Sony WM-D6C and Mic Issue

T

tobeythorn

New member
Hi,
I'm new to recording and trying to figure things out for a film project for which I will need to record audio for dialog between two actors using lavaliere mics, but am stuck on a few points. Your help is greatly appreciated because I haven't been able to find the answers by experiment or online searches.

I have a Sony WM-D6C tape recorder that I recently bought on eBay, and a new TDK MA90 tape fresh out of the original seal for recording. I also used 90% rubbing alcohol and a cotton swab to wipe off the head and roller, just to make sure they are clean. On the recorder, the tape type selector is set to metal, noise reduction is set to off, and the recording level dial is set in the middle, as is the headphone output level slider. FYI, to test playback, I also found a NIN album on cassette at Goodwill, which plays back great through the WM-D6C, albeit, there is a bit of noise, but that might just be the degradation of the tape.

When I try to recording using a cheap unpowered lavaliere mic from RadioShack plugged into the mic input:
-If attenuation is set to 0.0db, I get nothing but a loud pulsing sound like "thud thud thud thud thud..."
-Switching to 20.0db on the attenuation, and I get decent sound, but the level's seem too low unless the mic is right in front of my mouth. I've used this mic for Skype on my computer and I don't need to hold it so close then.
-There seems to be a lot of noise. A kind of steady fuzzy "eeeeeeeeee" sound.

I just bought some eletret condenser lavaliere mics for my film project(Pearstone OLM-10 purchased from B&H).
Unlike the lavaliere from RadioShack, they are powered by a button battery. When I plug one of those into the mic input and record:
-The signal is VERY weak, even when I turn the recording level dial all the way up and I have to speak loudly right into the mic. And yes, the power switch on the mic is in the on position and the batteries are fresh.

So what am I missing here? Why are the levels so low, especially on the powered lavaliere mics, and why the weird pulsing on the other mic? The amount of noise seems suspiciously high as well.

Again,
Thank you for your insights,

-Tobey
 
I used to own one of these recorders back in the early 80's when they were available new. I used mine for recording folly effects for an album project and found it to be a pretty decent recorder.

A couple of things to take note of.

The 20db switch position is an attenuator, not a booster. So it should only be in that position if you are recording very loud events such as concerts and jack-hammer festivals. :D

The stereo 1/8th inch TRS plug has built in proprietary phantom power for a select few Sony microphones which could make use of that. So you may get odd results going with any third party mics that are not specifically designed to work with that.

As far as I know, Sony still makes a few stereo point source mics that can work on this recorder and I'd recommend you try one of those out before making a judgment that the recorder is at fault. There is also a stereo TRS 1/8th inch Line In connection on the back which you might want to try with a portable CD player or similar source to see if that can produce a clean recording with healthy levels.

Also about the recording level control. It's adjustable and the unit has a level meter. So don't just put that control in the middle and hope for the best. Adjust it to get proper levels and keep the mic att switch at the 0db setting.

About the weird pulsing/throbbing sound you got, I don't know what that could be other then a really bad mic mismatch or short circuit of some sort...maybe the jack not plugged in all the way?

One more thing. The unit offers Dolby C noise reduction which will offer close to 20db of noise reduction of that hiss you were mentioning. Use it!

Cheers! :)
 
Thanks for your reply Ghost of FM,

I tried recording music from my computer's headphone out through the line-in on the WM-D6C. The sound is rich and I can get the levels right where they need to be with the recording level dial. There is a little bit of soft "sssssss". but it not bad. Both Dolby B and C noise reduction cuts out the "ssss" but to me, makes the music sound muddy and kills the nuances of the sound when I play back, so I'd rather leave it off. For some reason sometimes while I adjust the recording level dial, I get a some static, which stops as soon as I stop turning the dial. And yeah, I was adjusting the recording level dial before but it should not have to be maxed out nor should the headphone volume or I'm missing a lot of range, and I was still getting weak sound from the mics when it was.

I looked into Sony lavalieres with plug-in power. Sony as a cheap lavaliere (model ECM-CS10) with plug-in power, but its bulky and silver. I need something tiny that can be hidden, like the Pearstone lavalieres I bought. The much more expensive Sony ECM-55B does not appear to be plug-in power. Do you know of any other mics that would work?
 
Ah, the D6. What fond memories. You do know that Dolby NR is meant to be used during record as well as playback? Just checking.

Dolby NR worked great when the recorder was properly adjusted, but it tends to track poorly and kill the HF if there's something wrong with the deck. And in the world of cassettes there's almost always something wrong so most people end up blaming the Dolby when it was really their deck.
 
tobeythorn said:
Thanks for your reply Ghost of FM,

I tried recording music from my computer's headphone out through the line-in on the WM-D6C. The sound is rich and I can get the levels right where they need to be with the recording level dial. There is a little bit of soft "sssssss". but it not bad. Both Dolby B and C noise reduction cuts out the "ssss" but to me, makes the music sound muddy and kills the nuances of the sound when I play back, so I'd rather leave it off. For some reason sometimes while I adjust the recording level dial, I get a some static, which stops as soon as I stop turning the dial. And yeah, I was adjusting the recording level dial before but it should not have to be maxed out nor should the headphone volume or I'm missing a lot of range, and I was still getting weak sound from the mics when it was.

I looked into Sony lavalieres with plug-in power. Sony as a cheap lavaliere (model ECM-CS10) with plug-in power, but its bulky and silver. I need something tiny that can be hidden, like the Pearstone lavalieres I bought. The much more expensive Sony ECM-55B does not appear to be plug-in power. Do you know of any other mics that would work?
Click to expand...

A few points on what you just wrote.

1 - The static you heard while adjusting the control is just a dirty/oxidized control. Sometimes rapidly turning it back and forth a few times, (10-20), can clean the junk off the control's contact surface. If its still staticy after that, the control might need to be cleaned with a special contact cleaner fluid called DeoxIT which is available from www.caig.com.

2 - Dolby NR is an encode/decode process. If you want to make use of it, you must record with and play back with in the setting you recorded it with. If you record without and then turn it on, on playback, it will just suck all the high frequencies off the recording.

3 - Going from memory only right now, the Sony stereo point source mics that are compact and do a decent job with that recorder are the ECM-S77 and ECM-S99 which are around $60-$100 depending on market conditions. The "S" in the model number refers to it being stereo and is the only type of microphone that should be used on this recorder. Mono mics will short out one of the channels and possibly damage the recorder. Sorry if that's too much for your budget or whatever but doing the job properly sometimes requires more expensive tools.

4 - Glad to read you tried a recording on the Line In and that it worked decently. This means that you just need to get the correct mic, set the right levels and noise reduction settings and you'll be golden.

Cheers! :)
 
You are a treasure trove of information!

Going to try the recording dial trick tomorrow to see if that gets rid of the static. That makes a lot of sense. Come to think of it, I feel like the static is not as bad as when I first tried the unit.

I could afford $60-100 each for two mics, but I can't find either of those mics anywhere online. They don't seem to exist.

Hope that I didn't damage the mic-in using the wrong mics. The mics I have, although mono, have stereo jacks (same signal to ring and tip). Not sure if that matters. The line-in expects a stronger signal than mic-in right?, but otherwise could also be used with a mic and is a more standard input rather than Sony proprietary plug-in power mic-in? Would it be possible to use some kind of pre-amp with the mics I have if I can't find those Sony "s" mics?
 
An outboard microphone preamp would give you the option to use a much wider variety of mics and hopefully also lower the noise floor if the electronics in the outboard pre-amp are better then what's built into the Sony.

The only drawback to all that is the added bulk of such a set up. Presumably, you got the Sony because of its compactness, right?

Another option might be to look into wireless mic kits where the receiver unit has an unbalanced line output to connect to the Sony's line input. This would probably be the smartest route to take as that will allow you to just wire up your talent and not have to worry about keeping wires out of the shot if video is involved in the production. This would be my choice if I were doing this...though I'd probably be looking for a solid state digital field recorder at this stage of the game. :D Apologies to my analog brethren here.

Cheers! :)
 
I've been so tempted to buy one of these. Does anyone still service them? I'd hate to drop the cash for one and find out it needs some repairs I can't get.
 
leddy said:
I've been so tempted to buy one of these. Does anyone still service them? I'd hate to drop the cash for one and find out it needs some repairs I can't get.
Click to expand...

I'm sure there are still technicians out there working who have experience on this unit. But getting parts might be an issue as Sony normally only made a set quantity of spare parts that was designed to last 5 years on average. So, you might have to buy 2 of them, (hopefully fully healthy), and keep one for parts.

Cheers! :)
 
Turning the recording dial back and forth 10-20 times seems to have ended the static sound when adjusting it. Thanks for the great tip.

Dolby-c definitely does cut out a bit of noise, and engaging it for both recording and playback makes a big difference. I didn't realize that it involved an encoding scheme rather than just a filter. A worthwhile feature for sure.

For a number of reasons, I've made the decision to go with in-ear binaural mics on only one actor for my film project. Was going to make my own and then realized that such a product exists already. The samples I've listened to for the Sound Professionals SP-TFB-2 high sensitivity in-ear mics sounds excellent to me, run off plug-in power, and are affordable. Since these can not be returned after purchase, I want to know for sure that these will work with the WM-D6C. Are all plug-in power jacks the same, or is the one on the WM-D6C proprietary? If not, maybe I'll trade the WM-D6c for a Sony PCM-M10 or Olympus LS-11.

Again, thanks for your help. So glad I found this amazing forum.
 
Glad to hear the staticy record pot cleaned up with a bit of exercise!

About all plug in power schemes being the same, unfortunately, no. They're not. Standard phantom power is 48 volts and I believe the most the Sony can muster is 6 volts but probably closer to 3. Of course, there's no way to know for sure if it will work until you've tried it and some mics which require phantom power do not always require the full 48 volts. It's a crap shoot.

Best of luck.

Cheers! :)
 
Plug-in power is not phantom, it is a fairly standard 3V to 5V DC supply for condenser mics. I don't think you'll damage anything but there's a small chance it won't work. Although it's been many years since I did it I'm sure I connected a stereo condenser mic that had its own battery and didn't use the plug-in power without damaging either the mic or the recorder.
 
I could find virtually no reliable information on "plug-in power" (aka bias) for any device including the WM-D6C, but from what I can tell, all use standard stereo mini-jack, and most work on similar voltage (~3volts) to what the WM-D6C provides. Long story short, I'll be getting a Sound Professionals SP-TFB-2 in the mail soon and am exciting to try them (assuming they really do work).
 
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