I'll use the word "pre" to refer to any preamp, processor, or DAC that sends the analog signal to the amp.
Originally Posted by bear123
The pre has almost zero impact on how loud the speakers play....that's all amp.
I disagree (I currently own at least 10 pre's or DAC's)
Does the pre clip the subwoofer signal (like a Marantz/Denon pre/pro)?
Is the output fully balanced vs single ended?
What is the maximum clean output voltage of the pre?
Does the pre roll off the low frequencies or is it DC coupled?
Does the pre clip intersample peaks?
Does the bass management reduce the speaker levels or increase the subwoofer level when mixing the redirected bass?
Does the pre accumulate all volume adjustments to the end of the DSP chain or does it do them in order?
An audibly transparent voltage signal being sent to the amps from a $600 AVR will not "sound" any different than an audibly transparent signal being sent to the amps from a super expensive pre.
That is true, but you are assuming the $600 AVR has "an audibly transparent voltage signal." Even the $4,499 Marantz AV8805 has high (and audible) noise and distortion
compared to even a fairly cheap DAC. Besides that, many of the above list will affect how an AVR sounds. Here are some more items to consider:
Does the pre dither when converting back to 24 bits for the output?
What kind of dither is used?
What type of resampling is used by the pre?
Does the pre use resampling to reduce the jitter?
How good is the jitter suppression on the HDMI input?
How well does the pre's clock clean up the signal?
What bitrate does the DSP use for volume control prior to final output?
Does the pre have a 9 Gbps or an 18 Gbps HDMI input?
What type of filter does the pre use on frequencies over 20 kHz? (Some pre's offer 5-7 options just for filtering)
Does the buffer of the pre change size when different sample rates are used?
I have a unique business model in that I spec theaters and try to only sell products only from companies that I have a direct relationship and contact with the owner/engineer. All of these desire for their product to sound and look the best and design for that purpose. They aren't willing to compromise for lower quality to increase profit, but they also don't "upsell" something that doesn't produce any benefit. The only exception is that I don't actually know the person responsible for designing/programming JVC projectors. However, I work with their US reps and technicians.
Speakers - JTR Speakers (Jeff Permanian)
Amplifiers - Digital Amp Company (Tommy O'Brien)
Processor - StormAudio (Sébastien Gailleton)
DAC - RME (Matthias Carstens)
Music and Movie source - JRiver Media Center (Jim Hillegas and Matt Ashland)
Projector Screen - Seymour Screen Excellence (Chris Seymour)
Anamorphic Lens - Panamorph (Shawn Kelly)
Video Processing - Lumagen (Jim Peterson)
Acoustic Treatments - GIK Acoustics (Glenn & Shelly Kuras)
Jim at Lumagen recently talked
about a change he did on the Lumagen Radiance Pro in order to improve sound quality through the HDMI output:
I think there is still merit in viewing and listening tests, at least for your own use. I attended a demo in Germany by Cinemike to compare the original Pro design (which had higher jitter than current design) to the Cinemike "hot rod" version. Cinemike reduced the jitter (as measured on the Tektronix HDMI tester), and the electrical noise floor (as shown on a spectrum analyser). They wanted me to judge if there was a difference. I told them to consider me an "open minded skeptic" as to whether the improvements would be visible or audible. They played video/music with the original Pro and their hot rod version. I did hear an audible improvement. I describe this to be a more open sound stage, and I attribute this to the lower jitter out of the Pro. I considered the lower jitter version a closer match to my 2-channel Jeff Roland, Watt Puppy, based system (no longer have this). So, IMO, a noticeable, and appreciated, improvement. However, I did not see any visible picture difference. The original Pro was IMO without issue for video, but I thought there was room for improvement for audio.
How sure was I? I can tell you that I added significant cost in a revision of the Radiance Pro design to change to microwave capacitors in key locations to reduce output jitter, and to a small degree electrical noise. This was out of my profit since I did not increase the product cost at the same time. I can assure if I was not certain there was an improvement I would not reduce my profit for such a change. Not a chance. While I upgraded to microwave capacitors for audio, having lower jitter for video is not a bad thing and might put a "system" with a marginal cable or a marginal projector input into the "good enough" range.