KM84 DIY Body & PCB kit – CLOSED

Inject 1k to pin on spring housing , power up w 48v, adjust til you hear lowest distortion is the quickest/easiest way.

guismarquesrj said:

Still didn't get how to proceed to calibrate! Can any good soul help me?! 

Worried to do something wrong and screw the FET  :-[

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Got to love this guys!  A perfect copy of our pcb layout, a perfect copy of our mic body too! 

This type of project makes  manufacturers slow in their support of diy!

This is a current product in our line up and it is being reproduced.

What to do!

Not sour grapes but a little dissapointed guys!

You even referrence that all parts are compatible with the lulu!

mhbunch said:

Inject 1k to pin on spring housing , power up w 48v, adjust til you hear lowest distortion is the quickest/easiest way.

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Thanks for clarifying

Cheers

mics said:

This type of project makes  manufacturers slow in their support of diy!

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Come on - do you really mean to say that anyone trying to clone a classic microphone puts it into the category of "current production" and thus a nogo for DIY? (Now, it would be entirely different if Neumann would reissue it, I think...)

Jakob E.

No but its the exact body and the exact Pcb, even component placement is the same

When someone copies one of Poctops pcb’s they get Banned but if it is me, thats ok?

I’ve even heard you in a not so happy mood for this exact thing Jakob!

First a customer buys a mic from me, openly makes a copy and now its available as a kit!

gyraf said:

Come on - do you really mean to say that anyone trying to clone a classic microphone puts it into the category of "current production" and thus a nogo for DIY? (Now, it would be entirely different if Neumann would reissue it, I think...)

Jakob E.

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I am not saying that it shouldnt be diy’d but this isnt diy! this is diy- beesneez with all credit going to others!

The Lulu is not a clone of a km84, but this mic is certainly a clone of a LuLu!

Aah, I didn't realize that the PCB was an exact copy of yours - copying artwork is off course not at all decent behavior in DIY'ing!

If I were you, I'd PM whoever did the first run PCB's, and ask her to make sure she does her own artwork for the next run (if there's plans for such). And, in the process, make it a real KM84-clone (wasn't that the aim in the first place??).

/Jakob E.

mics said:

No but its the exact body and the exact Pcb, even component placement is the same

When someone copies one of Poctops pcb’s they get Banned but if it is me, thats ok?

I’ve even heard you in a not so happy mood for this exact thing Jakob!

First a customer buys a mic from me, openly makes a copy and now its available as a kit!

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Manufacturers generally copyright PCB layout to protect against outright duplication.

[superfluous comment removed ]

JR

If a current product in Beesneez's line up is a KM84 clone in a generic Chinese OEM body, then yes, sorry. We are definitely making one of those.

Should clarify the parts are compatible with MXL, Avantone, Mojave, Chameleon Labs, Telefunken and about a dozen other companies also making SDC's in generic Chinese OEM kits. Not only Beesneez. Sorry if that wasn't clear from the beginning...

As for the board, it's a pure KM84 clone, schematic provided on Page 1. About any similarities to Beesneez's board, there aren't a million ways to fit a KM84 circuit on a PCB this small. I'm happy to adjust anything that offends anyone, within reason. Because any similarities would be the result of both parties building a clone: expectations of radically different designs would be misplaced.

Especially since we're not reinventing microphone assembly, or creating anything revolutionary: the FET and hi-z are always going to end up on top, the transformer at the bottom, and everything else in the middle... As far as I can tell (I've never seen or heard one), the Lulu doesn't use anything proprietary or anything that is a Beesneez 'innovation' that we copied or needed to copy in order to make a KM84 circuit work inside this bodykit. There are projects on this site that are actual copies of people's hard work and innovations, and I can't really take this seriously if a KM84 circuit in a Chinese body is considered Beesneez intellectual property.

mics said:

No but its the exact body and the exact Pcb, even component placement is the same

When someone copies one of Poctops pcb’s they get Banned but if it is me, thats ok?

I’ve even heard you in a not so happy mood for this exact thing Jakob!

First a customer buys a mic from me, openly makes a copy and now its available as a kit!

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No-one copied Poctop. Poctop ripped off mic projects from the microphone forum, and sold them to someone else for profit. Those projects contained innovations and solutions to problems (such as VF14 tube replacements).

What you're claiming is that a KM84 circuit (that you didn't design) inside a Chinese OEM body (that you didn't design) is infringing on your rights. What you don't touch on, is what exactly we would have to gain by copying your board? The KM84 schematic is available online, for free. Anyone can make a clone.

gyraf said:

Aah, I didn't realize that the PCB was an exact copy of yours - copying artwork is off course not at all decent behavior in DIY'ing!

If I were you, I'd PM whoever did the first run PCB's, and ask her to make sure she does her own artwork for the next run (if there's plans for such). And, in the process, make it a real KM84-clone (wasn't that the aim in the first place??).

/Jakob E.

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Knowing first hand how much work went into this board (and its 5 revisions), I'm happy to put this to arbitration:

If Jakob accepts, we can send him our files. Ben can send his too. We allow Jakob to judge if it's a copy, and whether we need to make any changes.

Whatever he says, we accept.

Thanks for clarifying.

Edit:
was an original design or interpretation manufactured in Chinese mic factory?

If so unapproved product  on market is not surprising.

Is there some original design, technology or craftsmanship here?  I see 2 parties functioning as sales agents/importing capacity. 

There is some history of the PCB on this thread. Called "Beesneez Lulu Fet - KM84 SMD mod" https://groupdiy.com/index.php?topic=66037.0

There is a lot of grey area there.  I don´t think there was any bad intention.

you can also read on that thread.

Quote from: micaddict on May 25, 2017, 04:59:05 AM

    Ben might chime in, too. 


That would be lovely. I didn't even think to ask what his thoughts were about it, he would've been the first best sounding board given that he is the guru!! He might think I'm an idiot using SMDs!

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guismarquesrj said:

Still didn't get how to proceed to calibrate! Can any good soul help me?! 

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Connect a signal generator through a capacitor (~1000 pF) to the gate of the FET. 1Khz or so is fine.
Replace the source resistor temporarily with a 10 K.ohm trimpot.
Increase the level of the signal generator until you get distortion (oscilloscope or distortion analyzer).
Adjust the trimpot for lowest distortion and symmetrical clipping.
Measure the value of the trimpot and replace the trimpot with a fixed resistor with the value you measured.
That's it!

RuudNL said:

Connect a signal generator through a capacitor (~1000 pF) to the gate of the FET. 1Khz or so is fine.
Replace the source resistor temporarily with a 10 K.ohm trimpot.
Increase the level of the signal generator until you get distortion (oscilloscope or distortion analyzer).
Adjust the trimpot for lowest distortion and symmetrical clipping.
Measure the value of the trimpot and replace the trimpot with a fixed resistor with the value you measured.
That's it!

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Thanks very much for the help

My question is/was very "newbie", haha... It was about the actual mechanical approach, if I had to power up the mic without the capsule and measure after the XLR! Another good soul answered me above...

So, gotta connect the mic without the capsule attached to a preamp, power up 48V and then proceed, right?

Just didn't get the capacitor thing before the gate. Why? To simulate a load? Looking at the schematic, there's already a capacitor feeding to the gate (the 470pf)... The idea is to add another one for measuring?

Very sorry to ask so newbie questions. I'm trying my best to study about it so I can also contribute with everyone! Maaaany nights spent so far! haha

Thanks!!!

Just connect the capacitor to the 'pin' that connects to the capsule.
The audio generator signal feeds to the (not connected) side of this capacitor.  (And the ground wire of course.)
The capacitor is to separate the polarisation voltage. You don't want +46 V or so on you signal generator!
If you don't have an oscilloscope or a distortion analyzer, you can also do this by ear.
Turn the trimpot slowly until minimal distortion (on a sinewave) is heard.
Then increase the level of the signal level, and adjust the trimpot again.
Of course you need to connect the XLR to an amplifier!

RuudNL said:

Just connect the capacitor to the 'pin' that connects to the capsule.
The audio generator signal feeds to the (not connected) side of this capacitor.  (And the ground wire of course.)
The capacitor is to separate the polarisation voltage. You don't want +46 V or so on you signal generator!
If you don't have an oscilloscope or a distortion analyzer, you can also do this by ear.
Turn the trimpot slowly until minimal distortion (on a sinewave) is heard.
Then increase the level of the signal level, and adjust the trimpot again.
Of course you need to connect the XLR to an amplifier!

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PERFECT!

Yes, I have an oscilloscope here! \o/

I'll come back with some photos and the results!

Thanks very much again!

Best,

Gui

shabtek said:

Thanks for clarifying.

Edit:
was an original design or interpretation manufactured in Chinese mic factory?

If so unapproved product  on market is not surprising.

Is there some original design, technology or craftsmanship here?  I see 2 parties functioning as sales agents/importing capacity.

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Isn't the body the same as this?

http://recordinghacks.com/microphones/MXL/604

No, the MXL 604 has a switch, the Banzai one hasn't.

Matador said:

Isn't the body the same as this?

http://recordinghacks.com/microphones/MXL/604

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We asked them to remove the switch hole on ours, so guess we got this one:
http://recordinghacks.com/microphones/MXL/603S

They're all exactly the same though, every part compatible with each other.

(any and all value in our kit is in the capsule, board, and transformer)