Monday, March 25, 2019

Comparisons: Old School 1-Bit "Pulse" DACs VS their 24-bit Counterparts.


Hello, 2019.

Disclaimer Warning - Seriously
For all you Audiophiles here.
I'm not attempting to start a "Trigger Event" w/ this post. No matter what -please keep in mind that I'm honestly just attempting to share what information I found -with the results that I discovered with my 1st test comparisons.
OK?
OK - so now, some time back - I'm reading through some old audio magazines, right? Well, during the '90s, when the 1-Bit D/A converters hit the market, US-based Consumer Reports magazine tested dozens of different CD players.
Their Conclusion was that,
"All players had an excellent frequency response, reproduced sound accurately, & we found nothing to fault when testing for signal-to-noise ratio, distortion & speed accuracy. 
All had a negligible flutter, -zero audible hiss & no spurious tones that could be heard..."
They further stated that they could not perceive any differences in sound quality or reproduction between any of the player, regardless of the manufacturer or the price-point.
Therefore ( and I'm NOT making this up,)
"Sound Quality", was NOT EVER used as a performance factor in terms of rating or recommending, in the Overall Final Score, ANY particular disc player over another!
YES- you just read that correctly.
What I just stated is FACT.
Year after year, only a unit's features, track-finding speed, bump immunity & anti-skip performance was used to rate or recommend one machine over another. I found this info to absolutely incredible and quite frankly, simply mind-blowing.
Did I "believe it"?
Was it true that it was impossible to tell the difference between players analog outputs? With all the talk in different Audio Publications (like Stereo Review & WhatHi-Fi?) & different internet audio forums by so many different "experts" over which chip is "better" - I was now totally dumbfounded.
I openly and freely admit to having my own preference for the sound of a particular DAC - the 24-bit AKM4584,(For the record - NOT the one used in the Sony PlayStation!)
So we, my brother & I, decided to test some of these older players. 1st against each other, and then against their DVD player counterparts to see if we could hear ANY differences in those DAC's vs more modern Hi-Res 20-24bit DAC's
( for 2-Channel PCM Only ) All were tested using the same analog RCA interconnect cables ( Fusion AV's) and all players were plugged into my ONEAC ConditionOne Power supply.
We used tracks ( that also included vocals) other than the sample we recorded here, which was used in order to stay under the YouTube Copyright radar.
Forgoing the 5-6db volume output dropoff produced by the PlayStation,( which you really notice) I admit I was hard pressed to tell any of the difference in ANY the 1-bit "Pulse" players, like at all, except for One - the Pioneer PDM-423.
For some strange odd reason, Pioneer used a Toshiba Delta-Sigma DAC instead of their DAC - even though the unit clearly advertised "Pulseflow" on the front faceplate. (WTF Pioneer, WTF???).
This bastard of a Player sounds slightly different from similar machines manufactured by Pioneer that utilized the PD2026 1-bit DAC ( which may(?) have been produced by Nippon Precision Circuit, possibly based off their SM5864 DAC, but I've not been able to confirm that as fact.) This TC9268.DAC sounds slightly more forward, full-on, and more bassy.
(YES- You can actually hear this in the sample)
So at the time of the publication -
based on the hand-full of those older machines we have tested so far, we can actually begin to understand why CR took the position that they did. Besides - and let's be honest, how many people at that point in time actually tried out different CD Players to see how that particular one sounded at home??
I have to report, however, that I did hear Extremely Fine differences between the older players and their DVD players counterparts. I found it interesting The Toshiba DVD player with its 192kHz/24 bit DAC sounded way more relaxed.
( Again -using the word "differences" here on purpose, as opposed to using words such as "better" or "worse", as that is not only subjective to one's personal taste -but truth be told - would also depend of how that particular player integrates with the rest of the gear ( receiver, or amp & speakers) in your personal playback system.
For the record, we conducted all of our critical listenings test via headphones. We never tested more than 3 players head-to-head at once ( or during a single day) therefore attempting to prevent listening fatigue from setting in.
Disclaimer - we are Not comparing Higher Resolution samples here, only the same PCM sample on different players. And Yes- before anyone screams - "Well, my God man, you guys didn't include the Philips / Marantz DAC, or the JVC PEM DD DAC," or the whatever, rest assure those are going to be tested next in the second round of player comparisons.
( YES- I realize YouTube compresses the PCM File down to MP3 - but you can still hear differences.)
Here is the link to the 1st round of player comparisons, which included my personal Pioneer DVL-700 DVD/CD/Laserdisc Combo.