Psu question
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rock soderstrom
Tour de France
No, this will not work with any Neumann mic, for instance the U67 needs negative heater and better ripple filtering due to the biasing based on the heater voltage.
The capsule polarization is also implemented differently on different Neumann mics. It is not entirely clear to me where in the M&M circuit the switchable polarization voltage is send to the microphone?
Maybe I missed something, it looks strange
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This is what they say on their site:?
"Our Premium Microphone Tube transformer PSU in a vintage Hammered Gray design for all tube DIY microphone or Neumann, AKG, Telefunken, Blue microphone
the standard for years in the recording industry and studios around the world."
"Our Premium Microphone Tube transformer PSU in a vintage Hammered Gray design for all tube DIY microphone or Neumann, AKG, Telefunken, Blue microphone
the standard for years in the recording industry and studios around the world."Attachments
MagnetoSound
Well-known member
These generic PSUs are all basically the same. You just have to know how to adapt them and set them up for your needs.
I reversed the polarity of the heater section in two of mine (the T-bone ones) for fixed bias in my U47 and M49 builds. You can adjust the voltages quite easily.
That schematic is faulty though.
I reversed the polarity of the heater section in two of mine (the T-bone ones) for fixed bias in my U47 and M49 builds. You can adjust the voltages quite easily.
That schematic is faulty though.
Oh, how?
MagnetoSound
Well-known member
How is it faulty? Well, to begin with, as previously mentioned there is no connection from R6 to the mic socket.
Most of the China PSUs conform to the Stellar/Alctron circuit. It is probably this that M&M are selling if they’re calling it universal. The schem you posted looks hastily drawn and/or unfinished.
(As you can see, in this instance polarisation goes to pin 3)
Most of the China PSUs conform to the Stellar/Alctron circuit. It is probably this that M&M are selling if they’re calling it universal. The schem you posted looks hastily drawn and/or unfinished.
(As you can see, in this instance polarisation goes to pin 3)
Attachments
Interesting. I only make mics and other stuff from layouts that people kindley offer, so I am trying to get a picture of what actually is neede in a PSU, and what differences there are. So I was hoping the M&M one would clear it up, but then it just clutters things even more. And in addition they (m&m) have some kind of silly app acting as support. I begin to understand why so many avoid that company.
But they usually are a bit smarter, not outright liars?
You'd be surprised sometimes...
I am now.
rock soderstrom
Tour de France
No load measurement makes no sense for a passive PSU. Use a resistor as dummy load.
Matt Syson
Well-known member
The pair of 68 volt zeners tie the output down a bit so it doesn't get ridiculously high if the mic is unplugged or otherwise 'unloaded'. Of course the tolerance for these will be wide so 120 Volts COULD be almost withing tolerance and we don't know the mains and power transformer are exactly what was specified originally.
I goy this answer on what Neumann mic this M&M PSU was designed for, displayed erkier in this thread, I got this answer. (Is there a Neumann using this?)
"Our PSU is designed for use with all 120V tube microphones using a 6.3V filament voltage. As indicated, it is inspired by vintage models from brands such as Neumann, AKG and Telefunken, and is not intended for any particular model of microphone, all PSU are not suitable for all tube microphones, Neumann uses a PSU specific to their microphone-
"Our PSU is designed for use with all 120V tube microphones using a 6.3V filament voltage. As indicated, it is inspired by vintage models from brands such as Neumann, AKG and Telefunken, and is not intended for any particular model of microphone, all PSU are not suitable for all tube microphones, Neumann uses a PSU specific to their microphone-
