MK47 PCB tube mic kit - build thread

[zayance]

are you shure

I use to make the same mistake, fits the discussion tough haha...

 

[kante1603]

are you shure

I use to make the same mistake, fits the discussion tough haha...

Oooooppss....thanx zayance!Too many microphones surrounding me at work

 

[Andy Meyer]

I am stumped!

I have now tried new tubes, cleaned the flux off of the PCB and re-soldered a few connections without any luck.

I don't want to be stuck with this wind sound.  Any new ideas?

Thanks for the help so far.

Andy

 

[0dbfs]

Have you tried replacing the capsule with a capacitor (I don't know, maybe 40pf?) to see if that isolates the source of the sound to capsule or head-amp?

Best,
jb

 

[Andy Meyer]

I put in a 39pf capacitor in place of the capsule and the noise is there.  It looks like an issue somewhere in the head amplifier.

I am using rubber rings as a spacer between the plexiglass plate and the capsule mount.  Could this be contributing to the problem?

Maybe I got another set of bad tubes?

Thanks,
Andy

 

[ioaudio]

Andy,

does the noise disappear in the second after you turn of the PSU before the sound fade`s away?
Is your PSU based on a TL783?

 

[Andy Meyer]

Max,

The wind sound goes out right with the audio.

The PSU is based on a uA723.

Thanks,
Andy

 

[crackerzot]

Now I've got a problem...    :-\  Last night, I started getting this weird noise it seemed to start out of nowhere.  Don't know if it's the mic, the power supply or the cable.  I opened up the mic and poked around and everything looks good.  It HAD been working great.  So I'm a little puzzled.  I've probably got about 35-40 hours on the tubes now...  Any suggestions on what this might be?

http://www.megaupload.com/?d=F97JZE7F

 

[living sounds]

Now I've got a problem...    :-\  Last night, I started getting this weird noise it seemed to start out of nowhere.  Don't know if it's the mic, the power supply or the cable.  I opened up the mic and poked around and everything looks good.  It HAD been working great.  So I'm a little puzzled.  I've probably got about 35-40 hours on the tubes now...  Any suggestions on what this might be?

http://www.megaupload.com/?d=F97JZE7F

No idea about that sound, but how do you get so much bass from that mic? Mine sounds great, but even at close proximity its boxy compared to yours. I'm using the Beez Neez capsule.

 

[crackerzot]

"No idea about the sound", but how do you get so much bass?  Ha ha.  Well.  I'm using a different capsule than you are, for starters.  Thiersch Blue Line M7 (PVC, not mylar).  And you're going to really hate this, but I wasn't even close to the mic.  Well, a foot away, at least.  So, to answer your question, it's the capsule , the basket perhaps, and the magic of my audio chain. 

 

[ioaudio]

maybe a interconnection, something with the wiring/soldering/isolation of the highZ part.
Sometimes mechanical stuff, the grounding/conductivity between housing parts can bring up all kind of wired sounds.

 

[living sounds]

"No idea about the sound", but how do you get so much bass?  Ha ha.  Well.  I'm using a different capsule than you are, for starters.  Thiersch Blue Line M7 (PVC, not mylar).  And you're going to really hate this, but I wasn't even close to the mic.  Well, a foot away, at least.  So, to answer your question, it's the capsule , the basket perhaps, and the magic of my audio chain.  

I don`t think it's the M7, I've got mics with M7's in them that don't sound like that either. I've also got a reskinned M7 on its way to me that I might try in the mic, but highly doubtfull about the impact on the bass. So what was in that chain?

 

[crackerzot]

maybe a interconnection, something with the wiring/soldering/isolation of the highZ part.
Sometimes mechanical stuff, the grounding/conductivity between housing parts can bring up all kind of wired sounds.

Thanks, Max.  Are you talking about the mic or in the P/S?  The real strange thing is that it just started out of nowhere and is intermittent, so it's hard to trace.  Could it be a tube?  I bought some spares.  I suppose I could swap them in and at least eliminate that possibility...  It's the same kind of noise I get when switching the pattern.  ???

 

[0dbfs]

... and the magic of my audio chain. 

Man ! Gotta love that fairy dust

You should hear what he sounds like standing next to you.

Cheers,
Jb

 

[crackerzot]

PM sent about the chain.  But I left out one major element in the listing.  My voice.  Sorry.  Heh.

 

[Andy Meyer]

Could part of my "wind" issue be in the grounding?  If I take off the headbasket and body tube I am left with nothing but buzz.  Is that how it's supposed to be?  Like I said the wind sound is only in cardioid.

Just throwing out questions as I am completely stumped on this.  I am learning a lot though!

-Andy

 

[living sounds]

Thanks! So you actually EQed some low end in? But, yes, your voice is really low, too.

 

[crackerzot]

No EQ.  Some compression, though.  Andy, I recently had my basket and tube off my mic when I was troubleshooting a loose connection with the gent who built my power supply, and as I recall, we did NOT get ground hum when the mic was in that state.  I don't know how you mounted the PCB to your mic frame, but make sure nothing is touching any component on your PCB except on the ground planes on the sides.

 

[ioaudio]

If I take off the headbasket and body tube I am left with nothing but buzz.  Is that how it's supposed to be?

yes that's normal and the bothersome part when troubleshooting a mic - you have to assemble it after each change - or put it in a magnetic shilding box (cheap trick: cash box)

 

[crackerzot]

Just wanted to let you guys know that I solved my noise problem referenced above and it had nothing to do with the Mk47 kit.  That noise was isolated to an old toggle that was used on the P/S to switch the pattern.  Further up in the thread, I asked if it was common to hear a lot of scratchy pop sounds when switching pattern and was told "yes".  Well, that wasn't quite right.  After hitting the switch with contact cleaner and working it back and forth a few dozen times, all I hear now is one 'audio' "click" when switching the pattern and the random noise spikes are now gone.  Hip hip hooray.  ;D