My stereo system has been configured with tubed electronics for the last ten years. However, I own a PS Audio Perfect Wave Transport and PS Audio Perfect Wave DAC, which I use to listen to high resolution recordings and to provide a contrasting perspective to the sound of my tubed CD player.
During the last two years, my tube amplifier has required maintenance—tube changes, tube bias and repair, and as a result, I have considered replacing it with a solid state amplifier. Thus, for the past year I have been seeking an inexpensive solid state or class-d amp to review.
Having reviewed some expensive components in the past, and observing the many components selling for more than $10,000, I have been determined to try to review, relatively inexpensive and/or cost effective audio equipment.
The Nova 125SE may be a unique product in the audio industry. It combines the functions of D/A conversion (24/192 solid state), a headphone amp, a solid state preamp, a class-d amplifier and a tube (6n1p or equivalent) buffer stage all within one enclosure, for a retail price of $1499.
Break-in and Operation
Since the Nova 125SE is a multi-faceted component, break-in is a bit more complex. It is advisable to break in the DAC section, by sending a signal from a digital cable to one its digital inputs, sending a signal to the auxiliary input, and connecting it to a pair of speakers, for a duration of about two weeks. Additionally, I advise performing a simple test to ascertain when break-in has been completed. After sending the appropriate signals for two weeks, listen to your stereo system for at least three days in a row. If you hear no changes in sound over the three day period, break-in is probably completed. If the sound of your stereo system changes from day to day, additional break-in is required. Breaking in components is not an exact science. I have been surprised to hear changes in my system after the three day period I suggested, so I have provided a guide which may not be definitive, but has usually been an effective method for me.
I did not discuss tube break-in, because that is a very simple procedure. Engage the tube circuit on the remote and leave the component on for 24 hours. The unit is user friendly. Most of the functions can be accessed on the face plate and need no explanation. As I indicated, the tube buffer is controlled by the remote and all the cables are connected on the rear panel.
Follow this procedure to replace the tube:
Place a towel under the faceplate, such that the unit is in a vertical position. Then remove the 4 feet from the wood cabinet. The wood cabinet can then be separated from the chassis, exposing the tube. Make sure the unit is not plugged in while this is done.
When not in use, the unit should be left on.
Since this review will be longer than a typical review, I am eliminating the technical section. Visit the company’s website to read the owner’s manual.
Prior to the review, I placed 4 Sound Fusion Sound Boosters under the 4 feet attached to the lower cabinet. The Sound Boosters serve as anti resonant devices.
The review will be divided into several sections, corresponding to the functions provided by the Nova 125SE.
Listening Session Part 1—the preamp
In this section I am sending a digital signal from a tubed DAC to the auxiliary input, and passing that signal from the preamp output to my tube amplifier. Thus, I have substituted a solid state preamp for a tube preamp.
I recently acquired another recording of Bach’s “Chromatic Fantasy and Fugue”, played on the harpsichord by Ronaldo Allesandrini, from an Opus 111 disc, OPS 30-258. He, along with Pierre Hantai, are my favorite harpsichordists. After a short listening period, I was amazed at what I heard. The level of resolution was astounding. I perceived a reverberant field behind the harpsichord following the release of the harpsichord keys, as well as transient decay. The reverberation revealed the acoustics of the recording venue. The ambient retrieval and decay were phenomena I had not heard before. The level of resolution would make it easy to compare Allesandrini’s interpretation to that of other harpsichordists.
Another recent addition to my large CD collection was Patricia Barber’s recording Verse, Blue Note 7243 5 39856, track 7, “Regular Pleasures”. I heard the music at a friend’s house and was deeply affected by the lyrics, written by the singer. It also provides a test of bass and the opportunity to listen to a well recorded cymbal. I believe that the song I selected represents an existential statement of the culture in the U.S. The sound of the cymbal was airy, gentle, natural and never harsh, while the upright bass sounded muscular and controlled. One could also hear the sound of skin of the snare, as the wires under the drum were detached from the drum. The level of resolution made it easy to connect with the message of the poetic lyrics, reinforced by Patricia Barber’s delivery, as she deftly exuded a tone of cynicism from her voice. As I will indicate shortly, a singer’s delivery may not be consistent the message of the lyrics. Sufficient resolution is required to render such a determination.
Somewhere in every review I test bass and treble frequency response. I use a female voice and the sound of an electric bass, respectively, for this purpose. I believe Holly Cole, Don’t Smoke in Bed, track 1, Alert Z2 81020, is well suited to uncover any peaks in the upper midrange/lower treble region, as her voice is close miked. In addition, the sound of an upright bass reveals the quality of frequencies in the upper and mid bass.
I found the sound of the acoustic bass to be very controlled, with realistic impact from the vibrating wood body, while not obscuring the presence of the strings. Holly Cole’s voice exhibited some emphasis upon words with “s” consonants, which was not exaggerated. If the aforementioned words are characterized by sibilance, there is usually too much energy in the upper midrange/treble region. If these words sound overly smooth there probably exists a dip in the above mentioned frequency band. This CD is one of the best and quickest way to uncover “brightness” I am aware of. I noticed that Cole’s tone and inflections were often incongruent with emotions expressed, especially when singing “….bad feelings have disappeared”. She did not convey the joy or elation that should accompany such a statement.
The CD I selected to evaluate bass extension is also a useful test of bass control, i.e., bass quality, or in technical terms, damping factor of an amplifier. The recording I always use in most reviews is Bela Fleck, “Flight of the Cosmic Hippo”, Warner Brothers 9 26562, track 4, which is the title track. The sound of the bass was clear and articulate. At its lowest note, I heard both the vibration of the wood body as well as the strings. There was no loss of extension and neither strings nor wood were obscured.
As I enjoy the music of the French impressionist composers and their contemporaries. Such as Ravel, Debussy and Faure, I was anxious to acquire a recent release of the music of Faure, I heard on WQXR, a New York City public radio station. It features the Seattle Symphony led by its current director, Ludovic Merlot, released during 2014 on the orchestra’s own label, Seattle Symphony Media, SSM 1004. I was impressed with the sound and promptly added it to my collection of performances of “Masques and Bergamasques”, “Pavane”, “Pelleas and Melisande” and “Dolly”. It serves as an example of a well-recorded symphony orchestra.
I selected the overture to “Dolly”. I became immediately aware of a very wide soundstage. Instruments were arrayed across the entire width of my back wall behind my speakers. Depth was present as one sensed the orchestra well behind the speakers. I also perceived space between instruments and instrument sections. One could also observe the winds located behind the strings. Although I try to eschew audiophile terms when discussing music, I believe audiophiles would use the term “layering”, to describe what I heard. The orchestra sounded very natural, especially, wind and string instruments. As I was listening, I was aware of a rapid transition from soft to loud passages. I grabbed my Radio Shack SPL meter, set it to 70 DB and watched the needle. The meter registered a range of greater than 20 DB.
I recently received Reference Recordings latest release, Organ Polychrome, featuring Jan Kraybill, organist, Reference Recordings RR 133. I selected Widor’s 1st movement, from “Symphony Number 6 in G minor”. I was warned by Reference that some of the tracks could put a lot of stress on a stereo system. Not wanting to damage my speakers, I used my Radio Shack SPL meter to maintain an SPL, no higher than about 86 DB. I welcomed the opportunity to test my stereo system using a recording of a very demanding instrument, as the organ can play loud and has a frequency response of 20 HZ to 7000 Hz.
The organ was represented on a large scale, taking up about 75% of the width of the rear wall. While my speakers have usable frequency in the mid 30s range, I could hear air moving through the pipes, observed control of the instrument, without distortion, was reproduced clearly and with articulation and exhibited naturalness of timbre. I believe my stereo system passed this “torture test”.
I would conjecture that many readers of this review own hi-res files. Therefore, I am concluding my discussion of the preamp section of the Nova 125SE with a comparison of Redbook and hi-res disc of the same music. The Redbook disc was played on two transports, the Vincent CD S7 and the PS Audio Perfect Wave Transport (PWT), and the signals were sent to the Eastern Electric Minimax. The PWT read the high-res disc (not a file).
The music was the third movement from Rachmaninoff’s “Symphonic Dances”, Redbook version, Reference Recordings RR96, conducted by Eiji Oue directing the Minnesota Orchestra. The hi-res disc was a 2008 HRx DVD-R sampler, 24/176.4 Khz.
Initially, I auditioned the Redbook version on the Vincent CD S7. I observed a wide and deep soundstage, as instruments occupied the entire width of my rear wall behind the speakers. I also observed foreground background relationships. As the string section was located in front of the winds, brass behind the winds and percussion instruments further back into the orchestra. The presentation of the orchestra was smooth, spacious, and somewhat blended. Thus one heard the string section rather than the individual string players.
I then played the same disc on the PS Audio PWT. The difference(s) was like night and day. The orchestra was presented with greater clarity, articulation and precision. One could hear the contact of bows and strings on the violins. There was a trade-off, as string tone was emphasized and the sound of the wood body was less present. This occurrence was not audible on the Vincent, which sounded somewhat veiled, by comparison. While there was greater treble extension, there was less bass impact—a change in the spectral balance There was no difference in dynamic range between the Ps Audio PWT and the Vincent CD S7, however, I noticed a slight narrowing of soundstage width. The Vincent was closer to a rear hall perspective while the PS Audio transport was a much closer perspective, perhaps around the 5th row orchestra.
The HRx disc had the greatest bass impact, depth and space in front of the orchestra. Dynamics and soundstage width were the same as the Vincent, but the Hrx disc had more clarity. The orchestra sounded more full bodied and smoother than the Redbook version played on the PS audio transport, but less weight than the Vincent. The perspective was further back than the PS Audio/Redbook combination.
The most salient attribute of each “version can be easily stated. The HRx disc had the greatest bass impact, The PS Audio/Redbook combination had the most resolution, while the Vincent soundest smoothest and most full bodied.
I think the HRx disc is a good compromise between the other versions because it strikes a natural balance between weight and detail, is probably most timbrally accurate of the the three choices, and provides a perspective most typical of where concertgoers would prefer to sit, namely midhall center.
While I occasionally accessed the tube buffer, I did not notice an audible difference. I suspect the presence of two tube components in the stereo system—DAC and amp masked the effect of the tube buffer. Once tube components have been removed, I expect to hear some effect of the tube buffer.
Summary of preamp listening session
The preamp section of the Nova 125SE has the attributes of sound that are probably desired by serious listeners, namely, wide and deep soundstage, seamless dynamics, a high level of resolution and a balanced frequency response. As a consequence, it easily delineates differences in components in your stereo system. It has neither a tube nor solid state signature. I could not detect any sonic deficiencies.
Listening Session Part 2—DAC and Preamp
My investigation of the sonic properties of the DAC and preamp of the Nova 125SE began with an audition of Bach’s “Chromatic Fantasy and Fugue”, performed by Ronaldo Allesendrini, Opus 111 OPS 30-258, which I used as I began my evaluation of the preamp by itself. As I listened to the harpsichord, I noticed it sounded more robust, slightly rounded and fuller sounding and a bit less percussive. I heard reverberation following the release of the keys, as I did earlier in the review, but to a lesser extent. The slight loss in resolution is not surprising, since I substituted a 24 bit DAC chip for a 32 bit DAC chip. Had I not first listened to the Eastern Electric Minimax, I would not have indicated any loss in resolution. I noticed no change in the sound of the inner workings of the harpsichord.
I next checked the frequency response, commencing with Holly Cole’s recording, “Don’t Smoke in Bed”, Alert Z2 81020, track 1. The acoustic bass had more impact, and was slightly less controlled. There was slightly more emphasis upon the wood body and the sound of the strings had less presence. Holly Cole’s voice sounded a bit smoother, with slightly softer sounding sibilants. The piano had a bit more weight but sounded slightly less focused. Overall the presentation had slightly more weight and less resolution. Again, what I noticed is the difference between a 32 bit DAC and a 24 bit DAC.
The next selection was Bela Fleck, “Flight of the Cosmic Hippo”, Warner Brothers 9 26562, track 4. The electric bass had more weight and the cymbal sounded slightly less extended in the treble. The fingering of the steel strings was less incisive. That is, the sound a guitarist creates when moving along steel strings, was “softer” and more rounded. When reaching the lowest note, the balance of wood and strings favored the sound of the vibrating wood body, which very slightly obscured the sound of the strings, but in no way masked their sound. I am referring to minor differences, which a trained ear would notice. If one is not listening for such minutiae, this occurrence usually would not be noticed or consequential.
Based upon differences I noticed between the Eastern Electric Minimax Dac and the DAC section of the NOVA 125SE, I was curious as to how the DAC section would portray the leading and trailing edge of transients. A recording of Tchaikovsky’s “Capriccio Italien”, featuring Sir Alexander Gibson conducting the New Orchestra of London, Chesky CD 12, is appropriate for this purpose.
At the outset, one hears the sound of full-bodied trumpets in the background, centered behind my speakers. Somewhat later, one hears the string section positioned in front of the trumpets. I again grabbed my Radio Shack SPL meter and set it at 70 DB. I observed a difference of more than 20 DB from the softest to the loudest passages. Instruments blanketed the entire length of my rear wall, behind the speakers.
I continued to listen, awaiting the cymbal crash. When it occurred, I observed the placement of the cymbals at the very end of the rear wall to the left, a position further to the left than I had experienced with other components in my stereo system. The cymbals when struck, were fuller sounding, having greater lower mid range presence than I usually hear when auditioning this CD on any system. The leading and trailing edge of transients were clear and not rounded. After the cymbals were struck, decay was longer than usual.
I again wanted to further test the DAC/preamp using the Reference Recordings Organ CD, I introduced earlier in the review. As I had indicated, this CD was issued during 2014, and is Reference Recordings’ latest release, RR 133. It features Jan Kraybill, organist. I selected the Allegro movement from Widor’s Symphony number 6 in G minor.
I noticed that the organ was further back in the sound field, yet, I could still hear the air moving through the pipes. There was no loss in bass extension or control, and the instrument sounded solid and full. The size and scale I perceived matched what I heard when listening to the 32 bit DAC. The organ was positioned behind my speakers. Its position covered the middle of the left to right speakers
I conclude this part of the review, as I did in part 1, comparing a Redbook recording played on two transports, to a high-res recording of the same music.
The music is the third movement of Rachmaninoff’s “Symphonic Dances”, featuring the Minnesota Orchestra, led by Eije Oui, Reference Recordings RR96 (Redbook).
I first played the disc on the Vincent CD S7. The orchestra was positioned deep into the recording venue, like a rear hall perspective. Cymbal crashes were controlled, not splashy. There was a lot of impact from very full-bodied percussion instruments. Bass extension was deep, and there was a lot of space between instruments and groups of instruments. The sound stage was very wide, covering the width of the rear wall behind the speakers. The sound of the orchestra was very airy, smooth and sensuous. Solo instruments were located deep into the background of the orchestra. One could hear the wood mallet strike a xylophone. Some instruments sounded rounded, although timbre of most instruments sounded natural.
I next listened to the same disc on the PS Audio PWT. Immediately, I noticed greater resolution. Percussion instruments did not sound as full, but more controlled and exhibited greater definition. The orchestra was positioned closer to the listener, and there was a reduction in soundstage width. There was slightly greater bass and treble extension, and definition. Solo instruments in the foreground moved forward and the space between instrument sections was slightly reduced. The leading and trailing edge of transients was clearer than what I heard on the Vincent. Dynamics were unchanged. Overall, the presentation was more focused, less airy and it seemed the listener moved closer to the orchestra.
Lastly, I played the third movement of Rachmaninoff’s “Symphonic Dances”, recorded on a 2008 Reference Recordings 24/176.4Khz HRx sampler, on the PS Audio PWT. In many respects, I heard a presentation which was sonically a middle ground between the Vincent and PS Audio playing the Redbook recording. The location of the orchestra was in between the positions exhibited by the Redbook recording played on both transports. The sound of the cymbal crash was most controlled and the cymbals sounded most natural.
The sense of space between instruments and sections was also in between what I heard from the two transports, as was the level of resolution and perceived fullness. The harp and xylophone were about as clear as the Redbook recording played on the PS Audio PWT, but somewhat more detailed than what I heard from the Vincent. Percussion instruments sounded full, but not as full as what I heard from the Vincent.
I think the reader can discern the differences in the performance of the three transports. However, I will summarize the most significant attribute(s) of the sound of each transport. The Vincent was the fullest and most airy sounding, as well as having the greatest depth. The PS Audio generally had the greatest resolution. The HRx disc provides the most realistic timbral representation of instruments, as the Vincent sounded a bit euphonic.
Summary of DAC/preamp listening session
Note, I did not mention the tube buffer. I did access the tube buffer, but again, I had to strain to hear a slight smoothing in the treble region. It was so small in magnitude, that it was hardly noticeable.
The sound of the DAC/preamp was similar to what I heard auditioning the preamp by itself. In both cases, I observed a wide and deep soundstage, dynamic contrasts exceeding 20 DB, and in general natural timbre when provided by recordings. The audible differences that I noticed, on occasion, was a slight loss of resolution, an a fuller instrumental sound, and an increase in smoothness from a female vocalist in the upper midrange/lower treble region.
These differences were very small, and could be attributed to the difference between the resolution produced by a 32 bit chip compared to a 24 bit chip. Both are Sabre chips. The difference was insufficient to round or veil the leading and trailing edge of transients.
After completing part 2 of this review, and writing almost 9 pages, I needed a respite, and a brief suspension of critical analysis, before continuing with the last part of the review—the Nova 125SE as an integrated amplifier.
I took a little r&r, musically, listening to a CD of one of my favorite jazz pianists, Ray Bryant. He wrote a song for his daughter “Little Susie”, the album title of a Columbia LP. It was reissued by Sony on a Japanese import, Sony Records SRCS 9189. I listened to the title track. It was easy to “turn off my analytical mind”, the components disappeared and I was just enjoying the music. The song has an infectious melody, and Ray Bryant is an excellent blues pianist/improviser. If you can enjoy the music, the “sound” of components, even with their flaws is no longer paramount. What is important is being able to tap your feet and smile. I was certainly doing that.
Listening session part 3—the Nova 125SE as an integrated amp
I began my evaluation of the Nova 125 SE as an integrated amp, where I started, listening to Bach’s “Chromatic Fantasy and Fugue”, featuring Ronaldo Allesandrini, harpsichord, Opus 111, OPS 30-258. When I first encountered this recording, I stated that I was astounded. This time I was more than astounded. The sound of the CD improved. The action of the instrument was very precise. One could hear the strike and release of the keys. Upon release of the pedal, the sound of wood could be heard distinctly. The reverberation was more pronounced, and the acoustics of the recording venue were more evident than I had previously reported.
I next selected two CDs to investigate frequency response.
The first was Holly Cole, Don’t Smoke in Bed, Alert Z2 81020, track 1. Holly Cole’s voice now sounded full, natural and with little emphasis upon “s” consonants. The wood body of the upright bass was powerful in its impact, especially in its lower register, without masking the sound of the strings, and the piano had more weight than I have experienced, listening to this disc on my system and at audio shows.
The next selection was Bela Fleck, Flight of the Cosmic Hippo, Warner Brothers 9 26562, track 4. The cymbal had a lot of weight, was somewhat mellow sounding, and exhibited decay. During the electric bass solo, there was a delicacy to the sound of the cymbal. The fingering of the bassist on the steel strings was very clear. At its lowest note, the vibration of the wood body was very powerful, with lots of impact. Yet, the sound of the strings was not obscured.
I had originally intended to select a recording of Tchaikovsky’s “Capriccio Italien”, which I presented earlier in this review. Instead I introduced a jazz CD, which I hadn’t listened to for years. I selected this CD because I like the music of Lee Ritenour and Bob James—two members of the quartet.
The CD was Fourplay, Warner Brothers 9 266562, track 5, “Max-O-Man”. As I listened to this track, it brought back memories of the smooth jazz radio station in New York City, CD 101.9. After I listened to the entire track, and considering the sonic characteristics of the recordings, I already described, I believe I have heard the full potential of the NOVA 125SE, which I will reveal in the conclusion section.
With respect to the sonic attributes of Fourplay, I observed a soundstage that covered the width of the rear wall, behind my speakers, I noticed a transition from soft to loud passages, very quickly, in excess of 15 DB, a very natural representation of instrumental timbre, a powerful, deep, and controlled electric bass, a highly textured and smooth sound of a cymbal, and overall, a presentation which combined the best of tubes and solid state.
After listening to the aforementioned track, I felt it was not necessary to audition any other recordings, as the 4 recordings which I did audition embodied most of the attributes of the Nova 125SE.
Again, when I engaged the tube buffer, I hardly noticed a change in sound.
My stereo system came alive after accessing the Class-D amplification section. It provided the power and damping factor needed to properly drive the Magnepan speakers.
One of the salient factors that is responsible for the sonic attributes of the Nova 125 SE, is the presence of 4 Sound Fusion Sound Boosters, which replaced the stock feet. When I transported the Nova 125SE to a position close to my speakers, I noticed the 4 feet attached beneath the cabinet, were made of a hard material, probably rubber. I have had success using softer material, and all of my components, except for speakers, have the Sound Boosters, placed under the chassis.
I strongly suggest removing the stock feet, using a Phillips-head screwdriver, to remove metal screws which anchor the 4 feet to the bottom of the cabinet.
I would advise replacing the stock feet with a softer material, such as Sorbothane. There are other materials which also may be appropriate as well, to serve as anti resonant devices. Contact dealers and/or manufactures to find out about how they might affect the sound of a component and have in mind the nature of sound that you desire.
I would also stress the importance of considering an after-market power cord. The one I used, the MAC (My Audio Cables) Burley power cord, which was reviewed in Audiophilia several years ago, has three 10 gauge copper conductors.
The following describes the essence of the NOVA125 SE.
I can summarize in a phrase the nature of this component, as having the strengths of solid state and tube equipment, combined, without few weaknesses. It quickly differentiates the sound quality of recordings and components, with which it interfaces—an invaluable attribute for use in reviewing. It exhibits the solidity, weight and extension in the bass—typical of solid state amplifiers, the resolution of the best tube and solid state components, and the smoothness and delicacy in the treble—when present on the recording.
It has the dimensionality of a tube amp, the presence of the leading and trailing edges of transients, with ample decay time, typical of the best tube and solid state amps, the weight and fullness associated with tube amps, and above all, a balanced frequency response. It even occasionally displays the lushness and richness of tube components as well. It lacks euphonic coloration but it does not alter the musical content of recordings, and as it has a high signal to noise ration, it certainly is a very quiet component.
When I decided to review the Nova 125SE, upon the advice of a fellow reviewer, who was familiar with the model 125, I had trepidations that I might achieve transparency, along with a “hot” treble. Fortunately, I was wrong. I did not think it possible to achieve a level of resolution, weight, fullness and smoothness, simultaneously, provided by one component, which has no tubes.
A high quality stereo system can be achieved for less than $5000, consisting of the Magnepan 1.7s, a power cord, a digital cable, some anti-resonance devices, a computer, and the NOVA 125 SE.
Further information: Peachtree Audio