Topic: 4.7k Low Sensitivity Mod

[darktrain]

I have searched for over an hour now and can't find the pictures of that 4.7k Low Sensitivity Mod, i know they are here somewhere, anyone got the link to the page?

thanks

[illconditioned]

I have searched for over an hour now and can't find the pictures of that 4.7k Low Sensitivity Mod, i know they are here somewhere, anyone got the link to the page?

thanks

It depends on the mic you're modding.

In words: put a 4.7k resistor between the source of the FET and ground.  Often mics are set up so that the source of the FET is directly connected to ground.  In that case you have to break this connection and insert a 4.7k resistor there.

The exact wiring depends on the mic.  For example, audio technica mics from Sound Professionals usually have three wires: red, yellow, shield.  Yellow is usually shorted to ground (in the miniplug connector), and the mic is connected at red and shield.  To mod this mic you have to remove the yellow connector from the ground connection, and insert a 4.7k resistor in between.  This is hard to do in a (small!) miniplug casing, so you may instead perform the same wiring, either at the capsule end (if you can get it apart...) or somehow splice in the wire (messy, but works).

  Richard

[darktrain]

I have searched for over an hour now and can't find the pictures of that 4.7k Low Sensitivity Mod, i know they are here somewhere, anyone got the link to the page?

thanks

It depends on the mic you're modding.

In words: put a 4.7k resistor between the source of the FET and ground.  Often mics are set up so that the source of the FET is directly connected to ground.  In that case you have to break this connection and insert a 4.7k resistor there.

The exact wiring depends on the mic.  For example, audio technica mics from Sound Professionals usually have three wires: red, yellow, shield.  Yellow is usually shorted to ground (in the miniplug connector), and the mic is connected at red and shield.  To mod this mic you have to remove the yellow connector from the ground connection, and insert a 4.7k resistor in between.  This is hard to do in a (small!) miniplug casing, so you may instead perform the same wiring, either at the capsule end (if you can get it apart...) or somehow splice in the wire (messy, but works).

  Richard

for the MM-HLSC's

[illconditioned]

I have searched for over an hour now and can't find the pictures of that 4.7k Low Sensitivity Mod, i know they are here somewhere, anyone got the link to the page?

thanks

It depends on the mic you're modding.

In words: put a 4.7k resistor between the source of the FET and ground.  Often mics are set up so that the source of the FET is directly connected to ground.  In that case you have to break this connection and insert a 4.7k resistor there.

The exact wiring depends on the mic.  For example, audio technica mics from Sound Professionals usually have three wires: red, yellow, shield.  Yellow is usually shorted to ground (in the miniplug connector), and the mic is connected at red and shield.  To mod this mic you have to remove the yellow connector from the ground connection, and insert a 4.7k resistor in between.  This is hard to do in a (small!) miniplug casing, so you may instead perform the same wiring, either at the capsule end (if you can get it apart...) or somehow splice in the wire (messy, but works).

  Richard

for the MM-HLSC's

OK, those have three wires too.  I *think* they are red, white and shield.  Red is power, white is shorted to shield (at the connector).  So you just need to break this and put a 4.7k resistor there...

  Richard

[Church-Audio]

I have searched for over an hour now and can't find the pictures of that 4.7k Low Sensitivity Mod, i know they are here somewhere, anyone got the link to the page?

thanks

It depends on the mic you're modding.

In words: put a 4.7k resistor between the source of the FET and ground.  Often mics are set up so that the source of the FET is directly connected to ground.  In that case you have to break this connection and insert a 4.7k resistor there.

The exact wiring depends on the mic.  For example, audio technica mics from Sound Professionals usually have three wires: red, yellow, shield.  Yellow is usually shorted to ground (in the miniplug connector), and the mic is connected at red and shield.  To mod this mic you have to remove the yellow connector from the ground connection, and insert a 4.7k resistor in between.  This is hard to do in a (small!) miniplug casing, so you may instead perform the same wiring, either at the capsule end (if you can get it apart...) or somehow splice in the wire (messy, but works).

  Richard

for the MM-HLSC's

I am getting a pair of these mics to test from a customer I would hold off on the mod until I get them it might actually degrade the performance if we use the wrong resistor in there. I will test a bunch of values and determine the best one.. Just give me a week or so and I will post what I find here ok.

Chris

[Church-Audio]

My tests indicate a distortion of 5% at 114db at 1k far from the claimed 136 db distortion. I am working on a mod for these mics.. I also noticed that the pair I have is 2.5 apart from the other mic capsule at 1k. Not a good sign. I will post something when I find the "magic" value for this mic.

I think the major mistake that has been made here is the same mistake that was made with the AT853 mics, is that the 853 And the Sennhieser mics Manufacture specs are based on the mics being wired 3 wire NOT 2 wire, as they are commonly wired. When you wire most three wire mics via a two wire method you increase distortion. My mod works with the three wire mics converts them to 2 wire and lowers the distortion to the same performance level as three wire, but wile being able to use the mics with a 2 wire 2.5 volt to 12 volt plug in power.

Chris

[Belexes]

Thanks for doing the legwork on the MM's Chris and please keep us updated.

[aleal5687]

My tests indicate a distortion of 5% at 114db at 1k far from the claimed 136 db distortion. I am working on a mod for these mics.. I also noticed that the pair I have is 2.5 apart from the other mic capsule at 1k. Not a good sign. I will post something when I find the "magic" value for this mic.

I think the major mistake that has been made here is the same mistake that was made with the AT853 mics, is that the 853 And the Sennhieser mics Manufacture specs are based on the mics being wired 3 wire NOT 2 wire, as they are commonly wired. When you wire most three wire mics via a two wire method you increase distortion. My mod works with the three wire mics converts them to 2 wire and lowers the distortion to the same performance level as three wire, but wile being able to use the mics with a 2 wire 2.5 volt to 12 volt plug in power.

Chris

Chris

Any updates on the mod for the MM-HLSC's?

Thanks

[Church-Audio]

My tests indicate a distortion of 5% at 114db at 1k far from the claimed 136 db distortion. I am working on a mod for these mics.. I also noticed that the pair I have is 2.5 apart from the other mic capsule at 1k. Not a good sign. I will post something when I find the "magic" value for this mic.

I think the major mistake that has been made here is the same mistake that was made with the AT853 mics, is that the 853 And the Sennhieser mics Manufacture specs are based on the mics being wired 3 wire NOT 2 wire, as they are commonly wired. When you wire most three wire mics via a two wire method you increase distortion. My mod works with the three wire mics converts them to 2 wire and lowers the distortion to the same performance level as three wire, but wile being able to use the mics with a 2 wire 2.5 volt to 12 volt plug in power.

Chris

Chris

Any updates on the mod for the MM-HLSC's?

Thanks

Yes the updates are that this mic has a distortion of almost 6% when wired 2 wire at 114db at 1k.  After my 4.7k mod the distortion is decreased to .5% at 114db at 1k. So my mod will work with these mics but some form of preamp should be used to make up for the 12db of loss my mod introduces.

I also discovered that these mics might be more susceptible to induced interference because there is no fine mesh metal screen in front of the capsule to help block out stray RF.

I also discovered that when they are assembled the ground wire is soldered directly to the capsule it self, this can cause a deformation of the capsule and cause poor frequency response due to a stretched diaphragm from the heat of the soldering iron.

The pair I tested with 3.5 db apart from each others output level at 114db at 1k this would seem to indicate that the pair of microphones I was sent for modification were not closely matched at all.

This is based on the one pair of mics I was sent for testing and modification. This might not indicate that "all" of these mics are the same.

Chris

[darktrain]

My tests indicate a distortion of 5% at 114db at 1k far from the claimed 136 db distortion. I am working on a mod for these mics.. I also noticed that the pair I have is 2.5 apart from the other mic capsule at 1k. Not a good sign. I will post something when I find the "magic" value for this mic.

I think the major mistake that has been made here is the same mistake that was made with the AT853 mics, is that the 853 And the Sennhieser mics Manufacture specs are based on the mics being wired 3 wire NOT 2 wire, as they are commonly wired. When you wire most three wire mics via a two wire method you increase distortion. My mod works with the three wire mics converts them to 2 wire and lowers the distortion to the same performance level as three wire, but wile being able to use the mics with a 2 wire 2.5 volt to 12 volt plug in power.

Chris

Chris

Any updates on the mod for the MM-HLSC's?

Thanks

Yes the updates are that this mic has a distortion of almost 6% when wired 2 wire at 114db at 1k.  After my 4.7k mod the distortion is decreased to .5% at 114db at 1k. So my mod will work with these mics but some form of preamp should be used to make up for the 12db of loss my mod introduces.

I also discovered that these mics might be more susceptible to induced interference because there is no fine mesh metal screen in front of the capsule to help block out stray RF.

I also discovered that when they are assembled the ground wire is soldered directly to the capsule it self, this can cause a deformation of the capsule and cause poor frequency response due to a stretched diaphragm from the heat of the soldering iron.

The pair I tested with 3.5 db apart from each others output level at 114db at 1k this would seem to indicate that the pair of microphones I was sent for modification were not closely matched at all.

This is based on the one pair of mics I was sent for testing and modification. This might not indicate that "all" of these mics are the same.

Chris

So is it the same way you do the mod on the at853's? I don't have a lot of confidence now in the HLSC's i got recently so i may have to do that mod.

[BusDriver]

reactivation of thread ... 

i still have not gotten around to this modification, although i've asked in the past. i use multiple sets of the at853's. one set was purchased from sound pros - terminated in miniplug.

it crossed my mind (what's left ) that if i want to run in low volume setting the 3volt plugin power of the Sony M10  is OK. But, if i want to use the same mics for loud setting , battery box attached, or preamp'ed with PFA's why don't i just terminate them with mini xlr as are on my other sets.

The question here is, can the 4.7k mod be built into an adapter plug - 2 mini xlr > stereo mini - to be used, when needed, on the 853's when they are to be powered only by the 3 volt plug in power of the m10 (or 9 volt battery) instead of permanently modifying the mic set??

[SmokinJoe]

reactivation of thread ... 

i still have not gotten around to this modification, although i've asked in the past. i use multiple sets of the at853's. one set was purchased from sound pros - terminated in miniplug.

it crossed my mind (what's left ) that if i want to run in low volume setting the 3volt plugin power of the Sony M10  is OK. But, if i want to use the same mics for loud setting , battery box attached, or preamp'ed with PFA's why don't i just terminate them with mini xlr as are on my other sets.

The question here is, can the 4.7k mod be built into an adapter plug - 2 mini xlr > stereo mini - to be used, when needed, on the 853's when they are to be powered only by the 3 volt plug in power of the m10 (or 9 volt battery) instead of permanently modifying the mic set??

Yes, you could make Y-cables for mini-XLR to 1/8", and in that Y cable you put the 4.7k resistor.  You could make 2 cables, 1 with the resistors and 1 without.  For mellow acoustic stuff you could use the one without and you don't have to make up that extra 12db.  On louder stuff you use the one with resisters.

[Church-Audio]

reactivation of thread ... 

i still have not gotten around to this modification, although i've asked in the past. i use multiple sets of the at853's. one set was purchased from sound pros - terminated in miniplug.

it crossed my mind (what's left ) that if i want to run in low volume setting the 3volt plugin power of the Sony M10  is OK. But, if i want to use the same mics for loud setting , battery box attached, or preamp'ed with PFA's why don't i just terminate them with mini xlr as are on my other sets.

The question here is, can the 4.7k mod be built into an adapter plug - 2 mini xlr > stereo mini - to be used, when needed, on the 853's when they are to be powered only by the 3 volt plug in power of the m10 (or 9 volt battery) instead of permanently modifying the mic set??

Yes, you could make Y-cables for mini-XLR to 1/8", and in that Y cable you put the 4.7k resistor.  You could make 2 cables, 1 with the resistors and 1 without.  For mellow acoustic stuff you could use the one without and you don't have to make up that extra 12db.  On louder stuff you use the one with resisters.

That would work great. Or small box with mini xlr connectors to a pigtail 3.5 mm connector that you can then mount a small toggle switch to "bypass" the resistors for 10 to 12 db more gain.