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Re: low voltage DC phantom (was new firmware for M-Audio Microtrac=

Subject: Re: low voltage DC phantom (was new firmware for M-Audio Microtrac=
From: Klas Strandberg <>
Date: Thu, 24 Nov 2005 13:02:48 +0100
k  2496

At 09:16 2005-11-24, you wrote:
>At 9:50 PM +0100 11/23/05, Klas Strandberg wrote:
> >Of course, I share everything with you...
> >
> >He has a design which is completely stable at 100 kHz
>
>Hmm,.. is the "100kKZ" the switching frequency of the power supply?
>The Rolls PB224 apparently "utilizes a proprietary high frequency
>power supply to greatly reduce noise,"


The importance is not the switching freq. but that it is stable.

Klas.



> >(or whatever choose) any circumstances and can therefore never
> >become audible.They can be made portable, running from a 9 volt
> >battery. Big as a cig pack.
>
>Running on 9 volts would do it and an external DC input too. Still,
>its impressive that the Sound Devices MP2/Mic Pre uses 3 volts for 2+
>hours powering of phantom and pre.
>
> >
> >I will ask if he can think of producing a number of such power supplies =
and
> >the cost. Let me guess that he wants at least 2-3 times as much as a Rol=
ls.
>
>Thanks for asking. Might be some hard core folks willing to do this.
>
>Logically, if the Rolls is contributing noise, it can't be much if
>the 722's pre/phantom performance is considered near the best (based
>on consistent comparison tests). And, if the Rolls is adding noise,
>the HiMD pre becomes even more impressive. Rob D.
>
>
> >
> >Klas.
> >
> >At 04:16 2005-11-23, you wrote:
> >>Does the phantom power supply he's designed produce less noise? Are
> >>you free to tell us more? Is it portable? What operating voltage? Rob
> >>D.
> >>
> >>    =3D =3D =3D =3D
> >>
> >>At 9:15 PM +0100 11/22/05, Klas Strandberg wrote:
> >>  >According to my friend it is more or less by chance all the time if=

> a power
> >>  >device works or not. He sais that all modern IC-circuit for the purp=
ose
> >>  >have a tendency to drift away in frequency. In his experience only
> one of
> >>  >them work under all circumstances, stable and pure. In his opinion, =
the
> >>  >Rolls is a very conventional and thereby unreliable device. ... if i=
t
> >>  >works, it works... kind of.
> >>  >
> >>  >Klas.
> >>  >
> >>  >At 19:43 2005-11-22, you wrote:
> >>  >>One would think that a good phantom circuit would be easy to includ=
e
> >>  >>like a good mic pre, but the demands might be at odds with small si=
ze
> >>  >>and the low DC voltages involved. The 722 and 744 had phantom issue=
s
> >>  >>all the way through beta testing and they're ~11 volts and up. Ther=
e
> >>  >>are quite a few audio interfaces/pres that the run on AC wall warts
> >>  >>apparently because of phantom powering demands. Len Moskowitz cited
> >>  >>likely problems with the MT24/96's phantom when he first laid eyes =
on
> >>  >>it.  Are there other ~3-4 volt DC voltage devices that have good
> >>  >>phantom circuit performance besides the Sound Devices MP2 and MixPr=
e?
> >>  >>Rob D
> >>  >>
> >>  >>At 6:18 PM +0100 11/22/05, Klas Strandberg wrote:
> >>  >>  >Yes, I will appreciate that! It makes it a much better recorder.
> >>  >>  >Thanks Oryoki!
> >>  >>  >I just wish they had a better phantom power supply installed.
> >>Might come
> >>  >>  >with the next model.
> >>  >>  >
> >>  >>  >Klas.
> >>  >>  >
> >>  >>  >At 16:14 2005-11-22, you wrote:
> >>  >>  >>M-Audio has released a firmware update for
> >>  >>  >>the Microtrack 2496.
> >>  >>  >>
> >>  >>  >>Klas, you'll appreciate these two fixes:
> >>  >>  >>
> >>  >>  >>1. The level meters now work in REC/PAUSE mode.
> >>  >>  >>
> >>  >>  >>2. When recording from mic or line inputs, the
> >>  >>  >>headphone monitor now works in REC/PAUSE as well
> >>  >>  >>as REC mode.
> >>  >>  >>
> >>  >>  >>Before rushing out to buy this $350 machine,
> >>  >>  >>nature recordists should take note of its low
> >>  >>  >>record levels relative to the Sony Hi-MD
> >>  >>  >>recorder.  This is demonstrated in message
> >>  >>  >>20599 posted by Rob D.  Thanks again, Rob!
> >>  >>  >>
> >>  >>  >>--oryoki
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>"Microphones are not ears,
> >>  >>  >>Loudspeakers are not birds,
> >>  >>  >>A listening room is not nature."
> >>  >>  >>Klas Strandberg
> >>  >>  >>Yahoo! Groups Links
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >>
> >>  >>  >
> >>  >>  >Telinga Microphones, Botarbo,
> >>  >>  >S-748 96 Tobo, Sweden.
> >>  >>  >Phone & fax int + 295 310 01
> >>  >>  >email: 
> >  > >>  >         
> >>  >>  >
> >>  >>  >
> >>  >>  >
> >>  >>  >
> >>  >>  >"Microphones are not ears,
> >>  >>  >Loudspeakers are not birds,
> >>  >>  >A listening room is not nature."
> >>  >>  >Klas Strandberg
> >>  >>  >Yahoo! Groups Links
> >>  >>  >
> >>  >>  >
> >>  >>  >
> >>  >>  >
> >>  >>
> >>  >>
> >>  >>--
> >>  >>Rob Danielson
> >>  >>Film Department
> >>  >>University of Wisconsin-Milwaukee
> >>  >>
> >>  >>
> >>  >>
> >>  >>"Microphones are not ears,
> >>  >>Loudspeakers are not birds,
> >>  >>A listening room is not nature."
> >>  >>Klas Strandberg
> >>  >>Yahoo! Groups Links
> >>  >>
> >>  >>
> >>  >>
> >>  >>
> >>  >
> >>  >Telinga Microphones, Botarbo,
> >>  >S-748 96 Tobo, Sweden.
> >>  >Phone & fax int + 295 310 01
> >>  >email: 
> >>  >         
> >>  >
> >>  >
> >>  >
> >>  >
> >>  >"Microphones are not ears,
> >>  >Loudspeakers are not birds,
> >>  >A listening room is not nature."
> >>  >Klas Strandberg
> >>  >Yahoo! Groups Links
> >>  >
> >>  >
> >>  >
> >>  >
> >>
> >>
> >>--
> >>Rob Danielson
> >>Film Department
> >>University of Wisconsin-Milwaukee
> >>
> >>
> >>
> >>"Microphones are not ears,
> >>Loudspeakers are not birds,
> >>A listening room is not nature."
> >>Klas Strandberg
> >>Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >
> >Telinga Microphones, Botarbo,
> >S-748 96 Tobo, Sweden.
> >Phone & fax int + 295 310 01
> >email: 
> >         
> >
> >
> >
> >
> >"Microphones are not ears,
> >Loudspeakers are not birds,
> >A listening room is not nature."
> >Klas Strandberg
> >Yahoo! Groups Links
> >
> >
> >
> >
>
>
>--
>Rob Danielson
>Film Department
>University of Wisconsin-Milwaukee
>
>[Non-text portions of this message have been removed]
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>

Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email: 
        



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