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MD421 broken or not? Dynamic Microphones
Old 4th April 2012
  #1
Gear Nut
 

Thread Starter
MD421 broken or not? *sound samples*

I recently got an MD421-2 off ebay, even though the sticker must have come off because it doesn't say so on the mic. But I guess it's correct since it has no low cut switch of any kind.
Immediately after receiving it I stuck it in front of a guitar amp.
A pretty low-end heavy guitar amp I might add.
Listening back to the track, it seems like the mic is lacking a lot of low end. For some reason it sounds kind of thin.

However, I have no previous experience with MD421's, this is the first time I'm actually using one. So I have no clue what it's supposed to sound like.
Looking at a frequency inspector I see a lot of 100hz but below that it drops off rapidly. At first I thought hmm that's the low cut filter. But then I realized, mine doesn't have one!

Then I started reading about it and found that it's somewhat of a common problem that 421's lose their low end if they start to die.

I am seriously in doubt wether it is defective or not. Because after all, there isn't much below 100Hz on a guitar anyway.

So what do you think. Is that the natural sound of an md421? (strong focus on mid and especially high's?) and is it just me beeing shocked by not hearing my guitar thru that honky sm57? or is there actually a shot of it beeing broken?
Old 4th April 2012
  #2
Lives for gear
 

Quote:
Originally Posted by triple_dre View Post
At first I thought hmm that's the low pass filter. But then I realized, mine doesn't have one!
(I believe you mean high pass filter)

Also, if it's an MD421, it does have a high pass. It's located at the base, near the XLR connection. It should be a 5 position rotary switch that goes from S ('speech', high pass enabled fully) to M ('music', no high pass)
Old 4th April 2012
  #3
member no 666
 
Fletcher's Avatar
There should be a sticker on the mic under where the clip goes in... and there should be a rotary switch at the back of the mic near the output XLR connector [unless its a cream colored one - in which case I'm not sure if it has that rotary switch or not].

If it doesn't have the sticker and the rotary switch... then if very well could be a "Chinese knockoff" microphone. I am pretty sure I heard of those being made / confiscated as well as Shure 57 & 58 knockoffs.

FWIW - I've rarely found 421's to be great for guitar... unless you really love a festival of 3kHz in the sound in which case they're awesome.

Hope this is of some assistance.

Peace
Old 4th April 2012
  #4
Gear Nut
 

Thread Starter
Yes I meant high pass/ low roll off switch or whatever you want to call it.
Not all MD421's have them. And it is a cream-colored one
Old 4th April 2012
  #5
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lasso's Avatar
 

I have two that suffer from the same symptoms: lack low end. Also the filter switch is stuck - in M position but they sure don't sound "m" :D I was told that people has succesfully removed the variable hipass filter and replace with this: Sennheiser XLR-Connector f. MD 421 / 441 - Thomann danske Cyberstore

Supposedly fixed the problem for them. I want to try myself but I'm not good at soldering and you have to look out because the wires from the capsule to the filter are very thin and prone to breaking.
Old 4th April 2012
  #6
Gear Addict
 
RFZ DUDE's Avatar
There is lots of black and cream colored 421s without the bass switch around, some have been modified, some came that way stock.

People tend to replace that switch assembly with the aforemetioned sennheiser kit, no more switch (wich is really not that useful anyways) - no more switch problems.

Great as a complementary mic on some guitars, very nice on toms and can work on kick as well.
Just one of the great microphones out there, and this for a long time.
Old 5th April 2012
  #7
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5down1up's Avatar
 

Have two cream ones with the Music/Speech switch as well.
Ones lacking low end as described earlier.
Need to send it in for repair.
Old 5th April 2012
  #8
Gear Nut
 

Thread Starter
I recorded some very short samples.
Put my sm57 and the md421 in question on my 18inch floortom. The difference is night and day. I am pretty sure it's broken.. waddayathink?
Attached Files

tom sm57.mp3 (150.4 KB, 1985 views)

tom md421.mp3 (150.4 KB, 1931 views)

Old 5th April 2012
  #9
Gear Addict
 
RFZ DUDE's Avatar
except for the loss of bass that MD sounds pretty clean id say.
have the filter circuit bypassed and see whats going on, any tech should be able to perform that mod in a minute or two.

dont give up on her, MD421´s are great microphones.
Old 5th April 2012
  #10
Gear Nut
 

Thread Starter
Quote:
Originally Posted by RFZ DUDE View Post
except for the loss of bass that MD sounds pretty clean id say.
have the filter circuit bypassed and see whats going on, any tech should be able to perform that mod in a minute or two.

dont give up on her, MD421´s are great microphones.
Well that's the thing, it doesn't have a filter. it sounds like it has the low-cut engaged, but them md421-II's don't have one apparently.
Old 5th April 2012
  #11
Gear Addict
 
RFZ DUDE's Avatar
ouch.
in that case id say either send it to your sennheiser distribution company or to an experienced mic repair guy.
i really suggest Peter Drefahl in Germany, he usually does stuff in no time and at affordable rates.
He has probably seen more 421s than any of us..
Old 5th April 2012
  #12
Gear Nut
 

Thread Starter
Thanks for the tip.

I will discuss this with the seller first, see what he has to say about it.
Let's hope we can work something out.
Old 5th April 2012
  #13
Gear Addict
 
RFZ DUDE's Avatar
good luck
Old 5th April 2012
  #14
Lives for gear
If you have a Tuchel-DIN plug version, you may have the wiring wrong. It is the opposite of the AKG DIN wiring. If you do have it wrong, the result is a very thin sound.
Old 5th April 2012
  #15
Gear Nut
 

Thread Starter
Wow good one!
Do you know the correct wiring schedule?

1-3
2-2
3-1

or something like that?
Old 5th April 2012
  #16
Gear Addict
 
RFZ DUDE's Avatar
depends on if it is small or large tuchel.

large tuchel is 1 positive / 2 negative and 3 ground, small tuchel is 1 positive / 2 ground / 3 negative
Old 5th April 2012
  #17
Gear Nut
 

Thread Starter
Hmm that's not it.. seems to be wired properly.
Old 5th April 2012
  #18
Gear Addict
 
RFZ DUDE's Avatar
off to the doc id say.
Old 14th March 2018
  #19
Hi all,

brand new in here and sorry for waking this old thread to new life

I have this Sennheiser MD421HN (or HL - same I think). Bought it very cheap (DKK 25,-)!!!
It has the Kleintuchel connector, so I've bought a cable Kleintuchel-to-XLR.

But no sound is coming from the mic.

I've taken the mic apart.

I wonder if it's broken/dead/finished, since no sound is coming from it.
Anybody able to help here?

Slutty Gear Slutz will not allow me to post pix - yet!
Old 14th March 2018
  #20
Gear Guru
 
John Willett's Avatar
 

Quote:
Originally Posted by Springformband View Post
Hi all,

brand new in here and sorry for waking this old thread to new life

I have this Sennheiser MD421HN (or HL - same I think). Bought it very cheap (DKK 25,-)!!!
It has the Kleintuchel connector, so I've bought a cable Kleintuchel-to-XLR.

But no sound is coming from the mic.

I've taken the mic apart.

I wonder if it's broken/dead/finished, since no sound is coming from it.
Anybody able to help here?

Slutty Gear Slutz will not allow me to post pix - yet!
The HL version was unbalanced and dual impedance.

The Tuchel connector is wired as follows:-
Pin 1= 24 kohm (in phase)
Pin 3= 200 Ohms (in phase)
Pin 2= common for both impedance (out of phase)
Connector metal body= ground/shield

So you would wire +ve to pin 3, -ve to pin 2 and leave pin 1 unconnected.

You will have to open the Tuchel connector on your lead and move the lead from pin 1 to pin 3.
At the same time, move the lead on pin 3 to pin 2.

See attached diagram.
.
Attached Thumbnails
MD421 broken or not?-hl_din-3_mic.jpg  

Last edited by John Willett; 14th March 2018 at 01:21 PM..
Old 14th March 2018
  #21
Quote:
Originally Posted by John Willett View Post
The HL version was unbalanced and dual impedance.

The Tuchel connector is wired as follows:-
Pin 1= 24 kohm (in phase)
Pin 3= 200 Ohms (in phase)
Pin 2= common for both impedance (out of phase)
Connector metal body= ground/shield

So you would wire +ve to pin 3, -ve to pin 2 and leave pin 1 unconnected.

You will have to open the Tuchel connector on your lead and move the lead from pin 1 to pin 3.

See attached diagram.
.
I'm not sure I understand this the right way.

Open the tuchel on the cable, right?
But this is a brand new cable, why does it need to be modded?

Very confusing
Old 14th March 2018
  #22
Is it because it's a HN/HL model?
I imagine the other 421's does not need this Tuchel modding?

And thanx for your quick answer btw.
Old 14th March 2018
  #23
Gear Guru
 
John Willett's Avatar
 

Quote:
Originally Posted by Springformband View Post
I'm not sure I understand this the right way.

Open the tuchel on the cable, right?
But this is a brand new cable, why does it need to be modded?

Very confusing
Because you say you have the "HL" version, which is dual impedance.

Your cable would likely be wired:-
Tuchel pin-1 to XLR pin-2
Tuchel pin-2 to XLR pin-1
Tuchel pin-3 to XLR pin-3

This would be correct if it were a normal, balanced MD 421 - but, as you said, yours is unbalanced dual impedance.

With a cable like this you are connecting +ve high impedance to the +ve input and +ve low impedance to the -ve input - not a good idea.

By opening the Tuclel on the lead and connecting the cable on pin-1 to pin-3 you will be correctly sending the low impedance circuit to XLR pin-2.

Oh - and the lead connected to pin 3 should be moved to pin-2.

So it will then be connected:-
Tuchel pin-1 unconnected
Tuchel pin-2 to XLR pin-1
Tuchel pin-3 to XLR pin-2

This is an unbalanced mic.

The alternative......

Open the microphone and remove the transformer. Then connect the capsule directly to the Tuchel connector of the microphone.

+ve to pin-1
earth to pin-2
-ve to pin-3

This way the microphone will be balanced and your lead should work without modification.

The MD421 service manual is here - it doesn't show the HL version, but it does show how normal versions are wired.

I hope this helps.
Old 14th March 2018
  #24
Thanx again for replying

In the Tuchel:
move pin-1 to pin-3
move pin 3 to pin-2

So, if I understand you correctly, that leaves two leads for Tuchel pin 2, or?
Old 14th March 2018
  #25
Gear Guru
 
John Willett's Avatar
 

Quote:
Originally Posted by Springformband View Post
Thanx again for replying

In the Tuchel:
move pin-1 to pin-3
move pin 3 to pin-2

So, if I understand you correctly, that leaves two leads for Tuchel pin 2, or?
Yes - the HL version is unbalanced.

So the low impedance +ve is on pin-3 and the -ve and earth is on pin-2.

Pin-1 is unconnected.

NB: this is on the Tuchel on the cable.


The better option would probably to remove the HL transformer from the mic. and wire it as a low impedance balanced mic. and use your cable without modification.
Old 17th March 2018
  #26
Still no sound from the mic

Anybody knows what could be wrong with it?
Old 17th March 2018
  #27
Gear Guru
 
John Willett's Avatar
 

Quote:
Originally Posted by Springformband View Post
Still no sound from the mic

Anybody knows what could be wrong with it?
What did you do?

It could be a a wire off internally.

Personally, if it were mine, I would remove the transformer and make it a low impedance balanced mic.

If you have done this, it's wired correcte and still does not work I would send it to Sennheiser Service.
Old 17th March 2018
  #28
I resoldered the Tuchel adapter as described.

There must something wrong inside mic.

It's not a wire inside. I've had it dismantled. Has to be something else...
Old 17th March 2018
  #29
Md421 hd/hl

Quote:
Originally Posted by John Willett View Post
Personally, if it were mine, I would remove the transformer and make it a low impedance balanced mic.
I want to keep it as original as possible. Not very keen on modifying the mic...

But if I have to mod it, where to get a new transformer (don't know if that's the right word)? Don't tell me to make it XLR
Attached Thumbnails
MD421 broken or not?-img_20180316_220349.jpg  
Old 17th March 2018
  #30
Gear Guru
 
John Willett's Avatar
 

Quote:
Originally Posted by Springformband View Post
I want to keep it as original as possible. Not very keen on modifying the mic...

But if I have to mod it, where to get a new transformer (don't know if that's the right word)? Don't tell me to make it XLR
OK - looks as if the transformer is part of the module.

In which case I would ask Sennheiser Service - not sure what country you are in.
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