Serious defect in A7s XLR adapter - XLR-K2M

Redstreak

Redstreak

Active member
I've discovered a serious defect in the XLR-K2M adapter which you use to record XLR mics with an A7s. When I set the adapter to record from both XLR inputs simultaneously, each input "bleeds" into the other. A faint (but audible) distorted version of each channel is recorded in the other channel. This happens whether or not a mic is plugged into the second input, as long as the adapter is set to record both inputs.

I have confirmed that this issue is present in several different XLR-K2M adapters. I'm not sure whether this is an issue with a limited run of them or with all of them. If you have an XLR-K2M, could you check if this problem appears and post below? I'd definitely also like to know if your unit is free of this problem. Maybe it's actually a defect with the A7s instead of the XLR-K2M? I'm not sure.

The simplest way is to connect a single XLR mic to either input and then set the the adapter to record both inputs. If your adapter works correctly, you should hear the mic in one channel, and you should get total silence in the other channel. If it is faulty, you should hear a faint, distorted version of the first channel in the second channel.

Here's an example. In this clip I start out in the "single input mode" and then switch two inputs.
https://www.youtube.com/watch?v=9z0MYblm1NA

Note: Sony sells two different XLR hotshoe adapters. I have only tested the XLR-K2M, the newer one.
Note: The problem only appears when the adapter is set to record both inputs. If you set the adapter to record only one input to both channels, it gets recorded correctly.

Thanks,
- David Kong
 
I have the k2m. I haven't noticed any bleed from one channel to the other.

One quirk I've noticed is a very subtle low end hiss when recording, however when playing back I don't hear it. Still stresses me out.
 
I have the K1M and can confirm it has a low end buzz and hiss. I thought it was an issue with the unit, and then the A7S itself, but then heard from Matt Allard at NewsShooter that his exhibits the same issue. I think they're just badly made (but overpriced) half-useless adapters.

I'd like to try a beachtek or other adapter to see if I could get better sound. For some reason when I recorded to the Shogun running sound from Sound Devices 633 to K1M and the HDMI to Shogun, I did not hear the issue.

Running a Lectrosonics 411 receiver got a bad buzz. Running the same receiver direct (at mic level) with an XLR to 1/8" sounded great however.

Another Twitter user suggested only running source audio at mic level, using -10db attenuation and never raising audio past 5 on dial- I've yet to try this.
 
Sounds like a $35/$70 solution: 1 or 2 iRig Pres might work better: http://filmkit.net/posts/show/4589/tutorial-use-the-irig-pre-as-a-dslr-preamp
At Sony's price point, I'd pay the extra $300 and go with a Sound Devices MixPre-D (~$900). Even Sennheiser G3's sound pretty good into the A7S. After using Sound Devices level gear, it's hard to use anything lower quality (it's not that expensive for Pro level gear). Surprised to hear a $600 audio component from Sony has these issues- Sony usually provides very good audio quality for the price.
 
David did you ever solve this issue?

i had the same issue today. Had a feed from a mixing desk and the shotgun mic plugged in at an event. If I turned the shogun down I could hear distorted sound leaking into the that channel from the feed from the desk.

The same issue was showing up later in the day when I was using a radio mic. Very annoying.
 
I have two XLR-K2M units. They both display substantial buzz/hiss self-noise, particularly on my A7R II. Used on an FS7 to create tracks 3/4, the noise level is less prominent, but still very present. This noise is present and unchanged whether or not anything is plugged-in or an input is activated. It comes from the units themselves on both tracks.

I had actually put one aside, thinking that it was faulty. But when I pulled it out to send to Sony for repair I tested both units and realized that they both display the identical problem.

Has anyone contacted Sony about this issue?
 
I almost pulled the trigger on one of these to replace my Tascam recorder but I guess I'll pass. I take a signal from the Tascam in to the A7Sii mini jack but hiss on the camera recorded audio is not pleasant. For that reason I use the Tascom recorded audio and sync in post.
 
Tested it, wasn't completely happy with the audio and sent it back. I'll stick with the Zoom H6 and syncing in post even though it means an extra step and less convenience.
 
I know this thread is long dead and gone but sometimes an update is worth noting. I have 2 x Sony XLRK1M audio adapters and 1 XLRK2M adapter. For 2 years the K1M's worked nicely, but then they started to get noisier and noisier as if the pre-amps were slowly eroding. So frustrating. The K2M so far sounds okay but a little piece of the plastic near the hot shoe chipped off so it doesn't work anymore. I'll be sending it in for repair. As for the K1Ms...they might be getting the boot real soon. Can't deal with the unnecessary noise in both ports. Port 2 seems more noisy than input 1 but they both aren't great anymore. Maybe they need cleaning, I don't know. They've been through close to 100 weddings. I'd get 2 K2M's but I hate how they took away the cold shoe adapter on the top. So annoying! Why did Sony do this?! Time to rethink how we capture audio. I mean we do still record audio separately but I like also having it sync'd to my cameras. Oh, and as for the OP about sound bleeding...yes, we've experienced that on occasion. Usually a sudden loud pop will be heard on both tracks. You can see it on the waveform and it's annoying that it affects both inputs.

Just thought I'd update because updates are helpful for those looking to purchase. Again, these 2 K1M's have got a lot of use but its sad to see them fading. Outside of the heat elements here in SoCal they've been well taken care of.
 
I saw someone's comment: If noise from the unused jack bothers you, set the INPUT1/INPUT2 (LINE/MIC/MIC+48V) switch of the unused jack to LINE."
Looking to buy one of these soon, can anyone confirm they are still a POS?
 
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