> Has anyone done any tests of the spec of the modded and unmodded
> versions? Produced any tech specs? At mic levels THD is going to be
> vanishingly low whatever.
>
> Many years ago, the BBC Engineering Department did some tests and
> discovered that human ears are very insensitive to harmonic
> distortion. They found that 50% THD could be acceptable to many
> listeners. What we hear is enharmonic or intermodulation distortion
> which is not proportional to THD. THD is Hi-Fi bluffology.
Hi David,
I just received a sample file of an Oade-modded TASCAM HDP2 and compared it=
with my stock unit:
http://www.avisoft.com/scratch/TASCAM_HDP2_stock_vs_oade_mod.wav
The first section is the stock unit and the second one is modded one. Both =
sections were recorded at the maximum gain setting and the microphone input=
was terminated by a 150 ohm resistor.
Assuming a gain boost on the modded unit of 6 dB, then the (unweighted) bro=
ad-band noise floor of the modded unit is indeed reduced by about 1 to 2 dB=
. However, the slightly lower noise floor on the modded unit also exposes o=
ther intermittent noise components that obviously originate from the digita=
l part of the recorder. So, in my opinion, the overall improvement is relat=
ively small and probably negligible as long as the absolute inherent noise =
floor of the attached microphone is high compared to the system noise of th=
e recorder.
Regards,
Raimund
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