Neumann Vintage U87 Clone : Build Thread.

[Matador]

Also, here is a test recording I did with this U87 and the new Peluso capsule:

http://www.musicalsparks.com/images/u87/u87_guitar.mp3

I don't know the brand of the guitar, but it is a solid spruce top and mahogany sides and bottom.  It has a very tight and controlled sound I think.  Strings are medium gauge phosphor-broze.

This is not a raw sound file:  I did my normal "acoustic guitar only" mix tweaks:  high-passed it at 80Hz, dipped 3dB out of the 1.5kHz range (spanning about 800Hz to about 2.2kHz), and boosted everything above 3kHz by 1.5dB to bring out a bit more of the pick attack.  There is also a slight amount of compression (very little...this track still has over 15dB of dynamic range!) and a bit of room sized reverb.  Mike is about 1 feet away right at about the 12th fret, pointed at the space between the sound hole and the beginning of the neck.  This is a lot closer than I would normally go in this setup, however the room was untreated and very boxy sounding so I had to bring the mike in until it wasn't noticeable.  In a good room I would have backed this away at least another foot I think.

I'm still amazed at how good the mike does at capturing just about anything.  For solo acoustic I think it's perfect:  a good balance of the meat of the guitar in the 300-600Hz range, and great pick definition and transients in the 1-3Khz range.  This capsule is definitely a bit more detailed in the high-mids and high end as compared to the original.

However I'm not sure how well this track would sit with a male singer:  I would probably switch the guitar to something like a C12 and switch the U87 over to the singer as the C12 is midrange neutral in the areas where this U87 is pronounced (and vise versa).  I would take out a ton more low-mids and midrange anyways and boost the pick attack even more, which is what the C12 is kind of giving you for free.

 

[poctop]

Hey guys, I made a quick post shooting out my 87s. I apologize in advance for having to use my voice, I'll do more shootouts as I use these guys in sessions.

http://www.benlindell.com/2012/11/custom-87s/

Ben these are very amazing results you have there ,  The RK-87 seems to have a more air control than the Chinese one for sure , but WoW very impressive , Actually My Vintage (45V+ Polarisation) sounds more like the clone  ,  very warm in the mid range but not as airy, a bit darker than the sample i have heard from the AI ,  I am posting here a tweak that could even make it better to match the AI you have is in reducing the negative feedback cap just a notch,  this would bring back a bit of sheen and you could be really surprised,
note that the Original capsule K87 at 800$ need this compensation a that level but you could give it a shot ,
but for a 100$ capsule this is Fantastic,  I have to say that i still have an affair with the good old nude brass mic body  8)

I am attaching a post from Matador ( Thanks Matador)  about negative feedback cap and adjustment tweak you could do would make you even happier.  thanks for this great rewards to me 

3) Reduce negative feedback:  as I hinted at earlier in the thread, you can decrease the value of C6 (or remove it entirely) and it will give you back 3dB to 6dB, however the sound also changes as well.  If you like the "EQ-ed" sound, lowering C6 will take that away, however the mike will be hotter.  If you like/want the "air" it's a very simple mod to do and doesn't require any expensive or complicated circuit changes.  The sound change is FAR more drastic than #2 above (removing C6 can make it sound like a completely different mike).

Hey Ben did you have a chance to try the tweak,
Best,
Dan,

 

[3nity]

Ben how did you managed to get the labelled the mics??
the clips are amazing!
Thanks

 

[benlindell]

Ben how did you managed to get the labelled the mics??
the clips are amazing!
Thanks

Thanks man!

I labeled them with waterslide decals and some handywork in adobe illustrator.

 

[benlindell]

Hey Ben did you have a chance to try the tweak,
Best,
Dan,

Not yet, been too busy to open them up the last couple days. Hopefully I'll have a few minutes this weekend to do them. I'm really interested in what the C6 tweak will do.

 

[kevinkace]

So I did something quite stupid, and pulled the top pad off where the transformer connects at WS (either that or SW? Don't have the mic on hand right now). It looks as though the trace to that pad is duplicated on both sides of the board going to a cap (C16 or C17 I assume).

I should be safe to just ensure that the other side connection is made?

 

[3nity]

Any canadian who bought their parts from digikey or newark??
Just had some aditional fees from mouser last time that im trying to avoid this time.

If not im gonna look for...

 

[spudstyle]

Hi,

I can't find my old posts so anyone can tell me the PCB size in mm please ? Want to buy and try to put in an old T-Bone SC400. Thanks

 

[Volume11]

Any canadian who bought their parts from digikey or newark??
Just had some aditional fees from mouser last time that im trying to avoid this time.

If not im gonna look for...

Would it have something to do with the shipping method you chose? I know Mouser has plenty of shipping options.

 

[scottmichal]

I have an old MXL V57 (pretty much the same as an SP-1) that I can use for a donor body, but it is transformerless. Any suggestions on where I can get a Transformer Shield? I know some people have built without one, but I would prefer to mount my AMI T13 inside of a can if possible.

 

[rmaier]

Copper pipe caps in the plumbing aisle at Home Depot (see my post/pictures on p. 37 of this thread).

 

[scottmichal]

Thanks 

( I got my projects mixed up, the U87 is getting a cinemag CM2480, the T13 is for a U47 mod project  : )

 

[rmaier]

Cool. Cinemags will fit perfectly. Happy building.

 

[Delta Sigma]

Any canadian who bought their parts from digikey or newark??
Just had some aditional fees from mouser last time that im trying to avoid this time.

If not im gonna look for...

Would it have something to do with the shipping method you chose? I know Mouser has plenty of shipping options.

Always try and ship USPS. I think the standard charge from mouser is $8 for USPS to Canada and $20 for express which is quite reasonable and lower than what the USPS site quotes for the same services. When it crosses the border, USPS doesn't tack on ridiculous brokerage fees like UPS. You may pay duty but some of the time they just let small orders from mouser cross without duty which means you don't even pay taxes.

 

[kevinkace]

I'm considering using the connector that came part of the switch assembly, using a ribbon cable. Does anyone know the name of this connector? I couldn't find something on Mouser.

 

[kante1603]

I'm considering using the connector that came part of the switch assembly, using a ribbon cable. Does anyone know the name of this connector? I couldn't find something on Mouser.

Hi Kevin,

looks like an IDC header connector,have had this one with 10 pins in my hands a lot of times for various builds like those from joe at jlm audio.Available male and female in a lot of variations like for ribbon cables or solder style.

Hope to have helped,

Udo.

 

[spudstyle]

I just received the PCBs and it's cool, i can keep some piece of my Tbone Sc400 body, just need to machine a new tube but a friend can do it for free
Wait for the capsule and transformer now.

Thank you Dan !!!

 

[Hank Dussen]

I compared my build against a vintage U87 (not A or Ai version) and a C414 EB and my build has about 15 dB less output then either one of the vintage mics.
Sonically they're close although I didn't get into detail.
I know some other members here have reported the low output as well so I'm really wondering what is wrong.

(I build it with a Peluso capsule and the AMI transformer. All 'original' caps and only the pattern switch.)

Anyone?

 

[poctop]

I compared my build against a vintage U87 (not A or Ai version) and a C414 EB and my build has about 15 dB less output then either one of the vintage mics.
Sonically they're close although I didn't get into detail.
I know some other members here have reported the low output as well so I'm really wondering what is wrong.

(I build it with a Peluso capsule and the AMI transformer. All 'original' caps and only the pattern switch.)

Anyone?

I have you checked all the test voltage including the 40V polarization voltage to the capsule it is supposed to be 48V but with non high-Z probe you would get about 40V wich is what you should read  , is your pad shorted ,  how did you bias the FET,
have you checked the FET idss as Matador sugessted before putting it in the mic , 
what is your final drain voltage,  please make sure you have no error on mounting component to pcb ,
i know some of the builder had this problem that would be interestting to know what it ended up beeing the issue ,
so if anyone can chime in as per their mic output situation that would be nice , do you have a scope to bias the FET,
Hope this helps,

Dan,

 

[atticmike]

I compared my build against a vintage U87 (not A or Ai version) and a C414 EB and my build has about 15 dB less output then either one of the vintage mics.
Sonically they're close although I didn't get into detail.
I know some other members here have reported the low output as well so I'm really wondering what is wrong.

(I build it with a Peluso capsule and the AMI transformer. All 'original' caps and only the pattern switch.)

Anyone?

I have you checked all the test voltage including the 40V polarization voltage to the capsule it is supposed to be 48V but with non high-Z probe you would get about 40V wich is what you should read  , is your pad shorted ,  how did you bias the FET,
have you checked the FET idss as Matador sugessted before putting it in the mic , 
what is your final drain voltage,  please make sure you have no error on mounting component to pcb ,
i know some of the builder had this problem that would be interestting to know what it ended up beeing the issue ,
so if anyone can chime in as per their mic output situation that would be nice , do you have a scope to bias the FET,
Hope this helps,

Dan,

do yours have the output issue as well?