Neumann Vintage U87 Clone : Build Thread.

[Khron]

And not necessary to do another between RD and RBK?

Why would i have kept that piece of information obscured, IF it was essential?

 

[Potato Cakes]

Hello, Everyone,

Trying to wrap up a pair of M version PCB builds and I somehow forgot to order the 47uH inductors even though I remember clearly thinking I needed to make sure that I don't forget them since I did not have any on hand. The ones I do have laying around are 4.7uH. I noticed in the Version 16 schematic that L1,2 positions were sometimes bridged for certain versions. I am just wondering if using this low of a value will either create an undesired filter effect or if there will be insufficient EMI suppression.

Thanks!

Paul

 

[micolas]

Hello, Everyone,

Trying to wrap up a pair of M version PCB builds and I somehow forgot to order the 47uH inductors even though I remember clearly thinking I needed to make sure that I don't forget them since I did not have any on hand. The ones I do have laying around are 4.7uH. I noticed in the Version 16 schematic that L1,2 positions were sometimes bridged for certain versions. I am just wondering if using this low of a value will either create an undesired filter effect or if there will be insufficient EMI suppression.

Thanks!

Paul

Many times I didn't even put these inductors.

 

[Potato Cakes]

Many times I didn't even put these inductors.

Did you notice any unwanted effects such and RF interference when using a jumper instead?

Thanks!

Paul

 

[micolas]

Did you notice any unwanted effects such and RF interference when using a jumper instead?

Thanks!

Paul

In short, No.
I have never had any problems with RF interference although there is a local FM radio station nearby (which I personally founded in 1996 ) which has 100W power in the antenna. In addition, I live surrounded by dozens of wi-fi routers, and probably hundreds of switching sources of devices,several cable television networks and towers with mobile phone antennas.
In addition, I live in a block built over 60 years ago and the grounding of the electrical network is no longer efficient.

 

[Potato Cakes]

In short, No.
I have never had any problems with RF interference although there is a local FM radio station nearby (which I personally founded in 1996 ) which has 100W power in the antenna. In addition, I live surrounded by dozens of wi-fi routers, and probably hundreds of switching sources of devices,several cable television networks and towers with mobile phone antennas.
In addition, I live in a block built over 60 years ago and the grounding of the electrical network is no longer efficient.

Good to know. Thanks!

Paul

 

[joulupukki]

Where on this board would I measure to verify the polarization voltage?

 

[micolas]

Where on this board would I measure to verify the polarization voltage?

If you refer to the polarization voltage of the capsule: in point 6.
If you mean the jFET bias: at point D - drain.
Measurements are made against GND, with a DMM with sufficiently high input resistance.
Better post a clear picture of your PCB and have someone physically point out the measurement points for you.