DAC501-MK2-4ch & DAC502-MK2-4ch are Weiss 5 Series 2nd generation D/A converter and network renderer with unique DSP technologies. The different between DAC501 & DAC502 are 1) the width of the chassis 2) DAC502 has 4pin XLR balanced headphone amplifier output.

They have identical sound quality and features.

The Schwede Loudness EQ 

The loudness EQ is based on the Equalizer patent of Bernhard Schwede. The idea behind this equalization is based on psychoacoustic grounds.

Mainly the psychoacoustic quantity loudness is eponymous and essential for the EQ design by Schwede. In acoustics this loudness describes the subjective perception of sound pressure. Schwedes EQ design then considers this subjective perception to create a more pleasant playback regarding the sound intensity. The specific design of Schwedes patent is implemented in the presented plugin. Summing up this EQ offers you the possibility to influence playback volume in such a way that the resulting loudness impression becomes more authentic throughout the audible frequency spectrum.

Choose your desired loudness Level via the drop-down menu. These ten different level settings in dB are illustrated with comparisons benefiting an intuitive use of this plugin. Starting at the lowest level at 60 dB you can increase the loudness up to 105 dB.

This plugin is based on the patent: ”Equalizer, audio system with such an equalizer and method for equalizing a sound mix” by Bernhard Schwede. His design describes an audio equalizer with a special concept. In general Schwede’s algorithm aims the purpose of an aurally linearized equalization of a sound mix.The idea is based on the psychoacoustic characteristics of the human hearing and and its anatomy. 

Our auditory sensitivity is frequency dependent, which also effects the perception of loudness. 

This sensitivity regarding the loudness can cause an unauthentic sound experience when listening at home to audio recordings for example of a concert hall. So Schwede’s concept tries to overcome these non linearities of the human sense of hearing with a equalizer design which creates an optimized compensation curve based on the psychoacoustic and anatomical theory.

Basically this equalization consists of seven bands with predefined parameters deduced from Schwede’s design. Ten different setting options of the EQ plugin are presented. The users select the EQ setting option depending on the current listening level they enjoy the most with their audio equipment.

These ten options are described with dB levels. Some example comparisons shall illustrate the dB levels. Setting 60dB could be compared with the loudness of a verbal communication, 70dB for example with a vac- uum cleaner. 80dB can be visualized with street traffic, 90dB with a heavy truck and 100dB with a sawmill. 

Stereophile Reviews Weiss DAC502

Two of the highest-resolution D/A processors I have measured have been from Swiss pro-audio company Weiss Engineering: the Medea and the DAC202. Both offered superb resolution – almost 20 bit performance – and both paired that resolution with sound quality to die for.

Kal Rubinson wrote ‘The Medea remains in my mind as one of the only digital systems I’ve heard that could compete with the very best that vinyl has to offer while still doing what digital does best. In other words, there were warmth and musicality, staggering dynamics, and real silent background.’

Looking inside the DAC502 left an impression of a component constructed to a high standard.

The immediate impression was of extraordinary clarity. This wasn’t as if the edges of the objects within the soundstage had been enhanced, as can be done to images in PhotoShop, but as if the pixel count of the image had been increased. It didn’t manage this by emphasizing treble detail, but the DAC502 cleaned the window into the recorded soundstage to an impressive extent.

This soundstage clarity was a consistent feature of my time with the Weiss processor. I’ve never heard this so clearly delineated as with the DAC502. The layering of soundstage on this album, with various different instruments accompanied by different amounts of reverb, was also very audible.

The DAC502s’s low frequencies combined clarity with an excellent sense of what the late Art Dudley used to call ‘force’… there was an excellent sense of forward momentum with the bass guitar and kick drum. Similarly, the double basses were superbly well-defined but with good weight. On both these albums, I was again struck by the well-differentiated layering of the soundstage.

I took advantage of that processor’s [DAC502] balanced headphone output to audition it with my Audeze LCD-Xes. When you are creating a master file by splicing together musical selections from two different takes, it is critically important to be able to hear the differences. Crossfades that I thought were ok were revealed as needing more work when I listened with the Audeze driven by the DAC502. The Weiss processor preserved the dynamics, the subtle ambience around the drums, the weight of the double bass, and the sheer force of Frisell’s playing. Nice!

Ultimately, musical enjoyment is what this product is all about. The Weiss DAC502 made all these aspects clear, in service of the music. Which is what a great audio component should do.

Measurments:

The DAC502 will have no problem driving low-impedance headphones. Channel separation was simply superb. An increase in bit depth from 16 to 24 dropped the noise floor by 30 dB. This implies a resolution of 21 bits, which is one of the highest I have encountered. Even set to its highest output level, the DAC502 produced very low levels of harmonic distortion. The DAC502 offered excellent rejection of word-clock jitter. When I reduced the load to a punishing 600 ohms, the third harmonic distortion remained below -110 dB. The Weiss DAC has a bombproof output stage!

I summed my measurements of the Weiss DAC202 by writing ‘The DAC202 is the best-measuring D/A processor I have measured in my quarter-century career at Stereophile. It just doesn’t get any better than this.’ Weiss’s DAC502 matched the DAC202 by also performing supremely well on the test bench.

John Atkinson, Stereophile, 2020

Stereophile Class A+ Recommended Component

Click here to download a PDF of the full review.