kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #740 on: June 08, 2012, 01:39:43 AM »
Does anyone build and sell these (as I have no DIY skill for electronics...) I'd buy one from someone.
this is a diy forum....we all had to learn and practice and have put a lot of work in here....
So sorry but from my point of view no.


wave

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #741 on: June 08, 2012, 01:49:09 AM »
Does anyone build and sell these (as I have no DIY skill for electronics...) I'd buy one from someone.

Also, if you're trying to keep the cost down, someone can PM me as I've been in touch with the factory that produces the Peluso Capsules / Microphone Parts Capsules. They also make bodies/head-baskets. You could probably get an unbranded body/basket and the capsule together for less than the donor mic body....

If anyone wants to try doing a group buy for Capsules/Parts, we could try to arrange it.

LTJazz  Welcome to the forum!

I will build you one if you want.
I have my recommendations as far as components go (you can read the whole thread and see that)
You should strongly consider purchasing on of Eric's (tskguy) capsules. They are great. The Rk-87 is a great capsule for the money but you def need to go with the T-13 and all vintage caps with that capsule. I used that combo in my first mic and there are some samples I posted of it earlier in the thread.

I have been asked by a few other people to build mics for them and I'm pushing Eric's capsules to them as well.
Nothing against Peluso's, I just haven't heard one in my setup and I can get Eric's work for no shipping.

Think about it and PM me if you want.

Dave

wowi

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #742 on: June 08, 2012, 05:08:48 AM »
Hi Udo, great work.
And you are not the last one who get ist started.  ;)
Cause of some other projects i just started yesterday to build it based on the B2pro.
So if you have some hints for the B2Pro, that are not on the thread already, you are allways welcome  :D

Best
Wolfgang


geekmacdaddy

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #743 on: June 08, 2012, 05:52:35 AM »

Geek - you're gonna love Eric's capsule. What tranny are you teaming it up with?


Hi Wave,
 I was going to use the Tab, but after hearing the shootout clips, I can see no reason why not to save 50.00 and go with the cinemag. It sounded great, and I think tskguy's capsule will take me where I need to go.

Jeff

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #744 on: June 08, 2012, 10:44:32 AM »
So I made my very first comparison to a U87Ai today.
Just my voice running through 2 identical SPL Gainstations (no tube section active tec,just hpf at 50Hz).
I must say that I really liked what I heard,both are pretty close to each other on a first listen.On a second one there´s slightly more highs on the clone,really marginally,and it seemed a very slight bit more boomy when getting pretty close to it due to the proximity effect.All in all very very nice!
But:
What I didn´t like was that I needed tons of gain to get a useful signal from it,not some 10 to 12 but more like 16 and more dBs difference.
I wondered what this could be,the only thing I remember was that I used a fet with the lowest idss (around 8,xx mAs).
Since most of the fets I have here have  more like 10mAs I´m thinking to swap it to one of these.I´m not 100% sure if it is the right way to handle it,but as far as I can remember a higher idss gives less dynamic but more gain,no?

Must think about it....sh*t,this break caused by waiting for the T13s was way too long........

Any suggestions?

Udo.

LTJazz

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #745 on: June 08, 2012, 03:03:14 PM »
Thank's for the offer. You may find a message in your inbox shortly!

In response to the criticism, I do understand this is a DIY forum, and I'm reading and trying to learn but to be honest it's going to take some time to build up my skills. However, you also have a market section here. So until I am competent enough to work with electronic components, I have the option of buying a kit and botching it, wasting my money, buying an overpriced mic from a standard company, or possibly commissioning work from an established DIYer that has a passion for building quality mics.

I think I'll choose the latter. If that brings me criticism, so be it.  ;D

Does anyone build and sell these (as I have no DIY skill for electronics...) I'd buy one from someone.

Also, if you're trying to keep the cost down, someone can PM me as I've been in touch with the factory that produces the Peluso Capsules / Microphone Parts Capsules. They also make bodies/head-baskets. You could probably get an unbranded body/basket and the capsule together for less than the donor mic body....

If anyone wants to try doing a group buy for Capsules/Parts, we could try to arrange it.

LTJazz  Welcome to the forum!

I will build you one if you want.
I have my recommendations as far as components go (you can read the whole thread and see that)
You should strongly consider purchasing on of Eric's (tskguy) capsules. They are great. The Rk-87 is a great capsule for the money but you def need to go with the T-13 and all vintage caps with that capsule. I used that combo in my first mic and there are some samples I posted of it earlier in the thread.

I have been asked by a few other people to build mics for them and I'm pushing Eric's capsules to them as well.
Nothing against Peluso's, I just haven't heard one in my setup and I can get Eric's work for no shipping.

Think about it and PM me if you want.

Dave

wave

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #746 on: June 08, 2012, 03:10:33 PM »
Udo,
When I did my A/B against a U87AI I had a big difference in gain between the 2 as well.

LTJazz - Let me know whenever

Dave

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #747 on: June 08, 2012, 04:23:00 PM »

Udo,
When I did my A/B against a U87AI I had a big difference in gain between the 2 as well.
Thanks for the reply Dave,

As said before this is a really really nice microphone soundwise.

But what does "a big difference"mean in numbers approximately?
Given an expected difference of 11dB (taken from the Neumann specs,have posted about this part earlier) I thought I was too far off.Thinking say 6dB more gain equals twice(!) the level.
I can't remember we ever had problems concerning gain structure when we used the originals back in the early 80's.
Which kind of pres did you use?
At the moment I think that using it with my new vp28s might not fit.These have about 60dB of gain from the imput stages (another 12dB handy from the output fader gain stage of course....) and I wonder if I'll run into (preamp-) noise with it.Can check this during the next week,today it was a bit too much busines in our studios,and I did the before mentioned very first soundcheck pretty quick.

Anybody else here who can give us some "numbers"?

Thanks,

Udo.
« Last Edit: June 08, 2012, 04:32:43 PM by kante1603 »

wave

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #748 on: June 08, 2012, 05:04:21 PM »
Hi Udo,
Well I didn't have a way to gauge the gain difference numerically when I did my A/B test.
Here in my studio I have been doing my tests with my Amek 9098 mic pres.
They have about 72 db of gain. There is about 11-12 db of gain difference between my U1621 and my 414 TLII (the 414 being hotter)
That said, on the 9098s I'm not coming close to maxing out the gain knob with the U1621 (I'm getting up to 42 on the gain knob markings).

When we did the A/B at GC they plugged the mics into a Focusrite interface and it was almost maxed on input to get the same volume as the U87AI.
It would be nice to be able to get some extra gain from these mics internally. I can confidently say that they need to be used with pres that have some good headroom.

Dave

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #749 on: June 08, 2012, 05:29:01 PM »
Cool Dave!

That´s where I approximately ended up on my SPL Gainstations.
Gain knob marking was at around 39dB with the output set to +6dB,that seems to be in the ballpark.
On the U87Ai I had a setting of 29dB with no additional gain on output.

At least they´ll work on my ssl pres,the have tons of gain.And concerning the vp28s I´ll test them when I find the time,no biggie now.

Thanks for sharing!

Udo ;)


kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #750 on: June 08, 2012, 06:11:56 PM »
Here´s my next little thing for you B2Pro builders:

How to create a nice housing/bottom for the transformer

The B2Pro is a transformerless microphone.So it has nothing but a gap on it´s bottom end.
I thought a bit about how to securely mount my T13 in my build.
I have read people tried to do that with unbelievable techniques like cable straps or even let them wiggle around inside.This can cause shorts on the xlr connections and therefore is an absolute "NO-GO"(...I wanted to avoid the word "B**LS**T"....).
After some investigation of my cellar storage I found some old and broken kitchen chairs like this:



The construction is from chromium plated steel at a diameter of 28mm.Cool!
So I cut off a piece of 35mm length and inserted it to the bottom part where the xlr is seated.
Like this:



I put on some shrink tube over the blank solder joints prior to that.
For putting it in I used a 2 component glue-this construction withstands even a tank attack.
Next step was to cut some stripes of rubber foam and carefully insert the transformer.
Like this:



Once fully seated slide back the pcb assembly so it sits flush to the bottom tube.Tighten the screws.Now you have no more moving parts-prominsed!And here´s the spot where you can apply your AMI sticker ;D
After all wires soldered it should look kinda this:



Done!

Have fun,

Udo.

P.S.:I calulated that I can build around 700+ bottom tubes from my leftover broken chairs,not bad.....

geekmacdaddy

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #751 on: June 08, 2012, 06:30:40 PM »
DIY brilliance.

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #752 on: June 08, 2012, 06:57:11 PM »
DIY brilliance.
No,just having fun ;D

Udo.

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #753 on: June 08, 2012, 07:52:58 PM »
And another cheap but helpful hint:

Improving the continuity between the bottom part and the metal tube

A good ground connection between all metall parts is essential in this build,otherwise you´ll run into trouble with rf noise and hum.
Here´s a cheap way to make the contact way better.
Just take a piece of solid core wire,I used a silver plated type,known as bus wire.
Form a ring of it and insert it to the bottom part.
This increases the pressure from the bottom part to the tube and guarantees a very good conductive connection,at least it does on a B2Pro.
Look:





Some sanding/grinding is useful too because some metal parts tend to corrode pretty fast.

Cheers,

Udo.

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #754 on: June 08, 2012, 08:10:42 PM »
And finally

The peluso capsule mounting and wiring

I know,wiring has been covered a thousand times,but still sometimes confusing.
Thought some additional pictures might help.
For B2Pro builders:I purchased the capsule mount from Peluso too.
Found out that the upper part (the saddle/the white plastic piece) fits perfectly on the lower orignal rubber mount.
Just swap it.
Exchanging the rubber mount could only be done by drilling 2 extra holes in the metal mounting plate because the original part has a centered screw while the peluso uses 2 screws.
Here the pics:





Here you can see the wire (red/blue in my case) you have to put on by yourself.Solder before attaching!Use the flat washers that are supplied with the capsule.



Remember not to touch anything with your fingers in the high impedance area,wear gloves (colour doesn´t matter ;D)

Bye,

Udo.



wowi

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #755 on: June 09, 2012, 02:38:00 AM »
Hi Udo,

thanks for your tips. Your transformer mount is really DIY  :)
I will now go in my cellar and will see what i find.

Wolfgang

kante1603

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #756 on: June 09, 2012, 03:01:03 AM »
Hi Udo,

thanks for your tips. Your transformer mount is really DIY  :)
I will now go in my cellar and will see what i find.

Wolfgang
Hi Wolfgang,

Sanitärbereich hat auch viel Zeug,z.B. Haltegriffe oder Handtuchhalter,heheheheh....

Tschüsskes,

Udo. ;)

Matador

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #757 on: June 09, 2012, 05:42:22 PM »
We all might think about trying a higher gm JFET like a 2SK170BL....

HellfireStudios

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #758 on: June 09, 2012, 06:43:17 PM »
We all might think about trying a higher gm JFET like a 2SK170BL....

There has got to be a better FET than the one put in the chinese mic in the first place. Any suggestions?
"Tommorrow is just yesterday in reverse. Just like friends are enemies in reverse." -Gary Busey

Matador

Re: Neumann U87 Vintage Circuit Build Thread.
« Reply #759 on: June 09, 2012, 10:03:49 PM »
We all might think about trying a higher gm JFET like a 2SK170BL....

There has got to be a better FET than the one put in the chinese mic in the first place. Any suggestions?

What exactly is wrong with it?


 

Related Topics

  Subject / Started by Replies Last post
0 Replies
2746 Views
Last post March 12, 2012, 11:30:21 PM
by poctop
801 Replies
197825 Views
Last post July 17, 2019, 04:03:26 AM
by Spencerleehorton
338 Replies
84040 Views
Last post August 07, 2019, 03:20:39 PM
by Rlucas41
3 Replies
1256 Views
Last post April 02, 2018, 05:30:35 PM
by Wordsushi