Unfortunatelly the MD inputs are very different. Some are even "really
strange", no straightforward design at all, like a simple resistor from +V=
to the input.
The Telinga PRO4PIP normally has a 33nF condensor from one channel to the
other, thereby limiting the base response.
However, with the Sharp MT190, the 33nF has no effect at all, but needs to=
be replaced by a 10 nF condensor, or smaller.
It is just an example.
At 14:55 2004-08-21, you wrote:
>Guess I need to retire my Radio Shack mini
>mono->stereo adapter. Rather than sum identically
>for redundant channels, how about an in-connector
>modification for saturating one channel at ~10 dB
>less? This way, one could use the hotter channel
>to capture softer sounds and ambience with more
>saturation and the attenuated channel to capture,
>intermittent loud elements? Rob D.
> =3D =3D =3D =3D =3D
>At 9:38 PM +0000 8/20/04, Rich Peet wrote:
> >Knowing that Adam has a lot more experience with a lot better
> >equipment than I do I made sure to do my homework before I posted
> >For the high end recorders that Adam is use to, or for manufactured
> >products for universal use, I agree with his statements. But for
> >consumer minidisc use alone, I do not.
> >My tests I did today were conducted on a standard Sony Consumer
> >minidisc mz-r55 transfered to a computer by analog line out to a good
> >a/d converter and analyzed within Adobe Audition. The microphone was
> >a Sennheiser ME-62.
> >I favor a 1 uf tantalum on the line to cut subsonic noise and think
> >that 27uf is too high for consumer minidisc recorders. Recording one
> >channel straight in and the second through a 1 uf tantalum capacitor
> >showed no drop in gain above 90hz and less than 3 db above 35hz. The
> >channel with the capacitor had less compression above 14,000 cycles.
> >Consumer minidisc recorders favor low frequency sound no matter how
> >low it is and therefore it is better to get rid of some non audible
> >subsonic rumble.
> >Next a 10,000 ohm 1/4 watt metal film resister was placed on one
> >channel and the other straight through. The capacitor was removed.
> >The drop in gain was 10 db below 10,000 cycles. Above 10,000 cycles,
> >which in this test was very quiet, there was less of a drop due to
> >less atrac compression.
> >No additional noise could be detected anywhere on the channel with
> >the 10,000 ohm resister at any frequency.
> >So overall Adam is correct, but my prior post is preferred for
> >consumer minidisc use.
> >--- In "Adam Liberman" <>
> >> We use the Panasonic FC 27uF/25v cap in the Minidisc mic cables
> >> we sell. It is Digikey P11214 and it fits nicely inside the XLR
> >> connector.
> >> The FC series replaced the HFS series, and is regarded as a good
> >> audio cap - low dissipation factor and long life. The measured roll-
> >> off with a 200 ohm source impedance into a Sharp MD-DR7-A MiniDisc
> >> recorder is only 0.3dB at 20Hz. You won't find any poly cap that
> >> will fit inside the XLR connector and not have excessive roll-off.
> >> As far as the resistor, the value would depend on the input
> >> impedance of your MiniDisc. But any value will add noise, and some
> >> MiniDisc mic pre's are already not as quite as they should be, so I
> >> wouldn't use the resistor. Putting the same signal on both channels
> >> may be redundant, but redundancy can be a good thing as far as
> >> reliability is concerned, and it will also mean that both ears in
> >> your headphones will have an equal signal level which is more
> >> natural for monitoring.
> >> Thanks,
> >> Adam Liberman
> >> Liberman Sound
> >> --- In "Dave J" <>
> >> wrote:
> >> > That may be a good idea to have an attenuated channel
> >> > just in case I ever have a clipping problem. I thought
> >> > 100uF was rather huge but that is what they show in the
> >> > AKG booklet. Maybe because it is a low-z mic? Probably
> >> > of no concern unless I record bullfrogs. I will look in
> >> > Digikey for poly caps.
> >> >
> >> > --- "Rich Peet" <> wrote:
> >> > > 100 uf would be to big, 2uf in a quality cap would be
> >> > > better. I use tantalum but poly would be best. I recall
> >> > > the cap as really not needed if you short the channels.
> >> > > You may wish to try a metal film resister on one channel
> >> > > so that you have high and low gain channel to choose
> >> > > from. I would guess that 5,000 to 10,000 ohms would be
> >> > > about right but that is a educated guess right now.
> > > > >
> >> > > Rich
> >> > >
> >> > > --- "Dave J" <> wrote:
> >> > > > Am I correct that for mono microphones I can simply
> >> > > > short the L & R minidisc mic channels together? I'm
> >> > > > not inclined to do true mono recording so I'll just
> >> > > > waste disc space with bogus stereo. I realize there
> >> > > > is 2.5VDC on both of them so once I short them I'll
> >> > > > use a 100uF coupling capacitor to get the signal in.
> >> > > >
> >> > > > Thanks,
> >> > > >
> >> > > > Dave
> >"Microphones are not ears,
> >Loudspeakers are not birds,
> >A listening room is not nature."
> >Klas Strandberg
> >Yahoo! Groups Links
>University of Wisconsin-Milwaukee
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Yahoo! Groups Links
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S-748 96 Tobo, Sweden.
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