Simaudio Moon Evolution 750D CD Player/DAC Review

Results with tube and SS amplification

Over time the majority of systems I assemble for enjoyment are comprised of at least one component with tubes. There are two reasons for this: I generally find that tube amplification is more ‘forgiving’ in that it will tolerate a wider range of upstream gear and speakers before sounding harsh. Also, using tubes one has an additional means to alter the sound if it is not up to expectations. Solid-state amps can reveal the Achilles Heel of digital sources, as the combination can turn sterile in a hurry. In my experience, most solid-state amps are not able to “save” a rig, that is to bring enough suppleness and smoothness as to ameliorate whatever digital glare there may be.

The pair of Pass Labs XA160.5 monoblocks is an exception. The XA160.5 carries its weight lightly, something most solid-state amps do not accomplish. The sound of the unit is disarmingly sweet in the way that a low-power amp with a high efficiency speaker sounds sweet. Do not misunderstand; by “sweet” I do not mean prissy, but rather succulent. My in-laws have a grain farm in Manitoba and every time we visit we dine on local beef – wheat fed beef which is very sweet tasting in comparison to corn fed beef. The descriptor succulent perfectly describes the far richer taste of the meat, and succulent is an apt descriptor for the richness of the XA160.5’s sound. It is a wonderful match for the prodigious sounding Evolution Moon 750D. The gentleness of the Pass Labs with the formidable nature of the Moon combined to command my attention.

I also used the VAC Phi 200 vacuum tube stereo amps in Mono mode, but this was too much of a warm and mellow thing on the bottom-end. The Phi 200 has an abundance of power and fullness in the bass, but the 750D is also sloped tonally toward the bottom-end. The two together were impactful but less distinct than I wanted from the top of the midrange through the treble. This was a case in which a tube amp with the 750D yielded a very thick and weighty sound preferred by people who might seek timbre over technicality, an absolutely mellow sound with no surprises. (Or perhaps to tame edgy-sounding speakers? – Pub.) The VAC is not a boring amp, but when multiple components with a warm character are combined one is not assured that the result will be exciting enough. I do not find the 750D to be a “neutral” sounding player at all; it seems intentionally geared toward a warm, smoothed voice, so if you demand a riveting experience do not pair it with a more reserved tube amp.

An exciting combination with the 750D was the VAC Signature Preamplifier MkII and the Cambridge Audio Azur 840W amps in dual Mono mode and the Legacy Audio Whisper DSW speaker system. Here was a pairing of a very refined tube preamp with an ultra-clean, powerful solid-state amp; and the 750D fit in well. The Cambridge amps have an emphasis on purity over dynamic impact and low-end extension, but the Moon added some robustness to the mid-bass and beneath. The mellowness of the Moon was perked up by the crystal clarity of the VAC Signature. One can see that the quality of the 750D is suitable for the highest end systems but one will want to determine the degree of detail and warmth being sought when pairing it with other components.

Speaker selection

Just as I was careful not to overload the low-end by selecting more nimble amplification so the prospective owner needs to be purposeful about pairing this player with speakers. Recently, I have been working on review of the Salk Soundscape 10, a full-range hybrid ribbon/dynamic speaker with a lush and laid back character which reminds me of Vandersteen speakers. Despite the presence of a ceramic midrange and ribbon tweeter, both of which are capable of extreme precision, the Soundscape was anything but bright. A couple variants of rigs I established with the 750D and Soundscape literally relaxed me so much I kept falling asleep. For some listeners that is the Holy Grail of audio, to get a rig which is so comfy that one can nod off anytime. That’s not my goal; I have audio sessions to listen, not to sleep! If a rig sounds too nonchalant it gets boring to me. When I found myself losing focus I realized I needed a bit more spice in the system – that’s when I turned to the solid-state Azur amps.

Your source is going to “set the tone” for the entire rig. Is your goal to be lulled into oblivion? Do you love the idea of slipping off into sleep as you listen? Then put the 750D with a big Ol’ warm sounding tube amp and you’ll be in heaven. If that sounds boring then look for a perky solid-state, perhaps a Class D, amp to liven things up. The Azur 840W provided the zest needed so that the 750D and Soundscape didn’t keep me yawning.

The “excitement factor” of the rig turned upward decidedly when I put the Legacy Audio Whisper DSW speakers into the rig. These are more efficient and more “light” in the bass than the Soundscape. More of the 750D’s ability to resolve and project details in the music came through. Alternatively, there was less of a relaxed air about the system, but rather it moved toward the analytical end of the listening spectrum. It would keep me alert and involved but never caused listening fatigue from too much high-end energy.

In use of the King Sound the King full-range ESL the heft the 750D provided in the lower bass was welcome. The King is not bass-shy, but whatever extra impact the Moon provided was readily noticeable. I have owned Magnepan speakers in the past and have seen complaints, or shall we say reluctant acceptance, of the shallow low-end they have, all but the 20.1. A DAC/Player like the 750D supports the bass such that one perceives a more solid platform for the music rather than a flimsy one. I would not run a panel speaker which could not do less than 30 Hz nowadays, but if I had to use one which could only reach approximately 40 Hz, I would welcome a solid performer like the 750D.

32-bit player

Over the past year I spent considerable time evaluating DACs and players incorporating ESS Technology 32-bit chips for DA processing. My first exposure to ESS Technology was with the lovely Peachtree Audio Nova integrated amplifier/DAC, which has digital inputs for use of its internal 24-bit Saber DAC. It was sufficiently clean and inviting sounding to merit further exploration of ESS’s upper line of chips, specifically, their 32-bit processing technology.

When the Eastern Electric Minimax DAC appeared I jumped at the opportunity to evaluate what an affordable 32-bit DAC could do. At the time I opined that I would like to hear a higher-end effort with the Sabre Reference 32-bit chips. The Moon 750D has brought that very experience to my listening room with their “M-AJiC32(MOON Asynchronous Jitter Control in 32-bit mode),” and “32-bit Hyperstream” thus further moving me toward the position that I have little zeal remaining to hear 24-bit players/DACs. The stacked ESS Technologies Sabre Reference 32 chips for each channel explode the soundstage and extend the dynamics, both macro and micro, while obliterating jitter. The result is quite endearing.