Pocket 4K - weak preamps?

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Gene Kochanowsky

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Re: Pocket 4K - weak preamps?

PostWed Dec 05, 2018 3:47 pm

Kristian Lam wrote:Unlike URSA Mini Pro, the stereo 3.5mm inputs can either only be line or mic, hence when mic level is selected for one side, the other has to be the same which is why line is not available.

I can see why this could be confusing and the interface wi be tweaked to better communicate that the other option is not available.


A possible way to restrict selection for the PC4K is not to restrict line/mic selection for 3.5mm inputs but when a given channel is changed from line or mic to the opposite value, if the other channel is set to a 3.5mm input it is automatically changed to the corresponding line or mic value. That might be surprising to the user but I think they will quickly understand how it works and not jump to the conclusion that their camera is broken because it appears to be always stuck in line or mic mode and when they plug in a mic or line source their audio levels are way too low or high.
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Denny Smith

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Re: Pocket 4K - weak preamps?

PostWed Dec 05, 2018 9:20 pm

Good idea Gene, having both sides of the 3.5mm input set together, would reduce the confusion.
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rick.lang

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Re: Pocket 4K - weak preamps?

PostFri Dec 07, 2018 4:22 pm

That would be very interesting. Looking forward to it.


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John Paines

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Re: Pocket 4K - weak preamps?

PostFri Dec 07, 2018 4:29 pm

Australian Image wrote:However, my solution appears to be working quite well


As best I understand it, you're amplifying the signal and using another device in the middle to power the mic. That's fine, but it's not a "solution". It won't help anyone who wants to to plug directly into the camera and record audio, but can't because the levels are much too low.

The idea is to get the mic input working without additional equipment, at least for occasional use or convenience.
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John Paines

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Re: Pocket 4K - weak preamps?

PostFri Dec 07, 2018 8:01 pm

It's always been understood that by raising the level of the signal, using a mixer or similar device, you could record. That's never been in doubt. I'm glad that it's working for you, but what you're reporting doesn't answer the question being asked: what's going on with the camera's preamps?
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Re: Pocket 4K - weak preamps?

PostFri Dec 07, 2018 8:27 pm

In my own nonscientific testing the same mic plugged into the 3.5mm and the xlr is exactly 12db louder on the xlr and it sounds fuller and better on the xlr.

That being said, the xlr is still more quiet than I would like. I recently did an interview and had to set the gain to 100% using a professional sony clip on lapel using phantom power. A co-woker used the same setup with the same interviewee and his gain was set much lower on his sony ENG camera to achieve the same level.

It works as is, but for sure it's lower level than other cameras.
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John Paines

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Re: Pocket 4K - weak preamps?

PostFri Dec 07, 2018 8:45 pm

It was a crude comparison, but I couldn't equal the levels of the onboard mics even after adding 30db to the 3.5mm Sony mic recording in Resolve, with both at 50% gain in camera.
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Leon Benzakein

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Re: Pocket 4K - weak preamps?

PostSat Dec 08, 2018 4:52 pm

Ray, at the risk of the Aussie thunder raining down on me you keep mentioning how your solution works but I do not remember if you have ever described your solution aside from saying that you are waiting for a part to arrive.
If I have missed that post please forgive me, but what is your solution?

I am interested in knowing how you have gotten power to the Rode VideoMicro.

Thanks
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Benjamin de Menil

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Re: Pocket 4K - weak preamps?

PostSat Dec 08, 2018 6:21 pm

John Paines wrote:
Joe Giambrone wrote:This is new, and potentially important:

Does it mean the issue is solved, and it was just a matter of the correct setting?


No. He had some user error to contend with. It sounds like his mic is "hot" to begin with (and may have additional amplification even at zero), and he was recording loud electric instruments and drums. Too many unknowns here to conclude much of anything.


I've now tested at regular conversation and there seems to be plenty of level using the rode stereo video mic x set to zero gain. It's true that it's a hot mic. Not sure what the situation might be for a passive dynamic mic for instance.
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Benjamin de Menil

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Re: Pocket 4K - weak preamps?

PostSat Dec 08, 2018 6:28 pm

at various different gain settings, I've noticed clipping on the VU well below 0dB. I haven't listened to what it sounds like yet, but it looks to me like digital clipping - it very abrupt. If so, there are some issues with the pocket 4K's firmware. Digital clipping should not occur at less than 0 dB.
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Jim Giberti

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Re: Pocket 4K - weak preamps?

PostSat Dec 08, 2018 10:00 pm

I'm assuming that anyone doing any kind of professional work has a few preamp/dedicated recorder options as well as mic options.

None of that addresses the question of the thread - "weak preamps?"

The answer to that, for anyone recording direct to the P4K is - Yes, relatively speaking.

Using the basic audio principle of feeding a strong signal to any gain stage (to minimize the inherent self noise that virtually any gain stage will add) is predicated on the idea that you can then use low gain at the recorder. Even on the mini XLR we have to run the input gain high.

That said, the pres on the XLR stage are clean enough and so far cranking up the input to around 70% still results in a solid sound.

I haven't tried anything into the 3.5 but I'd like the option in challenging situations.

Mainly, because of it's design, small form factor - it's pretty important that it doesn't need to be rigged with anything in order to capture good audio.

We do most work with sparate audio but I really like the opportunity to record direct for a lot of other work and, at least with the XLR/phantom power setup with a simple ME-64, it does sound good - if a bit underpowered.
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Leon Benzakein

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Re: Pocket 4K - weak preamps?

PostSun Dec 09, 2018 1:44 am

Thanks Ray.
Got it.
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Re: Pocket 4K - weak preamps?

PostMon Dec 10, 2018 3:19 am

Although it's a workaround and not a solution, a Tascam DR-60d Mkii or DR-70D recorder can output a 3.5mm line level stereo signal from it's preamps to the mic input of the BMPCC 4K. For the DR-60D Mkii this is a 200 ohm signal with an output level of -10dBV to +10dBV. The DR-60D Mkii also has a 3.5mm camera low mic output at 200 ohms that has a separate volume control for a level of -50 dBV to -30 dBV. These units have 1/4-20 screws that bolt to the bottom of the camera and fit between it and a tripod. They have mixers and can be set to monitor the audio coming out of the camera and mixing it into a stereo mix on it's SD card or as a separate stereo file plus the stereo file of mics connected to the Tascam. A manually operated or automatically operated slate tone is provided to sync the SD card's files with the scratch tracks of the camera's video files in post. The class A discrete circuit preamps provide a generous 65 dB of gain and use up alkaline batteries in 2.5 - 4.5 hours, but they can be powered externally through the USB port (something you can't do with a Zoom H4N). There is also a Tascam DR-701D with more features including a time clock input.
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AndreeMarkefors

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Re: Pocket 4K - weak preamps?

PostMon Dec 10, 2018 7:54 am

While I agree that Blackmagic Design is aware of this, between the posts from BMD reps here, I still don't think we've seen anything that resembles a "yes, we've been able to replicate the issue and we are seeing the same thing—we're looking into it".

Maybe in another thread?
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Re: Pocket 4K - weak preamps?

PostMon Dec 17, 2018 11:48 pm

Still battling this, but a few things are looking better. Using an audio technica at875 in the xlr jack I am getting reasonable levels. Seems to be a good deal 'hotter' than the ntg1. So might be a mic solution for some (I like it because it's small!)
Also just bought a cheap saramonic - I think 'm3' - as an alternative to the rode videomicro (which has very low levels.) Haven't pushed the sound quality yet, but the level isn't bad for fx at about 70%, with its +10db boost. (It's battery powered, for what that's worth.) It's small, and fits in my bag, so I'm hoping it will be ok for basic fx.
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Re: Pocket 4K - weak preamps?

PostWed Dec 19, 2018 1:12 pm

Australian Image wrote:
I have previously stated that I use an Olympus LS-14 to provide power to my Rode VideoMicro, that's the first hurdle. I'm looking for a simpler solution to the LS-14. If you use a powered mic, then you don't have that issue.

To boost the signal I use a Cayin C5 headphones amplifier from the LS-14 to the camera. This provides all the needed boost to allow the camera to record even the lowest level sounds. There are many alternatives to the Cayin C5.

Alternatively, you can get any number of devices that perform all of this in one unit, but none are small or inexpensive.

I've posted much of what I've done here: https://australianimage.com.au/blackmag ... a-4k-pt-4/ and will post another story specifically on the audio issue at a later date, as I search for an alternative to the LS-14.


I was thinking of trying something similar with an Aputure a.lav module into a Fiio A1 amp, which would be a pretty compact workaround. However I'm not sure if the A.lav provides regular plug-in-power or something proprietary for the specific mic it comes with - does anyone have one to test?

I have the usual Zoom and Tascam recorders that can provide clean signals but I agree there must be smaller solutions for when a recorder isn't practical.
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3.5mm weak sauce explained?

PostSun Dec 30, 2018 8:45 am

Had discussion with Deity rep when I was buying the Deity D3 Pro mic

ME:
"I bought the BMPCC 4k. I see your site says it requires trs cable. Could yall just sell your 3.5 to xlr separately or make a 3.5 to mini xlr? How is the sound quality changed going from 3.5 to xlr. Bmpcc 4k as a mini xlr port."

Deity Facebook person:
"We sell our 3.5mm to XLR separately but its sold out currently
As for sounding different. It really shouldn't. The preamp in the 3.5mmTRS Jack on the BMPCC4K are just fine."

Me(im a newbie):
"I been watching **** ton of mic reviews. Mics have sounded different via 3.5 and xlr. Better on xlr."

Deity FB person:
"So the BMPCC4K actually has 4 inputs
They duplicated the same pre-amp across all for and added a phantom circuit to the TA3M port. The 3.5mm port actually is a TRRS with the first 3 pins being mic inputs and the 4th pin being the ground"

Me:
"I do not know much about this stuff. What will happen if I use Trrs? What is that extra pin doing that I guess disrupts things"

Deity FB person:
"I'd you use our TRRS cable that's included with our mics it wont work
We put ground on Pin 3 which is standard. Blackmagic put ground on pin 4 which is not standardized"

"So the TRS cable bridges the 2 pins which both our microphones and their cameras reads as a short and grounds them both out, turning the Jack into a fake TRS"


So this could have a lot to do with peoples 3.5mm issues???
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Al Slamecka

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Re: Pocket 4K - weak preamps?

PostFri Jan 11, 2019 7:21 am

After getting an RMA replacement from my first BMPCC 4K due to a defective XLR port, I've been testing out the XLR jack on the replacement.

My first camera just produced electronic noise from the XLR jack when using phantom power and I noticed that the noise was much worse when the camera was drawing AC power vs. battery power. It led me to wonder if all the components on the port side of the camera we're truly shielded.

The results of my tests with the new camera suggest a possible correlation between between audio noise and power draw. With a Sennheiser MKE 600 drawing phantom power from the XLR input and a Samsung T5 1TB drive attached, the camera records electronic noise that becomes pretty intolerable if the preamp gain is at 70% or above (roughly -40db noise floor in a otherwise silent room at 70% gain).

This occurs when the camera is powered by battery and the culprit seems more to be the SSD's power draw. I reached this conclusion as electronic noise is still there - albeit much fainter - even when using the internal mics with the SSD attached. With no SSD attached, I don't hear the noise whether recording with the internal mics or with the Sennheiser drawing phantom power.

Conversely, when connected to AC power, the noise goes away completely BUT additional tests lead me to believe there's still unnecessary noise in the audio signal. The Sennheiser MKE600 can be battery powered and when powered as such vs. by phantom power, there's much less audio noise. I'm familiar with phantom power adding a bit of noise but the benefit should be more sensitivity... a better SNR (signal to noise ratio). This does not appear to be the case as the recorded audio (not the noise) is no louder when the MKE600 is phantom powered vs battery powered.

So my layman's assumptions are:

1) the LP-E6 battery does not have sufficient power to drive the preamp, phantom power, and SSD drive optimally at the same time. An external battery solution should hopefully be able to address this.

2) Some external noise may be affecting the audio signal when using phantom power since there no noticeable SNR improvement.

The best solution for me is to battery power the MKE600. The signal appears strong enough and quiet enough when the camera preamps are cranked up. I will need to carry AA batteries but on the plus side the BMPCC 4K battery won't drain as fast.

I'd be very interested if anyone can confirm similar findings to ensure my subjective results aren't just a corner case.

Hope this was useful info.
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Re: Pocket 4K - weak preamps?

PostFri Jan 11, 2019 4:47 pm

Al Slamecka wrote:I'd be very interested if anyone can confirm similar findings to ensure my subjective results aren't just a corner case.

I've got an NTG-2 which can be powered either by battery or phantom, and I've got a v-mount battery solution so I can test the various combinations. My office is too noisy on a weekday, though I might try tomorrow.
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Re: Pocket 4K - weak preamps?

PostMon Jan 14, 2019 1:42 am

Australian Image wrote:Finally I can report some success. After several failures, I decided to buy an inexpensive Saramonic SR-M3 shotgun mic, to test out, and I can now confirm that it works, whether plugged directly into the camera or through my Cayin C5 amplifier.

Over the next few days I'm going to run audio tests to see how well it can capture audio in open environments (field use), which will be my intended use. I could find no real tests of this microphone being used to capture natural sounds like I want to record, as all have been more or less for vlogging (indoors and outdoors).


Has anyone tried the Azden SMX-30 (mono/stereo)?

Also looking at the Deity V-mic d3 Pro (it has a dial for gain as opposed to fixed positions).
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Al Slamecka

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Re: Pocket 4K - weak preamps?

PostTue Jan 15, 2019 4:54 am

Subsequent to my earlier post about potential audio noise issues related to 1) power draw on the battery and 2) a lot of white noise when using phantom power, I happened across a recent favorable review on Provideocoalition.com about the SS-1 mic preamp from The Simply Sound Company.

The SS-1 is an 'pre' preamp device that sits inline between a dynamic mic and a device's preamp. It's powered by 48v phantom power coming from the device (BMPCC 4K in this instance) and provides +27dBu gain boost to the mic's signal. It doesn't work with condenser mics however it works with both dynamic and battery powered mics (XLR connection required).

I ordered the SS-1 direct from The Simply Sound Company for US $60 and can confirm that it does boost the signal of my Sennheiser MKE600 considerably, allowing me to turn down the gain of the BMPCC 4K preamps. To be clear, the Sennheiser still needs to be using battery power as the SS-1 does not pass phantom power to the mic.

From a couple brief tests, I believe the signal should be sufficient in most normal conditions with the BMPCC 4k preamps at 30% - 40%. On the down side, the white noise issue is still prevalent however the expected electronic noise from powering preamps, SSD, and the SS-1 with the battery is not there! Perhaps something about powering the MKE600 directly thru phantom power had something to do with the noise I reported earlier. The other drawback of using the SS-1 is that it adds about 4" in length to the mic. My pocket camera is getting less and less 'pocket' with each workaround.

So I think I have two 'ok' solutions... powering the MKE600 via it's internal battery with BMPCC 4K phantom power turned off (quietest solution) or using the SS-1 in-line with MKE600 where the mic still uses it's own power but the SS-1 is powered by BMPCC 4k phantom power (still too noisy).

Either way - BMD needs to determine if they can boost the gain of the XLR (and 3.5mm) internal preamps as an external preamp should not be required to record a decent level. And they should look into the noise that appears to be generated when using phantom power... even at 30% gain levels.
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Re: Pocket 4K - weak preamps?

PostTue Jan 15, 2019 6:31 am

And since they copped such a lot of crap for it last time, why do it again.

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Re: Pocket 4K - weak preamps?

PostSat Jan 19, 2019 10:39 pm

I agree with the assumption that the designers of the BMPCC4K assumed with such an incredible price point, that the majority using it for either Indie or Broll would not use the mics at all, or if anything as a syncing track to the external audio. With Timecode capability and that you can get good audio recorders or a separate TC generator for not too much more, I would agree that the design was centered around video quality, (especially given that they were working on BRAW the whole time this camera was being built and knew it would be part of it eventually).

That said, probably would have been better to not add the mini XLR and just leave a basic 1/8" input. I would have rather have seen an SDI input over HDMI if that were possible and no XLR. Just my thoughts. I picked up an SD mixpre 10T with intentions of using external audio and TC input so I am not worried about the audio problems personally. But I do wish it worked for those that want it.
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Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 12:29 am

Yah, def with HDMI. Only thing I dislike is the worry of HDMI being yanked and possibly breaking the plug in the camera. On the other hand, SDI with locking might end up with the camera itself flying and landing/breaking.. so who knows whats better. I go back and forth on using HDMI clamp.. if someone trips and pulls it out, I lose a little footage.. but if its clamped in.. my whole rig could get knocked over and cause untold damage to it, and possibly injure someone too. I am starting to learn towards the idea.. and I tried this but had varying degree of success.. a small 6 inch HDMI cord with female end that is then plugged in to.. and that cord is clamped in place... but if anyone trips/pulls, the main cord plugged in to it could be pulled out, so that hopefully the rig is not pulled with it AND it protects/saves the HDMI plug of the camera. I DID this exact thing for my other setup (to my Atomos Inferno) and it worked for a bit, but then I started having odd video connection issues, wiggling the small cord seemed to be the problem so when I took it out of the equation, everything was fine again.

Really wish we could find some really high quality cables that were durable. I would pay a LOT more money to buy a couple of those that would last a long time and work well. Seems only thing you can find is cheap cables that may or may not work.
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Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 2:04 am

Zigen 4K high bandwidth cables come I; round and flat, are very flexible, and holdup. Additionally, the HDMI connector locks in for a secure fit. They are available from B&H.
Cheers
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Peter J. DeCrescenzo

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Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 8:35 am

I'm testing a relatively inexpensive Tascam DR-10X (which I've had for awhile) with my new Pocket 4K. Seems to work well as a mic pre-amp for the cam. And obviously it can also be used as a standalone audio recorder.
https://www.bhphotovideo.com/c/product/ ... inear.html

The DR-10X is extremely small & lightweight, can be powered by an internal AAA battery or externally via USB, has a full-size XLR input, flexible features, and nice sound quality. As the unit does not output XLR phantom power, the audio source must be self-powered. (I'm using it with a Sennheiser ME-64 w its power module). Connects to the Pocket via a 1/8" (3.5mm) mini TRS cable, or an appropriate mini-XLR-to-3.5mm-TRS adapter cable.

IMHO the downside of the DR-10X is its tiny tiny buttons which are colored black on black (!), making them difficult to see. But once the unit is configured, and especially if powered via USB, it can operate for many many hours (as a preamp) without fuss.

I use a IndiPro D-tap to USB power adapter when not powering the DR-10X via an internal AAA battery:
https://www.bhphotovideo.com/c/product/ ... to_5v.html

I made the following (boring!) video with the soundtrack recorded using the above hardware. Listen to the soundtrack and refer to the Vimeo page for details. ProRes LT 1080p "film" recording was edited in DR15.2, but the soundtrack is unchanged from the original recording (no audio adjustments were made in DR15.2).
Last edited by Peter J. DeCrescenzo on Mon Jan 21, 2019 2:44 am, edited 4 times in total.
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Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 6:33 pm

Al Slamecka wrote:The SS-1 is an 'pre' preamp device that sits inline between a dynamic mic and a device's preamp. It's powered by 48v phantom power coming from the device (BMPCC 4K in this instance) and provides +27dBu gain boost to the mic's signal.

Thanks for this tip. A very useful little bit of kit.
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Re: Pocket 4K - weak preamps?

PostMon Jan 21, 2019 3:14 am

Hi. If BM could make the camera activate and control wireless and USB interface audio recording devices (through normal standards, even if any audio over WiFi, through USB dongle or card, exists). Leaving our strong 7Gb/s WiFi I feel is a mistake. But external control of USB devices would be a great Quality enhancement.

It also means pickup and internal camera recording if sound from the device might be possible.
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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 4:42 pm

Peter J. DeCrescenzo wrote:I'm testing a relatively inexpensive Tascam DR-10X (which I've had for awhile) with my new Pocket 4K. Seems to work well as a mic pre-amp for the cam. And obviously it can also be used as a standalone audio recorder.
https://www.bhphotovideo.com/c/product/ ... inear.html

The DR-10X is extremely small & lightweight, can be powered by an internal AAA battery or externally via USB, has a full-size XLR input, flexible features, and nice sound quality. As the unit does not output XLR phantom power, the audio source must be self-powered. (I'm using it with a Sennheiser ME-64 w its power module). Connects to the Pocket via a 1/8" (3.5mm) mini TRS cable, or an appropriate mini-XLR-to-3.5mm-TRS adapter cable.

IMHO the downside of the DR-10X is its tiny tiny buttons which are colored black on black (!), making them difficult to see. But once the unit is configured, and especially if powered via USB, it can operate for many many hours (as a preamp) without fuss.

I use a IndiPro D-tap to USB power adapter when not powering the DR-10X via an internal AAA battery:
https://www.bhphotovideo.com/c/product/ ... to_5v.html

I made the following (boring!) video with the soundtrack recorded using the above hardware. Listen to the soundtrack and refer to the Vimeo page for details. ProRes LT 1080p "film" recording was edited in DR15.2, but the soundtrack is unchanged from the original recording (no audio adjustments were made in DR15.2).


Following on Peter's post.

I wonder how well this Tascam DR-10L with 3.5 mm plug (Digital Audio Recorder with Lavalier Mic (Black)) would work with a Rode VideoMicro plugged in, using Peter's work flow.

https://www.bhphotovideo.com/c/product/ ... order.html
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Peter J. DeCrescenzo

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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:22 pm

I haven’t used a Tascam DR-10L, but it appears to be very similar to the DR-10X I demonstrate above. My guess is it probably works equally well with the Pocket 4K cam’s mini TRS audio input.

Two points: 1/8” (3.5mm) TRS connectors aren’t very reliable and tend to cause static/crackle when moved or bumped. Also, the cable lengths are best kept short; typically 3’-6’ or less.

The purpose of my test above was just to hear what my DR-10X sounds like via the Pocket 4K 3.5mm input. I’m far more likely to use the cam’s mini-XLR input, subject to further testing. (My adapter cable arrives later today.)
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Leon Benzakein

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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:32 pm

Ray,
I could not use the Youtube link posted.
I did find the unboxing video for this product.

I am not sure how one would use this in a camera application since it seems to be app driven and has a USB-C input.
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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:36 pm

Peter,

Looking forward to your future test.
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Robert Niessner

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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 9:04 pm

I'd like to add to this discussion that I'm using a Sennheiser EW100 G3 receiver set to output +12dB and going into the 3.5mm input I get very usable interview audio even with the camera gain set to 50%.
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Robert Niessner

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Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 10:26 pm

Well, most of the time I'm a single operator too - doing the lighting, camera, and audio. Either it is a lav mounted to the interviewee or a journalist holding a reporter mic close to the interviewee.
Saying "Thx for help!" is not a crime.
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Leon Benzakein

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Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 12:54 am

Australian Image wrote:I never know why some links work and other don't.


I have had the same experience lately.

I have found that if you right click on the Youtube video, a menu comes up, the top item is COPY VIDEO URL, you left click on that to select, then you go to where you want to insert the link, right click to bring up the menu and then paste.(or ctrl V where you place the cursor)

That has solved the issue for me.
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Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:07 am

The best solution to bypass the new Pocket’s “weak” preamps, is to use a proper small mic preamp, like a Sound Devices MixPreD which has a proper impedance 3.5mm TRS connection to the camera to feed a mic/line level level stereo input, or the new MixPre3 which will also record the audio as well. Used MixPreDs are available at reasonable prices. The. IxPre3/6 has a line level unbalanced out, while the MixPreD has a specific camera Mic 3.5 output, which works with most cameras that do not have the Mic/Line option.
Cheers
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Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:37 am

After using the Pocket 4k as my main camera for the last few months (got mine mid Nov) I have changed my tune about the preamps.

When using a Sennheiser wireless handheld mic (and sennheiser wireless lavs) into the 3.5mm I generally set the output gain on the wireless pack to +6db or +12db and I'm able to set my in camera level to around 50%-60%.
When plugging into the mini xlr I can set the gain on the rx unit to +0db with the same 50-60% in camera.

When using a rode NTG-2 into the mini xlr I have the in camera level around 85%-90%.

So YES you do have to run it a bit high, BUT it has sounded really good in each scenario. The noise floor seems to be really low even when turned up to 100% in camera, and if I boost it up even higher in premiere it still sounds clean.

I always try to record my audio at -12 anyway and boost in my NLE rather than risk clipping if my talent gets too loud. So for me after a few months of real world use I can say that the preamps have done their job and haven't given me any issues.

I will say that it would be nice to have an auto gain feature that I could turn on when shooting things like sporting events that can get very loud very quickly. It's really easy to clip your audio when things get crazy, and if you set it low enough than you'll be missing things in the quiet moments.
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Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:39 pm

Hi,
jumping in on that audio level discussion:
my plan is to use the Saramonic UwMic9 lavs and XLR TX with NTG3 in a boom...
bringing the dual-receiver RX straight into the 3.5mm jacks of bmpcc4k

anyone has those?
will the levels be sufficient?

thx
Mike
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Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 4:29 pm

Australian Image wrote:or start considering an alternative device.


Ray

With all the energy that you have put into this(I feel your pain) why do you not look at a Rode Video Mic Pro.

https://www.bhphotovideo.com/c/product/ ... tml?sts=pi
Television: Lighting/Cameraman, O.B. Camera Operator, Experience in EFP, EPG and ENG , Grip, Lamp Operator
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Re: Pocket 4K - weak preamps?

PostFri Mar 15, 2019 6:22 am

I received my BMPCC4k the other day, and after putting a cage on it and testing it with my Rode Video Mic Pro, I also feel that the preamp levels are absurdly low on this/my camera.

Rode Videomic Pro (with +20DB switch on) has to be turned up to nearly 100 in camera to get decent audio levels, making it sound awful and noisy. This mic is designed to give a hot signal precisely so that you DON'T have to rely on noisy camera preamps. On my previous Sony and Canon cameras the audio levels would be correct at around 25% or less and the audio much cleaner as a result.

The on camera mics, when turned up to 100%, only go to yellow when I click my fingers loudly point blank in front of them.

I can't help but feel this cannot be working as intended. It may just be selected units, as other people in this thread have had varying opinions. I'm not interested in buying a separate pre-amp, as that is why I bought the Videomic Pro in the first place. For all intents and purposes it has a preamp built in. I have ordered the mini XLR cable and will be testing this shortly.

May I ask if anyone has had any luck talking to support about this yet?
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Re: Pocket 4K - weak preamps?

PostFri Mar 15, 2019 11:53 pm

For me, the last two firmware updates have largely resolved the issue.

When weak preamplification of microphones is a problem, I would first check whether your BM Pocket 4K has been updated to Firmware version 6.1 or higher.
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Re: Pocket 4K - weak preamps?

PostSat Mar 16, 2019 2:11 am

@australianimage I have read all your posts about your solutions, very creative! But I do not want to invest in more gear which I have to carry around, mount and power just to make the audio at an acceptable level, this seems to me like an unintended fault.

@Johan Cramer
I am on 6.2 firmware. I honestly think it must differ between different people's cameras. People like Australian Image, me and a couple of others appear to have extra quiet cameras. A friend of mine is getting his camera soon and I will be able to test whether his has higher levels with the same setup. Obviously more testing and proof is required and I will endeavour to provide this in the hopes of a solution.
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Re: Pocket 4K - weak preamps?

PostFri Mar 22, 2019 2:11 am

I'm glad I found this thread as I'm having the same issue running a Rode VMP.
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Components Defects

PostSat Mar 23, 2019 12:59 am

What audio chip do they use? If it is a computer audio chip, the industry is known for shipping low quality chips, particularly seconds, but even high quality they might ship 0.1 percent defect free. Meaning one in a thousand might be defective.

I'm all for setting up automated testing 'rigs' to test and log everything. Place, walk away, come back, read results. Of course, you really want to test the components before assembly, but that gets a bit fiddly.

Saw some amusing stuff the other day comparison between Alexa and Red, Alexa just worked, Red may or may not just work from camera to camera. Some cameras might be fine, some cameras might get random shutdowns etc issues (like stop working). Linus tech tips on YouTube (about 1/4 million didn't getting their Red 8k system) has an YouTube clip on it. Years ago when I heard Red One owners being charge $7k for a new board after their 30 or 90 day warranty expired (not enough for marginal defective components to all brwak down), I gave up wanting to buy a Red One. The defect rate might be 1 cent per component but you pay for a $7000 board exchange, no thanks.

So, looking at those things above, BM cameras seem pretty reliable. It only takes one component out of hundreds in there to produce issues, so it indicates to me there is a low rate of component problems otherwise everything would be a very lot worse with most users have many issues, but they are not. Just one in a hundred defect rate in each component would be at least one defect in each camera. So, defect rates in cameras as a whole (going past the sensor coating) maybe 1 in a thousand or more. Which is good.
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Re: Pocket 4K - weak preamps?

PostSat Mar 23, 2019 2:20 am

pnguyen720 wrote:I'm glad I found this thread as I'm having the same issue running a Rode VMP.


Thank you for replying. The more people who share their experience the more chance something can be done about it. It seems like this is not uncommon and I think as more people get their cameras we will hear about it more.
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Re: Pocket 4K - weak preamps?

PostSat Mar 23, 2019 4:31 am

Hi Ray,
Just to be clear, do you have your Rode plugged into that eBay recorder and you synch in post?
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Re: Pocket 4K - weak preamps?

PostThu Apr 04, 2019 3:58 pm

Australian Image wrote:I posted this in another related thread, but to inform as widely as possible, here is my inexpensive and effective solution to all the audio issues with the BMPCC4K: https://australianimage.com.au/blackmag ... -4k-pt-10/. The video at the end shows how it works.


Hi Ray,
Just circling back.. are you just plugging into your audio recorder for sound now or are you still using the Pocket's 3.5mm input?
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Solution for weak audio levels

PostMon Jun 17, 2019 1:56 am

Hey all, Just FYI, my BMPCC 4K had similar issues with low audio-levels, using mics that have worked fine on many other cameras for years. I found a fix. It's the Dynamite, +28db inline preamp. It's about $99, and just uses the on-board Phantom Power to give you a nice, clean, noise-free boost. Here's a video, with link in the description. Hope this helps you all.

https://www. youtube.com/watch?v=mU7uHTCwnjw
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Re: Pocket 4K - weak preamps?

PostFri Jun 21, 2019 4:55 am

Read some of this a long while back, but is the gist of this that battery powered mics will work OK on the 3.5mm, but non powered will not? I bought a cheap but semi well reviewed mic just to have a slightly better boom option than the built in mics, though they actually do record pretty decent sound.
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Re: Pocket 4K - weak preamps?

PostFri Jun 21, 2019 9:34 pm

why do you wanna use the internal audio recorder?
why not using external?
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