Fake Behringer B-5?

[k brown]

I found it interesting that the output resistors are 470ohm, rather than 47 or so.

Is the wax blob about damping inductor resonance?

What's the reason for polarizing with a negative voltage? If one were to use these capsules with a DIY circuit, what would be the disadvantage of positive polarization?

Is it just about having non-inverted signal on pin 2?

 

[Icantthinkofaname]

The SMD version reminds me a lot of the insides of my t.Bone SC140's, which are supposed to be some knockoffs of Rode NT55's (same as this, including the negative capsule bias voltage, but with added 3-position pad). This would be an NT5 "remake" then? No idea what the "original" circuit might look like though...

Does the capsule of the t.Bone come off? I was looking at them for donor mics.

 

[Khron]

Does the capsule of the t.Bone come off? I was looking at them for donor mics.

It does, actually, and i think i had read somewhere that Rode SDC capsules actually fit on; haven't had a chance to try myself though.

I found it interesting that the output resistors are 470ohm, rather than 47 or so.

Is the wax blob about damping inductor resonance?

What's the reason for polarizing with a negative voltage? If one were to use these capsules with a DIY circuit, what would be the disadvantage of positive polarization?

Is it just about having non-inverted signal on pin 2?

Indeed, that's quite high.

More like keeping them in place. At least in theory, you can tweak the actual output voltage by altering how well the magnetic fields of the two inductors couple, but no idea if they bother with that in the factory at all.

That last bit's a good question; it would be great to hear from some of our more experienced members here (i'm not necessarily one of them )

 

[tinn]

As Khron and k brown mentioned: 470Ω is quite high.
It is a mistake in the old drawing and I corrected it.

In a non inverting circuit the polarisation voltage is mostly negative to get the
non inverting output on pin 2. Neumann KM 140 has inverted signal
on Pin 3 and no signal (reference) on pin 2.

Threads on RØDE and BEHRINGER capsules have same diameter but different pitch.

RODE NT5: M19x0.4
BEHRINGER B-5:M19x0.45
BEHRINGER C2: M18x0.7
KM184: M20x0.4
OKTAVA 012: M18x0.5

The updated schematic of the B-5

 

[MichelN]

Schematic Behringer B-5:
Old reverse engineering of my Behringer B-5.
Coupling cap at the gate seems fine, C11 (1µF ceramic) is somewhat microphonic.

Small correction: the output resistors have a value of 47 ohm, not 470 (marking 470 means 47 x 10 to the power of 0 = 47 ohm)