Neumann Vintage U87 Clone : Build Thread.

[HellfireStudios]

Glad to hear it. Let us know how it sounds when you're done.

-James-

 

[ianhu]

Well....I had a rode NT1a.

I guess when I bought it and had it here with nothing to compare it too it sounded good.

Then I heard my friends NT2 and that sounded better, perhaps a little more on the high end hz

Then I heard my other friends NT2a and that sounded better again.

Then, tonight, I recorded some vocals on my clone U87. Well I am so happy it sounds so much better than anything before.

I am so pleased.

Thanks to all the guys on this site who have made that possible for me and those so many others who have built one, from using your experience and knowledge.  I could never afford or justify the amount of spend it would have taken to get a real u87. This is bar far the best thing and worth every penny it cost me to make.

Ian

 

[JessJackson]

68 MOhms Resistor

http://www.mouser.com/Search/ProductDetail.aspx?R=GS1%2f4LC686Jvirtualkey66000000virtualkey660-GS1%2f4LC686J

Out Of Stock, any replacements?

 

[poctop]

68 MOhms Resistor

http://www.mouser.com/Search/ProductDetail.aspx?R=GS1%2f4LC686Jvirtualkey66000000virtualkey660-GS1%2f4LC686J

Out Of Stock, any replacements?

71-RNX02560M0FKLB

They are actually in the BOM already so you have some replacement number already as the 68M are only 0.14 cents each

you can go with these one original value, then a bit more expensive tough,
Both will do fine but sometime mouser is out of luck also,
Best,
Dan,

 

[JessJackson]

Thanks brother

68 MOhms Resistor

http://www.mouser.com/Search/ProductDetail.aspx?R=GS1%2f4LC686Jvirtualkey66000000virtualkey660-GS1%2f4LC686J

Out Of Stock, any replacements?

71-RNX02560M0FKLB

They are actually in the BOM already so you have some replacement number already as the 68M are only 0.14 cents each

you can go with these one original value, then a bit more expensive tough,
Both will do fine but sometime mouser is out of luck also,
Best,
Dan,

 

[jnTracks]

me again!

i had a few minutes tonight so i got in there with my DMM to see if i was crazy about the microphone being very, very quiet, or if any voltages were off that might help me track down the problem.

everything is right except....  the backplates read 13.5 ish volts. 

so remember i said i got a capsule that has a shared backplate?  well for future reference in the case of using a capsule with shared backplate in this circuit just wire the backplate to front backplate pad and leave rear backplate pad open. 
i knew going in that figure 8 wouldn't work but i should be able to do cardioid and omni.  so that's where i am now.  40v on the backplate and the it's about 10db quieter than modern condencers, just as Dan said.  (instead of the -25dB i was seeing before)
it sounds beautiful.  best condenser in my cabinet, hands down.

hope that little tidbit helps the next guy who does the dumb thing i did!
thanks!

 

[Volume11]

Can someone please recommend a place where I can get the eyelet style terminal ends for the capsule wire? Also, is 24awg stranded wire ok for this application? I just received my beesneez capsules, and I'm very eager to get them going. Thanks!

 

[JessJackson]

off topic a little... does anyone think it might be possible to fit the u87 circuit inside a TLM103 body.

 

[HellfireStudios]

off topic a little... does anyone think it might be possible to fit the u87 circuit inside a TLM103 body.

Doubtful. It would be difficult, if not impossible, to fit two PCB's, three switches, and an output transformer in the smaller TLM103.

-James-

 

[kpearsall]

plus, I think the TLM103 would be a hell of an expensive donor body! There's cheaper ways to achieve the same result. You could sell the 103 and buy enough parts for two 87's

 

[JessJackson]

plus, I think the TLM103 would be a hell of an expensive donor body! There's cheaper ways to achieve the same result. You could sell the 103 and buy enough parts for two 87's

i have a couple sitting around, not worried about selling them, just like compact for traveling, hotel room recording.

 

[TheGuitarist]

Hey guys, having a couple of issues with my build... i think i might have a short somewhere... but im only reading 17.6~ across pins 1 and 3 of the xlr connector (was reading about 42 when it wasn't working then i realised one of the inductors wasn't soldered)

I'm passing signal from the capsule, but its low level, i have a massive hum and an "ocean" sound in the background. I'm guessing most of it is due to my grossly low voltage, but any suggestions on where to look for the short? I'm only getting about 6-9v across CC.

 

[poctop]

Hey guys, having a couple of issues with my build... i think i might have a short somewhere... but im only reading 17.6~ across pins 1 and 3 of the xlr connector (was reading about 42 when it wasn't working then i realised one of the inductors wasn't soldered)

I'm passing signal from the capsule, but its low level, i have a massive hum and an "ocean" sound in the background. I'm guessing most of it is due to my grossly low voltage, but any suggestions on where to look for the short? I'm only getting about 6-9v across CC.

Have you followd the convention on the silk screen and not the number ,  hot pin 2 gnd= pin 1 cold pin 3
?  it is probably in the front end,  , at the 2K2 divider network,  what do you get for the zener voltage,
Hope this helps,
D

 

[TheGuitarist]

Yeah, i've connected the hot cold and ground as per the silkscreen not the numbers, i'll double check the voltages, but it does seem to be something fairly early on.

voltage at the zener is 8.07

seeing about 9.51 on the leg of r19 if that helps at all

 

[poctop]

Yeah, i've connected the hot cold and ground as per the silkscreen not the numbers, i'll double check the voltages, but it does seem to be something fairly early on.

voltage at the zener is 8.07

seeing about 9.51 on the leg of r19 if that helps at all

Can you measure the 48 V with the cable disconnected and then check your zener diode this might be leaking current big time if it is faulty and they are very sensitive device,

Hope this helps,
Dan,

 

[TheGuitarist]

Yeah i'm getting 48v from the preamp... hmm... ive got a second mic with the exact same problem... sounds like it could be zeners have been damaged in transit?

I don't have the all time greatest DMM, it couldnt be that my 2k2 network is slightly mismatched (i did match as close as i could using my DMM), i don't see how i could lose that much... the zener is sounding like the culprit...

 

[kante1603]

Hi,

if you've got the same issue on two mics the possibility to have something soldered or populated wrong is much higher than broken zeners during transport ( did you mean that by saying " in transit"?).Although they might be damaged now.....we don't know what happened (yet).
Can you show us some (high res) pics of your builds?

Best regards,

Udo.

 

[3nity]

Doing some test, nothing really scientific but purely entertaining.
My 1272s preamps and U87 dont really get along very well! 1272 low gain!
However my 1290 and U87 really like each other..

 

[kante1603]

Hello,

that's to be expected.
From what I know the  1272 is mainly a line-in amp and often used for summing on the bus,something around 50dB gain.
The 1290 has a three gain stages and can easily go far beyond the 70dB mark.
This all is load-dependent of course.

Hope to have helped,

cheers,

Udo.

 

[3nity]

Yeah i wanted to verify that on u87.
However its a sweet sounding mic!

Thanks