Re: Neumann U87 Vintage Circuit Build Thread
« Reply #340 on: April 17, 2012, 04:59:39 PM »
Thanks Kante,
I will start this tomorrow night or some time this weekend.  Between regular work, showcases and wedding parties free time seems to exist no longer, errrrrrr.. But at least I am keeping busy, or else I would poor buying tons of other DIY projects, hahahaha.  Thanks again.

-Scott

ps what does a probe actually do on a scope?  Is there two probes or just one?  Would seem like you would need two?  one for like a ground and the other for "hot" stuff that you are measuring.


kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #341 on: April 17, 2012, 05:23:41 PM »
Thanks Kante,
I will start this tomorrow night or some time this weekend.  Between regular work, showcases and wedding parties free time seems to exist no longer, errrrrrr.. But at least I am keeping busy, or else I would poor buying tons of other DIY projects, hahahaha.  Thanks again.

-Scott

ps what does a probe actually do on a scope?  Is there two probes or just one?  Would seem like you would need two?  one for like a ground and the other for "hot" stuff that you are measuring.
Hi Scott,

my name is Udo,not "kante" ;).

I know this feeling very well since I had to work pretty hard the last few months,and ton s of my diy things are on hold now too.
A probe is  pencil-style thing with a tip for a scope to get a signal in it by either using a little clamp on front of it (when pulling the plastic front back you can see it) or pulling off the complete front part.You then have a small tip on it like the ones you know from your dmm.The cable has normally a bnc connector at the end and carries both the signal and the ground via the shield,somehow same as in a video- or antenna cable.Right on this "pencil" you can attach a short clamp ("U"-profile) to it having an alligator clamp on the other side.Since this is very short you can also derive the ground from a 4mm banana jack at the front of the scope.
In the englisch language this seems to be named "probe",whether on a dmm or scope.In german we have different words for that ("Mess-Spitze" and "Tastkopf").
The difference between "normal" probes and those for scopes is that there are a lot of varying impedance types available,each makes sense in a special measuring method.Also most of times a scope probe has a little slide switch on it.This is a voltage divider,normally working in dekades,e.g. 1:10 or 1:100.

Hope to have helped,

good night,

Udo.

Edit:Pics added.
« Last Edit: April 18, 2012, 03:43:57 AM by kante1603 »

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #342 on: April 18, 2012, 06:01:07 PM »
Hi All,

i have a couples,  of Microphone transformer for sale , cinemag , peluso , AMI, for diefferent project  8)

PM me if your are interested i will send you a list of what i have,

Cheers,

Dan,
 

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #343 on: April 18, 2012, 06:17:53 PM »
Thanks for the offer Dan,

if everything fails (what I´m not hoping,have ordered my t13s via the german supplier and paid) I will pm you.
Btw:Have you tried throwing one over the ocean? ;D

Udo.

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #344 on: April 18, 2012, 06:36:52 PM »
Hi all,

Has anybody received the capsule from the group buy yet in germany or europe?

Udo :-[

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #345 on: April 18, 2012, 06:55:02 PM »
Btw:Have you tried throwing one over the ocean? ;D

Udo.

I started an import export company a while ago and i kept trying throwing stuff in ocean but never worked i never made any money,
 :P
D

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #346 on: April 18, 2012, 07:10:02 PM »

I started an import export company a while ago and i kept trying throwing stuff in ocean but never worked i never made any money,
 :P
D

Wrong ocean? ;D ;D ;D

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #347 on: April 18, 2012, 07:59:47 PM »
Udo and others,

Here is what I have done so far.  I am using Tone Generator 1.0.2 to send a signal out of my 2408MKII.  I am sending this out channel one or the left side right into the mic PCB on the Rt and Sw points.  The capsule is unplug of course.  The Mic is plug into an xlr cable going to channel 2 of my mackie 1604 which is then sent to channel 2 of the MOTU 2408MKII through the insert on the mackie channel.  I then use Audio Explorer 1.3.1 for the oscilloscope.  I have to set to read channel 2 of the 2408mkII or the right side.  It is set to realtime and display is set to 5ms with a positive slope.  I have X & Y set to automatic. 

A few concerns.

How much gain do i have to use on the mackie channel where the mic is connected to.  I have it the normal position for mics. 

I can't really adjust the output of the tone generator volume wise.  How loud should the signal be going to the PCB?  I can measure it in volts too right?

If I tighten the pot all the way in it shuts the mic off but when I fully open it past the 11vdc mark I don't heard or see any distortion on the scope program.  Only when I turn the gain up on the mic channel do I hear some distortion but I don't think thats the right way to do it.

I am probably doing something wrong or its not set up right but I did do the test of using the tone program into the oscilloscope program.

I think i need to find a different program in which I can adjust the output of the tone generator.

What should is be set to volume wise or volts wise.?

My brain is fried, hahaha

-Scott

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #348 on: April 18, 2012, 09:20:03 PM »
Ok I think i got it now.

I am taking the signal and sending it out of my computer into channel one on the mackie.  I then take the insert of that channel and hook it up to the pcb on the mic.  This give a gain adjustment to the signal going into the pcb. I then plug the mic into channel 2 of the mackie with no gain.  I send that back into the computer to feed the oscilloscope.  When I adjust the gain of the signal to the pcb I see the volts go up to 50v before I hear distortion in the headphones.

tskguy

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #349 on: April 18, 2012, 09:48:30 PM »
Hey everyone,

Wanetd to post a bit of a success story. First of all I built this mic and had zero issues! Dan did a fantastic job creating this pcb as well as documenting everything. Thanks!! Second I just insatlled my first DIY capsule, and it sounds great!! so far I havent done much recording but I sent a sample to Dan and he said it was pretty spot on!! I am to say the least a bit pleased. I hope to have a decent recording that I can post on here. The one I sent to Dan is a bit embarrassing, I am a drummer not a guitarist and I recorded some really poor guitar playing mixed wih my 2 year old girl grabbing the mic and singing twinkle twinkle :) And yes that's a celebratory beer.
Anyway, Here are some pics.


« Last Edit: April 18, 2012, 09:56:11 PM by tskguy »


Re: Neumann U87 Vintage Circuit Build Thread
« Reply #350 on: April 18, 2012, 10:02:52 PM »
NICE JOB TSKGUY!!!!!!!


Ok Success,
I was able to use the scope but did more by ear.  I set the out put of the signal to 4v as it said on the oscilloscope screen / chart.  I found my lowest  point when the distortion started to be 8.55 volts on the drain.  Then i found the highest point to be 13.00volts.  So when I take 13-8.55 I get 4.45 difference.  I then took 4.45 and divided in half to get 2.22 and then at that to 8.55 which equals 10.77.  So I take it this is the middle section between the distortion points and is probably the optimum point to have for this FET.  So I will then set drain voltage to 10.77volts.  Am I right in this thinking.  I had fun tonight figuring out this stuff.
Thanks guys

-Scott





kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #352 on: April 19, 2012, 06:24:51 AM »
@tskguy:

Congrats,building an own capsule is simply stunning;I´m not capable to do that,so therefore have my deepest respect-CHAPEAU BAS!!!

@Scott:

Sorry for replying late.
Seems you´ve got it now without really using the scope-Congrats!
It´s a great experience hearing the distortion on a sinewave,isn´t it?
You´ll remember this "sound" forever because it doesn´t compare to anything in the world (be aware that a sine is the purest wave we are able to hear and has absolutely no overtones;any other waveform has them and sounds completely different!).

If you still want to scope again:
I must first download your programs then,install them and then learn how to use them.I have a couple of 1604s at work to check back,this is no biggie.But it will take a couple of days to get this all managed due to a lot of "real work".Also be aware that I still don´t have a trafo,so must find a work-arround for that.

From what you described by listening to it sounds pretty good to me,you seem to be spot-on.

Just curious:
May I ask if you have measured the idss of your fet and what value it had?I had a higher drain-vdc at approx.12,xx volts,but the fet had an idss of 8,7mAs,so is right.It was the lowest of 40 fets or so.
If you don´t know leave it in place-seems you´re done my friend ;).

Now have fun recording with your new toy,

cheers,

Udo.

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #353 on: April 19, 2012, 06:48:29 AM »
Udo,

I just remember that the fet was the highest one out of the three I had.  Don't know if that was a good or bad idea to use the highest one.  I really don't know if I measure it right too.  I think it was the two out side legs and got a 12 number or something.  I will measure the others and see what they say.    Don't worry about checking the programs I feel pretty confident that I got the mic optimized to its fullest specs.  Was a lot of fun too.  Thanks for everything.  I hope your transformer  comes today.

-Scott


wthrelfall

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #354 on: April 19, 2012, 06:57:14 AM »
I'm looking to get my next mic started soon, finally having finished my first successful mic (very nice!).
It would be great to source a decent capsule and transformer from Europe, to save on import duty and shipping - does anyone have some suggestions of suitable parts or manufacturers?
ps.  I spoke to Brian Sowter but they don't have a suitable transformer..

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #355 on: April 19, 2012, 07:01:51 AM »
I hope your transformer  comes today.

-Scott
Transformers (plural) ;D ;D ;D

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #356 on: April 19, 2012, 07:20:45 AM »
It would be great to source a decent capsule and transformer from Europe, to save on import duty and shipping - does anyone have some suggestions of suitable parts or manufacturers?
Hi,

I made an inquiry at AMI/TAB Funkenwerk a couple of weeks ago.Joe over there wrote that they wanted to push as much as possible through D.A.S.,a german company located in Hamburg.So I went this way,I´m waiting for them at the moment.
Here´s their site:

http://www.digitalaudioservice.de/

You can switch to english language at the top right of the page.

Hope to have helped,

Udo.

wthrelfall

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #357 on: April 19, 2012, 07:28:58 AM »
It would be great to source a decent capsule and transformer from Europe, to save on import duty and shipping - does anyone have some suggestions of suitable parts or manufacturers?
Hi,

I made an inquiry at AMI/TAB Funkenwerk a couple of weeks ago.Joe over there wrote that they wanted to push as much as possible through D.A.S.,a german company located in Hamburg.So I went this way,I´m waiting for them at the moment.
Here´s their site:

http://www.digitalaudioservice.de/

You can switch to english language at the top right of the page.

Hope to have helped,

Udo.

Thanks Udo, I looked on the DAS site but I can't find the Tab Funkenwerk transformer - I presume you contacted them and placed a special order?

kante1603

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #358 on: April 19, 2012, 07:35:51 AM »
Thanks Udo, I looked on the DAS site but I can't find the Tab Funkenwerk transformer - I presume you contacted them and placed a special order?
Yes,I contacted them on the phone.I was led to a guy named Michael Bucur,he´s responsible for repairs an therefore for (spare) parts.Ask for him,he´s a very friendly guy.

Udo.

wthrelfall

Re: Neumann U87 Vintage Circuit Build Thread
« Reply #359 on: April 19, 2012, 10:06:19 AM »
thanks Udo.

Thanks Udo, I looked on the DAS site but I can't find the Tab Funkenwerk transformer - I presume you contacted them and placed a special order?
Yes,I contacted them on the phone.I was led to a guy named Michael Bucur,he´s responsible for repairs an therefore for (spare) parts.Ask for him,he´s a very friendly guy.

Udo.


 

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