On 13/02/2011, at 10:41 PM, Raimund wrote:
> Are you sure that this non-steady state system noise is something that is=
already present in the microphone output signal or the HDP2, which is just=
exposed by the Oade mod?
The noise was present in 150ohm terminated full gain recordings of preamp n=
oise. The Oade modded HDP2 used for this recording had +6dB gain above tha=
t of the stock unit. There are noise traces visible in sonograms at aroun=
d 10 and 14khz which are only just visible in the EIN tests on the stock HD=
P2, hence my suspicion that the Oade mod is uncovering what was previously =
hidden in the preamp noise floor.
Bear in mind that this recording was made in the quietest location I have =
ever recorded in. A jet passing a high altitude cruising level (location w=
as 760km/470miles from the nearest major city, Sydney) peaks at -5.6dB, and=
a 4x4 passing on a gravel track some 500 meters away clips when those port=
ions of the original recording are boosted to the same level as the clip I =
posted.
I really don't think you can draw any meaningful conclusion in regards to t=
he performance of the Oade mod based on this recording. This was an extreme=
recording situation posted to illustrate a situation many list members may=
never encounter and I don't think you can really draw much from the levels=
of hiss of a recording presented at something like +18dB above the maximum=
gain of a stock unit. Listen to my Bennet's Gorge clip, which was recorde=
d some 30 minutes later and 100 metres away with exactly the same rig for a=
"real world" recording situation:
http://soundcloud.com/offtracksound/dawn-on-bennets-gorge-track
cheers
Paul
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