OPEN SOURCE DIY Mic Project - ORS 87 - Stripped Down u87

[AdamFrisen]

Do you have an audio interface and a computer you can install RoomEQ Wizard on? If the answers is "yes" to both, you don't need any (more) fancy hardware than that

I am using Focusrite Clarett+ 2Pre as the audio interface and periodically I get sudden noisy measurement (TRS cable directly from Focusrite output to input).

Don't know what causes it but got me to discard few op-amps before I realized. 1 kHz pure sine wave:


I recorded it in Audacity and it shows lots of glitches:






Insufficient power supply (default adapter)? REW is also a possible source of error (v. 5.31.1).

 

[Khron]

I am using Focusrite Clarett+ 2Pre as the audio interface and periodically I get sudden noisy measurement (TRS cable directly from Focusrite output to input).

Are you using the ASIO driver in REW? Audacity might not even have that...

 

[mic test]

Hello do you know someone who can put a new mebran on a capsule for me still have a Capsul from a brown VM 1 was once defective bought on ebay I had it replaced by a new one wanted to use it for the project ORS87

 

[Khron]

Hello do you know someone who can put a new mebran on a capsule for me still have a Capsul from a brown VM 1 was once defective bought on ebay I had it replaced by a new one wanted to use it for the project ORS87

Just grab an Arienne Audio K87?

 

[micolas]

Hello do you know someone who can put a new mebran on a capsule for me still have a Capsul from a brown VM 1 was once defective bought on ebay I had it replaced by a new one wanted to use it for the project ORS87

@mic test
Welcome to groupdiy!
If you want to get as close to the U87 sound as possible, follow the advice of @Khron and many others.

Just grab an Arienne Audio K87

https://store.arienneaudio.com/micr...k87-microphone-capsule.html#/1-options-normal
Note:
The Brauner capsule (stock or reskinned) will not take you to area 87.

 

[mic test]

Thank you very much I will do it but I have 5 PCBs I would like to use the Capsul again but it is from a 4000€ mic the membrane is defective I need a new gold foil is there anyone who can do that? Many greetings from Germany

 

[micolas]

Thank you very much I will do it but I have 5 PCBs I would like to use the Capsul again but it is from a 4000€ mic the membrane is defective I need a new gold foil is there anyone who can do that? Many greetings from Germany

Yes, that's understandable, the VM1 is a good, modern microphone.
Below is the FR
Those who produce microphones can also help you with a reskin, they are here in the group or follow the posts, probably whoever wants to will help you.

 

[mic test]

can you have this repaired somewhere ?

 

[micolas]

can you have this repaired somewhere ?

Maybe @soliloqueen (who owns Arienne Audio and produces those absolutely wonderful capsules) can help you.
I think she was once willing to help out with a capsule reskin for a group member.

 

[mic test]

Thank you I'll try

 

[micolas]

Thank you I'll try

I think because you don't have enough posts yet, you can't contact Soliloqueen directly on group conversations, but she will see the post.
Or you can send an eMail on the official Arienne Audio website

 

[mic test]

yes have sent an email via the site let's see

 

[micolas]

yes have sent an email via the site let's see

Good luck!
In any case, my belief is that this capsule will sound beautiful, open, airy, modern, in a body and circuit similar to the Brauner VM1.
So you'll have to build the best clone possible

 

[AdamFrisen]

Are you using the ASIO driver in REW? Audacity might not even have that...

Focurite has their own ASIO which I can select in REW. In Audacity, I am using Windows DirectSound or WASAPI.

Looks like the 1 meter TRS patch cable I used might be bad (https://www.cordial-cables.com/en/products/em-vv). Both cables I have.

Doesn't cause noise problem when I use this Behringer GIC-90 4SR cable: https://www.amazon.se/-/en/gp/product/B09MQK9GLN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[mic test]

tahnks yes I have a lot of brown mics brown phantom brown valvet x brown valvet but I love the brown phanthera it is 16 years old and still has the old capsule over time it has been changed again and again I don't like the new ones anymore the mic is still like new I also bought on eBay and tested a lot from Manley ref Neumann TLM49 TLM 102 TLM103 TLM107 T-Bone Monky Banana etc but with the Phantoma the sun rises (=
There is also a different circuit installed than in the new Phantoma. There is no Lundahl amplifier in it like in the new ones and there are many more components on the board than in the new ones. I always wondered why the mics are so different

 

[micolas]

tahnks yes I have a lot of brown mics brown phantom brown valvet x brown valvet but I love the brown phanthera it is 16 years old and still has the old capsule over time it has been changed again and again I don't like the new ones anymore the mic is still like new I also bought on eBay and tested a lot from Manley ref Neumann TLM49 TLM 102 TLM103 TLM107 T-Bone Monky Banana etc but with the Phantoma the sun rises (=
There is also a different circuit installed than in the new Phantoma. There is no Lundahl amplifier in it like in the new ones and there are many more components on the board than in the new ones. I always wondered why the mics are so different

Aha, excellent! Impressive
Now I understand the desire to repair that capsule. I hope Ari can help you!

 

[AdamFrisen]

tahnks yes I have a lot of brown mics brown phantom brown valvet x brown valvet but I love the brown phanthera it is 16 years old and still has the old capsule over time it has been changed again and again I don't like the new ones anymore the mic is still like new I also bought on eBay and tested a lot from Manley ref Neumann TLM49 TLM 102 TLM103 TLM107 T-Bone Monky Banana etc but with the Phantoma the sun rises (=
There is also a different circuit installed than in the new Phantoma. There is no Lundahl amplifier in it like in the new ones and there are many more components on the board than in the new ones. I always wondered why the mics are so different

Regarding Lundahl transformers. They were considered as the one of the best ones to use back in time, but I don't see them being mentioned much in here. Anyone tried or would be suitable for U87 diy?

 

[micolas]

Regarding Lundahl transformers. They were considered as the one of the best ones to use back in time, but I don't see them being mentioned much in here. Anyone tried or would be suitable for U87 diy?

Stam used a Lundahl output transformer
in the MK3 revision of SA-87
The MK1 and MK2 used a Sowter output transformer

 

[mic test]

​

 

[AdamFrisen]

Thanks for info about Lundahl being used in Stam.

Stam Audio SABV13, on the back-side of the mic, I see Lundahl 1935 being printed. Maybe rebranded was used?

https://www.lundahltransformers.com/wp-content/uploads/datasheets/1935.pdf

https://www.lundahltransformers.com/microphone/

What would be required to use this transformer instead in ORS build?

Or these below would be even a better choice? "Probably the best beer in the world..." - kinda statement.