Pocket 4K - weak preamps?

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John Paines

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Re: Pocket 4K - weak preamps?

PostThu Nov 08, 2018 6:18 pm

Denny, for gawd sake -- nobody said he/she intended to use the 3.5mm jack as a sole or primary recording device. Some of us tested the input, as one would with any new camera, and came up with the results here.

That's all. A feature advertised to work doesn't. That's not decisive for me personally, but whether it is or not is beside the point. I'd like to see the audio at mic levels working, as would others.
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Denny Smith

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Re: Pocket 4K - weak preamps?

PostThu Nov 08, 2018 6:25 pm

OK, it kind of sounded like that was, what the fuss was all about. :roll:
The unbalanced (3.5mm) mic preamp inputs on BM cameras has never been very good. The Line level works fine however for feeding an external mixer. This is true of the original Pocket camera, and the Micro cameras. Yes, they had a “working” level, and a boosted mic like the BideoMicPro did work OK.
Point taken, that the new PC4K has a worse unbalanced mic preamp input on the 3.5mm jack.

Have fun with your new camera!
Cheers
Last edited by Denny Smith on Fri Nov 09, 2018 1:27 am, edited 1 time in total.
Denny Smith
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Justin Jackson

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Re: Pocket 4K - weak preamps?

PostThu Nov 08, 2018 7:03 pm

Hmm.. maybe its good my camera wont be in my hands for 2 more months.. hopefully they figure this out and fix it, possibly with recall for those already owning.

One post said that BM indicated a possible fix with a firmware update down the road, attenuating input by 6db. I am no expert.. but if they attenuate the input, could that cause distortion in the audio vs if there is a real problem with the input circuit replacing/fixing it? I would be a bit disappointed if the firmware simply increases input gain that results in crappier recorded sound.

To Denny's point though, I would typically assume anyone using this camera (or at least most people) would either record externally and use audio as a sync track in post, or use the XLR input only. When I first read of the 3.5mm being a two way in/out, I was curious why they even bothered. Heck, would have been better to just put two mini XLRs for stereo input.

Before anyone slams me for those wanting to use the audio in because it is advertised as high quality audio.. I suspect (or at least read it as) the XLR is high quality, didnt really assume the 3.5mm was high quality. Again I question why not 2 XLR minis for audio in this case..but its done now. I would always feel like the 3.5mm is purely for an audio sync track. But I can see how the lure of this cameras size and video quality would have some wanting an easy 3.5mm mic input to work well, so I would agree that if it is indeed either a software issue (firmware fix) or hardware issue (recall/fix) BM should (and they are apparently) resolve it.

As for those saying BM is not responding is deafening.. I actually have seldom see anyone from BM reply in these forums. I have seen more regarding Resolve/Fusion respond, but the couple dozen threads around hardware I have been part of or read, I havent really noticed any response. Does irk me sometimes.. like why there is apparently no way to tell us how long the wait is to get our camera, etc.
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joe12south

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Re: Pocket 4K - weak preamps?

PostThu Nov 08, 2018 7:43 pm

I appreciate the spirit of looking for solutions, but I think it is wrong-headed to proliferate the idea that XLR = quality/professional and 3.5mm = inferior. There is no technical reason one connector must perform better than the other, outside of the obvious benefits of a balanced connector for long runs, etc.

It's also wrong to suggest that the XLR input on the P4K doesn't suffer from the same weak pre-amp as the 3.5mm jack, because it does.

The problem is real. The workaround is to use an external amp or particularly "hot" microphone. Which jack is utilized is something of a red herring.
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Robert Niessner

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Re: Pocket 4K - weak preamps?

PostThu Nov 08, 2018 10:36 pm

Yesterday I was filming with the Sennheiser G3 receiver plugged into the mini-XLR. That is a real pita, because you have the 50 cm 3.5 mini to XLR cable from the receiver, then the 50 cm XLR to Mini-XLR adapter cable dangling around your camera. And I don't see the quality benefit in up-converting the 3.5mm output into XLR, XLR and mini-XLR instead of just going 3.5 to 3.5 mm with small footprint.
Robert Niessner
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Chris Frechette

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 2:22 am

This is really unfortunate. I haven’t had time to do much with my camera yet, but had to test out the 3.5mm after seeing this thread. Tried a Rode VideoMicro, Rode Videomic Pro and an Audio Technica 2.4ghz wireless lav. Pretty much unusable as a mic input at the moment. Hopefully it can be improved in a firmware update.
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John Butler

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 3:59 am

HMMMMM. I can deal with intermittent touch screen functionality, poor battery life, buggy media recognition & faulty battery doors, but this preamp issue is a deal breaker. Looks to be the reason I'm opting out of purchasing a BMPCC4K. I hope it gets sorted/fixed for everyone that owns a BMPCC4K. :(
Digital killed the video star
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Ian Henderson

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 4:31 am

I’ve just never understood manufacturers putting poor quality audio stages in cameras.

I mean - SURELY an extra $100 spent on preamps and DACs would have dramatic impact on component quality and minuscule impact on purchase price. Maybe my needs are special but I’d happily pay several times that for it.

I would give my back teeth for top quality audio on my UMP for use in a doc setting and this news about the Pocket 4K is pretty disappointing for those of us still waiting for one and wanting to use it as a lightweight, small second camera (with audio) in that context.
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Jcorbz

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 11:30 am

Robert Niessner wrote:Yesterday I was filming with the Sennheiser G3 receiver plugged into the mini-XLR. That is a real pita, because you have the 50 cm 3.5 mini to XLR cable from the receiver, then the 50 cm XLR to Mini-XLR adapter cable dangling around your camera. And I don't see the quality benefit in up-converting the 3.5mm output into XLR, XLR and mini-XLR instead of just going 3.5 to 3.5 mm with small footprint.


I soldered a new cable for this - locking 3.5mm to mini xlr. No real difference in size between the 3.5mm cable and so much better than having adapters dangling around.
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Robert Niessner

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 12:09 pm

Jcorbz wrote:I soldered a new cable for this - locking 3.5mm to mini xlr. No real difference in size between the 3.5mm cable and so much better than having adapters dangling around.


Yeah, I am planning to do that too.
Robert Niessner
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Justin Jackson

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Re: Pocket 4K - weak preamps?

PostFri Nov 09, 2018 6:01 pm

Can you put a picture of that here.. would like to see what you mean and what it looks like.. the cable ends connected, apart, etc. I think I get what you are saying but not 100% sure.

I agree that the camera should not have such severe attenuation issues on the 3.5 and especially not the mini-XLR.

Me personally I plan to use external audio.. which is why I bought the Mixpre 10T, and feed the XLR mini out from that to the XLR mini in on the camera to provide a sync track (though I think timecode will be better.. never used it so not sure yet).

Would definitely be nice if a firmware update can fix this issue though. I can see the lure of just run-n-gun with the camera, lens and a small shotgun mic on top.
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Benjamin de Menil

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Re: Pocket 4K - weak preamps?

PostSat Nov 10, 2018 11:44 pm

Sorry to hear about the crappy audio. I guess I'll be hanging on to my Bolex D16
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