Behringer B2 Pro Electronics upgrade

kingkorg said:

No, not at all, i replaced it a while ago to get rid of HF i have original still in the drawer. I would like actually to buy several used now and experiment with different mods. I'd like to have one with rk47 and one with  stock capsule with HF roll off. I have also one B1 with Dave Pearlman TM47  capsule.  Both mics with 47 style capsule have lower output.

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Chinese mics have a reputation for being bright and harsh. But those are separate things. A decent K67 will sound bright (and yes, more often than not it's left untamed in Chinese mics), but it shouldn't be harsh.

Indeed, if you have several B2 Pros, do experiment. I think the stock K67 capsule isn't quite as bright as a Neumann. You could tame one and leave another untamed. If you have more than one in the locker it may be nice to have a brightish mic at hand, too. As long as it ain't harsh. But proper electronics should take care of that.

Oh, and while you're at it, do make one with a CK12-style (edge terminated) capsule. 

There are capsule groupbuys here on a regular basis.

ln76d said:

Could you measure R15/R16 voltage?

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R16 3.1 VDC
R15 13.29VDC at FET junction and 3.1VDC at C9 junction

Thanks for measurements!

One thing - did you measured each point to ground?

For the mods, remove R23 and replace C24 with jumper, check is it k47 sounds better as also check hod omni and figure of eight sounds now

50 seconds?  I think you should rather clean soldering points. None of parts changing should affect that.
For caps you can try double 22nF. Each combination will show you different result, but these are subtle differences.
Still - if you are using that for k47, then i would suggest not use it at all.

My suggestion for k47 - remove any lpf cap, remove r23 and c24(jumper), remove  C1/C2/C25/C26, disconnect back diaphragm, disconnect C23 from front diaphragm. Check is it better in cardioid mode. I would also remove internal mesh.

I have B2-pro now with RK47 capsule.  Advice from In76d for K47 type :

" My suggestion for k47 - remove any lpf cap, remove r23 and c24(jumper), remove  C1/C2/C25/C26, disconnect back diaphragm, disconnect C23 from front diaphragm. Check is it better in cardioid mode. I would also remove internal mesh."

Why disconnect back diaphragm?  Only temporarily?  I'd like pattern options.

Yeap, to hear is it better for you - then it's so called pure cardioid. Original circuit have cardioid pattern made with voltage applied to the back diaphragm. As for test.
If it's positive modification to you, then if you will look closer to the whole topic, then you will find my schematic how to apply "pure cardioid" with use of two other patterns.

Hello everyone. I introduce myself, my name is Lionel de France. I have seen this topic and I am not familiar with forums, forgive me if I miss some rules, I use a translator.
I have a problem with my microphone B-2 pro, I had no sound at all, I replaced the chemical condensators. Now I have some sound, with rising breath and the sound collapses completely as soon as I raise the voice, then the sound comes back gradually, deaf and clear after a few minutes. Can you help me please? Thank you very much.

Sounds like a dirt-on-the-capsule and/or humidity issue.

Does the Behringer B2 Pro have corrective EQ or just a less bright capsule?

Does anyone know of any replacement PCBs/kits that fit the new B2 Pros with the SMD components? I'd much rather replace the circuit if I can than sell one at a loss just to have to find an older model.

Thought I'd throw this in there since this thread is more active. 

Tossed in a k47 capsule, level is at least a good 15-20db lower than the stock capsule.    Any suggestions, it's sensitivity pretty much feels like that of a dynamic, I tossed in my akg p5 and levels feel about the same so that's not good.

Also with these component removals such as the caps like c1/c2, would I need to make a jumper for the empty contact points?  I have answered my own question, you do not make a jumper.  Tried it, no sound with jumpers and sound without.

Hi everyone...

Is there any chance someone could condense this thread into a final post please? I only want to get rid of the noise and make this mic usable as an overhead (with no PAD mod, stock 797 capsule)?

I've been looking at this mod of the later model, and he swaps out some of the resisitors too. Would Silmics be better than the Panasonics (in the Mouser list)?  http://audiomods.datsunzgarage.us/b2/

Your final deductions are a little hard to follow, so can one of you good chaps possibly write the final decided-upon capacitor (68uf or 100uf - what's the difference?)/diode values (7.5 or 8..5 if you're not doing the pad mod?); whether anyone tried adding a trimpot circuit (and could you show me how to do this please?!); did you decide on swapping out C1+C2 for a lower value (for the RF, as discussed); whether any resistors could do with upgrading to audio/military grade (as in the above link)?

Many thanks for all your hard work so far. It's very much appreciated.
I want to do this to prove to a friend - who called this 797 mic 'a p-o-s' on the basis that 'it's Behringer' - that he's wrong. 

Hello guys! Sorry for ressurrecting this.
Does somebody still have some of the reference materials somewhere, attachments/pics?

I got a bunch of the older B2 Pro, most not working, and want to do something cool with them.
Also, any other suggestions? I'll turn 2 of them into Dany's U87 since I still have a couple of those taper PCBs laying around, but no ideas for the rest of them. I have no good 67ish and no good 47ish mics.

Thanks in advance and cheers!

Hello!
Here is mine final B2 Pro in"pure cardioid" . ( Behringer engrave logo removed and new paint).
I have swapped out parts and removed some parts as per In76d.Thank you In76d.
Please images attached.

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ln76d said:

Remove these two wires

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please post a photo of the modifications where are the details to remove? Or the last attachment where the scheme is all there? And is it also possible to replace the capsule in the microphone with a cr12 edge? Or will it require a change in the feeding and output scheme to the capsule?

kingkorg said:

I couldnt imagine it to be that noisy that you couldnt use it stock on overheads. Is it faulty? Could the capsule/pcb be dirty?

There is a rumour about these and other Behringer gear to be noisy, but i never came across b1/b2 with that problem. Have you compered it to some other mic?

The only components you really should upgrade are the two ceramic ones in 'black box' below the capsule. Upgrading resistors wont get you anywhere.

This is (dare i say it) Sony C800 type of sound mic. It is pretty bright, and needs some high end attenuation. If it were 3.000$ mic people would call it open and detailed, however its a Behringer so people call it harsh. Btw it has almost exact same voicing as Rode Classic I.

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If you remember how you modified your b2, you still have photos of the steps of reworking the b2 berhinger. I dug up the first model B2 with the usual parts and would like to make a mod. Please, can you briefly write what it is not difficult to change? I'm a beginner.

Dimon said:

If you remember how you modified your b2, you still have photos of the steps of reworking the b2 berhinger. I dug up the first model B2 with the usual parts and would like to make a mod. Please, can you briefly write what it is not difficult to change? I'm a beginner.

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It is pretty difficult mod to pull off, and honestly not worth the hustle. In76d did remarkable effort to make it work, but unfortunately in practice doesn't do much to improve the performance. Theory behind the mod is relatively solid, but real world application is something else. The only thing i would do is to change the cheap ceramic capacitors in the black "box" under the headbasket to c0g type capacitors of the same value.

kingkorg said:

It is pretty difficult mod to pull off, and honestly not worth the hustle. In76d did remarkable effort to make it work, but unfortunately in practice doesn't do much to improve the performance. Theory behind the mod is relatively solid, but real world application is something else. The only thing i would do is to change the cheap ceramic capacitors in the black "box" under the headbasket to c0g type capacitors of the same value.

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Thanks. And what kind of mod would you recommend doing? Based on B2 or some other microphone.

You should really just change this ceramic cap to c0g type. The mic has a lot of that bright Sony c800 character, be aware of that and don't go crazy boosting high end. You can try some other capsule in it, something like k47, or CK12.

The greatest thing about this mic is that the headbasket is detachable. So you can buy another one, make for example tube circuit in it, or u87 type circuit, use two different capsules and swap them as you like. I have 4 different circuits one of which stock b2, and 4 different capsules. You can make any combination. Extremely versatile.