are unlikely to ever need to do that for concert recording.

Secondarily, some folks use a preamplifer to impart certain qualities to the sound that are felt to be desirable - a certain "flavor" or "color" that the "dry and clean" amplification input stage of the F-series recorders intentionally seeks to avoid.  More subtly, one might perceive a different sense of "dimension" or "depth" or whatever, which might be described as presenting a different "soundstage".  Using a preamp ahead of the F3 for these purpose will be common for some concert tapers.

Lastly, some microphones require special powering through a dedicated preamp, or have excessive phantom power requirements which might exceed what the recorder is able provide.

Once the signal has been digitized by the F3's ADC into the 32bit floating-point format, it shouldn't matter how you digitally adjust the signal level after that - which might be via F3 the magnification setting, or afterward in an digital editor capable of working with the 32bit-float format.

[Ozpeter]

With the Zoom M3 (the "MicTrak" device) all this is taken to another level of simplicity because there's no level setting of any kind (apart from headphone monitor volume control) nor even a display (so you don't need to concern yourself with "magnification" 'cos there's nothing to see being magnified).  You just press the "record" button, and enjoy the show.  This concept is made easier to achieve because the mic capsules are obviously chosen to suit the preamp - or the other way round - which removes any concerns about a mismatch in that respect.

[Chanher]

I do want to apologize for continuing to harp on a subject that has been covered ad nauseam (32FP). But I suppose it's relation to this specific recorder, the Zoom F3, and the confusion with it's "magnification" settings justifies the discussion.

If anyone is still considering an F3 or has one and is confused, don't worry. You can't mess anything up. Hit record, enjoy the show and this new technology. Your recording will be fine. I'm actually planning on taping a loud show with this set at the maximum x1024 magnfication setting to just prove this.

Secondarily, some folks use a preamplifer to impart certain qualities to the sound that are felt to be desirable - a certain "flavor" or "color" that the "dry and clean" amplification input stage of the F-series recorders intentionally seeks to avoid.  More subtly, one might perceive a different sense of "dimension" or "depth" or whatever, which might be described as presenting a different "soundstage".  Using a preamp ahead of the F3 for these purpose will be common for some concert tapers.

One thing I did not mention is how the F3 sounds. My initial impressions would agree with the "dry" and "clean" adjectives others have used to describe it. I would throw in "transparent" as well. The CM4's are pretty transparent and realistic mics and that super quiet outdoor classical concert I recorded sounded exactly how I remember it. I find the preamps to be very quiet; when I boosted the levels in my DAW software A LOT there was still no significant audible hiss. They are definitely quieter than the Tascam DR70D preamps.

I would recommend the F3 for sure, even if you're adverse to newer and confusing technologies. Like everyone says, it's smaller than it appears in pics. I got a tiny 5000mAh portable cell phone charger off Amazon and I'm pretty sure I would get festival run times. I only got 3 hours and 15 minutes off cheap Amazon Ni-mh AA rechargeables using my CM4's at 48v, but I got 6+ hours off the same rechargeable AA's powering my at853Rx's at 24v. I plan on running at853Rx > F3 as my go to on-the-fly rig and the smaller, super simple setup will get me taping more. The bag I've been using is so small I've been hanging it off the plastic knobs on my Manfrotto stand.

I wasn't even gonna get an F3 but some video guy on Facebook marketplace kept lowering the price until I couldn't say no. Glad I bought it!

[voltronic]

Just in case anyone is still confused:

1) The F3 (and also F6 and F8n PRO when set to 32-bit float mode) have a fixed input gain. That's because in this mode [Borg voice]: Gain is irrelevant. More accurately, it's set to a conservatively low level.

2) The multiple auto-ranging DACs take over from there, and are the special sauce that allows to you realize the benefits of the 32-bit FP data format the way it is being leveraged by Stagetec, Zoom, and Sound Devices.

3) Any adjustment of levels now is in the digital domain (and within the enormous dynamic range of the 32-bit FP data stream or container). That's why digital overs beyond 0 dBFS can be fully recovered.

4) Zoom's use of "magnification" terminology in regards to the F3 is confusing and/or misleading. You are adjusting the level being recorded, as a digital fader.

5) This tech still has limits. The analog input stage could be overloaded, and any clipping or distortion there is not recoverable. In practice, it is highly unlikely to happen unless recording extremely loud sources with extremely sensitive (hot output) mics. But input pads exist for a reason - you'll know if you need to use them.

[Gutbucket]

^ That all seems correct to me.  A few comments-

Just in case anyone is still confused:

1) The F3 (and also F6 and F8n PRO when set to 32-bit float mode) have a fixed input gain. That's because in this mode [Borg voice]: Gain is irrelevant. More accurately, it's set to a conservatively low level.

2) The multiple auto-ranging DACs take over from there, and are the special sauce that allows to you realize the benefits of the 32-bit FP data format the way it is being leveraged by Stagetec, Zoom, and Sound Devices.

Don't want to take this thread down the rabbit hole, but the comment DSatz made over in the "Is levels peaking at 0 to high?" thread and my question about it posted earlier this morning is in currently in mind.  To sum up- it may be more accurate to think of these systems as being auto-ranging combinations of multiple, specifically "tuned" input-gain-stages>ADCs, than as a single input stage feeding multiple auto-ranging ADCs.  If so, this is something of an "ah-ha" moment for me in regards to understanding what is actually going on under the hood, but doesn't change how the recorders are used.

4) Zoom's use of "magnification" terminology in regards to the F3 is confusing and/or misleading. You are adjusting the level being recorded, as a digital fader.

I think "magnification" is less confusing than "level", but the "digital fader" concept is accurate.  We are not adjusting level ahead of the ADC but after it, and in doing so are not affecting the accuracy of the data.. because (I think, the mathematics of this is where I'm weakest.. referring here to the Wikipedia entry on Floating-point arithmetic, which explains, In computing, floating-point arithmetic (FP) is arithmetic that represents subsets of real numbers using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base.) "magnification" is likely adjusting the floating-point exponent value, and not effecting the significand.  In other words, "magnification" is scaling the output written to the file via the exponent but not otherwise changing what tapers call the "bit-accurate" output of the ADC, which is the significand.

To any mathematicians reading, please correct me if I'm off-base on this.

[Rairun]

Secondarily, some folks use a preamplifer to impart certain qualities to the sound that are felt to be desirable - a certain "flavor" or "color" that the "dry and clean" amplification input stage of the F-series recorders intentionally seeks to avoid.  More subtly, one might perceive a different sense of "dimension" or "depth" or whatever, which might be described as presenting a different "soundstage".  Using a preamp ahead of the F3 for these purpose will be common for some concert tapers.

I know it's more work, but if the F3's preamps are so 'transparent' (and can't be skipped anyway), shouldn't you be able to run the recording through a preamp of your choice afterwards and get the same results? If 'flavor' or 'color' is what you're after.

[Gutbucket]

Sure. Or emulate whatever particular sound you are listening for using plugins "in the box".  I know some tapers who apply some light saturation in search of something like transformer or tape emulation.  An advantage of good clean preamps is that you can always choose to alter things later when called for, or not, without that particular sound being permanently "baked in".

[voltronic]

Sure. Or emulate whatever particular sound you are listening for using plugins "in the box".  I know some tapers who apply some light saturation in search of something like transformer or tape emulation.  An advantage of good clean preamps is that you can always choose to alter things later when called for, or not, without that particular sound being permanently "baked in".

Add me to the list of people that prefer to record "clean" and add toppings later. The software is now good enough that you can get whatever flavor or adjustment you want. And can undo it.

Or if you prefer, you can still go old-school and do effect send/return through an analog mixer, if you have a great piece of gear that adds the flavor you want. But keep your unaltered original in case you change your mind down the road. I would try to keep AD/DA conversions to as few as possible, though.

[mepaca]

Sure. Or emulate whatever particular sound you are listening for using plugins "in the box".  I know some tapers who apply some light saturation in search of something like transformer or tape emulation.  An advantage of good clean preamps is that you can always choose to alter things later when called for, or not, without that particular sound being permanently "baked in".

Add me to the list of people that prefer to record "clean" and add toppings later. The software is now good enough that you can get whatever flavor or adjustment you want. And can undo it.

Or if you prefer, you can still go old-school and do effect send/return through an analog mixer, if you have a great piece of gear that adds the flavor you want. But keep your unaltered original in case you change your mind down the road. I would try to keep AD/DA conversions to as few as possible, though.

Agreed. Blood and guts can always be added later.