GroupDIY

Marketplace => White Market => Topic started by: Banzai on February 25, 2018, 09:51:01 PM

Title: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 25, 2018, 09:51:01 PM
(https://s20.postimg.cc/gxjazazv1/Banzai_KM84.png)

DIY KM84 kits - Sold Out

Parts included in kit:
– KM84 DIY PCB designed by Graeme Woller
– Maiku cardioid SDC capsule
– Raw brass body-tube
– Polished and plated capsule head and connector housing
– Fairchild 2N3819 JFET

Parts needed to complete build:
– Components outlined in Mouser BOM
– BV-107 type transformer (Cinemag CM-5722, AMI T8, or 3U GZT-84)

That's it  ;)

------------------------------------------

Pricing incl. all charges and shipping:

EU / CH – €130,00
Rest of world – €136,00

If ordering more than one kit, only add €110 for every extra unit.

3U GZT-84 transformers are also available for €25
Just add however many you need to your total.


How to order:
Send your Paypal payment in EUR directly to [email protected] with your name and shipping address.

Sale is on FCFS basis, no holds.

Payments only accepted in EUR.
Don't send CHF, your payment will be incomplete.


------------------------------------------
Title: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!
Post by: Banzai on February 25, 2018, 10:16:52 PM
Graeme's Build Guide:
http://bit.ly/2ML5aOv

PCB Schematic:
https://www.dropbox.com/sh/s2pfjwo7bb3a0zr/AABnKkG5hzBzXf-Ha7VlZ7Kaa?dl=0

Mouser BOM:
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=f5036488e2

NB: 279-RGP0207CHK1G0 can be replaced with 588-MOX-200001007JE
Title: Wiring for 3U transformer
Post by: Banzai on February 28, 2018, 01:50:39 PM
3U GZT84 wiring:

RED wire -> G
BROWN wire -> R
YELLOW wire -> B
ORANGE wire -> Y

Transformer board pads:

(https://i.postimg.cc/CxZYGpHb/KM84-PCB-Transformer-pads.png)


Stock 3U diagram:
(https://i.ebayimg.com/images/g/s~YAAOSwUV9Wo7EI/s-l500.jpg)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: TillM on February 28, 2018, 02:22:35 PM
Hi Mike,
Payment send for one.
I’m interessted in a groupbuy for the cinemag too
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on February 28, 2018, 02:54:55 PM
Hi Mike,
Payment send for one.
I’m interessted in a groupbuy for the cinemag too

Thanks!  :D
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Ericbazaar on February 28, 2018, 04:18:30 PM
Hello Banzai,

Can you tell me more about the micbody? Internal diameter and length?
More Infos about the capsule would be nice.
Is it possible to fit a submini tube inside?

Best
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: TillM on March 01, 2018, 03:28:53 AM
Hello Banzai,

Can you tell me more about the micbody? Internal diameter and length?
More Infos about the capsule would be nice.
Is it possible to fit a submini tube inside?

Best
I know Banzai could give you better informations but as far as I know, if they have the same diameter like the beesneez lulu a submini tube should work. Ben use the same body for his tube mic small condenser mics.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Vac11 on March 01, 2018, 03:38:26 AM
Is there compatibility between this body and the geniue Neumann KM84 capsule?
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 01, 2018, 08:51:46 AM
Hello Banzai,

Can you tell me more about the micbody? Internal diameter and length?
More Infos about the capsule would be nice.
Is it possible to fit a submini tube inside?

Best

Original Neumann is 21 x 110mm
This body is 22 x 130mm. It's short and fat, very nice looking mic.

Capsule is based on KK84. Same materials (mylar/gold)

No problem for sub-mini. Plenty of space inside (ø19mm)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 01, 2018, 08:58:18 AM
Is there compatibility between this body and the geniue Neumann KM84 capsule?

The connecting pin is different and the Neumann is slightly smaller in diameter. But unless you have one lying around, it's not really worth it: new KK84's are €535. Might as well buy a complete vintage KM84  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: midwayfair on March 01, 2018, 09:18:57 AM
Aw man, This is a great deal and we really don't have many options for these, and I even have the transformer Ina drawer upstairs, but I don't think I can swing this while in classes.

Is this likely to be a one-time thing, or do you plan on doing runs every once in a while?
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: TillM on March 02, 2018, 04:00:43 AM
PAyment sent for a second one.  ;)
I will try it, really like the sound of the KM84, will see how it sounds compared to each other.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 02, 2018, 09:38:06 AM
PAyment sent for a second one.  ;)
I will try it, really like the sound of the KM84, will see how it sounds compared to each other.

Thanks x2  :D


Aw man, This is a great deal and we really don't have many options for these, and I even have the transformer Ina drawer upstairs, but I don't think I can swing this while in classes.

Is this likely to be a one-time thing, or do you plan on doing runs every once in a while?

For the moment it's just a one time thing. With Graeme we wanted to create a high quality project that's really easy to build and accessible to anyone with a soldering iron. This might be the simplest project on Groupdiy: fill the board, set bias, screw on the capsule and you're done!

The metalwork is also a custom run made for this project, the only off the shelf parts being the springy bit and the connector housing. We left the body tube raw on purpose, so everyone can decide whether they want to leave as is, polish, beadblast, powdercoat, spray paint, or plate. Leaving as is, it should get a nice patina finish after a while (you can accelerate the process by beadblasting).
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Potato Cakes on March 02, 2018, 02:23:39 PM
I would like four of these. PM sent.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Potato Cakes on March 02, 2018, 02:41:28 PM
Payment sent for four (4) kits.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Ericbazaar on March 02, 2018, 03:18:07 PM
Money sent for two Kits. Will build nice little Tube Sticks  ::)

Thanks Mike for doing this!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: midwayfair on March 02, 2018, 07:54:58 PM

For the moment it's just a one time thing.

Sigh ... time to see if I can move some guitar pedals on Craigslist then before these sell out. Or might just ask the wife for an indulgence :)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: r2d2 on March 03, 2018, 05:41:08 AM
Hi
Any info about capsule and rest of parts cost to complete the mic ?

Any sound sample like acoustic guitar and voice  recorded with a transparent preamp (as well) ?
And better more  some sound comparison with an original unit .

Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: TillM on March 03, 2018, 08:01:48 AM
Hi
Any info about capsule and rest of parts cost to complete the mic ?

Any sound sample like acoustic guitar and voice  recorded with a transparent preamp (as well) ?
And better more  some sound comparison with an original unit .
this is a first time offer, so there will be no sound comparison at this time.
Anyway, Banzai uploaded a schematic and a BOM.
And as Banzai already said, the capsule is based on the KK84.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 03, 2018, 08:56:04 AM
Payment sent for four (4) kits.

Thanks!

Paul
Money sent for two Kits. Will build nice little Tube Sticks  ::)

Thanks Mike for doing this!

Thanks!  :D

Hi
Any info about capsule and rest of parts cost to complete the mic ?

Everything is included except for parts listed in Mouser BOM and transformer
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: mohausler on March 03, 2018, 01:42:00 PM
Quick question.

Will this mic have a -10dB pad switch like the original?

Thank you
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 03, 2018, 02:45:08 PM
Quick question.

Will this mic have a -10dB pad switch like the original?

Thank you

We've left that out. It's the exact original circuit minus the 10dB pad.

You can see it better in the schematic.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: jrasia on March 03, 2018, 03:08:36 PM
Couple questions

1.  If buying pairs, are the capsules matched?

2.  What are the differences between the two PCBs exactly? One is labeled floating high z.  Sonically, what does this translate in to?

Thanks!!

This looks great!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: GraemeWoller on March 03, 2018, 03:50:33 PM
2.  What are the differences between the two PCBs exactly? One is labeled floating high z.  Sonically, what does this translate in to?

Hi jrasia!

Lifting the HiZ components avoids any current leakage between components across flux or moisture which is then amplified by the FET as extra noise.

We should be cleaning our PCBs after soldering anyway, but lifting the front-end parts helps avoid noises from anything that isn't completely clean.

Graeme
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 03, 2018, 05:10:21 PM
Couple questions

1.  If buying pairs, are the capsules matched?

We don't offer matching, but the capsules are made within a tight tolerance.

No issues using these as a pair  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: TillM on March 03, 2018, 05:20:23 PM
You could also match the jfet to get a higher tolerance
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: chipss36 on March 03, 2018, 06:23:13 PM
Errrr just upgraded Scope and signal gen, going to be broke for awhile, then I see this, looks fantastic!   Hope the project stays around awhile!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: jrasia on March 03, 2018, 09:02:02 PM
payment sent for x2
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 04, 2018, 12:48:30 PM
payment sent for x2

Thanks!  ;)

25 kits sold so far...
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: fsalter on March 04, 2018, 01:04:57 PM
Payment sent for 2. Thanks Banzai!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 04, 2018, 03:49:20 PM
Payment sent for 2. Thanks Banzai!

Thanks!  ;D

Just a note about the shipping: only EU is 122. Everywhere else is 128. Be careful not to come up short when sending payments.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Pignouf on March 04, 2018, 05:46:52 PM
Also sent a payment for 2 pieces.

Cheers!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 04, 2018, 06:03:52 PM
Also sent a payment for 2 pieces.

Cheers!

Thanks for the order, and the drinks bonus too!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: audiomsg on March 04, 2018, 06:48:23 PM
Hi Banzai
Payment sent for 2 units
I'll partake in a group buy for the transformers if you get enough commitment from everyone else
Thanks!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: GraemeWoller on March 04, 2018, 08:20:10 PM
I'm in on the Cinemags group buy too... Anything saved on those are worth it!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: fsalter on March 04, 2018, 10:10:47 PM
Banzai. Just added a 3rd kit with the missing 6 euros. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Winetree on March 05, 2018, 12:15:24 AM
Payment sent for 4 kits.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: 59flame on March 05, 2018, 08:35:14 AM
payment for 2 kits sent
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: mdmitch2 on March 05, 2018, 09:37:57 AM
Payment for 2 kits sent.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: fsalter on March 05, 2018, 01:00:47 PM
Just to confirm Banzai, that's a total of 4 for me. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 05, 2018, 01:33:10 PM
Thanks for the orders!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: yoons on March 05, 2018, 03:09:26 PM
Hi!
Payment sent for 2 kits.
Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 05, 2018, 03:20:39 PM
Hi!
Payment sent for 2 kits.
Thanks

Thanks!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Tungstengruvsten on March 05, 2018, 04:18:40 PM
payment sent for 2x kits
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: AudioHammer on March 06, 2018, 07:06:42 AM
Payment sent for one kit

Thanks !!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: AttamanuBe on March 06, 2018, 07:26:20 AM
Hello,
Payment for 2 kits sent.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: iturnknobs on March 06, 2018, 09:55:20 AM
Payment sent for 2 kits. Hoping i'm not too late.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: mhbunch on March 06, 2018, 11:17:55 AM
Sent payment for 2 kits  8)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 06, 2018, 01:20:10 PM
Thanks for the orders!!!

I've kept a large reserve in case there's more demand, so units are still available.
Will let you know here when it runs out.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: RuudNL on March 06, 2018, 01:41:37 PM
I suppose you will have received my Paypal payment for two kits.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: lkipod on March 06, 2018, 03:03:45 PM
Hi Banzai and Graeme,
Thanks for doing this
Sent payment for two kits.
If there is going to be a cinemags group buy count me in please.

Cheers
Moshe
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: GraemeWoller on March 07, 2018, 03:32:19 AM
Hi Banzai and Graeme,
Thanks for doing this
Sent payment for two kits.
If there is going to be a cinemags group buy count me in please.

Cheers
Moshe

A pleasure, Moshe! :)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: ArnoldLayne on March 07, 2018, 08:10:33 AM
Been waiting a long time for this project !
Payment sent for two kits, and I'm down for the tranny group buy  :P
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: iturnknobs on March 07, 2018, 09:09:40 AM
Please count me in for the cinemag (2pcs) group buy. Just contact me with price and I will send funds immediately thereafter.

Thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: mdmitch2 on March 07, 2018, 11:50:31 AM
Payment for 2 kits sent.

I placed a 2nd order for 2 additional kits, a total of 4 kits. Paypal payments were sent from ShadowTree Studios and Heiserman Audio. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 07, 2018, 02:56:36 PM
Thanks for the orders!  :D

60 kits sold so far
Around 30 still available from reserve
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: buckethead on March 07, 2018, 08:37:03 PM
Sent payment for 1 kit
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: delaymix on March 07, 2018, 10:02:44 PM
Payment for 2 kits sent.
Please count me in for the cinemag (2pcs) group buy.
Thanks you! This is a great project!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 08, 2018, 09:40:23 AM
Thanks!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: AW_music on March 08, 2018, 02:22:00 PM
Payment sent for 2kits !
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Fenix511 on March 08, 2018, 02:54:10 PM
Payment sent for 2 kits. If I need to sort anything out let me know. Also, I'm in for 2 Cinemags if that happens.

Thanks for  setting this up. I have something to look forward to now hahaha.  ;D
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: jordan s on March 11, 2018, 12:13:24 AM
Just sent payment for 2. I'm into in the Cinemag buy.
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: rainton on March 11, 2018, 08:11:40 PM
Payment sent for 2 kits - Thanks Mike
Also in for the cinemags group buy :)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: 4earstudios on March 12, 2018, 02:21:58 AM
Hey are there still kits left?
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: 4earstudios on March 12, 2018, 02:27:14 AM
Would be in for 2x with Cinemag when this happens...
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: mhbunch on March 12, 2018, 02:29:53 AM
Also in for 2x cinemags
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: Banzai on March 12, 2018, 02:31:01 AM
Hey are there still kits left?

Yes, still available!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: 4earstudios on March 12, 2018, 03:00:38 AM
yeahhh, i will send the money for 2 kits
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: 4earstudios on March 12, 2018, 03:04:09 AM
and paid ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!!
Post by: morbleu on March 12, 2018, 09:21:41 AM
sent money for 2 kits - Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: evanmurphy on March 12, 2018, 06:55:34 PM
Count me in for a CM-5722 group buy (2x)
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: buckethead on March 12, 2018, 08:59:31 PM
I would also be interested in the Cinemag group buy (1 pc.) in case it happens
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: chipss36 on March 12, 2018, 09:18:22 PM
Missed out, oh well.
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: lampas on March 13, 2018, 01:08:53 PM
Send payment for 2pcs. I am also for 2pcs Cinemag groupbuy.
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: guismarquesrj on March 13, 2018, 03:56:35 PM
Payment sent for 2 kits also!!!! yeeeey! :)

I'm also for the Cinemag groupbuy...

Please note I sent a comment included in the paypal transfer!

Again, thank you very much for what u did!

Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: morbleu on March 14, 2018, 07:53:16 AM
forgot to mention: I am also in for  Cinemag group buy - 2pcs!
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: usatrene on March 14, 2018, 11:32:31 AM
Hello Banzai,
Payment sent for 2 kits.
Also, I'm also in for 2 Cinemags if that happens.
Big thanks for setting this up.
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: wowi on March 14, 2018, 11:49:16 AM
Just send the payment for 4 x KM84
Thanks for your work.

I would also join the Cinemag group buy for 4 pc

Wolfgang
Title: Re: Neumann KM84 DIY Body & PCB kit – 20 kits left @ €100!!!
Post by: Mulmany on March 14, 2018, 12:03:29 PM
Payment sent for 2x. Also in for a group buy on tx.
Title: Re: Neumann KM84 DIY Body & PCB kit – SOLD OUT
Post by: Banzai on March 14, 2018, 12:55:05 PM
We're now sold-out!
Title: Re: Neumann KM84 DIY Body & PCB kit – SOLD OUT
Post by: okgb on March 14, 2018, 03:55:05 PM
 Just saw this , will there be another run ? I'm in for two!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on March 14, 2018, 04:25:26 PM
Anyone knows if I can use a lower voltage WIMA capacitor (470pf 2.5%)? Like 100V instead of 250V? 250V is out of stock here :( Any solution? Thanks! :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on March 14, 2018, 08:11:13 PM
The KM84 from a friend of mine use 100v. So this would be definitely work
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!
Post by: Winetree on March 15, 2018, 02:00:24 PM
PCB layout, schematic and BOM available here:
https://www.dropbox.com/sh/s2pfjwo7bb3a0zr/AABnKkG5hzBzXf-Ha7VlZ7Kaa?dl=0

Graeme made 2 versions of the board. Once everyone decides which one they prefer, we'll produce the boards and include them in your shipments. Lead-time is 7-10 days after all orders are in.

Has the version of the P.S.B. been decided?  Are they being made?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: janps on March 16, 2018, 03:47:53 AM
Just see it now ... I'm in  for a couple ....as possible
Congratulations for this project 
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on March 16, 2018, 05:00:10 AM
The KM84 from a friend of mine use 100v. So this would be definitely work

Yep, absolutely. 100v will be fine, it's not using more than +46 so go hard. The components are personal choice and I've tried to keep the footprints a little bit flexible if you want to put something else in a hole. :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 16, 2018, 04:27:19 PM
Has the version of the P.S.B. been decided?  Are they being made?

PCB's will be ordered on Monday!

Just processed a few refunds. Sale went a bit quick at the end and we oversold a few units. Sorry for the inconvenience!!!

If you haven't received a refund by now, then your order is confirmed.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 16, 2018, 04:32:44 PM
Cinemag Groupbuy:

Confirmed yesterday, it's $50/unit with a 6-week leadtime.
To add to that is a one-time shipping fee from US to CH.

We should expect it to arrive around 7-8 weeks after we order.
Price is only valid if we get more than 50pcs, which I think we can manage.

Long wait, so up to you!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: buckethead on March 16, 2018, 06:06:51 PM
Sounds good to me, I'm still in for 1pc.

Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on March 16, 2018, 06:25:13 PM
I'm still IN for 2 pieces!

I'm paying attention here \o/

After that will u send the pieces to everyone? Sorry for the question! I'm a first time buying things this way! haha

Peace!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Mulmany on March 16, 2018, 08:28:02 PM
Any chance that US buyers for the tx can be shipped direct. Seems a little odd to pay double for shipping to and from Europe when they are here in the US.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 16, 2018, 11:34:20 PM
Any chance that US buyers for the tx can be shipped direct. Seems a little odd to pay double for shipping to and from Europe when they are here in the US.

Of course you can, but you'll pay the single unit price. For that just order direct.

The shipping here won't be double. The leg from Europe to US is already covered in your kits. The leg from US to Europe is split between 20 to 40 people.

Just to be clear, anyone who enters the groupbuy won't receive their kits until the Cinemag's are included. Those who don't want any transformers, your kits ship as soon as the boards are done.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: audiomsg on March 17, 2018, 04:37:39 AM
Definitely still in for 2 Cinemags!
Let us know when you need payment.
Thanks Banzai
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Pignouf on March 17, 2018, 09:48:15 AM
Idem, I'm in for 2 Cinemags, just say when and how much to pay and I'll do the necessary.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on March 17, 2018, 10:26:13 AM
As an alternative to the Cinemag, there is the 3u GZT-47, which is quite nice. It is 6.5:1 instead of 6.9:1. Will it make much of a difference?  It certainly is quite cheaper.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: wowi on March 17, 2018, 01:07:47 PM
I am also still in for 4 cinemags.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: lkipod on March 17, 2018, 03:00:40 PM
Hey there I'm still in for 2 cinemags..
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Mulmany on March 17, 2018, 10:08:05 PM
Of course you can, but you'll pay the single unit price. For that just order direct.

The shipping here won't be double. The leg from Europe to US is already covered in your kits. The leg from US to Europe is split between 20 to 40 people.

Just to be clear, anyone who enters the groupbuy won't receive their kits until the Cinemag's are included. Those who don't want any transformers, your kits ship as soon as the boards are done.

Ah... Thanks. That makes a lot more sense! I am in for 2.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Hank Dussen on March 18, 2018, 03:40:08 PM
2 Cinemags for me please.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on March 18, 2018, 07:12:57 PM
One for me please, sir. :)
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 50 kits available @ €100!!
Post by: GraemeWoller on March 18, 2018, 07:18:56 PM
Has the version of the P.S.B. been decided?  Are they being made?

Sorry for the delay on replying, Winetree!!

Yes, the overwhelming majority wanted the floating HiZ version which is understandable. I voted for that one too, and I'm the one who designed them, but it was nice to float the option. For those who wanted the isolation, that's what they get, and for those who weren't to worried it won't make much difference. Plus the shiny turrets look cool...  8)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 19, 2018, 02:31:41 AM
Mail sent with sign-up for transformer buy
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: alex24bit on March 20, 2018, 04:47:58 AM
Yep, absolutely. 100v will be fine, it's not using more than +46 so go hard. The components are personal choice and I've tried to keep the footprints a little bit flexible if you want to put something else in a hole. :)
HI THERE.  The only ones i found, close to the Wima Film Capacitor 470 pF 250 VDC 2.5%   are:
https://www.reichelt.com/gr/en/FKP2-250-470P/3/index.html?ACTION=3&LA=514&ARTICLE=172469
& @ Banzai    http://www.banzaimusic.com/WIMA-FKP2-5-470pF-250V.html
with 5% tolerance. are these OK? Will they work ? I am referring to the tolerance in specific.
thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on March 20, 2018, 04:56:31 AM
Yes it’s okay. You can also take 100v.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 21, 2018, 06:23:24 PM
2 more days to sign-up for Cinemag buy, then we order
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Ericbazaar on March 21, 2018, 06:49:38 PM
If i do not need a cinemag transformer or a km84 style pcb, is it possible to send this mic bodys earlier out? ::)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 21, 2018, 06:53:43 PM
If i do not need a cinemag transformer or a km84 style pcb, is it possible to send this mic bodys earlier out? ::)

Ships in 2 batches. Without transformer and with transformer.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on March 21, 2018, 08:37:02 PM
What's the Cinemag group buy price per transformer? Shipping back to U.S.A. or direct buy for U.S.A.?
I'm a few cities over from Cinemag here in California and got a price for the 4 I need.
I'd like like to compare or be able to buy local at group buy prices.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 22, 2018, 02:14:01 AM
It's all in the thread 1 page back
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on March 22, 2018, 09:16:44 PM
HI THERE.  The only ones i found, close to the Wima Film Capacitor 470 pF 250 VDC 2.5%   are:
https://www.reichelt.com/gr/en/FKP2-250-470P/3/index.html?ACTION=3&LA=514&ARTICLE=172469
& @ Banzai    http://www.banzaimusic.com/WIMA-FKP2-5-470pF-250V.html
with 5% tolerance. are these OK? Will they work ? I am referring to the tolerance in specific.
thanks

I couldn't access the first link, but yes, they should be fine at 5%. I just like to see how intolerant I can be... ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 23, 2018, 04:38:24 AM
...
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Hank Dussen on March 23, 2018, 05:19:29 AM
Please make sure you're on the list before tomorrow.

OK, I really feel stupid but I cannot find this groupbuy list. Can someone please direct me to it?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on March 23, 2018, 05:46:01 AM
Banzai send a mail last week
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 25, 2018, 02:34:37 AM
Cinemag groupbuy is closed – no more changes possible, order sent
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on March 25, 2018, 04:27:42 PM
Send my 4 bodies without transformers.
I'll get the transformers locally.
Thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 26, 2018, 02:47:24 AM
Mouser BOM updated:
https://www.mouser.ch/ProjectManager/ProjectDetail.aspx?AccessID=f5036488e2

NB: 588-MOX-200001007JE can be replaced with 279-RGP0207CHK1G0
Both are in BOM, please pick the ones you prefer.

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Catrunes on March 27, 2018, 07:49:31 PM
im bummed i missed out on this. any chance of another run in the future?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on March 28, 2018, 05:20:15 AM
im bummed i missed out on this. any chance of another run in the future?

Not sure. Depends on how this first one works out  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on April 01, 2018, 11:40:11 PM
How is it going the cinemag transformer group buy?!

I've filled the spreadsheet but don't know what happen next!

Thanks!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 02, 2018, 07:07:28 AM
How is it going the cinemag transformer group buy?!

I've filled the spreadsheet but don't know what happen next!

Thanks!!!

Now we wait 6-8 weeks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: 59flame on April 05, 2018, 02:39:41 PM
have the kits been shipped to those who are not apart of the cinemag group buy?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 05, 2018, 03:29:17 PM
have the kits been shipped to those who are not apart of the cinemag group buy?

Not yet – will update here when the boards arrive. Should be any day now.

Boards are done with Eurocircuits. Very high quality, european made. Worth the wait!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on April 05, 2018, 03:34:08 PM
Awesome!

@Banzai
Tell us when we need to pay for the transformers!

:) Thanks!!!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Jim50hertz on April 09, 2018, 02:48:17 PM
How did I miss  this?  I’d it possible to get a hold of two kits?
Peace
Jim
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BramK on April 10, 2018, 01:57:42 AM
How did I miss  this?  I’d it possible to get a hold of two kits?
Peace
Jim

Sounds like there might be enough interest for a possible 2nd run for those of us who missed this one.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Carnesd on April 10, 2018, 07:12:07 PM
I'd be in for 2 if a second run happens.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 12, 2018, 03:28:49 PM
Boards arrived today!!!  :D

No idea why it took so long, but at least we have them now.

Thanks for the patience and your orders will be packed&shipped over the next few days.
Title: ORIGINAL HAUFE BV107 Group Buy
Post by: rainton on April 16, 2018, 04:43:00 AM
Hey guys,

since I'm from Germany and also bought 2 of the mic body kits, I checked directly with HAUFE who made the original BV107 transformer for the KM84 and asked if they could make it available again.
I just heard back from them and they are checking with their engineers. But I was also asked how many I need and I'm pretty sure the chances are better if it's more than the 2 trannys I need for my builds  ;D

I'm now waiting on their reply with an estimated price - I also asked them what the price would be for 10+ and for 20+ of the trannys...who would join me?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: morbleu on April 16, 2018, 06:23:48 AM
I'm already in the group buy for the cinemags but would be definitely interested in a pair of Haufe.

Andreas
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: lampas on April 16, 2018, 07:38:55 AM
Me too for 2pcs.
Title: Re: ORIGINAL HAUFE BV107 Group Buy
Post by: TillM on April 16, 2018, 09:23:15 AM
Hey guys,

since I'm from Germany and also bought 2 of the mic body kits, I checked directly with HAUFE who made the original BV107 transformer for the KM84 and asked if they could make it available again.
I just heard back from them and they are checking with their engineers. But I was also asked how many I need and I'm pretty sure the chances are better if it's more than the 2 trannys I need for my builds  ;D

I'm now waiting on their reply with an estimated price - I also asked them what the price would be for 10+ and for 20+ of the trannys...who would join me?

Really !? That’s amazing.
When I write them a month ago, they told me, that they don’t produce them anymore.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BramK on April 16, 2018, 11:06:37 AM
I'd be in for 2 HAUFE trannies, thanks Rainton!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on April 16, 2018, 01:39:33 PM
2- Haufe 
Title: Re: ORIGINAL HAUFE BV107 Group Buy
Post by: rainton on April 16, 2018, 03:15:57 PM
Really !? That’s amazing.
When I write them a month ago, they told me, that they don’t produce them anymore.

What they wrote me is (kind of): "These transformers haven't been produced since 2001 and we have to check our manufacturing options. How many would you need?"

So I replied that I will ask around but that I'm pretty positive that we would reach 10+ or even 20+ pieces... ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: 59flame on April 16, 2018, 03:30:12 PM
i would be interested possibly in  a couple haufes.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: lkipod on April 16, 2018, 04:23:06 PM
I also ordered Cinemags....
Now I want the Haufes too :P

Yeah I'm in for two, depending on price.

Thanks for asking  Rainton! :D

Cheers
Moshe
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on April 16, 2018, 05:21:21 PM
Morning guys!

re: the Haufes.

I couldn't say what dimensions those transformers  going to be, but the space in the PCB was specifically for the Cinemag sizing so odds are they won't fit. Certainly if they're the dimensions of the originals. That said, it'd certainly be exciting to hear these kits with an "original" tranny in it, so maybe if it doesn't fit the current cutout the board could be jiggled around to fit the other transformer in a future kit.

Depends on a few things, of course, interest being the main thing. :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: rainton on April 20, 2018, 04:23:36 AM
Good news everybody,

I just talked to someone from Haufe and indeed they  CAN DO a reissue of the original BV107 transformer for us!!
I'll get a quote later today or Monday.

Looking at the pcb layout - even if the original tranny doesn't fit the board it should be easy to modify the pcb to make it all fit into the body tube.
But of course for future versions it would be cool to have the original trannys fit without modding :)

stay tuned

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: rainton on April 20, 2018, 05:34:24 AM
Ok, I already received the quote :)

if we buy up to 10 pcs. they will be EUR 85.00 ea.
11-20 pcs. will be EUR 81.00 ea.

lead time is 10 weeks - ouch!

But hey - considering they haven't been in production for almost 20 years, 10 weeks is nothing, right  ;D
So should we start a list here, or should I start a dedicated thread for it?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on April 24, 2018, 03:24:57 PM
Got 4 mic bodies and Mouser parts order on the same day.
Got busy last night and stuffed the boards with everything but a couple of backordered parts and transformers.
Are there any build pictures for reference?
I'm on the fence about the transformers. The Haufes will cost me twice the price of the Cinemags.
Wonder if there's a sound difference?  But, It could be the only chance to get the original transformers.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: yoons on April 24, 2018, 03:38:16 PM
I would be in for 2 Haufe transformers if it happens!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: rainton on April 24, 2018, 03:39:40 PM
I would be in for 2 Haufe transformers if it happens!

I decided to open a new thread for the Haufe Group Buy:

https://groupdiy.com/index.php?topic=68862.new;topicseen#new
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on April 24, 2018, 06:17:34 PM
Get my bodies tomorrow.
I’ve now every single part except the bodies at home.
I will post some build pics.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on April 25, 2018, 02:10:13 AM
I received the KM84 kits yesterday.
I tested the microphone capsules on an existing microphone and they sound well balanced.
Not the peaky HF that is usually produced by cheap SDC's.
The sound makes me indeed think of a KM84.

By the way: it would be nice if I could just get two capsules to replace the ones on my test microphone(s) permanently...
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on April 26, 2018, 11:50:17 AM
Everything arrived yesterday and I start my built.
Well maybe I’m to dumb, but I don’t get the Capsule on the mic body.
Do the mod on the plastic spring. Don’t get it, everytime when I want to push the Capsule on the XLR part has minimum 4mm space.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 26, 2018, 08:25:12 PM
Everything arrived yesterday and I start my built.
Well maybe I’m to dumb, but I don’t get the Capsule on the mic body.
Do the mod on the plastic spring. Don’t get it, everytime when I want to push the Capsule on the XLR part has minimum 4mm space.

No, you're absolutely right – the sizing of the spring isn't accurate because it's a standard part.

Once you have the board installed, you need to shorten the brass pin of the springy part to the correct length. It's correct when the capsule fully closes whilst pushing down the spring.

Careful not to cut too much. Best to do in stages, and check if it fits.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Mulmany on April 26, 2018, 08:40:28 PM
What is the status of the tx group buy, and estimate on delivery for those units?

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 26, 2018, 08:45:41 PM
What is the status of the tx group buy, and estimate on delivery for those units?

Thanks

Status is same – order went in after we closed the list, with lead-time of around 6-8 weeks.

Should have them in about a month.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Ericbazaar on April 26, 2018, 11:19:59 PM
Hello Banzai,

i‘ve build a tube version out of your body kit with a german made transformer.
Its the first time i have used a circuit designed by myself. The mic sounds well balanced with a sweet top end (not to much) and very fast transient response.
Nice!

What is the max Capsule Voltage i can get? Now i have ca 40V. Can i get up to 50 or 60V?

Best
Andreas
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 26, 2018, 11:48:09 PM
No problem for 60V – as long as you like what you're hearing, then it's fine!

Pictures??  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on April 27, 2018, 01:45:11 AM
No, you're absolutely right – the sizing of the spring isn't accurate because it's a standard part.

Once you have the board installed, you need to shorten the brass pin of the springy part to the correct length. It's correct when the capsule fully closes whilst pushing down the spring.

Careful not to cut too much. Best to do in stages, and check if it fits.

Hi Banzai,
Thanks for the advice !
That’s what I also think about, but I want to be secure.
I forget to thank you for the great offer and the quality of the kits.
As always your packaging was perfect !
Thank you so much.
I will cut 2mm away from the brass and than I can bias it.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Glutamatjunkie on April 27, 2018, 12:38:58 PM
Hey Banzai,
if you plan a new run, I'm in for two KM84 Bodies with PCB Kits.

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on April 27, 2018, 01:33:39 PM
So now I’m ready.
It sounds amazing with the Cinemag transformers.
I really like the detail. Test it on my hi hat and I don’t have to eq it.
It just sound good.
With my second mic I made a mistake in the hi Z area.
It has extremely low output, I have to resolder it.
But this I will do tomorrow.
It sounds great with just biasing by ear.
Will bias the FET also this weekend.
Thanks for the kits Banzai !
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 27, 2018, 04:43:59 PM
You're welcome!  ;)

Just a quick note as i'm getting a lot of tracking number requests:

The guys who already received their kits didn't join the Cinemag groupbuy. The rest of the orders will only ship when the transformers arrive.

( https://groupdiy.com/index.php?topic=68360.msg872206#msg872206 )
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on April 27, 2018, 07:53:56 PM
As an alternative to the Cinemag, there is the 3u GZT-47, which is quite nice. It is 6.5:1 instead of 6.9:1. Will it make much of a difference?  It certainly is quite cheaper.
This one is closer with 7:1 ratio.
https://picclick.com/3U-Audio-GZT-84-Output-Transformer-for-SDC-Microphone-112882929558.html
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Ericbazaar on April 28, 2018, 07:53:46 AM

Pictures??  ;)

shure: :D

the rest of the electronic components are backside
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on April 28, 2018, 12:33:03 PM
Yes, after Guosheng's recommendation, that's what i ended up getting. I received my kits yesterday. Will post when done.

This one is closer with 7:1 ratio.
https://picclick.com/3U-Audio-GZT-84-Output-Transformer-for-SDC-Microphone-112882929558.html
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 28, 2018, 03:15:50 PM
shure: :D

the rest of the electronic components are backside

Beautiful!!

Good picture of that mega spring pin too.
If you cut it shorter, you can gain more inside space.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on April 28, 2018, 06:51:06 PM
The Ohmite 1gig resistors are expensive, and the TE ones are backordered till June.
Do you think these are usable? I have a few lying around from canibalised chinese mics.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on April 28, 2018, 07:56:21 PM
...Sorry, pic did'nt show up.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on April 28, 2018, 08:08:02 PM
The Ohmite 1gig resistors are expensive, and the TE ones are backordered till June.
Do you think these are usable? I have a few lying around from canibalised chinese mics.

Do you try Digikey ?
https://www.digikey.de/product-detail/de/te-connectivity-passive-product/RGP0207CHK1G0/A106006CT-ND/3477617
https://www.digikey.de/product-detail/de/stackpole-electronics-inc/HVA12JA1G00/HVA12JA1G00CT-ND/6195878
https://www.digikey.de/product-detail/de/vishay-dale/RNX0381G00FNEE/RNX1.00GCCT-ND/2712940
and so on...
maybe this help.
But I also think, that you can use the Chinese ones.

After troubleshot my second mic, I found out, that I've a cold solder joint at the trimmer.
If a second run ever happen (which would definitely really, really nice) my only wish is to make the solder pads a bit thicker, this would be awesome.
I get the Cinemags last week, cause I already ordered them before the group buy.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 29, 2018, 10:22:51 AM
Nice build!!

Because of size constraints, seems best to stick to 1/4W 1GΩ resistors (0207 package)
Will give more space to work with.

Have updated Mouser BOM.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on April 30, 2018, 06:23:57 AM
How about the use of C0G’s instead of the Polypropylenes. Other than this recent debate about them having better dialectric properties, the lead spacing and their size would make them fit better?
Is 100v really necessary?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on April 30, 2018, 03:13:22 PM
Hey Fred,

No harm in trying C0G's, doesn't cost much to get both. The boards are also good quality – they'll survive desoldering if you want to play around with options.

I've otherwise never used them, can't tell you if it would be an improvement. Maybe Graeme?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fsalter on April 30, 2018, 07:13:24 PM
Thanks for the reply Mike. It's just that the Wima's prescribed are backordered. I found some subs, but i'll try the C0G's too.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on May 04, 2018, 12:54:43 AM
I've got my kits in and I have a couple of questions as I gather parts:

The schematic says 2n3891 for the FET but the Mouser cart has 2n3819. Does the schematic have a typo?

There is a screen in the bag with the white spring assembly. Is this used somewhere in the build that I can't find? I don't see it used in the couple of build pictures.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 04, 2018, 01:03:09 AM
I've got my kits in and I have a couple of questions as I gather parts:

The schematic says 2n3891 for the FET but the Mouser cart has 2n3819. Does the schematic have a typo?

There is a screen in the bag with the white spring assembly. Is this used somewhere in the build that I can't find? I don't see it used in the couple of build pictures.

Thanks!

Paul

Hi Paul,

The Mouser cart is correct (2n3819)

The screen is to cover the slots right underneath the capsule. It's not attached in case you wanted to plate or paint the body first.

To install, no need for anything special. You can just push it into place – glue is optional, it will hold without it.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Ericbazaar on May 04, 2018, 02:33:15 AM
Beautiful!!

Good picture of that mega spring pin too.
If you cut it shorter, you can gain more inside space.

More space between the capsule and the tube ist better to reduce the heat. I have experimented with underheat the tube in the last week and the 6s6b works perfect with 4,4v @ 105mA, it will reduce the heat in the mic strongly. I have reduce the capsule and circuit noise. This mic sound thicker and better in the bottom like the UM57 Microphone i had here for reair. Well balanced Capsule.

I hope this tube works long with this heavy underheating ::) btw i could underheat the tube up to 3,2 V without loosing performance. Stunning little russian tube...

Thanks Mike for these beautiful Mic Kits
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on May 04, 2018, 08:34:44 AM
Hi Paul,

The Mouser cart is correct (2n3819)

The screen is to cover the slots right underneath the capsule. It's not attached in case you wanted to plate or paint the body first.

To install, no need for anything special. You can just push it into place – glue is optional, it will hold without it.

Good to know.

I'm waiting on transformers then hopefully I can get these together and put them to use. I haven't decided on what color to paint them.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on May 05, 2018, 07:26:50 PM
What threading is used for the spring assembly to attach it to the PCB?

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 05, 2018, 08:00:40 PM
What threading is used for the spring assembly to attach it to the PCB?

Thanks!

Paul

M2
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on May 05, 2018, 08:13:30 PM
Fantastic.

Also of note, when using the Mouser cart, one should double check the lead spacing as there are a number of capacitors that should be 2.5mm pitch and are 5mm in the cart, and vise versa. But I do appreciate having the cart as there are couple of items on it that I wouldn't have know which category to search in to find the correct part.

Hoping to get these put together when I get home next week. Thanks again for putting this project together.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 05, 2018, 08:41:57 PM
Fantastic.

Also of note, when using the Mouser cart, one should double check the lead spacing as there are a number of capacitors that should be 2.5mm pitch and are 5mm in the cart, and vise versa. But I do appreciate having the cart as there are couple of items on it that I wouldn't have know which category to search in to find the correct part.

Hoping to get these put together when I get home next week. Thanks again for putting this project together.

Thanks!

Paul

Fixed!

C3-4-5-6 changed to 5mm spacing
C7-8 changed to 2.5mm spacing
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on May 06, 2018, 11:56:56 PM
Hi folks, sorry I've been afk for a bit.

These build pics look great, I'm super pleased that things are going well with the kit for everyone. I'm also really keen on that tube build. Awesome!

Poly or C0G. To be fair I haven't noticed much of a difference and there's always a lot of "discussion" about which is best. Like Mike said, the pads will take a bit of desoldering with no issues so it'd be really interesting to try various ones out and report back. Maybe we can start another war about the subjective sound qualities of each type!! LOL!

Sorry about the typo on the diagram for the FET. The BOM is correct... Might have to add components to my autocorrect!

I reckon we need to have a thread of people's recordings with these wee guys. It'd be wonderful to hear what everyone is doing with them when they're completed!

Graeme
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: delaymix on May 07, 2018, 06:32:56 PM
I wuld to have a valve circuit in the microphone, which scheme of interest to follow?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on May 08, 2018, 02:18:07 AM
I would look for a Neumann KM54 schematic or any other small condenser tube mic.
But I would go for the KM54.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Ericbazaar on May 08, 2018, 04:04:25 AM
I would look for a Neumann KM54 schematic or any other small condenser tube mic.
But I would go for the KM54.

KM54 Schematic won't work with this Mic Kit. The Front Capsule here is on 0V Pontential. KK54 Capsule and Schematic are different.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on May 08, 2018, 06:10:00 AM
You are right!
Next time I take a Bette look on the schematic. ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: delaymix on May 08, 2018, 07:58:37 PM
KM54 Schematic won't work with this Mic Kit. The Front Capsule here is on 0V Pontential. KK54 Capsule and Schematic are different.

So, what is an appropriate approach for a valve microphone?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: damianschwartz on May 19, 2018, 05:24:08 AM
Will you make more available?? interested in two units and missed this  :-\
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 20, 2018, 06:09:15 AM
Will you make more available?? interested in two units and missed this  :-\

We'll definitely do another batch in a few months.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mrcase on May 20, 2018, 07:00:57 AM
In for two in the next batch! ;D
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on May 20, 2018, 01:06:34 PM
Has anybody painted or power coated the mic bodies?
I'm thinking of power coating.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on May 20, 2018, 01:07:43 PM
I want nickel plate them, but it will take some time, need some parts.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on May 22, 2018, 05:22:26 AM
I would be interested in two microphone capsules (only the capsules, no body, PCB or XLR part) to replace the capsules of a pair of existing microphones. Would this be possible?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 22, 2018, 06:32:08 AM
Hi Ruud, every available part was sold out in the current run.

For the next batch we'll make some extra capsules as well.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on May 22, 2018, 07:58:19 AM
Great! I am looking forward for the next batch!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BramK on May 22, 2018, 11:23:45 PM
We'll definitely do another batch in a few months.

Great to hear! Will you make an option to fit the Haufe transformers for those of us who joined in on rainton's order?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: adeptusmajor on May 26, 2018, 05:13:17 PM
We'll definitely do another batch in a few months.

I'm in for at least 2 on the next batch
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on May 26, 2018, 08:52:47 PM
Hi Bram

"Will you make an option to fit the Haufe transformers for those of us who joined in on rainton's order?"

There's been some thoughts on that, and it's a good idea. The trick will be tweaking it all to fit the Haufe trafo and that will take time. I haven't had one in my hand but if it's the same dimensions as the original BV then it's going to require a redesign of the board.

The next run will most likely be for the same Cinemag sizing, but there's some good thoughts in the pipeline to stay tuned for.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BramK on May 27, 2018, 02:59:02 AM
Nice, thanks for the heads up!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mesajoe on May 30, 2018, 11:22:10 AM
I'm in for two from the next batch please..
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jarvis on June 01, 2018, 01:10:37 PM
Hi Ruud, every available part was sold out in the current run.

For the next batch we'll make some extra capsules as well.

That sounds awesome, I'd be in for at least one capsule as well!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on June 02, 2018, 01:19:57 PM
I'm interested in a pair, keeping my eye open on this thread...
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: audiomsg on June 05, 2018, 12:41:22 AM
Hi Banzai

I'm having trouble finding the 2N3819 JFETs, as they have sold out at Mouser and elsewhere, and now the manufacturer is re-designing them.
Is there something you can suggest that will work as a replacement?

Regards

Olly
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 05, 2018, 07:16:36 AM
Hi Olly,

A great place to still buy 2N3819's is ebay. You can get them from European or US sellers.

Hope that helps!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: audiomsg on June 06, 2018, 01:44:32 AM
Yes it does, thanks!

I've got 5 on the way from the UK now

Cheers

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 07, 2018, 08:19:36 PM
e-mail sent for CM groupbuy
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: bugfight on June 08, 2018, 01:59:08 AM
i'll get 2 of these whenever it reboots, will there be another transformer run too?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 08, 2018, 06:19:22 AM
Sure!  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: partycentral on June 14, 2018, 03:09:27 AM
I'm also in for 2 kits of any second run that happens. Let me know! My luck is I'll next check this thread when the second run's spoken for and done.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: HarmonyUnited on June 17, 2018, 12:51:57 PM
Im in for two kits too! :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: earlfsmith on June 19, 2018, 04:51:36 AM
i'll be in for two kits also for the next batch
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: 12afael on June 19, 2018, 04:57:08 AM
i´m also interested
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: stelin on June 19, 2018, 04:55:22 PM
I'll also be in for two kits also for the next batch!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mhbunch on June 21, 2018, 11:57:27 AM
Any word on when orders will ship for those of us that have already paid?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: JuanV on June 21, 2018, 12:11:04 PM
I'm in for two kits. Let me know, Thx.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 22, 2018, 08:35:54 AM
Any word on when orders will ship for those of us that have already paid?

All orders without transformers were shipped a long time ago.

For orders with transformers, we can only move forward once everyone has paid.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: iturnknobs on June 25, 2018, 04:18:35 PM
...not looking for names, just numbers. How many haven't paid, and can others purchase their trafos to move this along? I'm sure they could be sold later. Looks like there's plenty of interest for another round. I'm just sorta anxious to get to this build.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mhbunch on June 25, 2018, 04:31:11 PM
...not looking for names, just numbers. How many haven't paid, and can others purchase their trafos to move this along? I'm sure they could be sold later. Looks like there's plenty of interest for another round. I'm just sorta anxious to get to this build.

It looks like we are mostly waiting on one person who ordered 15 transformers and hasnt paid. I am anxious as well and wondering the same thing.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 26, 2018, 09:12:51 AM
All payments are in! ;)

Transformers on the way.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: yosh on June 26, 2018, 12:32:36 PM
I'm in for two if a second run happens! Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: craigmorris74 on June 27, 2018, 02:00:01 PM
I'd be in for one kit of a second run.
Craig
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on June 28, 2018, 04:34:03 AM
Is there a quick and dirty way to set the bias? If someone could share what they are getting where R3 connects to T1 (2N3819).

I thought I was going to be able to finish one of these up tonight until I realized I didn't have the 470pF capacitors. I do have 330pF, but I've made all the effort getting everything else I might as well use what is specified on the BOM. Plus I already have to order more parts for another project. Looking forward getting these done!

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on June 28, 2018, 09:23:50 AM
Is there a quick and dirty way to set the bias? If someone could share what they are getting where R3 connects to T1 (2N3819).

I thought I was going to be able to finish one of these up tonight until I realized I didn't have the 470pF capacitors. I do have 330pF, but I've made all the effort getting everything else I might as well use what is specified on the BOM. Plus I already have to order more parts for another project. Looking forward getting these done!

Thanks!

Paul
I thought biasing was easy, but I ended up with two broken 2N3819.
I dont install the capsule and the spring and gave the mic the 48v from the xlr input.
Then I put a 1khz sinus though the 1Gohm resistor.
My oscilloscope I place on the JFET. Usually the same method like on the U87 build from Poctop.
But I ended up two times, with as I said, a broken JFET.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on June 30, 2018, 12:09:48 PM
If you power up the microphone first and then connect something to the input, the gate of the FET will get a pulse of -46 V.
(The charge in C1) The FET may not like this!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on June 30, 2018, 01:10:14 PM
If you power up the microphone first and then connect something to the input, the gate of the FET will get a pulse of -46 V.
(The charge in C1) The FET may not like this!

Hell no I,m so dumb !
Thanks Ruud for explaining it again.
With my u87 builds I first connect everything and then power it up.
Don’t know why I don’t do it with the KM84.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: dasnevestheo on July 01, 2018, 11:43:37 AM
interested in 2 kits if there's another batch ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: indraperkasa on July 01, 2018, 03:56:00 PM
also interested in 2 kit if there's a next batch  ;D
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: iturnknobs on July 02, 2018, 09:06:42 AM
I haven't received my stuff yet, but should we start a build thread? I wonder if it might be difficult to look
for pertinent info in between all the "I'll take 2 on the next run" posts. Hats off to Banzai.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Le Roux on July 02, 2018, 04:10:42 PM
In for 2 for the next run! 😉
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: thekim1 on July 08, 2018, 11:19:32 AM
I'm in for a pair if there will be another run
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: roger.unc on July 08, 2018, 02:44:03 PM
I would be in for 2 if there is another run!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on July 10, 2018, 12:52:23 AM
Just finished building four (4) of these. Worked great the first time. They still need to be biased, but I was getting plenty of headroom without making any adjustments. Also, these are extremely quiet. I've haven't recorded anything thing with them just talked into each mic and snapped my fingers, but my reaction was that this circuit is indeed very smooth and pleasant in the high mids, unlike most any other name brand commercial SDC that are considered audio engineering essentials.

Couple of tips to make the build easier:

Use a small flat file instead of a razor when test fitting the white spring housing that connects the capsule to the PCB. I found it much easier and faster (and safer) to get a great fit to the PCB without the risk over trimming.

Trimming the small brass rod that makes contact with the capsule so that it is flush with the microphone body threads will be just enough material so you can fully screw the capsule on the body.

A small amount of gentle persuasion will be required to insert the XLR housing into the body when the PCB is attached. The XLR housing does not line up exactly with the body once you get to this point of assembly as the PCB is not perfectly centered to the XLR when soldered in place. At least that is they way it was for me. It didn't take much effort but one should be aware this may be the case upon completion.

Now I just need to get the bodies painted.

Thanks for the excellent project!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on July 10, 2018, 12:56:42 AM
The back.

This where I placed the 470pF capacitors between the isolated turrets. The leads where small enough to pass through their hollow centers to be soldered on top.

I cleaned the solder connections and the 1Gohm resistors after this photo was taken.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 10, 2018, 10:25:08 PM
Great work – thanks for pics !!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 13, 2018, 09:22:35 AM
Transformers are here – remaining orders being packed!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on July 14, 2018, 06:09:15 AM
Lovely work Mr. Cakes! Looks great!!

I was just about to butt in and suggest you might need a little isopropyl on there, but then you bet me to it! :)

I cleaned the solder connections and the 1Gohm resistors after this photo was taken.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: icemanaman on July 15, 2018, 05:26:55 AM
In for two kits in the next run!  :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on July 15, 2018, 09:07:20 AM
Lovely work Mr. Cakes! Looks great!!

I was just about to butt in and suggest you might need a little isopropyl on there, but then you bet me to it! :)

The one thing I will do I is put a little hot glue to hold the transformer in place to the PCB. it's not completely necessary when it's all assembled, but it think a little more stability would be nice.

Hopefully later this year when I get back to recording stuff I'll get to put them to use.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: HosaMogami on July 16, 2018, 10:29:16 PM
Bummed I missed this. Would be in should there be another run.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: eternal slang on July 18, 2018, 03:16:58 AM
I'm in for 2 as well  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on July 20, 2018, 10:41:43 PM
Just curious: has anyone tried the AMI T8 transformer? It seems to be the same size and, as far as I can tell, the same ratio and other values as the Cinemag.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 21, 2018, 02:41:46 PM
Just curious: has anyone tried the AMI T8 transformer? It seems to be the same size and, as far as I can tell, the same ratio and other values as the Cinemag.

Haven't tried it, but at $120 it wouldn't even be an option for me.

Rather get two Cinemag's, or the original Haufe ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mhbunch on July 21, 2018, 05:46:29 PM
Just got my 2 kits in the mail. Looks amazing, can’t wait til I find some free time to put em together. Thanks for the hard work!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: usatrene on July 23, 2018, 09:37:15 AM
The parts were delivered yesterday to the far east.  Thank you again for handling and the support, Bonzai. ;)

I am wondering how can I paint the body.
It would be great if you guys share how are you going to paint the surface.
Ordinary color paint with a primer underneath or powder coat?

Anyway, thanks again and hope everything works fine.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: rChrome on July 24, 2018, 08:52:23 AM
This looks great! Dont know how i missed it.  I'd be down for a pair next run.  Keep up the good work.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Hawkmoon on July 24, 2018, 11:04:54 AM
Cool kit!!

I would be in for 2 if there is another run!

cheers!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 25, 2018, 03:14:13 AM
This is my first FET mic, can someone please help with the biasing technique?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on July 25, 2018, 04:42:21 AM
same procedure like the U87.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 25, 2018, 04:37:06 PM
For anyone like me trying to find info on how to bias the FET, here's the different techniques I've found so far. I haven't tried any of them yet.

http://www.vintagemicrophonepcbkit.com/Neumann%20U87%20Build.htm
 (http://www.vintagemicrophonepcbkit.com/Neumann%20U87%20Build.htm)"It’s time to pump a little 48v phantom power into this baby to see what we have cookin!  Connect your mic preamp of choice, preferably one that works, and turn on the phantom power.  We’re going to calibrate the drain on the microphone to 11.5 volts.   Take your multimeter and put the red probe on r6. This is right next to the FET.  Take your black probe and put it on the ground hole.  Take a small flat-head screw driver and tweak the pot until you measure 11.5 volts. "

http://repforums.prosoundweb.com/index.php/topic,11630.0.html
 (http://repforums.prosoundweb.com/index.php/topic,11630.0.html)"I feed a 1K sine wave signal to the gate and slowly increase the source resistance from 0-10k Ohm with a temporary trim pot (10k) until I reach the lowest distortion of the FET.

This will be a pretty precisely defined point right after the highest output of the mic, right after the first heavy distortion audible when the FET turns on, and right before the more gradual onset of the distortion as the FET's output decreases again.

The trick is to feed enough 1k into the gate that at this ideal bias point the distortion is indeed barely audible or gone altogether, and clearly audible to each side of the ideal bias point.

All of this is best done at very low listening levels over headphones in a quiet environment. If you don't want to do it aurally, you can use an oscilloscope.

I then copy the ideal value I found  with the trim pot and choose a fixed source resistor of the same value for final installation."


https://groupdiy.com/index.php?topic=46109.40
 (https://groupdiy.com/index.php?topic=46109.40)"First, you set the adjustable source resistor (R7, or the source resistor that is in parallel with the bypass cap C4) to maximum resistance.  Then, with the capsule disconnected, you inject a test signal into the coupling cap leading to the gate of the JFET).

Here's a shot of the incoming signal (1kHz, 200mV peak-to-peak in this case).  The JFET device is a 2N3819 in this case.

Then you set your scope to AC coupling, and place the scope probe on the drain of the JFET.  You then start increasing the input amplitude until one side of the signal begins to flatten out.  Here's what this looks like (you can see the top of the signal is starting to flatten):

After this, you decrease the value of the source resistor until the signal again looks symmetrical:

You keep repeating this process (increase input amplitude until one side of the signal distorts, then decrease the source resistance until the waveform looks symmetrical), and after three or four iterations, you'll see that the waveform begins to clip evenly on both the top and bottom of the waveform as you increase the input amplitude.  Here's what this looks like:"
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 25, 2018, 09:10:40 PM
I just finished my two mics and I am getting some odd results. At the 21.5 and 10v measure points, I get around 23v. The 46v and 24v spots are accurate but it doesn't drop from there. I have 24v on the drain of the fet no matter what I do with the trim pot. Also the 46v spot on the schematic between the  1G and 10M resistors is measuring only 16v. It's happening on both of mics. I used the parts from the Mouser BOM so I don't think I got any parts wrong. I've gone over the parts and my soldering multiple times and can't figure it out. Is it possible the fets from ebay are bad? Photos below.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 25, 2018, 11:03:26 PM
Top
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 25, 2018, 11:04:35 PM
Bottom
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on July 26, 2018, 10:27:05 AM
The voltage you measure is lower than in reality, because you are loading the circuit while measuring.
That is why the voltage drops.
To measure the voltage correctly, you would need a meter with an infinite internal resistance.

Example: your meter is 20 K.ohm/volt. In the 50 V. range the internal resistance of the meter is 1 M.ohm.
Now you measure with a series resistance of 10 M.ohm.
What you are measuring now, is 1/11 of the real voltage!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrasia on July 26, 2018, 05:48:27 PM
What are you guys doing with the extra flap of foil on the Cinemag CM-5722?  Are you connecting it to pin 1 or should I just leave it floating?

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on July 26, 2018, 07:16:04 PM
What are you guys doing with the extra flap of foil on the Cinemag CM-5722?  Are you connecting it to pin 1 or should I just leave it floating?

The excess foil on the axial end? I tore it off. I had trouble getting it to fit in the PCB with it still attached.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 26, 2018, 11:01:36 PM
The parts were delivered yesterday to the far east.  Thank you again for handling and the support, Bonzai. ;)

I am wondering how can I paint the body.
It would be great if you guys share how are you going to paint the surface.
Ordinary color paint with a primer underneath or powder coat?

Anyway, thanks again and hope everything works fine.

Hey Usatrene,

To paint with a professional looking finish, the easiest and cheapest option is powder-coat. Round here it would cost about €10.

Otherwise for wet paint, just lightly sand the tube by hand to get rid of any oxidation, wipe clean with some rubbing alcohol, apply a coat of primer, and finish with a spraycan for a smooth and even finish.

For a really shiny and smooth paintjob, you can apply a finish layer of clear varnish, then buff the tube with some polish.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: usatrene on July 27, 2018, 01:57:49 AM
Hey Usatrene,

To paint with a professional looking finish, the easiest and cheapest option is powder-coat. Round here it would cost about €10.

Otherwise for wet paint, just lightly sand the tube by hand to get rid of any oxidation, wipe clean with some rubbing alcohol, apply a coat of primer, and finish with a spraycan for a smooth and even finish.

For a really shiny and smooth paintjob, you can apply a finish layer of clear varnish, then buff the tube with some polish.

Thank you again, Bonzai!
I was just thinking about powder-coat.
There are powder-coat companies but it they mainly work on auto-parts as far as I looked in the ads.
I hope they would be interested in this project.

I still waiting for the JFET, it seems parts company like Mouser does not have one at the moment.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 27, 2018, 04:06:54 PM
Thanks for the info but unfortunately the mic does not work and it would seem that the bias voltage staying constant despite tweaking the trim pot would be a problem. I suspect a bad batch of fets from eBay/China. Ordered some legit fets from small bear and will report back. I've gone over the pcb a thousand times and everytbing is flawless so it's the only thing I can imagine.

The voltage you measure is lower than in reality, because you are loading the circuit while measuring.
That is why the voltage drops.
To measure the voltage correctly, you would need a meter with an infinite internal resistance.

Example: your meter is 20 K.ohm/volt. In the 50 V. range the internal resistance of the meter is 1 M.ohm.
Now you measure with a series resistance of 10 M.ohm.
What you are measuring now, is 1/11 of the real voltage!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on July 28, 2018, 10:12:55 PM
Haven't tried it, but at $120 it wouldn't even be an option for me.

Rather get two Cinemag's, or the original Haufe ;)

I was just curious if anyone noticed an audible difference. The price disparity is daunting.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BramK on July 30, 2018, 01:25:53 AM
Those who have completed your mics, how do they sound? Like an 84?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on July 30, 2018, 03:05:26 AM
This is how the 2N3819's I got from China/eBay tested. I guess now I know why my mics don't work. Don't trust Chinese components on eBay regardless of what the markings on the components say. Small bear carries these.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on August 01, 2018, 05:29:30 PM
Finally got these working after replacing the bad FET's from China. I highly recommend Small Bear for a source of good 2N3819's. Got through the bias procedure with a scope, using my DAW as a signal generator. After multiple unsatisfactory patina attempts, I decided on a simple satin clear coat, we'll see how it holds up. One problem is that I seen to have lost the inner mesh for one of them. Can anyone recommend a place to find a replacement? Right now I'm thinking about taking a piece out of one of those splatter screens for cooking.
(https://farm1.staticflickr.com/938/42887551385_ec1d5564c8_z.jpg)
(https://farm2.staticflickr.com/1799/41982412450_f60f3903c0_z.jpg)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: AW_music on August 02, 2018, 09:34:49 AM
Hello everybody,
all received here.

A couple of questions:

Can someone please explain me exactly where to intall the mesh included in the package?
I presume it's for the capsule, but i cannot figure out how to open the capsule and install the mesh ....or i'm in the wrong direction ?

Can i replace with 2N3819  with a J113  ->  https://www.mouser.it/ProductDetail/ON-Semiconductor-Fairchild/J113?qs=sGAEpiMZZMvAvBNgSS9LqrkM%2fzSS1Sxk . ???

Cheers
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: lkipod on August 02, 2018, 01:51:22 PM
Hello everybody,
all received here.

A couple of questions:

Can someone please explain me exactly where to intall the mesh included in the package?
I presume it's for the capsule, but i cannot figure out how to open the capsule and install the mesh ....or i'm in the wrong direction ?

Can i replace with 2N3819  with a J113  ->  https://www.mouser.it/ProductDetail/ON-Semiconductor-Fairchild/J113?qs=sGAEpiMZZMvAvBNgSS9LqrkM%2fzSS1Sxk . ???

Cheers


Hey
I suppose it's for the slots under the capsule.


BTW banzai and Graeme, all received well here.
Amazing looking kit, many thanks!
Didn't get around to building just yet.

One question though, which type of screws goes into the white plastic thingy?

Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 03, 2018, 03:02:16 AM
Hey everyone

I've just built my first one and no luck yet... It's "windy", like with lots of constant artifacts and VERY LOW gain... Something is very wrong...
Double checked all the solder joints and looks fine...

BUT, first I figured out that I placed the C4 inverted (duhhhhh), tested it with 48V on, etc... and of course it won't work properly...

Then I corrected it and nothing changed...

Any ideas?! Maybe I screwed the FET?

Thanks!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: usatrene on August 03, 2018, 04:19:54 AM
Hi, jordan s
Congratulations! ;)

Would you kindly tell me how you exactly calibrate the bias if you don't mind?
How and where did you put probes on?
How did you use your DAW signal to the circuit?

This is my first trail draining the volts.
Thanks
Got through the bias procedure with a scope, using my DAW as a signal generator.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on August 03, 2018, 06:23:34 AM
I posted 3 different methods borrowed from the U87 project above.

Hi, jordan s
Congratulations! ;)

Would you kindly tell me how you exactly calibrate the bias if you don't mind?
How and where did you put probes on?
How did you use your DAW signal to the circuit?

This is my first trail draining the volts.
Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 03, 2018, 12:08:11 PM

Hey
I suppose it's for the slots under the capsule.


BTW banzai and Graeme, all received well here.
Amazing looking kit, many thanks!
Didn't get around to building just yet.

One question though, which type of screws goes into the white plastic thingy?

Thanks!

Hey Ikipod,

The screws were included in the spring/mesh bag. If you have a couple of units, it will be in one of the bags.

Size is M2.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 03, 2018, 12:10:50 PM
Can someone please explain me exactly where to intall the mesh included in the package?
I presume it's for the capsule, but i cannot figure out how to open the capsule and install the mesh ....or i'm in the wrong direction ?

Mesh covers the air-slots of the bodytube, right underneath where you screw on the capsule. They're not installed in case you want to paint the tube first.

The capsule is fully ready. Once your mic is finished, just screw them on and you're good to go.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on August 06, 2018, 01:17:07 AM
Where can I find a replacement mesh? I am missing one.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 06, 2018, 11:25:15 AM
Where can I find a replacement mesh? I am missing one.

Hey Jordan, I can send you a replacement sheet – you can cut a few new ones out. Shipping would be a few bucks.

Otherwise you can find them in specialised hardware stores: anything around 50 mesh should be similar (stainless steel).
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: lkipod on August 06, 2018, 02:55:48 PM
Hey Ikipod,

The screws were included in the spring/mesh bag. If you have a couple of units, it will be in one of the bags.

Size is M2.

Great!!
Thanks a million!
Moshe
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: usatrene on August 07, 2018, 04:54:41 AM
Thank you, jordan s
I see.
Still, it seems difficult to try any of these methods.
I need to experiment.
Thank you anyways.
I posted 3 different methods borrowed from the U87 project above.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 07, 2018, 03:25:55 PM
Hey everyone

I've just built my first one and no luck yet... It's "windy", like with lots of constant artifacts and VERY LOW gain... Something is very wrong...
Double checked all the solder joints and looks fine...

BUT, first I figured out that I placed the C4 inverted (duhhhhh), tested it with 48V on, etc... and of course it won't work properly...

Then I corrected it and nothing changed...

Any ideas?! Maybe I screwed the FET?

Thanks!!!


Any ideas?! Heeeeeelp!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 07, 2018, 05:27:30 PM
Just built the second one and it's exactly the same!!! DAMN!!!

Is there something really dumb that I'm missing?!

To measure the voltages, I plug the XLR without the capsule screwed and then measure the test points as in the schematic?

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on August 08, 2018, 02:08:43 AM
If you're like me, you bought bad fets from China/ebay.

Just built the second one and it's exactly the same!!! DAMN!!!

Is there something really dumb that I'm missing?!

To measure the voltages, I plug the XLR without the capsule screwed and then measure the test points as in the schematic?

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 08, 2018, 02:43:12 AM
Feeling REALLY dumb... I missed connecting the white/red and white/brown xformer wires together... :/

damn...

Now the mics are working perfectly... VERY nice sound!

I'm in for another pair! haha

THANKS!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on August 08, 2018, 09:38:45 PM
Sorry folks, I've been way off-grid doing trying to clear a backlog of recording/mixing work.

For those who have had a go with something other than the 2N3819 and it's not playing the game, I'd say it's worth double checking the pins on the FET.

I got caught with that a while back using a J211. Good FET, but totally user error! It was super quiet when powered up and I buggered around for ages trying to work out what the hell was going on. Turns out the pins are different on that FET and I hadn't picked up on it when I looked at the data sheet. It could be the same with some of the other things (maybe Chinese rip-offs) that people are using so it's worth a check, I reckon.

G
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on August 09, 2018, 09:24:27 AM
..the last two batches of 2N3819 I bought turned out fake, just some rebranded generic NPN transistor..

They were branded, with laser marking:
(Fairchild-Logo-F)
BJ12
2N3819
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Winetree on August 09, 2018, 01:20:48 PM
I just ordered some 2n3819s from china.
I bought 30 of them to check the HFE and use the highest ones.
Is that enough testing?
If they are fake, will they work?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on August 09, 2018, 05:24:43 PM
I would highly recommend NOT buying the Chinese FET's as gyraf has pointed out, they are rebranded BJT's and will not work. The ones I got from Small Bear were very cheap and good quality. Why deal with fakes?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on August 09, 2018, 11:10:33 PM
To be fair, even though the prices are good for the Chinese ones it's not much use if it doesn't work in the circuit. You're better off getting them from a better source,  or try some equivalents. Just double check those pins... Like I said above, it's a simple mistake, but it got me.    ::)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on August 10, 2018, 03:05:24 AM
I just ordered some 2n3819s from china.
I bought 30 of them to check the HFE and use the highest ones.
Is that enough testing?
If they are fake, will they work?

No Hfe on JFETS, has infinite current gain

I simply test with a transistor tester like https://www.banggood.com/DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-Resistor-NPN-PNP-p-929603.html - it clearly identifies your transistor type and idss etc for jfets

Jakob E.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 10, 2018, 01:00:40 PM
Simple questions about BIASing the mics when feeding 1Khz at the gate:

Is it meant to be measured with the capsule disconnected and feeding 48V trough the XLR?! Or simply with everything disconnected?!

Can I feed the 1khz trought the spring connector? Doesn't it make sense?!

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mhbunch on August 10, 2018, 04:34:22 PM
Just finished and calibrated my pair. Amazing sounding mics! Thank you for putting this together.   :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on August 11, 2018, 07:22:05 AM
Are there already thoughts about a next batch?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: dissonantstring on August 12, 2018, 02:09:39 AM
I was thinking the same thing!  Second round would be very much appreciated Banzai!  :)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 12, 2018, 05:31:55 AM
Still didn't get how to proceed to calibrate! Can any good soul help me?!  :)

Worried to do something wrong and screw the FET  :-[
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mhbunch on August 12, 2018, 09:13:39 PM
Inject 1k to pin on spring housing , power up w 48v, adjust til you hear lowest distortion is the quickest/easiest way.

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

Worried to do something wrong and screw the FET  :-[
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mics on August 13, 2018, 12:41:11 AM
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!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 13, 2018, 04:21:04 AM
Inject 1k to pin on spring housing , power up w 48v, adjust til you hear lowest distortion is the quickest/easiest way.

Thanks for clarifying :)

Cheers
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on August 13, 2018, 04:45:42 AM

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


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.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mics on August 13, 2018, 05:05:47 AM
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!

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mics on August 13, 2018, 05:14:48 AM
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.

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!

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on August 13, 2018, 06:29:32 AM
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.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: JohnRoberts on August 13, 2018, 09:55:53 AM
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!
Manufacturers generally copyright PCB layout to protect against outright duplication.

[superfluous comment removed ]

JR
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 13, 2018, 12:39:26 PM
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.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 13, 2018, 12:46:08 PM
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!

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.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 13, 2018, 01:02:45 PM
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.

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.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: shabtek on August 13, 2018, 02:58:49 PM
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. 
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: 12afael on August 13, 2018, 03:11:03 PM
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
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!





Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on August 13, 2018, 03:48:12 PM
Still didn't get how to proceed to calibrate! Can any good soul help me?!  :)
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!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 13, 2018, 05:56:46 PM
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!

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!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on August 14, 2018, 08:32:32 AM
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!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: guismarquesrj on August 14, 2018, 09:49:34 AM
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!

PERFECT! :)

Yes, I have an oscilloscope here! \o/

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

Thanks very much again!

Best,

Gui
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Matador on August 14, 2018, 10:49:43 AM
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.
Isn't the body the same as this?

http://recordinghacks.com/microphones/MXL/604
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: RuudNL on August 14, 2018, 12:28:21 PM
No, the MXL 604 has a switch, the Banzai one hasn't.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 14, 2018, 01:56:57 PM
Isn't the body the same as this?

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

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)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on August 15, 2018, 04:45:16 AM
There's an interesting physical difference between the MXL 603s and our kit.

Visually they're identical except for a fine mesh grill on the 603s capsule verses the punched plate on our one. BUT, the XLR housing of the 603s is longer internally and screws directly to the board, then the XLR pins are wired to the board not soldered directly to the PCB like ours. The MXL board is 3mm shorter and has no cutouts for the housing so our boards don't fit in the 603s body.

The capsule sounds different too, brasher and brighter, without the wonderful open, but mellow, character of our kit. That's what I noticed testing the 603s capsule with the same KM84 circuit as we're using anyway. I'm not sure if all 603s are like that but the one I was testing with this circuit was "interesting". Not bad, as such, just "interesting" and not to my tastes.

The original 603s circuit is transformerless too, but I didn't bother testing that, I just dumped it in favour of the Neumann circuit.

That's just the differences I noticed for sake of interest. All these mics are pretty much identical, just Chinese gear that helps us all make cool mics for much less cost.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: HosaMogami on August 20, 2018, 03:24:25 PM
This was a super fun little build. Thank you guys so much for the work you put into this! Will definitely order more when the next run comes out!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on August 21, 2018, 09:01:58 PM
This was a super fun little build. Thank you guys so much for the work you put into this! Will definitely order more when the next run comes out!

Great to hear, and thanks for the confidence!  :D
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on September 02, 2018, 01:56:15 AM
I'm having an issues with these guys on my first session with them. I set all the mics up on a drum kit, adjusted everything to my liking, tried out various mics on different parts of the kit and tuned everything up, they sounded great as overheads. Then I powered everything down, covered the mics with regular soft cases while still on the stands and left for the night.  When I came back the next day to record, both mics were fading in and out and distorting with loud drums. Unfortunately I had tracked a whole song before realizing. When I switched over to the little blondies I usually use, they worked perfectly fine.  Anyone have any ideas why they worked perfectly one day and not the next while nothing had changed? The symptoms sound like humidity or a dirty capsule but on brand new mics that had only been out overnight, partially covered, seems odd.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on September 02, 2018, 04:56:20 AM
humidity in the covers? that´s about the only obvious explanation, isn´t it, if both mics were affecterd?

Jakob E.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jordan s on September 02, 2018, 04:42:40 PM
humidity in the covers? that´s about the only obvious explanation, isn´t it, if both mics were affecterd?

Jakob E.

I suppose so. I find it odd because I've never experienced this before. I thought the covers would protect them from humidity. Maybe some time in a dehydrator would do the trick?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Matador on September 02, 2018, 06:59:28 PM
A day or two in a bag with desicant salts usually takes care of it.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on September 03, 2018, 02:36:14 AM
Unless having set up outdoor, I see no reason to ever cover up microphones (that are in use) overnight..?

Jakob E.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on September 06, 2018, 02:10:56 AM
I suppose so. I find it odd because I've never experienced this before. I thought the covers would protect them from humidity. Maybe some time in a dehydrator would do the trick?

Covers are great for dust, but can also trap humidity if not breathable enough. Especially in summer (or basements).

If you have a humidity gauge, you can check your room: 40-50% humidity is normal/ideal.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: AW_music on September 08, 2018, 07:40:27 AM
Hello ,

I'm completing the assembly,
is it correct that i have to cut the moving pin on the plastic part screwed to the pcb?
This pin is way too long and i cannot  screw the capsule into the body.
Anyone has the same problem?

Nick


 
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on September 08, 2018, 11:46:39 AM
Yes everyone has this “problem”.
Just cut it. Be careful with trimming .
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on September 08, 2018, 10:00:34 PM
I'm having a problem with mine - the level is very, very low. I checked my voltages and there's one anomaly:

R9 + R10:  46.3V

R5 + R6: 23.1V

R4 + R5: 19.6V

C2 + R4: 10V

R1 + R7: 15.5V,  should be 46V

What would cause that, and is that what is also causing my level problem? I worked carefully and I believe everything is in the correct place and orientation. The only difference is that I replaced C1 with an axial polystyrene cap. I installed the original polypropylene cap incorrectly and I had to cut it out. I had the polystyrenes on hand. Thanks.

Thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: gyraf on September 09, 2018, 04:12:22 AM
Voltmeter impedance?

Jakob E.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on September 09, 2018, 10:36:56 AM
Voltmeter impedance?

Jakob E.

Thanks Jakob. Any thoughts about the level problem?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on September 09, 2018, 03:27:33 PM
Hi all,

It was me. The trafo wasn't hooked up correctly. Seems to be working fine now. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on September 21, 2018, 08:21:34 AM
Hi all,

Thought you might like to know that I tried the AMI T8 transformer in my mic and it makes the mic sound much more like my real KM84s. The Cinemag had a nice rich bottom but was noticeably darker than my KM84s - both of which are later ones with 5000 serial numbers. With the AMI it's much, much closer to the authentic tonal balance. The Cinemag is not at all bad, just not as authentic. Whether it's worth the additional cost is another question. I have no connection to the company, btw.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on September 21, 2018, 01:38:21 PM
Hi all,

Thought you might like to know that I tried the AMI T8 transformer in my mic and it makes the mic sound much more like my real KM84s. The Cinemag had a nice rich bottom but was noticeably darker than my KM84s - both of which are later ones with 5000 serial numbers. With the AMI it's much, much closer to the authentic tonal balance. The Cinemag is not at all bad, just not as authentic. Whether it's worth the additional cost is another question. I have no connection to the company, btw.

Thanks for trying it out!

Still waiting on the Haufe's to come through, to see if they're also a viable option in terms of price and availability.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Hank Dussen on September 22, 2018, 07:36:05 AM
Anybody has some extra 2N3819's?
They're not so hard to find but shipping costs are often €10 or more...
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on September 23, 2018, 09:08:19 AM
Anybody has some extra 2N3819's?
They're not so hard to find but shipping costs are often €10 or more...

I can spare a couple!

Only have the two available though.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: Banzai on December 25, 2018, 04:22:51 AM
Sale open!

To place your order, please follow instructions here:
https://groupdiy.com/index.php?topic=68360.msg869537#msg869537

(https://i.postimg.cc/hGf1DX0n/GDIY-KM84.jpg)
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: RuudNL on December 25, 2018, 05:08:56 AM
It was mentioned before that you were planning to sell some capsules separately.
Will this still be the case?
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: craigmorris74 on December 25, 2018, 08:55:08 AM
I'll take 2, please.
Craig Morris
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: PG_Sax on December 25, 2018, 09:08:04 AM
Just sent my order through! :)
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: Guff on December 25, 2018, 11:58:28 AM
payment for 2 sent
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: Banzai on December 25, 2018, 12:09:48 PM
Thanks!  :D
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110/kit – OPEN for orders
Post by: mhelin on December 25, 2018, 12:56:19 PM
T
*** Please send EUR payments only – no CHF ***
Sorry about that, resent.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Potato Cakes on December 25, 2018, 12:58:37 PM
Payment sent for two.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: TwentyTrees on December 25, 2018, 01:47:41 PM
Payment sent for two kits. Merry Christmas!

Best,
Andy
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: craigmorris74 on December 25, 2018, 05:22:03 PM
Decided to just go with one.  Payment sent.  Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: BramK on December 26, 2018, 11:49:37 AM
Payment sent for 2 kits. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Aleguitarpro on December 26, 2018, 01:01:14 PM
Payment sent for 2kits. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: kominak on December 26, 2018, 04:13:14 PM
Payment sent for 2 kits. Many thanks!
Martin
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on December 26, 2018, 04:15:38 PM
Thanks for the orders!  :D

Around 30 kits sold so far.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: jarvis on December 26, 2018, 06:03:31 PM
I'd be in for two capsules as well, if there are a few left over.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Vernois on December 26, 2018, 06:20:17 PM
I’ll take two! Payment will be sent right away.
Thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: rodaffleck on December 26, 2018, 08:33:30 PM
Also in line for a couple of capsules if there are leftovers.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: kilmister on December 27, 2018, 09:16:07 AM
Payment sent for a pair.

Cheers,
Paavo
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: RuudNL on December 27, 2018, 12:45:04 PM
Would be interested in a couple of capsules, if the price is right.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: HosaMogami on December 27, 2018, 10:41:01 PM
I will take two please & thank you!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: iturnknobs on December 28, 2018, 12:20:48 AM
Please count me in for 2.

Thank you,
Brian
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on December 28, 2018, 02:49:22 AM
Please count me in for 2.

Thank you,
Brian
I will take two please & thank you!

Thanks guys! Whenever you're ready to order, all details are in the first post.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Bichon on December 28, 2018, 05:04:23 AM
Ordered two kits!

Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on December 28, 2018, 05:56:39 AM
Thanks for the orders!  :D

Two notes:

– For anyone who ordered in the first round, we made a custom spring connector for this batch. No more need to cut the spring pin to length, and the board will fit directly into the slots without any cutting/filing needed.

– The 3U GZT-84 is a great low-cost transformer option for this kit. Ebay price is €34 shipped

I can get a 30% discount by ordering in bulk, and include it with the kit for €25/pc extra. No leadtime involved as we can buy from existing stock. Will need at least 50pcs ordered to make it happen, but for now:

Only available to anyone who's ordering the kit in this batch, just send €25 extra for each one you need

Paypal fees are included in price making it easy, and there are no limits on quantity – for eg., if you bought two kits but want to order 3 transformers, no problem.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: fsalter on December 28, 2018, 01:44:26 PM
Hi Banzai
Just ordered one kit with 3u transformer. Note that as i mentioned to you earlier, i would be interested in 2 bodies only. I see that RuudNL wants capsules only. Can we make that happen?
Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on December 29, 2018, 06:09:28 AM
Hi Banzai
Just ordered one kit with 3u transformer. Note that as i mentioned to you earlier, i would be interested in 2 bodies only. I see that RuudNL wants capsules only. Can we make that happen?
Thanks

Thanks for the order!

If you guys want to split kits up between you, please do.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Mworthin on December 30, 2018, 02:31:07 AM
2 kits ordered. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: dasnevestheo on December 30, 2018, 07:59:51 AM
Is anyone interested in just capsules and body ? I already have those but need the PCBs...
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on December 30, 2018, 05:56:24 PM
Thanks for the orders!  ;)

Some pics of the capsule – polished and nickel plated capsule head & filter mesh plate + new diaphragms:

(https://i.postimg.cc/nzSTVDq7/DIY-KM84-capsule-A.jpg)

(https://i.postimg.cc/Z5PcBgrJ/DIY-KM84-capsule-B.jpg)

(https://i.postimg.cc/QM0JST4P/DIY-KM84-capsule-C.jpg)

Fresh skins  8)

(https://i.postimg.cc/LXKXGHCp/MAIKU-Mylar-3.png)
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: RuudNL on December 31, 2018, 01:13:42 PM
Is anyone interested in just capsules and body ? I already have those but need the PCBs...

I have two PCBs I am not going to use. If you are interested, send me a PM.
  SOLD!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: rodaffleck on December 31, 2018, 06:42:58 PM
Thanks for the order!

If you guys want to split kits up between you, please do.


fsalter, I defer to Ruud having first dibs, but if he backs out maybe we can make a deal. We are both in Canada which could make things much easier shipping-wise.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Le Roux on December 31, 2018, 06:43:12 PM
Paid for two kits

Thanks
Neil
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: AttamanuBe on January 01, 2019, 06:44:16 AM
Hi,

What's the difference with the older kit's diaphragm ?

Thanks for the orders!  ;)

Some pics of the capsule – polished and nickel plated capsule head & filter mesh plate + new diaphragms:

Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Glutamatjunkie on January 01, 2019, 09:42:46 AM
Ordered two kits
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 02, 2019, 09:36:45 AM
Hi,

What's the difference with the older kit's diaphragm ?

Same. For both batches the capsules received the plating treatment and fresh Maiku skins.

As a sidenote, no idea how the stock version sounds since we always received the capsule in parts. But altogether it's a great capsule for this kind of rework - no flaws in the metalwork design to mess up the freq response.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: adeptusmajor on January 02, 2019, 11:13:46 PM
Payment sent for two kits!!! 8)

Thank you!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: iturnknobs on January 03, 2019, 11:38:50 AM
Payment sent for 2 kits.

Thanks for your efforts.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: 12afael on January 03, 2019, 01:33:05 PM
I paid two some days ago , thanks

Rafael
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Max51 on January 06, 2019, 12:08:04 PM
Hi Banzai,

I'm just discovering the project. Nice stuff !!
I'm thinking about to buy two kits with trafos.
Do you provide building instructions ? 

Thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: GraemeWoller on January 06, 2019, 04:31:56 PM
Do you provide building instructions ? 
Thanks

There's a schematic and a BOM for components, but I'm hoping to put together a simple "how it goes together" tutorial in the near future for those who'd find it handy.

Luckily it's a nice straight forward little fulla that pretty much anyone can tackle!  ;D

Graeme
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Max51 on January 07, 2019, 12:08:36 PM
There's a schematic and a BOM for components, but I'm hoping to put together a simple "how it goes together" tutorial in the near future for those who'd find it handy.

Ok thanks,
I placed an order for 2 kits with trafos,

Cheers !
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: audiomsg on January 07, 2019, 04:23:43 PM
Hi Banzai
Payment sent for 2 kits plus 2 transformers
Cheers!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: jolmot on January 07, 2019, 05:19:22 PM
Hi Banzai,

Order sent for 2 Kits + Transformers,

Cheers!

Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Hank Dussen on January 07, 2019, 06:10:39 PM
Is there a super-cardiod or hyper-cardiod capsule I can use with this mic?
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: tjhealy on January 08, 2019, 05:30:51 PM
Hi there Banzai,

I have sent an order for 4 x Kits + 4 x Transformers,

Kind regards
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 08, 2019, 06:03:31 PM
Is there a super-cardiod or hyper-cardiod capsule I can use with this mic?

Don't really know any except for the generic Chinese MXL types. Those will screw on the bodies no problem.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 08, 2019, 06:10:09 PM
Thanks for all the latest orders: over 70 kits sold  :D

There's no hard limit at 75 kits, as we have some reserve - but if anyone still wants to get in, nows the time.

As long as the thread is marked OPEN, kits are still available.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: kvintus on January 10, 2019, 01:30:35 AM
Payment sent for
4kits + 4transformers
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: earlfsmith on January 10, 2019, 04:06:58 AM
I would like two capsule only.  Is this still an option or was that for the first batch on the hopes of some left over? :o :o :o
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 10, 2019, 08:52:44 AM
I would like two capsule only.  Is this still an option or was that for the first batch on the hopes of some left over? :o :o :o

Not sure. Priority is on supplying full kits
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: alistair_ross on January 10, 2019, 11:35:13 PM
Hi Banzai

Payment sent for 2x kits and 2x transformers.

Thanks very much!
Alistair
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: maarvold on January 11, 2019, 06:14:04 PM
Have kits shipped yet?  If not, approximately when will they ship and maybe a guesstimate of shipping time?  Thanks!!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Deflator on January 12, 2019, 01:31:00 PM
Payment Sent for 2 kits.
Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 13, 2019, 10:06:21 AM
Have kits shipped yet?  If not, approximately when will they ship and maybe a guesstimate of shipping time?  Thanks!!

Hey Maarvold,

Packing/shipping will only start once sale is closed. All orders will ship together.

Shipping time depends on location (europe/US is usually about 7-days).
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: indraperkasa on January 13, 2019, 10:17:07 AM
Hi Banzai,
payment sent for 1 kit + transformer.
thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: nyoung on January 16, 2019, 10:43:36 AM
Payment sent for 2 mic kits and 2 transformers.  Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: stelin on January 17, 2019, 06:28:01 PM
Hi Banzai
Payment sent for 2 kits plus 2 transformers
Cheers!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: RoyBoy on January 17, 2019, 09:48:10 PM
Payment sent for two kits and two transformers.  Thanks.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Fuzz Face on January 18, 2019, 08:44:31 AM
First time poster here. This must be the greatest forum I’ve ever seen.

Thanks for all the great info and projects like this. I ordered 2 kits and 2 transformers last night.

Can’t wait to hear these on drums compared to my KM184s 8)

Thanks so much guys!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Jim50hertz on January 22, 2019, 01:58:25 AM
Hey Banzai

How long do you think this will be open for?  I don’t want to miss out this time but will need to sort my tax out first.  Looking to jump on a pair of kits.

Cheers

Jim
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: damianschwartz on January 22, 2019, 03:07:24 AM
Hey Banzai

How long do you think this will be open for?  I don’t want to miss out this time but will need to sort my tax out first.  Looking to jump on a pair of kits.

Cheers

Jim
Exact same situation here ... :/
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Jim50hertz on January 22, 2019, 08:53:58 AM
Yup, tax time sucks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: guismarquesrj on January 22, 2019, 11:54:14 AM
Just sent a payment for a pair, without transformer...

Now I'll have 4!!! Lucky me I got a pair in the first batch  ;D

 :-*
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 22, 2019, 08:34:55 PM
Thanks for all the new orders!  :D

How long do you think this will be open for?  I don’t want to miss out this time but will need to sort my tax out first.  Looking to jump on a pair of kits.

Hey Jim, how long do you need?

We'll be hitting a hard limit pretty soon. Will remain open until then.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Jim50hertz on January 23, 2019, 02:28:14 AM
A week would be great, hoping to have this sorted in the next couple of days though.  May be able to pay Sunday or Monday 👍🏻
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: damianschwartz on January 23, 2019, 04:01:09 AM
Thanks for all the new orders!  :D

Hey Jim, how long do you need?

We'll be hitting a hard limit pretty soon. Will remain open until then.
About the same here, Monday - Tuesday i'll be in for 2 sets..
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 23, 2019, 06:40:24 AM
No problem, next week will be fine. Plenty still left.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: TwentyTrees on January 25, 2019, 01:51:35 PM
Payment sent for a further two kits (in addition to previous order of two), and four 3U GZT-84 transformers!

Thanks
Andy
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Pignouf on January 27, 2019, 01:14:39 PM
Payment send for 4 kits + 4 transfo's.

Enjoy the drinks!

Thy
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 27, 2019, 02:03:09 PM
Thanks for the new orders!!

Once the transformers arrive this week, we'll start packing & shipping all orders  8)
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Miami Nice Studios on January 28, 2019, 09:17:22 AM
Just sent payment for 2 kits +Transformers.  :) I´m excited!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 28, 2019, 01:58:28 PM
Thanks!!  :D

*** 3U transformers now sold out ***

Anyone who missed out, they are available to order directly from 3U on ebay.

KM84 kits without transformers still available.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Gregor Zelder on January 29, 2019, 03:58:50 AM
Just sent payment for 2 kits. So excited - was waiting for a good KM84 kit for ages!
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Nele on January 29, 2019, 07:33:05 AM
Payment sent for 2 kits.
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Jim50hertz on January 30, 2019, 08:12:56 AM
Tax sorted, payment sent for two kits
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: damianschwartz on January 30, 2019, 10:03:23 AM
Will send payment for 4 today-tomorrow,  do you include the trafos as an option? (i don't see it on the 1st post)
Title: Re: Neumann KM84 DIY Body & PCB kit – 75pcs available @ €110 – OPEN for orders
Post by: Banzai on January 30, 2019, 10:08:23 AM
Will send payment for 4 today-tomorrow,  do you include the trafos as an option? (i don't see it on the 1st post)

Transformers are sold-out, but you can still buy them direct from 3U on ebay:

https://www.ebay.com/itm/3U-Audio-GZT-84-Output-Transformer-for-SDC-Microphone/112882929558?hash=item1a4858cf96:g:CiYAAOSwW5lasiBg:rk:10:pf:0
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: duantro on January 30, 2019, 09:13:23 PM
Payment sent for 2 kits. So glad I squeezed in this round!
Edit: I paid for the paypal fees, just read that the price included fees, looks like another drink bonus!
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: GraemeWoller on January 31, 2019, 12:32:12 AM
Payment sent for 2 kits. So glad I squeezed in this round!

I'm a little biased, but they are well worth it!  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: TillM on January 31, 2019, 02:28:54 AM
Payment send for two kits.
Thanks Banzai !
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: duantro on January 31, 2019, 12:12:09 PM
I'm a little biased, but they are well worth it!  ;)
Ha! I'm glad. Are there any other comments on the different transformers?  so far I've read AMI t8 sounds like the original (but $120!), Cinemag's have good low end, but are darker than original, and Haufe made a round of the originals, but are they still available? How do the 3U gtz 84's sound? any thoughts?
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: SM on February 01, 2019, 07:03:06 AM
Are there still kits available for this? €240 for a pair (EU), correct?
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: Banzai on February 01, 2019, 10:21:59 AM
Are there still kits available for this? €240 for a pair (EU), correct?

Correct  ;)
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: RuudNL on February 02, 2019, 05:21:20 AM
You mentioned before that it would be possible to order the capsules separately.
Later, there was a restriction: full kits first and if there were capsules left they could be sold seperately.
So: what is the situation now?
And if capsules are for sale seperately what would be the price?
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: damianschwartz on February 02, 2019, 02:27:14 PM
Sent For 2 kits
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: GraemeWoller on February 03, 2019, 03:41:10 PM
Hi folks,

Here's a .pdf build guide for those who need a helping hand getting their kits started and whipped up into shape. I've aimed it at those who might need the help, most of you guys are pretty expert so it doesn't really apply, but hopefully it'll be a handy resource for putting the kit together without any problems.

http://bit.ly/2ML5aOv

Cheers

Graeme
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: damianschwartz on February 03, 2019, 04:59:31 PM
Hi folks,

Here's a .pdf build guide for those who need a helping hand getting their kits started and whipped up into shape. I've aimed it at those who might need the help, most of you guys are pretty expert so it doesn't really apply, but hopefully it'll be a handy resource for putting the kit together without any problems.

http://bit.ly/2ML5aOv

Cheers

Graeme

Thank u!
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: GraemeWoller on February 03, 2019, 08:07:16 PM
A pleasure, Damian!  :)
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: BramK on February 04, 2019, 12:09:15 PM
Thank you for the great build guide!
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 4 kits left !!! – OPEN for orders
Post by: madreza on February 06, 2019, 11:32:59 AM
I take the last 4 kits :D
Title: Re: Neumann KM84 DIY Body & PCB kit – Only 4 kits left !!! – OPEN for orders
Post by: Banzai on February 06, 2019, 02:22:49 PM
I take the last 4 kits :D

Done :)
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: HosaMogami on February 06, 2019, 07:55:36 PM
Thank u!

Great job with this! Thanks for sharing.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: dinesh on February 07, 2019, 05:51:37 AM
Hello,
PM sent for PSU.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: shabtek on February 07, 2019, 02:55:41 PM
If there is a list for spare capsules I’d like to be on it.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: choolder on February 07, 2019, 05:29:45 PM
any kits available in the near future? Would like to buy 2 :-)

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: samsquanch on February 08, 2019, 04:30:45 PM
If there is a list for spare capsules I’d like to be on it.

Same here.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 10, 2019, 11:40:53 AM
Thanks for the orders  :D

Everything will ship out this week, with tracking numbers sent out latest Friday.

Please whitelist/add [email protected] to your address books, to make sure you receive all notifications.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on February 10, 2019, 09:38:57 PM
Thanks for the orders  :D

Everything will ship out this week, with tracking numbers sent out latest Friday.

Please whitelist/add [email protected] to your address books, to make sure you receive all notifications.
Thanks! I’ve got my pair of cinemag transformers on the way also. They informed me that they have 1,000 in stock. Also that  if I didn’t want to build one, I could get a warm audio 84. They must get a percentage?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 13, 2019, 01:23:27 AM
Also that  if I didn’t want to build one, I could get a warm audio 84. They must get a percentage?
Cheeky... Strange though, as he probably makes more from clients buying transformers direct.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Le Roux on February 15, 2019, 05:27:48 PM
Hi

I just received this from cinemag. I assume we’d connect the wires anyways, just want to make sure I’m good to go, thanks!

All of the leads internally hooked up so that there are 2 wires for the primary and 2 for the secondary.  P/N CM-5722W.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on February 15, 2019, 07:20:58 PM
Thats how I did mine. You should be good.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Le Roux on February 15, 2019, 07:30:32 PM
Thank you! 🙂
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 16, 2019, 10:35:22 AM
Sorry guys for the slight delay – finished packing everything last night, all goes out on Monday (guaranteed). Will provide tracking asap.

Thanks to everyone for your patience!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on February 16, 2019, 04:52:11 PM
Sorry guys for the slight delay – finished packing everything last night, all goes out on Monday (guaranteed). Will provide tracking asap.

Thanks to everyone for your patience!
Thanks for the info, and for all of the work.. Cheers!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Max51 on February 20, 2019, 04:28:44 PM
Well received ! Thanks !
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: indraperkasa on February 21, 2019, 02:27:59 AM
just got my tracking, thank you banzai!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TwentyTrees on February 21, 2019, 01:26:14 PM
Kits arrived today - looking great, very smart and great packaging! Now to investigate getting the bodies powdercoated locally...

Thanks for all your work on this gents!

Andy
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TillM on February 21, 2019, 08:32:49 PM
everything arrived today !
thank you very much!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Jim50hertz on February 22, 2019, 11:40:55 AM
Mines arrived today.  Look great.  Thanks Mike
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 22, 2019, 03:20:11 PM
Kits arrived today - looking great, very smart and great packaging! Now to investigate getting the bodies powdercoated locally...

Thanks for all your work on this gents!

Andy

Another easy option is to polish the brass. Could come out really well.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 22, 2019, 03:23:43 PM
A note about the current kit:

The plastic spring connector is already the right size for the boards. No need to widen the slots – just push in PCB and secure with M2 screws.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: maarvold on February 22, 2019, 04:26:40 PM
I built 3 KM84's--2 with the Haufe Group Buy transformers.  When following the wiring diagram shown on Page 4 of the of the Haufe BV107 Group Buy thread, the microphones are Pin 3 = High; said another way, positive air pressure at the capsule yields a waveform that begins negative.  In my world, and the world of nearly all professional audio, this is not a good thing. 

This could easily be avoided by swapping the orientation of the white and blue wires on the output side.  I have to run out the door, but will try to elaborate when I get back. 

=======================================================

After talking to someone more knowledgable than me in interpreting the Haufe transformer diagram, I now 'get' that the 'positive pressure' side of the Haufe primary is the Black wire and the 'positive pressure' side of the secondary is the White wire.  So my note (above) is still a warning, but a warning not to interpret the transformer diagram the way I originally did. 
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: adeptusmajor on February 22, 2019, 06:09:00 PM
Kits arrived in Virginia, they look great!

Any tips  for painting/powder coating the body without screwing up the mesh behind the slots in the top?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on February 22, 2019, 07:23:28 PM
I believe the mesh is easily removed. So do that. If the new bodies have the mesh soldered in you can just desolder it and then remove it.

Thanks!

Paul
Title: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 23, 2019, 12:55:19 AM
Wiring for 3U transformer:

RED wire -> G
BROWN wire -> R
YELLOW wire -> B
ORANGE wire -> Y

Transformer board pads:

(https://i.postimg.cc/CxZYGpHb/KM84-PCB-Transformer-pads.png)


Stock 3U diagram:
(https://i.ebayimg.com/images/g/s~YAAOSwUV9Wo7EI/s-l500.jpg)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Jim50hertz on February 23, 2019, 04:57:10 AM
If anyone has used the AMI T8 can they lend me a hand with the wiring?

Cheers!

(http://i288.photobucket.com/albums/ll162/jim50hertz/6EA3B34A-2A78-44D0-ADD1-5746E02889A5_zpsd3ebflsd.jpg) (http://s288.photobucket.com/user/jim50hertz/media/6EA3B34A-2A78-44D0-ADD1-5746E02889A5_zpsd3ebflsd.jpg.html)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on February 23, 2019, 10:24:07 AM
(http://www.sethglassman.com/AMI%20T8.jpg)

Leave enough extra grey wire to reverse the leads if the mic's polarity is reversed.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 24, 2019, 03:22:44 AM
Anyone using the stock Cinemag 5722 (8 wires), just follow the markings on the board:

R - Red
G - Green
B - Blue
Y - Yellow

Cinemag 5722W (4 wires):

R - Red
G - Brown
B - Orange
Y - Yellow
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 24, 2019, 04:03:46 AM
When unpacking, your box should contain:

- mic bodies + capsules
- PCB's
- FET's and M2 screws
- plastic capsule pins + XLR connector
- transformers (if ordered)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fripholm on February 24, 2019, 04:07:30 AM
Anyone using the Cinemag 5722, just follow the markings on the board:

R - Red
G - Green
B - Blue
Y - Yellow

That is true if you're using the stock version of the CM5722, where you have to connect the center taps yourself.

But David from Cinemag offered me the internally hooked up version where the colors are vastly different. If I had read his description more carefully it would have saved me a lot of trouble.  Brown/Red is primary - Orange/Yellow is secondary and there are only four wires.

The letters on the board correspond to the following wire colours on the transformer:

G = Brown
R = Red
B = Orange
Y = Yellow

There are no green or blue wires on this version. Keep that in mind!

BTW: thanks Mike for the kit - it's a great sounding mic!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on February 24, 2019, 04:28:48 AM
Thanks! Updated to contain both.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Fuzz Face on February 24, 2019, 11:33:06 AM
Got my kits and transformers and couldn’t be more excited. Really great job on the kits and build doc. Thanks so much!
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: iturnknobs on February 26, 2019, 09:06:39 AM
Ha! I'm glad. Are there any other comments on the different transformers?  so far I've read AMI t8 sounds like the original (but $120!), Cinemag's have good low end, but are darker than original, and Haufe made a round of the originals, but are they still available? How do the 3U gtz 84's sound? any thoughts?
I don't want to bash someone's product, but you might want to steer away from the Haufe trafo. Mine, along with others are literally falling apart. AMI is expensive, but that won't happen with their product. Dennis at AMI is fantastic and will help to his full ability. David at Cinemag was so helpful, he deserves a raise. These are the things I have learned throughout this project and over the years of DIY.
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: TillM on February 26, 2019, 12:15:57 PM
I don't want to bash someone's product, but you might want to steer away from the Haufe trafo. Mine, along with others are literally falling apart. AMI is expensive, but that won't happen with their product. Dennis at AMI is fantastic and will help to his full ability. David at Cinemag was so helpful, he deserves a raise. These are the things I have learned throughout this project and over the years of DIY.

I must say, that the difference between my mic with the Haufe Transformer and the other one with the cinemag is nearly zero.
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: jrmintz on February 26, 2019, 08:48:29 PM
I must say, that the difference between my mic with the Haufe Transformer and the other one with the cinemag is nearly zero.

Wow, that's unexpected. The difference between the Cinemag and the AMI is not subtle.

For anyone who's interested here is a comparison between my first DIY KM84 with the Cinemag transformer and also with the AMI: https://www.dropbox.com/sh/z4hcoqk8nprezza/AACrOkfG3ztepQpGmk3azS1ca?dl=0
Title: Re: Neumann KM84 DIY Body & PCB kit – 100pcs available @ €110 – OPEN for orders
Post by: Potato Cakes on February 26, 2019, 09:48:57 PM
Wow, that's unexpected. The difference between the Cinemag and the AMI is not subtle.

For anyone who's interested here is a comparison between my first DIY KM84 with the Cinemag transformer and also with the AMI: https://www.dropbox.com/sh/z4hcoqk8nprezza/AACrOkfG3ztepQpGmk3azS1ca?dl=0

Are those with the same preamp gain settings? Besides the level difference, even on my not 100% Macbook Pro speakers I the difference is very much quite discernible.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: craigmorris74 on February 27, 2019, 12:10:01 PM
Yes, thanks for posting those clips.  The acoustic clips are a little tough to compare because of pretty big performance differences, and it does sound like the AMI is driving the mic pre harder than the other two.  When level matched the AMI is darker than the KM84 or the Cinemag on acoustic.

But still good stuff. I think I'm hearing different signatures of the transformers.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: craigmorris74 on February 27, 2019, 01:23:21 PM
Double post, sorry.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: jrmintz on March 02, 2019, 11:56:57 PM
Are those with the same preamp gain settings? Besides the level difference, even on my not 100% Macbook Pro speakers I the difference is very much quite discernible.

Thanks!

Paul

Yes, same preamp settings. It's a Neve 1064 with the EQ bypassed. It's hardly a carefully controlled scientific comparison, but it gets the point across.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on March 03, 2019, 02:16:46 AM
Yes, same preamp settings. It's a Neve 1064 with the EQ bypassed. It's hardly a carefully controlled scientific comparison, but it gets the point across.

I agree. Even if you matched the levels to where it seems more like the same volume so one doesn't suspect they are being given the old HiFi salesman trick, one could still tell a difference in the frequency response. No need for anechoic chambers and white lab coats when it's that apparent.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on March 03, 2019, 02:39:02 PM
I got my pair together and had to bias by ear, as my old  tek 465b scope looks to have died. I used these on drum overheads this weekend, and they sound really huge and great. Thanks a ton for offering  this.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: maarvold on March 06, 2019, 06:46:23 PM
I recorded a 24-96-Wave comparison on acoustic guitar of my 2 well-matched Neumann KM84's vs 2 builds of the DIY KM84.  Couldn't be happier.  If you want to check it for yourselves, download here:

https://www.dropbox.com/s/evvmsf7d1wpns6y/Test%20DIY-Neumann%20KM84s.zip?dl=0
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fripholm on March 07, 2019, 04:16:38 AM
I recorded a 24-96-Wave comparison on acoustic guitar of my 2 well-matched Neumann KM84's vs 2 builds of the DIY KM84.  Couldn't be happier.  If you want to check it for yourselves, download here:

https://www.dropbox.com/s/evvmsf7d1wpns6y/Test%20DIY-Neumann%20KM84s.zip?dl=0

Thanks for the comparison. I can't open ProTools sessions, so have to listen to the WAV files directly.

Audio 1_01.wav
Audio 2_01.wav

KM84_Red SN 51518Run 1.wav
KM84-Brn SN 32547 Run 1.wav

KM84-Brn SN 32547  run 2.wav
MC KM84 w C3 Is 1.5 uF run 2.wav

KM84 w 100 uF C3 -C4 run 3.wav
KM84-Brn SN 32547  run 3.wav

The file names doesn't make it obvious which ones are the DIY mics and which ones aren't. I'm noticing "Audio 1" and "Audio 2" are sounding dull compared to the rest. So, as long as this was not supposed to be a blind test, which one is which? :)

I'm also noticing a very narrow stereo field when two pairs are panned hard left and right. How was the placement of the mics?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: craigmorris74 on March 07, 2019, 09:04:51 AM
I recorded a 24-96-Wave comparison on acoustic guitar of my 2 well-matched Neumann KM84's vs 2 builds of the DIY KM84.  Couldn't be happier.  If you want to check it for yourselves, download here:

https://www.dropbox.com/s/evvmsf7d1wpns6y/Test%20DIY-Neumann%20KM84s.zip?dl=0

What transformer did you use for your builds?  EDIT- See its the Haufe BV107.  Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: maarvold on March 07, 2019, 10:07:18 AM
Actually, the one with MC in the name is an AMI T8; the one with MA (me) in the name is Haufe. 
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: maarvold on March 07, 2019, 10:23:42 AM
Audio 1 & Audio 2 weren't meant to be included--sorry. 

The ones with SN (serial number) in the name are real Neumann KM84's.  SN32547 is the Control mic; the rest are considered Test mics and are compared, one at a time, to the Control.  This is all explained in the ReadMe file I included; Unfortunately, it looks like my neatly-formatted file got a little weird-looking, but all the info is there and readable, in spite of the formatting. 

I included the Pro Tools session in case it makes things more convenient for some.  But the files can certainly be played directly in any DAW. 

A narrow stereo field is the whole point--see the included JPG.  Perfect mono would be even better, but the mics can't occupy the same physical space at the same time, so we have to settle for very close together. 



Thanks for the comparison. I can't open ProTools sessions, so have to listen to the WAV files directly.

Audio 1_01.wav
Audio 2_01.wav

KM84_Red SN 51518Run 1.wav
KM84-Brn SN 32547 Run 1.wav

KM84-Brn SN 32547  run 2.wav
MC KM84 w C3 Is 1.5 uF run 2.wav

KM84 w 100 uF C3 -C4 run 3.wav
KM84-Brn SN 32547  run 3.wav

The file names doesn't make it obvious which ones are the DIY mics and which ones aren't. I'm noticing "Audio 1" and "Audio 2" are sounding dull compared to the rest. So, as long as this was not supposed to be a blind test, which one is which? :)

I'm also noticing a very narrow stereo field when two pairs are panned hard left and right. How was the placement of the mics?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: fripholm on March 07, 2019, 03:59:36 PM
Audio 1 & Audio 2 weren't meant to be included--sorry. 

The ones with SN (serial number) in the name are real Neumann KM84's.  SN32547 is the Control mic; the rest are considered Test mics and are compared, one at a time, to the Control.  This is all explained in the ReadMe file I included; Unfortunately, it looks like my neatly-formatted file got a little weird-looking, but all the info is there and readable, in spite of the formatting. 

I included the Pro Tools session in case it makes things more convenient for some.  But the files can certainly be played directly in any DAW. 

A narrow stereo field is the whole point--see the included JPG.  Perfect mono would be even better, but the mics can't occupy the same physical space at the same time, so we have to settle for very close together.

Aaahhh, now that you say it - there's a Readme included... d'oh  :-[

Guess a closer look would've helped. Everything makes sense now, thanks!

And while we're at it. I used my KM84 builds as drum overheads for a live recording I did about two weeks ago. The following folder contains a short snippet of the show. One file is the full stereo mix and one is just the two overhead mics without any processing:

https://www.dropbox.com/sh/7fkb22jw6d57jrs/AABONPgqjcGg4Y0ZDSqwBf2Fa?dl=0

As I intend to use the mics mostly as drum overheads, I replaced the 4pF cap with a 22pF as a permanent pad. Otherwise the mics are overloading all the time with most drummers.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: TwentyTrees on March 08, 2019, 01:44:47 PM
Thanks for sharing the results of this test Maarvold - illuminating!

Audio 1 & Audio 2 weren't meant to be included--sorry. 

The ones with SN (serial number) in the name are real Neumann KM84's.  SN32547 is the Control mic; the rest are considered Test mics and are compared, one at a time, to the Control.  This is all explained in the ReadMe file I included; Unfortunately, it looks like my neatly-formatted file got a little weird-looking, but all the info is there and readable, in spite of the formatting. 

I included the Pro Tools session in case it makes things more convenient for some.  But the files can certainly be played directly in any DAW. 

A narrow stereo field is the whole point--see the included JPG.  Perfect mono would be even better, but the mics can't occupy the same physical space at the same time, so we have to settle for very close together.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Lamont Replevin on March 11, 2019, 02:17:59 PM
I ordered two kits--finished one of them, biased it, it sounds dope. Clear, full, gorgeous, inspiring.

Problem! When i was biasing the second one i was careless and neglected to shut off the phantom power while turning the screw on the trim-pot. Aaaaand i must have short-circuited the whole thing with the screwdriver and fried something. I am pretty inexperienced, so i'm not sure how to diagnose what i blew up and so forth. The tip of the screwdriver must have just drifted to the next component... Anyway I think i may have blown the JFET because i get total continuity between the gate and source/drain with no power applied. I would heartily appreciate any tips on how to trouble-shoot the circuit. What else could i have blown? Am i right that continuity in the JFET means it's borked? Please use small words! I am not too bright, but very enthusiastic and appreciative.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on March 11, 2019, 02:27:16 PM
I ordered two kits--finished one of them, biased it, it sounds dope. Clear, full, gorgeous, inspiring.

Problem! When i was biasing the second one i was careless and neglected to shut off the phantom power while turning the screw on the trim-pot. Aaaaand i must have short-circuited the whole thing with the screwdriver and fried something. I am pretty inexperienced, so i'm not sure how to diagnose what i blew up and so forth. The tip of the screwdriver must have just drifted to the next component... Anyway I think i may have blown the JFET because i get total continuity between the gate and source/drain with no power applied. I would heartily appreciate any tips on how to trouble-shoot the circuit. What else could i have blown? Am i right that continuity in the JFET means it's borked? Please use small words! I am not too bright, but very enthusiastic and appreciative.

This has already been addressed in the official build thread. Head over there and check it out.

Thanks!

Paul
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Lamont Replevin on March 11, 2019, 02:59:21 PM
Thanks, Paul--I see it now.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Dr nEon on May 07, 2019, 07:32:33 PM
Hey guys!

Wondering what your opinions are on the sound of the 3U GZT-84 transformers.  Has anyone compared the 3U tx to the cinemags / AMI or original KM84s ..?

I'm hoping to do a couple of these mics, whenever  the next round of kits are available, and so I'm keen to hear of others experiences!

Reading thru this thread a few times,  and I see a couple of others have also asked for info about the 3U GZT-84 , but so far no-one has offered an opinion. Would love to hear a review..

Cheers y'all,

nEon.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on May 24, 2019, 02:47:04 PM
Reading thru this thread a few times,  and I see a couple of others have also asked for info about the 3U GZT-84 , but so far no-one has offered an opinion. Would love to hear a review..

There should be about 50 of these built with 3U transformers from the last round. Hopefully someone who's compared them can help you out!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 24, 2019, 02:48:46 PM
Now taking orders for 3rd round. Transformers available too.

All information needed is in 1st and 2nd posts.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Fuzz Face on May 24, 2019, 06:04:15 PM
Great news! I’m thinking about grabbing another pair
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Mrosso on May 24, 2019, 10:22:11 PM
Great! Just sent PayPal for 2 kits plus a separate PayPal (my mistake) for the 3U GZT-84 transformers. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: BladeSG on May 24, 2019, 11:23:38 PM
Awesome! Payment sent for 2 kits.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: TLRT on May 25, 2019, 02:36:02 AM
Payment sent!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: donzo93 on May 25, 2019, 06:25:31 AM
Payment sent for 2 kits + 2 transformers
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: fripholm on May 25, 2019, 09:31:23 AM
Yessss! :)

Payment sent for my second pair including transformers. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: iampoor1 on May 25, 2019, 09:49:59 PM
Payment sent for 2x kits and 2x transformers. Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: guismarquesrj on May 26, 2019, 06:45:16 AM
Hey @banzai

The price for the 3u transformers includes worldwide shipping?

If yes, I'll transfer immediately.

If not, please let me know the total for 2 units, shipping for Brazil... Again  :)
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: julien31 on May 26, 2019, 09:47:11 AM
Payment sent for 2x kits and 2x 3U transformers.
Thanks
Julien
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: kosi on May 26, 2019, 12:08:21 PM
Also money sent for 2 kits w tx !

thanks for doing this :)

Andreas
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 26, 2019, 12:30:28 PM
Thanks!  :D
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: litlit on May 26, 2019, 02:16:11 PM

Money sent for 1 Kit + 1 Trafo.
Merci!
LG
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 28, 2019, 01:10:03 PM
Thanks for the orders!

Around half sold, still 30 or so kits available.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: guismarquesrj on May 28, 2019, 01:14:20 PM
Hey @banzai

The price for the 3u transformers includes worldwide shipping?

If yes, I'll transfer immediately.

If not, please let me know the total for 2 units, shipping for Brazil... Again  :)

Can I order 2 tx?
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 28, 2019, 02:14:28 PM
Can I order 2 tx?

Transformer deal only with kits.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: duantro on May 28, 2019, 04:29:13 PM
Paid for 2 mic kits with transformers. Love my pair from the second round!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 29, 2019, 05:44:50 PM
Please double check your totals before sending.

Some of you are overpaying – additional units are only €110.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: duantro on May 29, 2019, 11:16:44 PM
Damn, I overpaid last round also.  I keep forgetting that shipping charges are combined
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: damianschwartz on May 30, 2019, 08:56:07 AM
When unpacking, your box should contain:

- mic bodies + capsules
- PCB's
- FET's and M2 screws
- plastic capsule pins + XLR connector
- transformers (if ordered)

@Banzai, i was just ordering to build my mics from the February batch (didn't have the time yet) and my box doesn't contain the Fets. I understand it should?
Edit, neither the M2, not that that matters...
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 30, 2019, 09:45:42 AM
Hey Damian, FET's and screws were packed together in a tiny ziplock bag. They weren't inside any of the bubble bags.

Double check everything carefully, and send me a pm if they're missing. I can replace that for you.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on May 30, 2019, 09:56:00 AM
Out of stock 47K resistor @ Mouser can be replaced with this:

https://eu.mouser.com/ProductDetail/?qs=8kFZCSt8PPG4zBeH2lzuZg%3D%3D
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: qmp audio on May 30, 2019, 08:24:38 PM
Payment sent for 2x mics + 2x transformers.  Thanks!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Banzai on June 01, 2019, 01:45:21 PM
Damn, I overpaid last round also.  I keep forgetting that shipping charges are combined

It's my bad. The way I've written it isn't ideal.

Probably better if I split kit price from shipping, and make everything simpler.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: duantro on June 01, 2019, 06:37:26 PM
It's my bad. The way I've written it isn't ideal.

Probably better if I split kit price from shipping, and make everything simpler.
No worries, thanks for the effort of putting this together.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: boji on June 01, 2019, 06:49:05 PM
Ordered a pair, minus tx's.   Thanks for extending the availability of kits!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: duantro on June 01, 2019, 07:05:45 PM
What would the possibility of doing some sort of input pad on these? Would it be hard to make a threaded pad section to screw under the cap like oktavas? Just curious, as I bet these would sound good on snare.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: Fuzz Face on June 01, 2019, 10:38:44 PM
What would the possibility of doing some sort of input pad on these? Would it be hard to make a threaded pad section to screw under the cap like oktavas? Just curious, as I bet these would sound good on snare.

In the Neumann, it is done by adding a 15pf cap parallel to C2 (4pf). 

Using a 20pf cap for C2 would be about the same, or you could try to add a toggle switch
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: mickdundee63 on June 02, 2019, 12:04:57 AM
Payment sent for 2 X kits and 2 X tfmrs. Cheers.
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: audiomsg on June 02, 2019, 03:27:47 PM
Payment sent for 2 mics and 2 transformers.
Thanks again, this is my 3rd set!
Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: choolder on June 03, 2019, 06:45:24 PM
Payment sent for 2 mics + 2 trafo's

Looking forward!

Title: Re: Neumann KM84 DIY Body & PCB kit – 70pcs available – Open for orders
Post by: partycentral on June 03, 2019, 07:41:15 PM
Just paid, in for 2 mics and 2 transformers. Thanks!
-Jeff
Title: Re: Neumann KM84 DIY Body & PCB kit – 15 pcs available – Open for orders
Post by: Banzai on June 04, 2019, 03:20:29 PM
Thanks for all the orders!  :D

There are 15 kits left.
Title: Re: Neumann KM84 DIY Body & PCB kit – 15 pcs available – Open for orders
Post by: Dr nEon on June 04, 2019, 08:00:03 PM
Hi Banzai,

Payment just sent for 2 kits and 2 transformers.

Many thanks for this great offer ! :)

Cheers

nEon.
Title: Re: Neumann KM84 DIY Body & PCB kit – 15 pcs available – Open for orders
Post by: mcrowe on June 06, 2019, 09:47:54 PM
Just put in an order for two kits. Looking forward to this.
Title: Re: Neumann KM84 DIY Body & PCB kit – 15 pcs available – Open for orders
Post by: jheronymo on June 07, 2019, 12:50:21 PM
Paid for two kits! Thanks for making this available.
Title: Re: Neumann KM84 DIY Body & PCB kit – 8 pcs available – Open for orders
Post by: Banzai on June 08, 2019, 08:57:12 AM
Thanks again for the orders!

Only 8 kits left

Once kits are sold-out I'll mark the thread "closed".
Until then you can send your orders as normal.
Title: Re: Neumann KM84 DIY Body & PCB kit – 8 pcs available – Open for orders
Post by: Hawkmoon on June 08, 2019, 09:08:10 AM
 Payment send for 2 kits and transformers :)

Regards!!!!
Title: Re: Neumann KM84 DIY Body & PCB kit – 8 pcs available – Open for orders
Post by: kante1603 on June 08, 2019, 09:30:58 AM
Payment sent for 3 kits and 3 transformers.


Dankeschön!


Udo.
Title: Re: Neumann KM84 DIY Body & PCB kit – 3 pcs available – Open for orders
Post by: Banzai on June 08, 2019, 09:48:04 AM
Thanks!!

Only 3 left
Title: Re: Neumann KM84 DIY Body & PCB kit – 8 pcs available – Open for orders
Post by: kante1603 on June 08, 2019, 10:05:55 AM
Deleted.
Title: Re: Neumann KM84 DIY Body & PCB kit – 3 pcs available – Open for orders
Post by: Chrisfromthepast on June 08, 2019, 10:55:23 AM
Sent paypal for 1 kit and 1 xformer.
Excited!
Title: Re: Neumann KM84 DIY Body & PCB kit – 2 pcs available – Open for orders
Post by: Banzai on June 08, 2019, 11:01:25 AM

Only 2pcs left!
Title: Re: Neumann KM84 DIY Body & PCB kit – 2 pcs available – Open for orders
Post by: Leon on June 08, 2019, 01:06:49 PM
Just placed order for the last two plus two transformers .
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 08, 2019, 02:10:44 PM
Thanks everyone for your orders!

We're all sold out
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: iampoor1 on June 08, 2019, 04:36:27 PM
Thanks everyone for your orders!

We're all sold out

Sweet! What's the approximate lead time before the kits ship out?  ;D
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on June 08, 2019, 07:41:15 PM
Thanks everyone who's grabbed one of these mic kits! It's been so gratifying to see so much interest and hear about all the joy people have been getting from putting them together and using them. It's just brilliant!

Cheers!!

G
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mcrowe on June 09, 2019, 01:37:07 PM
Graeme, I'm reading through the build guide now, and I thank you most sincerely for putting this together and making it entertaining. Sometimes these can be terse and tricky to follow, so this is refreshing.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: GraemeWoller on June 09, 2019, 08:29:20 PM
Thanks, mcrowe, I'm pleased you like it. I get bored by accountancy professors writing guides so the entertainment additives are a must for me!!  I don't think I could do it any other way. ;D

Graeme, I'm reading through the build guide now, and I thank you most sincerely for putting this together and making it entertaining. Sometimes these can be terse and tricky to follow, so this is refreshing.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 10, 2019, 07:50:32 AM
Sweet! What's the approximate lead time before the kits ship out?  ;D

Should be around 2 weeks. Just waiting for transformers and FET's to arrive.

Everyone's order will ship the same day.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Anthon on June 10, 2019, 09:59:22 AM
Will there be another batch of the kit? Noticed it a bit to late  ;D
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on June 26, 2019, 03:49:43 PM
Have these shipped  out  yet?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on June 27, 2019, 07:54:56 PM
Have these shipped  out  yet?

All orders will ship next week. Still waiting on FET's to arrive.

Thanks for the patience!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on June 28, 2019, 12:02:28 AM
All orders will ship next week. Still waiting on FET's to arrive.

Thanks for the patience!
Great. Thanks for the update.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 02, 2019, 09:04:51 PM
Quick update: all non-EU boxes have shipped. EU to follow tomorrow.

Will send e-mail with tracking numbers over the next few days.

Thanks again for all your orders !!!  8)
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mcrowe on July 04, 2019, 08:37:34 AM
Thank you for making this happen! I had been looking for a project exactly like this.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: kante1603 on July 08, 2019, 07:26:31 AM
Package received here in germany last saturday (to be precise),looking good.The fets look like Fairchild,I hope they are  ;D .


Thank you very much,


best regards,


Udo.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: kosi on July 08, 2019, 04:38:05 PM
Mine arrived today, also Germany !

looks very nice, thanks alot !

Andreas
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Colorblind on July 09, 2019, 06:58:58 PM
My kits arrived in Canada today.  They look great.  Thanks again Banzai!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: duantro on July 09, 2019, 07:44:33 PM
Arrived in middle of USA. Thanks!!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mcrowe on July 10, 2019, 03:07:29 PM
Picked mine up today from a stern lady in my local Chicago post office. Everything looks great.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mickdundee63 on July 11, 2019, 07:45:32 AM
Received in Boston! Many thanks
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: salz-elektronik on July 11, 2019, 08:40:02 AM
They sound really good! count me in for another pair!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: BladeSG on July 13, 2019, 12:45:57 AM
Arrived in Australia. Thank you
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Mrosso on July 13, 2019, 09:13:38 AM
Arrived Thursday in California. Thank you!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 08:45:06 PM
My pair arrived last week too.  Just built one today. Everything went fine and I was able to bias up to 1v with nice looking wave form. However, when I put on the capsule and gave it a test. Nothing but a constant hum. Any idea what went wrong? Thanks in advance.

Leon
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 14, 2019, 08:52:56 PM
My pair arrived last week too.  Just built one today. Everything went fine and I was able to bias up to 1v with nice looking wave form. However, when I put on the capsule and gave it a test. Nothing but a constant hum. Any idea what went wrong? Thanks in advance.

Leon

Hi Leon, did you try the other capsule to rule it out as a problem?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 08:54:13 PM
Thanks for your help. Yes. Tried both with same problems.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 09:05:23 PM
Here is a pic of the finished board:
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 09:10:35 PM
and the back side:
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 09:51:49 PM
I did have to enlarge the hole slightly  in order to fit the transformer. Could that cut off  some hidden circuit traces?
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Banzai on July 14, 2019, 10:17:10 PM
I did have to enlarge the hole slightly  in order to fit the transformer. Could that cut off  some hidden circuit traces?

Possible if you enlarged sideways. 2 traces run on each side of the transformer.

Traces are visible on the boards if you look closely. You can use your second one as a guide to see where traces connect, and check if everything is still okay with your first. Just test for continuity between pads above and below where you enlarged.

I'd test the entire board anyway, starting from the spring contact all the way down to the connector. Could be something simple.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 14, 2019, 10:43:27 PM
Thanks. Both sides of the hole are tested to be  continuous. I will do a more thorough test and will update if I found the cause.

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 15, 2019, 01:47:24 AM
I tested point to point but didn’t find anything wrong. Also cleaned the whole board. I gave it another 1kHz signal, but this time I didn’t get a clear tone like when I did the bias earlier. I suspect the FET is broken and will try a new FET tomorrow.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Fuzz Face on July 15, 2019, 08:28:15 AM
I tested point to point but didn’t find anything wrong. Also cleaned the whole board. I gave it another 1kHz signal, but this time I didn’t get a clear tone like when I did the bias earlier. I suspect the FET is broken and will try a new FET tomorrow.
When I first connected the mic circuit (without capsule) to my DAW for biasing it was picking up all kinds of noise. I recorded a track of it with no gain applied and could wave it around my desk and change the hum dramatically

I gave everything another thorough cleaning (make sure not to touch Hi Z section with fingers) and used my DMM to set the trimmer to 3.9K in order to get the FET at least in the ballpark for biasing. When I connected again to my DAW, everything was much more manageable

Since this uses a 20K trimmer, if you leave it at the center you have about a 10K source resistor, which in my experience is high enough to make this thing go wild

Good luck, these sound fantastic when they’re done and the supplied FETs should be totally working
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 15, 2019, 12:55:27 PM
When I first connected the mic circuit (without capsule) to my DAW for biasing it was picking up all kinds of noise. I recorded a track of it with no gain applied and could wave it around my desk and change the hum dramatically

I gave everything another thorough cleaning (make sure not to touch Hi Z section with fingers) and used my DMM to set the trimmer to 3.9K in order to get the FET at least in the ballpark for biasing. When I connected again to my DAW, everything was much more manageable

Since this uses a 20K trimmer, if you leave it at the center you have about a 10K source resistor, which in my experience is high enough to make this thing go wild

Good luck, these sound fantastic when they’re done and the supplied FETs should be totally working

Thanks a lot for the help. I have a bunch of J113 so I installed one. I now can get least get a clear 1kHz tone. The hum is also quieter but still there. A steady 60HZ hum. The hum exists even with 0v signal, but doesn’t become louder as I turn up the signal.  I settled on a trimmer resistance of 5.1k and installed a fixed resistor there.

I also tried with the capsule on, still only hum but nothing else. No response to any sound. Guess I still have to dig hard.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Fuzz Face on July 15, 2019, 02:37:35 PM
Would you care to continue this discussion at the build thread? I have a couple ideas but the build thread seems to be a better place for this
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Leon on July 15, 2019, 03:37:13 PM
Would you care to continue this discussion at the build thread? I have a couple ideas but the build thread seems to be a better place for this
Thanks. I was not aware of a build thread. But anyway,  I found the problem. I was not aware the mic body needs to be grounded. A rookie mistake but it was not mentioned in the build guide. There is a small screw on the “4th” leg of the XLR that can be screwed up to make contact with the body. Once that was done, the mic worked beautifully. No hum so I guess the 60Hz hum I had previously was from the signal generator. Anyway, just throw it out here so newbies like me will not make the same mistake as me.

Thanks all!
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Andre on July 16, 2019, 02:58:03 PM
I should have noted that I received my kits in New Orleans a week or so ago.  They were packed very nicely.  I'm quite impressed by the whole thing.  Now I'd just like to hear them.  The boards are stuffed but Im waiting on transformers from Cinemag.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: mcrowe on July 17, 2019, 04:19:54 PM
Edit: never mind. False alarm. Thought I had messed with the BOM project, but I checked in another browser and it's fine.
Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Dr nEon on July 19, 2019, 02:57:37 PM
Hey Banzai, Graeme...

Just to  let you guys know,  mine also arrived safely, a week or so back.   :)

 As soon as I've finished this album project, I will get straight onto the build!

One question (probably I should ask in the build thread, too):  The brass bodies have quite a few stain marks/tarnish .  What is the preferred method for polishing those marks off.  I'd rather not sand, if possible, as I like the polished brass, and don't like the idea of spray painting these for fear of upsetting the width of the slot gaps behind the capsule. Clearcoat alone would probably flake off eventually.  I'd just like to be able to clean and polish them..   Would something like brasso liquid to clean, followed by turtle wax to finish, do the job, do you think?  Or has anyone got any good ideas...

Many thanks again for this excellent project!

nEon.

Title: Re: Neumann KM84 DIY Body & PCB kit – CLOSED
Post by: Potato Cakes on July 19, 2019, 03:04:14 PM
Unfinished brass naturally tarnishes. You can use a polish, but I think the idea for is to have it painted. Otherwise you would have to apply polish every time you handled them.

Thanks!

Paul