Topic: details on countryman b3 source resistor

[weroflu]

just want to confirm before i get a set of b3's. i know you need a source resistor for them. i have my soldering iron handy and a mini plug and resistors. just wondering about the specifics of doing this myself. the b3's are shipped stripped and tinned, should i snip off most of the resistor leads to make things neater? is shrink tubing a must to make it all neat? are people using surface mount resistors on these?

i can't visualize completely what needs to be done  all wrapped up in a cable

[adrianf74]

just want to confirm before i get a set of b3's. i know you need a source resistor for them. i have my soldering iron handy and a mini plug and resistors. just wondering about the specifics of doing this myself. the b3's are shipped stripped and tinned, should i snip off most of the resistor leads to make things neater? is shrink tubing a must to make it all neat? are people using surface mount resistors on these?

i can't visualize completely what needs to be done  all wrapped up in a cable

From my own experience (in having bought B3's recently), I wouldn't do this "on your own" by throwing "any old resistor" into the equation.   Depending on many differing factors, it's not as simple/straight-forward as you might think. 

Without giving away more trade-secrets, and angering a particular individual who runs his own business, the "standard" resistor was *NOT* used in terminating my B3's which were 0.4dB apart (consecutive serial numbers).  There would have been too much distortion had he done this.   When dropping good money on mics, sometimes it makes more sense just to send them in to get terminated than to "roll your own."

I know enough about soldering and terminating myself that I wouldn't have minded attempting it but better results can be found by testing various resistances then it's worth the extra few dollars to send them in, pay for termination, and get them back.

[bryonsos]

just want to confirm before i get a set of b3's. i know you need a source resistor for them. i have my soldering iron handy and a mini plug and resistors. just wondering about the specifics of doing this myself. the b3's are shipped stripped and tinned, should i snip off most of the resistor leads to make things neater? is shrink tubing a must to make it all neat? are people using surface mount resistors on these?

i can't visualize completely what needs to be done  all wrapped up in a cable

From my own experience (in having bought B3's recently), I wouldn't do this "on your own" by throwing "any old resistor" into the equation.   Depending on many differing factors, it's not as simple/straight-forward as you might think. 

Without giving away more trade-secrets, and angering a particular individual who runs his own business, the "standard" resistor was *NOT* used in terminating my B3's which were 0.4dB apart (consecutive serial numbers).  There would have been too much distortion had he done this.   When dropping good money on mics, sometimes it makes more sense just to send them in to get terminated than to "roll your own."

I know enough about soldering and terminating myself that I wouldn't have minded attempting it but better results can be found by testing various resistances then it's worth the extra few dollars to send them in, pay for termination, and get them back.

tgakidis did the 2.2k mod on mine for a nice price. He does great work.

[weroflu]

i don't mind paying a little extra for someone else to do it. it's just getting complicated shipping these things all over the world, and now i have to make sure that PSS will ship to an address other than on my card.

if it's just a matter of squeezing an extra few db of headroom out of the mics i don't care too much, the 2.2k would be fine. but if it's going to make a considerable difference in the sound then maybe i should think twice and have the unnamed person do it. i emailed countryman to see what they recommended.

[bryonsos]

i don't mind paying a little extra for someone else to do it. it's just getting complicated shipping these things all over the world, and now i have to make sure that PSS will ship to an address other than on my card.

if it's just a matter of squeezing an extra few db of headroom out of the mics i don't care too much, the 2.2k would be fine. but if it's going to make a considerable difference in the sound then maybe i should think twice and have the unnamed person do it. i emailed countryman to see what they recommended.

I didn't realize you weren't in the US. PM or email tgakidis, he'll let you know what/how to use the resistors. He does do work internationally too.

It's my understanding, the different resistors don't make a sonic difference, they just effect the ability to handle different SPLs. I went with 2.2k because I don't tape in ear bleeding situations.

[weroflu]

here's some interesting info from countryman...

   << i'll be using a sony pcm-m10 to record to. i read that they provide 3v with no load and slightly less with a load. if it is slightly less then it's ok for me to sacrifice a little headroom. if that doesn't work as planned then i have  preamp that will supply 9v plug-in power, but i think i'll be ok with moderate volume levels just going straight into the m10 since other people have done it successfully.>>

 
The PCM-M10 provides 3V through 4.7kOhms to the mic, which is not enough power for the B3.  I would highly recommend going with an EMW instead.  So the following will be my suggestions for an EMW -- approximately the same cost as the B3 (maybe even slightly lower), and very similar performance specs.
 


  <<  i'd be wiring these into a single stereo mini mini plug, one mic left, one mic right. i thought that the wireless mics had two wires, maybe i'm mistaken.>>

 
They have three wires, but they are often used in three-wire mode.  By tying black and shield to ground, you are effectively turning it into a two-wire mic.
 
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<<some people are using a source resistor, either 2.2k or 4.7k depending on how loud their material is, to prevent overloading. i'm not sure if i need to do this, but that was one of my questions.>>>********

 
There is already a source resistor internally in the recorder, which is already providing barely enough power to operate our mics (and not enough for the B3), so I would strongly discourage the addition of an extra source resistor.
 

<<<<<  XXXXX (named hidden) also goes a step further in measuring each individual mic's resistence and calculates a source resistor value accordingly. what do you think about this? is it necessary?>>>

 
This could be for other mics, or possibly other recorders.  It is not necessary, and I would even recommend against it since you are already in a very low voltage / low current mode of operation.
 

<<< the people who have used these mics in the same manner that i intend, stereo connector into an m10, also report asymmetrical waveforms when not using a source resistor.>>>

 
Not sure what you mean by assymmetrical waveforms.  The mics will not be a matched pair (we don't sell them that way) but will be close in their frequency response and gain.
 

<<<also, when ordering the microphones from a vendor, does countryman supply the connector and put it on, or would i have to solder the connector on myself.>>>

 
We can definitely wire the mics for you into the 1/8" plug.  Please just call us first to get the part number and pricing, then you can order through your normal dealer or directly through us if you do not have a dealer.  But I strongly recommend going with EMW or B6 mics rather than B3 mics for this application.
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so the emw might be the better way to go. anyone have opinions on the sound vs the b3?
or i could just go b3 and only expect it to work in medium volumes.

does the emw use the same capsule as the oscarsoundtech mics?

i'll edit this post after replies because i probably got some technical things wrong...
 

[adrianf74]

^^ QFT.  If supplying 9V to the mics (using a battery box or preamp), you'll want a resistor in there.  The M10, on its own, does not supply enough juice to power the mics without sacrificing headroom.  I know illconditioned uses the B3's to mic in on the M10, however, there is distortion on the smaller club shows he's recorded and posted clips of. 

Again, you'll want to get the mics measured properly for what we're doing.  Many of the mic manufacturers are not aware of our uses/application.

[illconditioned]

The crazy thing is that these mics have no source resistor when wired for XLR (black and shield are shorted in the XLR barrel).  I asked Countryman himself (the son of the founder) and he would/could not disclose what FET wiring is inside.

There is a very small chance that a P-fet is used instead of an N-fet.  I've seen that in some hearing aid capsules made by Sonion.  In this case no source resistor is the correct thing to do.  It is unlikey that B3 do this, though.

I'm probably going to add a resistor to these XLR mics as well.  They could sound even better!

  Richard