GroupDIY

Project Specific Discussions => Microphones => Topic started by: rainton on April 21, 2018, 04:32:04 PM

Title: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on April 21, 2018, 04:32:04 PM
Hey guys,

as some of you I also bought a pair of Banzai's KM 84 kits from his group buy (which look VERY nice btw - my pair arrived just today :))

But as I'm located in Germany where the original KM84 were manufactured back then, I kind of found it weird to order a transformer from the US to build a clone of a German mic...

The original transformer in the KM84 was the HAUFE BV107. And since Haufe is located right here in Germany (actually like only 150 miles from here) I thought I'd get in touch with them and ask if they can do a reissue of the BV107.

They said it went out of production almost 20 years ago, but they would check their manufacturing options.

Now they got back to me yesterday - they CAN do a reissue of it!!  :D

I thought maybe anybody else is interested - so we can do a group buy.

If we take 10-19 pcs. the price will be EUR 85.00 ea. and if we take 20-30 the price will be EUR 81.00 ea.

Shipping & pp fees will have to be added.
But as you probably know Don-Audio in Germany is taking care of shipping & handling for all my chassis kits, so I could ask him if he could ship the transformers too. So you could combine shipping with an order from don-audio.com (or an order of one of my chassis kits ;) )

Anyway I think if we get at least 10 transformers together I'll place the order with HAUFE

Lead time with Haufe is 10 weeks, so I suggest we don't stretch this out too long. Let's say I'll keep this thread open until May 5th.

Who wants to join me? I'll take 2 transformers :)


GROUP BUY LIST:

rainton 2 (paid)
iturnknobs 2 (paid)
winetree 4 (paid)
59flame 2 (paid)
TillM 2 (paid)
Banzai 2 (paid)
Craig 2 (paid)
yoons 2 (paid)
BramK 2 (paid)
tskguy 4
mesajoe 2 (paid)
lampas 2  (paid)
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: Banzai on April 21, 2018, 05:11:26 PM
Very nice, 2 please

 8)
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: iturnknobs on April 23, 2018, 09:30:59 AM
Anyone know if these Haufe and Cinemag trafos will both fit in an original KM84? If so, I will put my name on the list.

-Brian
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: rainton on April 23, 2018, 09:41:45 AM
Anyone know if these Haufe and Cinemag trafos will both fit in an original KM84? If so, I will put my name on the list.

-Brian

At least the Haufe should, since it’s the original design...
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: iturnknobs on April 23, 2018, 01:11:41 PM
Count me in for 2 Haufe trafos. Please PM with your preferred payment method and exact cost once you have enough orders. Thank you.

-Brian
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: craig on April 24, 2018, 05:02:03 AM
Put me on the list for two
Thanks
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: beneficjenci on April 24, 2018, 01:10:02 PM
Hi Everyone. I am new here. My friend who builds microphones for me,  showed me this thread. I am about to order to mics
from him and I am almost positive I would like two of those Haufe trafos. Will confirm before May 5th but for now please count me in for two.

Cheers
ms
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: Murdock on April 24, 2018, 01:57:33 PM
Thanks for making this Martin! I'm definatelly interested.
What is the ratio of these transformers? 7:1?
I read that they are not that different from the transformers used in the KM5x series... Do you know anything about that?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: yoons on April 25, 2018, 02:13:58 PM
I'm in for 2 of course ;)
Thanks!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: BramK on April 25, 2018, 03:12:45 PM
I'm down for 2. Thanks!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: TillM on April 28, 2018, 08:09:44 PM
I'm in for one.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: tskguy on April 30, 2018, 08:26:06 AM
I would be in for 4
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: Winetree on May 02, 2018, 01:27:31 PM
Put me down for 4 transformers here.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: 59flame on May 02, 2018, 01:52:29 PM
put me down for 2 here
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: mesajoe on May 03, 2018, 12:35:37 PM
I will take 2 transformers please
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: lampas on May 03, 2018, 03:58:37 PM
I'll take 2.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: beneficjenci on May 05, 2018, 05:23:41 AM
Is the May 5th the final deadline? I am a bit short with cash now...
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY OPEN UNTIL MAY 5th!
Post by: rainton on May 05, 2018, 02:34:45 PM
Is the May 5th the final deadline? I am a bit short with cash now...

Yes because production has a lead time of 10 weeks after placing the order. And I can only place the order after the funds are collected.

BTW I’ll close the group buy now and will get in touch with all of those who are part of it.
After I have your shipping details I can calculate shipping fees and let you know how to proceed with payment.

Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Banzai on May 05, 2018, 02:42:49 PM
Thanks for organising!!!

Excited to try them out  :D
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: hop.sing on May 06, 2018, 11:06:10 AM
I want to add, that I  just built a km54  circuit into a Gefell 691 body, using a bv107  and a 6s6b Tube and it works and sounds great. Perfect frequency and distortion behavior. This is a great transformer for that purpose, too.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: 4earstudios on May 09, 2018, 12:27:18 AM
Hi, is there a chance to set me on the list for 2? I just read it yesterday...greets Daniel
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on May 14, 2018, 07:16:40 AM
Hey guys, so far only 4 people sent their payment.
I was hoping to have all transformers paid for until end of last week.

I really want to move forward with this group buy, so I'll wait until end of the week.
Those who paid until then will be on board.
So please make your payments as soon as possible.
Thanks folks!! :)

Martin
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: bremusound on May 14, 2018, 04:27:34 PM
If someone changed his mind, i would jump in for two Bv107!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on May 16, 2018, 02:53:53 AM
I couldn't decide between these transformers and the Cinemags.
Even though I live 20 minutes from Cinemag and they would be less money,
I figured when would there be a chance to get the original manufacture transformers.

SO PLEASE EVERY ONE SEND IN YOUR MONEY, So this can happen. I Did.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on May 17, 2018, 02:40:59 PM
LAST CALL EVERYONE!!

I still haven't received payment from some of you - if you wanna be on board, please make sure you make the payment before tomorrow afternoon 3 PM  CET.

Thanks :)

Martin
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: lampas on May 17, 2018, 04:02:45 PM
please make sure you make the payment before tomorrow afternoon 3 PM  CET.

Thanks :)

Martin

Try to send amount a few times, but something is wrong with my PP account ... Tomorrow I will have appointment on my bank to solve the issue ... I hope that it will be until 3pm...

Regards.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: BramK on May 22, 2018, 11:26:43 PM
Stoked! Also a 2nd batch in a few months of the DIY KM84's confirmed. Glad I jumped in on these trans. Thanks rainton
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on May 23, 2018, 08:36:34 PM
So. the group buy is going through with the people that paid?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: HA_DA_JA on May 23, 2018, 09:40:44 PM
I guess I will be in for 2 on the next group buy. Cheers
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on May 24, 2018, 02:23:26 AM
So. the group buy is going through with the people that paid?

Yes exactly - transformers already ordered and paid for :)
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on May 28, 2018, 08:19:13 PM
"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.

This quote from mic group buy has me wondering if there is going to be a problem fitting the Haufe tranformers.
Reassure me they will fit with some minor mods?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: BluegrassDan on June 27, 2018, 09:38:36 AM
Hey guys,

My KM84 transformer just died due to a lightning strike. Anyone here happen to purchase a spare BV-107 that they would be willing to sell?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on June 29, 2018, 03:38:26 AM
Hey guys,

My KM84 transformer just died due to a lightning strike. Anyone here happen to purchase a spare BV-107 that they would be willing to sell?

Maybe you write Martin (Rainton) or directly to Haufe. The made them esspecially for us, so maybe they build some more.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on August 05, 2018, 07:07:06 PM
ANY WORD ON THESE TRANSFORMERS?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on August 06, 2018, 04:16:34 AM
Haufe has massiv shipping delays since some weeks.
So it’s not Martins fault.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on August 07, 2018, 03:09:20 AM
Not blaming anybody.
It's just that there hasn't been any word since the transformers were ordered and paid for in May.
Still patiently waiting.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on September 03, 2018, 12:54:41 AM
ANY WORD ON THESE TRANSFORMERS?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: iturnknobs on September 05, 2018, 11:59:31 AM
Rainton-

Could you please verify that Haufe is the hold up?  We haven't seen a public post from you regarding this order since May 24th. I think it would be reassuring for all. I am aware and part of another order that receives virtually no responses from the organizer and it has been 3 years now with the order unfulfilled. It would be great to know that GDIY members are not being "Riggler-ed" by another peer.  I do not want to place you in this "category". Just looking for peace-of-mind for all.

-Brian
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Banzai on September 05, 2018, 12:56:04 PM
Don't worry, Rainton is solid - no chance of getting Rigglerd
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: iturnknobs on September 05, 2018, 01:17:54 PM
Thanks, Banzai. Looks like I created a new verb.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on September 08, 2018, 04:14:23 PM
Martin send me a mail 3 days ago.
Haufe has delays cause a machine in the factory is broken. I also get the information from a friend of mine who works with Haufe for other parts.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: analogguru on September 08, 2018, 05:33:20 PM
Martin send me a mail 3 days ago.
Haufe has delays cause a machine in the factory is broken. .....
Hmmmm.... just wondering: How expensive can such a machine be that Haufe can't afford one as reserve ?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: [silent:arts] on September 09, 2018, 01:53:38 AM
Hmmmm.... just wondering: How expensive can such a machine be that Haufe can't afford one as reserve ?

For vintage transformer designs they often need to use the old original machines, you can't just buy a new one.

Anyway, lead times are a major pain with Haufe at the moment, my Haufe ST8456 order I placed in July 2018 is announced to ship in January 2019 (and the ST8456 is not a vintage design).
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on September 28, 2018, 11:12:12 AM
I also just received another mail from Haufe that our order delivery date was postponed for the 2nd time   :(

Initially I was told the transformers will be ready in week 32 of 2018.

Then they let me know it will be week 38 due to a machine being broken or something like that.

And today I received another mail that the new ETA will be week 48!!!
Due to health issues of their staff members...

WTF?!
That’s a delay of 16 weeks when initial lead time was 9-10 weeks!

Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: maarvold on September 29, 2018, 06:11:38 PM
Since the transformers won't be made until December, any chance of adding 2 more units to the group buy?  Or am I dreaming?  I just now discovered this thread. 
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: iturnknobs on September 29, 2018, 06:39:11 PM
Thanks for the update. :)
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on December 10, 2018, 06:34:05 AM
Hey everyone,

I received word from Haufe that our transformers are ready!!
They are on the way here at the moment - I'll keep you posted

Martin
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: 59flame on December 10, 2018, 02:22:18 PM
yes
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: GraemeWoller on December 10, 2018, 05:00:05 PM
Awesome!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: BramK on December 14, 2018, 12:04:59 AM
Great to hear!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on December 19, 2018, 12:14:39 PM
The transformers arrived!!!

(https://www.mediafire.com/convkey/4b79/bh848833qal076q5g.jpg)

I'll try to send them out as soon as possible, but please forgive me if I'm not making it before Christmas - there's just so much going on right now.
But I'll try my best  :)

Martin
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on December 19, 2018, 03:18:16 PM
incredible :D
but I'm curious if they will fit the pcb and the body.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on December 19, 2018, 06:28:23 PM
They sure look big in the picture. I heard It might take a little filing on the P.S.B.
That transformer would sure look funny strapped to the outside of the mic.
My 4 mics have been waiting to be transformed.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on December 19, 2018, 06:39:21 PM
They look much bigger in the picture than they actually are - maybe also due to the perspective of the camera which makes the transformers in the foreground look kinda huge compared to the gear in the background  ;D


Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on January 06, 2019, 04:48:56 PM
Hi Martin,
do you deliver the Transformers, or will we get them from Don—Audio?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: rainton on January 09, 2019, 05:11:41 AM
I'm taking care of it.

I'm back from family vacation and already shipped the first 7 packages yesterday -  the rest of 6 packages will be shipped today :)

sorry I didn't make it before our xmas vacation, but there was just so much going on...

Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on January 09, 2019, 06:30:47 AM
Cool, thank you so much.
Don’t understand me wrong, family time is always important 😊
Thank you for this groupbuy
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on January 09, 2019, 01:11:26 PM
Thanks for all the work on this group buy.
Great news on the shipping.  Any tracking available?


Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on January 11, 2019, 08:06:20 AM
Hi Martin,
transformers arrived today !
Awesome !
They seams to fit the PCB from Banzai.
I'm really excited how they sound compared to the cinemag.
Again, thanks for the groupbuy.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: maarvold on January 11, 2019, 05:01:42 PM
Quote
They seams to fit the PCB from Banzai.

That is GREAT news!!!
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: delaymix on January 11, 2019, 05:09:24 PM
I'm really excited how they sound compared to the cinemag.

Do you think there is so much difference? Is it clearly remarkable?

Maybe there are people interested in arrange a second round of these transformers...
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on January 11, 2019, 08:34:28 PM
So guys, I can confirm that the Haufe fits Banzai's PCB.
The only thing is, that you have to extend the transformer cables, cause they are really short.
Put everything together 10 minutes ago and it works perfect.
Was to lazy to bias the fet right now, but will it do another day.
Tomorrow I can test it together with the cm5722 transformer.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: [silent:arts] on January 12, 2019, 03:29:21 AM
Maybe there are people interested in arrange a second round of these transformers...
Good luck. I was on the phone with Haufe yesterday
(since I'm still waiting for transformers I ordered in July).
They told me leadtime for new orders is 50 weeks at the moment.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: kominak on January 17, 2019, 02:52:30 PM
Just trying my luck here, but if any of you guys decided you don't need 1-2 of these transformers, send me PM...

Martin
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TwentyTrees on January 17, 2019, 05:03:30 PM
Just trying my luck here, but if any of you guys decided you don't need 1-2 of these transformers, send me PM...

Martin

Heh! Ditto.  ;)
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Jim50hertz on January 22, 2019, 01:09:01 PM
This is presumably now an available part from Haufe then Rainton? But a custom order?

If I manage to get in on Banzai’s bodies before it closes I would very much like the original trafos on board.

Any chance of another group buy?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: duantro on January 31, 2019, 12:09:20 AM
I’d be in on a pair of these if available.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Avgatzeblouz on January 31, 2019, 12:05:26 PM
I’d be in on a pair of these if available.
[/quote

Me too.]
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: iturnknobs on February 09, 2019, 06:24:59 PM
So guys, I can confirm that the Haufe fits Banzai's PCB.
The only thing is, that you have to extend the transformer cables, cause they are really short.
Put everything together 10 minutes ago and it works perfect.
Was to lazy to bias the fet right now, but will it do another day.
Tomorrow I can test it together with the cm5722 transformer.

Could you provide any info for wiring this trafo to KM84 circuit? Mine seems to test properly except I cannot seem to come up with a 200 ohm secondary impedance, regardless of my configuration.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: maarvold on February 16, 2019, 10:41:33 AM
Just a warning: on one of my group buy BV107's, a couple of extremely thin lamination shims fell out of the stack on one side; also one of the end U-shaped laminations moved a little bit.  I replaced the shims and pushed the U back into place and everything looked perfect.  Then I called my friend--former chief engineer for Jensen Transformer.  He suggested putting clear nail polish on them so that "capillary action" (a phrase he used several times) would wick little of the polish in between the edges of the laminations and glue the whole stack together. 

The only polish I could find on the shelf was a bit thick; using internet advice, I thinned it down a bit (a couple of drops of isopropyl alcohol in maybe 8 drops of polish) and painted it on with the brush from the nail polish.  Work quickly--mine seemed to be fully dry in just 2-4 minutes.  If I had it to do again, I might make the polish even a bit thinner and put a bit more on the laminations (for better "capillary action"). 
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: iturnknobs on February 16, 2019, 10:49:02 AM
I just had the same issue occur, literally 4 minutes ago. I think it may benefit us all to use clear nail polish around the plates before assembly.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on February 22, 2019, 11:14:49 AM
at one of mine BV107, the black wire fall out the lamination, when I soldered it to the pad.
Really really s****y !
Write Haufe and hope, that I can fix the problem.
The black wire should be ground, any ideas how I can fix it?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: volker on February 22, 2019, 03:23:10 PM
If the wire colors are identical to the old transformers, black is the beginning of the winding. So I wouldn't get my hopes up for an easy fix... Post a photo?
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: Winetree on February 22, 2019, 04:21:39 PM
I had the white/black wire pull out when trying to solder the 2 whites together.
The end of the white wire was tinned but didn't look like it was soldered to anything inside.
Can this be fixed.
Having the same lamination problems. Thanks for solution.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on February 22, 2019, 08:48:14 PM
So here’s a photo.
I can’t not measure any resistance.
The other coil has 65ohm resistance.
Well, I think it’s hardly to fix, maybe it’s impossible.
First time this ever happens to me and in the meanwhile I build tons of things.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: volker on February 23, 2019, 06:22:01 AM
So the wire is still connected? If you can see part of the actual magnet wire, you could try to resolder. Otherwise there isn't much to be done other than rewind, since the black wire is the beginning of the wind.
Title: Re: HAUFE BV107 original Neumann KM84 transformer GROUP BUY CLOSED!
Post by: TillM on February 23, 2019, 07:14:56 AM
Hi Volker,
No it’s not connected, I put it in for the photo.
Also talked to Moby meanwhile, the transformer is not repairable.
Just what you say, only a rewinding will rescue them.
I build so many mics and other stuff, this is the first time this happened to me.
As we say in Germany, I paid “Lehrgeld”.