U87/67 Capsule options & u87 circuit questions

[gary o]

Hi I didnt want to jump into the U87 build thread with this.... Im gonna make a U87 type mic maybe from a kit or just by myself on a perfer board..... I only need cardiod really, I think I read somewhere there was a better way to wire the capsule if only cardiod is needed ..... Can anyone shed some light

I have been experimenting with a KM84/83 which seems very similar to 87.... Im trying to add the de emphasis section ( I think I know what Im doing ....) the circuit sounds great so far with a flat capsule no de emph good op level I have been reading kinda complaints about DIY U87 level being lower than modern mics ....Questions AMI T13 is 9.5:1 Cinemag 2840 is 10.5 1 fro U87 the KM84/83 call for 7:1  .....so why are they different wouldnt U87 be better off with 7:1....

Capsules..... before the U87 kits came along I was reading that the china K67 were good copies of neumann capsule but sounded bad because of flat amp circuits makes sense.....DIYers were using china K67s and were happy saying the the de emph circuit was making the chinas sound like neumann.....is tha the case would love to hear from anyone who can compare chinaK67 to the current crop of K67s & are the current crop made from scratch or modded or just sourced..... I did read the there are smaller 32mm versions too

So which is best haha silly question but here a little list would love to hear any thoughts on these capsules and more....As I say Im just need cardiod my my mic not sure if all these capsules will do all three polar patterns of the 87

Chnia free £000 with any shite mic haha

Mic parts.com
K67 $119
RK87 $109 3 micron membrane ?
K67 le $189  brass 6 microm membrane

Beez nee
z K8 ?is that for 87 ? $330

Tskguy $250

Micandmods
Mk67 49 euro
Mk 67 premium  99 euro        these are cheap sizes look right cant see difference between the two other than price

Peluso PK67 $255

Any others

In my quick little bit of research I read some sellers offereing hybrids slightly different versions different sizes Advanced audio hav a less boosted high freq but I think I going to ignor those as circuit was optimsed for the original spec capsule.

Cheers Gary O.

 

[micaddict]

Pure cardioid.

For that you only need one side. Best case scenario IMO would be a quality capsule that's deliberately single sided or has a passive rear membrane or is maybe B-stock for having one less perfect side. Sumpin' like that.
Perhaps Tskguy or Beesneez could be persuaded to offer such animals at a reduced price?

 

[poctop]

I have been reading kinda complaints about DIY U87 level being lower than modern mics

Hi Gary,  this is not a complaint but a real fact , the Vintage U87 is actually 10db lower output than modern mic but not a tad more.
By experience i use an Original U87i (vintage) and a D-U87 in all my sessions and i could not be happier on how it sounds, the capsule polarisation 45V and circuit design single fet  transformer coupling and the " neumann- de-emphasis" touch is all responsible for his lower output and it is certainly also responsible for  the signature sound of this classic mic almost every studio has. 


just my 2 cents, 
Best,
Dan,

 

[gary o]

Pure cardioid.

For that you only need one side. Best case scenario IMO would be a quality capsule that's deliberately single sided or has a passive rear membrane or is maybe B-stock for having one less perfect side. Sumpin' like that.
Perhaps Tskguy or Beesneez could be persuaded to offer such animals at a reduced price?

Thanks micaddict Im all for the single sided & cheaper price capsule & B stock is great idea thanks but was wondering about the actual wireing of single capsule....

Hi Dan thanks yeah I will no complaint about the level of a U87 was just noticing the 7:1 transformerin the KM circuit ( maybe because smaller lower output capsule) I had a Haufe T14 11:1 tran on my KM84 circuit sounded great I have a cheapy OEP 7:1 ish on the mic now sounds great too.... The KM circuit has sparked my interest in the U87 circuit

I tried adding an external polarisation voltage to my KM84 circuit via battery & also vai PSU I made for tube mic, it didnt seem to make much difference to the sound & level of the mic , as I say Im not unhappy with it as is but fun toexperiment & learn a little..... that brings me as to what capsule to get for when I add the de emphasis components going to try a cheap china first

 

[gary o]

http://store.studio939.com/product/35mm-k67-style-capsule Nice and cheap for anyone slightly less top the original capsule ? so I guess not what is needed for 87/67 de emphasis circuits great price tho .....