[BC] QUESTION FOR THE

[Robert Orban]

At 09:19 PM 12/9/2005, you wrote:
>From: DANA PUOPOLO <dpuopolo at usa.net>
>Subject: Re: [BC] QUESTION FOR THE
>To: Broadcast Radio Mailing List <broadcast at radiolists.net>
>Message-ID: <707JLiV336544S22.1134165294 at cmsweb22.cms.usa.net>
>Content-Type: text/plain; charset=ISO-8859-1
>
>Run conservatively, rechipped, recapped 8000s with diff. input stages (or
>Jensen Transformers) and good release time modules can blow away many DSP
>based processors.
>
>As Bob knows, the two weaknesses the 8000 had were the power supply and its
>stereo generator. Both can be upgraded, resulting in a marvelous sounding unit
>that is still quite loud.

Sonically, the 8000's main weaknesses compared to later processors were an 
HF limiter that was designed to never distort on sinewave material (because 
at that time, many major broadcasters still insisted that an audio 
processor in "operate" mode must exhibit negligible distortion on arbitrary 
test tones) and no distortion-canceled clipper (because it had not yet been 
invented). Why is such an HF limiter a "weakness"? Because it will 
inevitably sound duller on program material compared to an HF limiter that 
has been psychoacoustically optimized with real-world program material.

Both of these weaknesses were addressed when we introduced the 8100, but 
our later DSP-based processors each introduced more sophisticated and 
effective HF limiting/clipping.

The 8000's stereo generator was capable of 50 dB of separation across the 
spectrum, which is more than enough to create a subjectively "perfect" 
sound field when compared to infinite separation. Because of dual servos 
(referenced to the regulated power supply) for 38 kHz amplitude and phase, 
it was also acceptably stable with time and temperature.

Our one big package design miscalculation in the 8000 was to put the main 
power supply filter caps next to the heat-sunk regulator transistors, which 
guaranteed that the caps would dry out every 5 years or so. Now we know 
better :-)

Bob Orban