[HarmonyUnited]

Greetings All,

I've been on and off trying to track down the white noise in my D-251 build for about a year now. I have noise tested the 6072a and its super quiet, Replaced the CT12 capsule, de-soldered the whole thing, cleaned it, re-soldered it up again, changed the output caps, twisted the audio wires in the power supply and kept them from the filter caps, tried filtering the B+.... all to no avail. The white noise makes it pretty un-usable for any voiceover/vocal or acoustic guitar application as the hiss is too noticeable.  I am going to post a few sample recordings, perhaps anyone has any ideas. Listen to the lead in before the guitar comes in... I am posting a recording with my D251 and next with my IO Audio U67. The 67 is dead quiet in the lead in...

251 link: https://www.dropbox.com/s/doga2sonunml4u6/Will%20She%20Be%20Gone%20%28251%29.mp3?dl=0

u67 link: https://www.dropbox.com/s/1dmqcloash2avqx/Will%20She%20Be%20Gone%20%28u67%20no%20filters%29.mp3?dl=0

At this point I am wanting to hire someone to track down and fix this problem for this mic system. Anyone feel up to the challenge and have the knowledge and experience with such a job!?

Thanks a ton!

-Eric

[Pip]

Can I ask what resistors you used and if you double checked the values, also what cable are you using between the mic and PSU and how long is it?

[HarmonyUnited]

Hey Pip,

im using a 25' GAC-7 cable with shield to case on both ends.

I've double checked the resistor values.

E

[rmburrow]

Have you tried substituting a good quality fixed capacitor for each side of the capsule (in the 50 to 70 pF range) and listened for noise?

[gyraf]

Are you sure you have high noise, not just low sensitivity (these are different entities with very different origins)?

Jakob E.

[ruffrecords]

Are you sure you have high noise, not just low sensitivity (these are different entities with very different origins)?

Jakob E.

I was going to ask the same question in a different way. What were the mic pre gain setting for the D251 and the U67?

Cheers

Ian

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