Wisycom MTP41s outputting distorted/clippy sound

[Tinu]

Hi JWsoundgroup

 

A freelancer of ours recently had a gig recording a panel discussion with 4 people. MCR54 with betso bowties into 833, 2x MTP40s and 2xMTP41s operating in the 650mHz range.

One of the transmitters started sounding worse over time. At first, there was slight saturation when talent got loud, after an hour, the signal was all but unusable. Bodypack was mounted

on pants at the back, talent wasn't sweaty and the antenna didn't touch the skin directly. MCR54 showed good reception throughout the entire ordeal. After the shoot, said freelancer

replaced the mic to see if the mic was faulty. But he got the same distorty sound on the other lav as well. The next day, he let the transmitter run for an hour, but it sounded fine.

 

Setting on the MTP41s was 2wires+bias, gain set the same for the entire shoot.

So... any ideas what might be wrong here? I cut out some files from the recording..

 

At the beginning after 20mins:

After 40 mins:

After 50 mins:

 

After 60 mins:

 

 

I suspect the battery being bad and influencing the bias power on the transmitter. I'll test thoroughly, but i'm wondering if i should have the TX checked by Wisycom. 

 

I'd love to hear some veteran's opinion on this, maybe you instantly recognize the sound.

 

Best and happy recording

Martin 

 

 

 

[VASI]

There was something in the room, like induction kitchen technology where the wireless does not like it. Happened to me with a shaver machine when was on. If the transmitter and lavaliers in next day was fine, then this not the problem. 

[Tinu]

So to anyone interested - figured it out. It was the line input on my 833 which was defective.... Jeez.

 

Picture on the left: 1k -20dB sin into channel 6

Right: into channel 5

 

Not cool, especially since i had the unit serviced already for the exact same occurrence on CH1.

[Peter Mega]

This exact same problem happened to a friend of mine with his 833 on channel 5 IIRC. 

 

This has not occurred with my Scorpio on any input and I’ve used them all on long days. 
 

Seems to be an 833 thing after the machine warms up. 
 

Sorry to hear about your problem but at least you know what it is now.

 

Good luck 

[filmsalang]

SD QC is not good, old days were fantastic, Sorry. 

[Tinu]

8 hours ago, Peter Mega said:

This exact same problem happened to a friend of mine with his 833 on channel 5 IIRC. 

 

This has not occurred with my Scorpio on any input and I’ve used them all on long days. 
 

Seems to be an 833 thing after the machine warms up. 
 

Sorry to hear about your problem but at least you know what it is now.

 

Good luck 

 

Hi Peter! Wow.. so this seems to be a recurring issue then huh?

 

Did he get it serviced, or what happened in his situation?

I wonder if the 833 just has a worse construction than the 633. Might have

to downgrade if this happens one more time..

 

Best, Martin

[VASI]

12 hours ago, Tinu said:

So to anyone interested - figured it out. It was the line input on my 833 which was defective.... Jeez.

 

Picture on the left: 1k -20dB sin into channel 6

Right: into channel 5

 

Not cool, especially since i had the unit serviced already for the exact same occurrence on CH1.

 

Wow

[filmsalang]

1 hour ago, VASI said:

 

Wow

 

14 hours ago, Tinu said:

So to anyone interested - figured it out. It was the line input on my 833 which was defective.... Jeez.

 

Picture on the left: 1k -20dB sin into channel 6

Right: into channel 5

 

Not cool, especially since i had the unit serviced already for the exact same occurrence on CH1.

Just wondering what SD said when you got serviced before? They mentioned anything about the issue and how they fixed? 

 

[Tinu]

53 minutes ago, filmsalang said:

Just wondering what SD said when you got serviced before? They mentioned anything about the issue and how they fixed? 

 

I didn't get any info on this and i didn't ask, it just worked after testing input 1 thoroughly. But this time, i certainly will ask. 

Probably it's somekind of capacitor/resistor that was bad. Or at least that's what i suspect while being a total electronics n00b.

 

11 hours ago, Peter Mega said:

This exact same problem happened to a friend of mine with his 833 on channel 5 IIRC. 

 

 

 

It'd be interesting what Peter's friend's experience was. Any info on this? Did they tell him what was wrong with the recorder?

 

 

[Peter Mega]

So I have to apologize first of all. My bad memory! It wasn’t my friends 833 with this same problem, it was his Scorpio on one of the TA5 inputs. 
 

Same issue though, distortion after a while. 
 

He hasn’t had it fixed yet so no info regarding repair. 
 

Confirming my Scorpio does not display this problem. 
 

Sorry for the confusion. 
Regards 

[Peter Mega]

What revision firmware are you running in your 833? 
 

8.91 caused an issue with analog inputs 5 and 6 in some 833’s. Not sure what the issue was exactly. 
 

8.92 fixed the problem. 
 

Regards 

 

[iasonas]

I have exactly the same problem on my brand new 888,  same channel input !

Unfortunately it wasn't a Firmware issue .

After a communication with   SD, they asked me to send the device for 

repair plus I have to pay for the shipping costs for a device that is being used  just for a couple of  months until I realize the problem. 

Totally unfair, unpleasant  and  frustrating .

 

Still on the way for repair.

And now I am relying again on my old like a dinosaur, but still trusty backup 633.