ALTAVISTA AUDIO - aria WV 11 XL line stage preamp
 

Review: Aria WV5 XL (Line Stage only) Tube preamp

http://forum.audiogon.com/cgi-bin/fr.pl?rprea&1216705824&read&keyw&zzariaaudio

Jafox

07-22-08

The product under discussion is the line stage of the Aria WV5 XL full-function preamp. The WV5 contains a phono stage (MM and MC) and a fully balanced line stage as a single integrated design. A stepper-motor remote volume control is an option.


To report on the performance of the line stage AND the phono stage at one time would be too much information. And I still have much to learn of the WV’s phono stage capability. Therefore I will only focus on the performance of the line stage.


WV - The Counterpoint ancestry


The WV is the first start-from-scratch high-performance preamp design by Michael Elliot since his groundbreaking Counterpoint SA-9/SA-11 phono/line stage products of the late 80s/early 90’s. Upon the closure of Counterpoint in 1998, Mr. Elliot established a new company, [url=http://www.altavistaaudio.com]Alta Vista Audio[/url]. There were to be no “new” products through Alta Vista Audio, but repair of all Counterpoint products and upgrade paths for many were rapidly becoming available, including those for the SA-9/SA-11. Up to the end of 2007, the SA-9 and SA-11 in premium upgrade status remained as Mr. Elliot’s top preamp. The WV’s arrival in 2008 changed this.


Mr. Elliot has reported that listening sessions of the WV compared to his Counterpoint preamps, stock or upgraded, result in the WV outperforming them all. After all, that was the intent of the WV design. The SA-9/SA-11 upgrade options are no longer available as the upgrade cost for these is more than the purchase of a new WV. Retiring the upgrade paths for the 9/11 models makes sense.


Following the successful re-design of the SA20/220 and NPM/S series amps into a 3rd generation NP220 amp series, Mr. Elliot was preparing for a new product line that would take his amplifier designs to a new level. This ultimately resulted in another new company, [url=http://www.ariaaudio.com]Aria Ltd[/url], in 2000. The Aria amps got little press coverage but from what I had read about them, and owning an upgraded NPS400 myself, I had a good feeling that they could be special. However, I was more interested in Mr. Elliot’s preamp efforts, past and what was to come.


WV – The design and development


After a few years’ production of the Aria amps, Mr. Elliot began the effort to create a preamp that would not only outperform the SA-9/11, but would mate well to the performance of the Aria amps. The full-function WV (whole vinyl) preamp was now under design. Throughout 2004-2007, Mr. Elliot maintained a blog of his progress on the WV design. This blog has been removed which is unfortunate as it gave the reader an opportunity to follow the design decisions for the power supply, audio circuit, volume control, comparison of several step-up transformers, choice of passive parts, etc.


The initial WV design put the PS and Audio sections in two separate chassis. The final design puts these under one main chassis. Only the power transformer is in a separate chassis; this is less than half the size of the main chassis. An umbilical cable of customer-specified length (typically 6 feet) and captive at the transformer-chassis connects to the audio chassis with a 9-pin connector.


The WV’s PS tube compliment of 4 tubes is similar to many Counterpoint preamp designs, e.g., SA-2/5/9/11. Clearly Mr. Elliot has improved upon what worked well in those products. I still have to wonder what the sound of the WV might have been with the beefy PS design but the added reliability of the simpler design has its merit as well. A picture of the original prototype PS can be found [url= http://www.ariaaudio.com/WVImages/WV%20Proto%20Power%20Supply.jpg]here[/url].


WV – The product


Now that the WV is in production, the relevant page for this is [url= http://www.ariaaudio.com/WV.htm]here[/url]. And the online owner’s manual is [url=http://www.ariaaudio.com/WVmanual.htm]here[/url]. This page has much detailed information about the WV and its various configurations. I will highlight only a few things here.


The WV comes in two parts-quality levels. And each comes in line-and-phono or line-only or phono-only configurations. Beyond this, there are options to upgrade the Cardas RCA jacks to WBT, upgrade to the new top-level Vishay TX2575 resistors and a silver-wired umbilical. The model reviewed here is the WV5 XL (line and phono model) with the TX2575 resistors, the silver-wired umbilical, and the remote volume control.


A pair of 6922-family tubes is used in the phono stage and a pair of 6922 is used as the “nominal” tube type for the line stage. The WV ships with 2 pairs of EH 6922 tubes but Mr. Elliot makes it clear that the WV is worthy of far better performing tubes. He also notes that rolling the power supply tubes, particularly the rectifier, will significantly increase the WV’s performance as well. My experiences echoed his findings.


One of the unique design aspects of the WV is its support of 12-volt based tubes (12AU7, E180CC, 7062, 6829, 5965, etc.) in the line stage. This is done with a flip of an internal switch. The benefits of this are covered in the listening evaluations discussed below.


Another attractive WV feature is the ability to use this as a home-theater pass-through and NOT require the WV to be powered on. I looked for such a tube line stage a few years ago, and contacted some manufactures to find this feature for the HT system that I have in another room. I was unsuccessful to find such a product and thus stayed with a solid-state product for the HT setup.


When the WV is put into Standby mode, the HT inputs are routed directly to the outputs. One not-so-obvious benefit here is that the amps do not need to be powered off if the user wants to power down the WV. With the volume all the way down, the WV in Standby, and then powering down the WV, there was a faint buzz through the speakers for a few seconds. This “feature” is great for tube-rolling tests without the need to power down the amps.


A few “issues”:


The WV has only one balanced input and one balanced output. And the HT pass-through does not support balanced connections as well. This is untypical for a product with a truly balanced design. Granted, the intent is to use the built-in phono stage. But for a system configured with balanced sources, I would think at least 2 balanced inputs would be needed….for a digital player and a tuner or balanced external phono stage. Also, if the WV were to be used in an HT setup, it would likely be part of a top-tier HT setup, and these are often balanced systems as well. With the custom work that is often available with Mr. Elliot, I am sure any customer could have these additional connections made to a WV upon order.


As nice as the stepper-motor based remote volume control is here, I wish I had remote mute capability rather than simply the level adjustment. Once I set the volume, I am typically fine with that setting. But with regular interruptions, being able to silence the system in an instant would be nice. However, adding a stepper motor is one thing; adding additional switching or circuitry to accommodate a muting function would likely compromise the performance that Mr. Elliot worked hard to achieve.


Many people might find the 24-position volume control not acceptable for fine adjustment. This has not been an issue for me whatsoever.


Mr. Elliot also writes that the WV must be used with shielded ICs to the power amp(s). The unshielded Jade Hybrid ICs have worked flawlessly for me. Perhaps the one-meter length with the amps directly behind the WV helps here.


On the preamp quest:


I have consistently found the preamp to be the most challenging link. With the exception of a few IC’s, nearly all other components auditioned in my system have retained the portrayal of space and decays to some level of acceptance. However, I have dismissed far too many preamps and line stages as they failed in this key parameter. Only a dozen or so preamps / line stages that I have auditioned over the last 25 years have impressed me enough to be worthy of consideration for purchase.


When I heard the ARC SP-8 at a dealer in 1983, the preamp bar had been raised; I came to realize the significant role that a preamp played in the result of a system’s musicality. As a Linn LP12 owner at that time, I was very familiar with the Linn/Naim sound for which I had always been impressed. But this new experience was altogether different. I was not admiring the accuracy of pace, rhythm or timing, and I was not tapping my toes. Musicians and instruments had body and occupied real space. Harmonics, ambiance and decays were there like I had not before heard from an audio system. I purchased an ARC SP-10 a few years later.


I followed the SP-10 with the ARC PH2/LS5 pair and then onto the BAT P10/31SE. Each upgrade here was a refinement from the previous with greater tonal coherency, a lower noise floor and clearly more retrieval of information. But retaining the dimensionality that I had before each change was critical. The BAT brought on a different presentation with the music now at the plane of (and behind) the speakers whereas the ARC projected the sound more out into the room. I quickly came to like the BAT “sound”. And all subsequent preamp models have had this presentation back at the plan of the speakers.


After a few years with the BAT units, I was ready for a major leap in performance like I had attained with the SP-10 purchase 17 years before. With all the praise of the Aesthetix Io and Callisto, I was eager to hear these products. I started with the Io and then followed with the Callisto two years later. The experience with these was like the first time I heard the SP-8. Such times are rare and special. The Io/Callisto combination conveyed harmonic textures and a most strong fundamental of the notes, particularly noticeable with piano, like no other preamp I had tried. Tube rolling took these to yet another level of musicality, most notably, smoothness.


I had a 1-month home trial of a CAT Ultimate II. This made me well aware of the Aesthetix weakness, e.g., much less extended and detailed top octaves, not quite the power in the bottom octave and clearly more compressed dynamic contrasts. But what the Aesthetix conveyed in the middle octaves the CAT could not match. There was clearly a compromise for which one set of priorities had to be chosen over another.


In mid 2007, I had simplified the CD playback by changing to a one-box player. With the 4 chassis Io/Callisto, I was becoming more and more eager to simplify the preamp as well. A passive volume control had great appeal to possibly replace the Callisto. When a Bent TX-102 TVC (with the rare silver transformers) was available in late 2007 at a local dealer, I took it home to play.


There were immediate pros/cons between the Callisto Sig and the Bent. With the Bent, there was a presence in the upper octaves that was very much lacking with the Callisto. The added level of treble information was a new experience in my system. And this gave a sense of greater dynamics with percussion. A return to the Callisto and the magnificent midrange harmonic textures were back. I had never heard another line stage do this like the Callisto. And with this came incredible decays. I compared the Callisto and Bent for several weeks until I passed the Callisto onto a new owner. I missed the Callisto and yet I was enjoying the new musical presentation with the Bent. The Bent/Io turned out to be a very good combination. But by Spring 2008, I took delivery of the WV …. an entirely new experience.


WV – The sound (Line stage only for now)


With my focus on portrayal of space, other sonic attributes such as a strong bass foundation, low-level resolution and upper-frequency extension and detail have been secondary to me. With each upgrade from the SP-10 and beyond, I achieved more refinements in these areas. But unlike any preamp change before, the Aria WV line stage (and phono stage) has made it clear to me what I have missed up to this point. And for the first time, with the WV, I do not feel cornered to choose one set of strengths/weaknesses of a preamp vs. another. The WV brings through the 3D. But unlike before here, the WV allows a wealth of musical information into the room. After the first night with the WV, I concluded there was one effect taking place that was a new experience to me….in a word, purity.


I think we often equate sonic characteristics such as tonal coherency, extended trebles and dynamic contrasts as contributors to clarity and purity. With the Bent, I had these sonic characteristics. And overall, I was mightily impressed. And then a few months later, I inserted the WV into the system. The result was altogether different: the smearing and grain that I had been accustomed to hearing for so many years was gone. There was suddenly a distinct silence between the notes. I can discern lyrics on old rock LPs that had me stumped for years. And this was the first night with the WV…with its stock EH tubes in the line and phono stages and stock PS tubes as well. The temptation for me to swap those tubes was strong but I needed to hear the WV’s sonic signature for a few days. And I followed Mr Elliot’s suggested burn-in process for two weeks with the CD player driving the phono stage’s MM input during the night and day for 2 weeks to achieve 300 hours.


I was scrambling for a high-resolution source to get a handle on the WV’s line stage capability compared to the Bent. The APL Denon player has much more treble extension than the Io Sig, but I needed to hear LPs. Rachmaninoff’s, “The Rhapsody on a Theme of Paganini”, got much time here. Even with the Io Sig’s softened trebles and average dynamic capabilities, with the WV line stage there was a greater hint of massed strings as a collection of stringed instruments rather than simply a “beautiful” sound. The Io Sig renders the fundamental of notes in the mids like no other phono stage I have heard. But this comes at a cost with the follow-on of the notes’ tonal signature highly truncated.


With the WV line stage in place of the Bent, there was ”openness” to the sound. The Io Sig’s strong fundamental was still prominent but there was now some “available time” for the notes to breathe and show some of their own presence rather than to immediately be smeared by the subsequent note. I could still hear the smearing but the benefits of this new silence between the notes were becoming clear. Low-level detail in the music by other musicians was now coming through that had been previously masked. I was aware of the cable upgrades (done months ago) to bring on greater resolution to the system, particularly in percussion, but the WV took this to a new level of refinement over its peers.


A return to the Bent and the silence along with the carry-on of the harmonics as they decayed, was much diminished. The fundamental was now overly prominent and unnatural. After hearing the WV for only a short amount of time, returning to the Bent made me only want to get the WV back into the system. The Bent had excelled in similar ways over the Callisto. But the WV was altogether in a different league as it was not only about upper-frequency coverage but also in the purity of the delivery of the trebles, and the all-important mids as well.


A return to the WV and the difference was significant: midrange and upper-midrange piano tones had much more energy in their harmonics. It was not in the loudness level of the tones but rather a “dimensional” signature of the tones. This was a significantly new experience for me that I still don’t know how to describe. The added follow-on treble energy that had been smeared/masked before was creating a sense of depth to the tones. These tones decayed several seconds from behind the speakers as if the speakers were much further into the room. Still the trebles were a bit weak (due to the Io Sig) compared to piano music that I tried on the APL CD player but I was hearing musical details with the Io Sig like I had not before with the Bent or the Callisto Sig. This all reminded me of my first experience with the Kubala-Sosna Emotion cables and their “see-through” capability unlike all the cables I owned/tried at that time. The WV has this same purity that is far beyond any other line stage to ever be tried in my system.


Surprisingly, the tonal-coherency of the Bent and the WV is nearly identical. There were no immediate peak/valley differences between the Bent and the WV in any region of the frequency range. The difference was all about the tonal signature of each instrument from its initial sound through the follow-on.


After the initial impressions of the WV line stage with the Io Sig and APL player for a couple nights, I played a little bit with the WV’s phono stage before I started the line-stage tube-rolling trials. I wanted to hear the WV’s phono stage after 30-40 hours burned in. And it was only a matter of seconds coming off the Io Sig and into the SUT MC input of the WV, that I realized it was not only the WV’s line stage here to redefine performance. This is for a later discussion on the phono performance of the WV. But it was the SUT input and the WV’s phono stage that I was to use for 2 months for all subsequent listening sessions for the line stage and power supply tube-rolling efforts. I would bring in the APL player to confirm the tube differences I heard when changing line stage or power supply tubes.


As Mr. Elliot discusses in his website, the stock tubes in the WV are a good starting point but the WV’s performance will be significantly improved through the efforts of the customer to try many tubes. The one tube that he has regularly stated to make a major improvement is the power supply rectifier tube. My experience confirmed this but I was to make a far greater discovery for the line stage.


As stated earlier here, with the flip of an internal switch, the line stage supports tubes of the 12au7 family. With the stash of 6922/6DJ8/7308 tubes I had here, and along with many 12au7 varieties I have used in the CAT JL-3 amps, I had 15-20 tubes from all the major NOS brands. Out of these, the Amperex 6922 PQ pinched waist tubes were my favorite as they have been in the CAT 6922 sockets. But I was still eager to try many of the other 12v based tubes. I tried the E180CC, E80CC, 7062, 5963, 6829, ECC99, 5965 and 6414. I knew nothing about these other than some success with the 5963 in the CAT amps. But two tubes here took the WV to yet another level beyond the Amperex 6922 PQ with one clearly being the top performer in smoothness, harmonic structure and dynamic contrasts without adding any anomalies that the Amperex 6922 did not have. And it was mighty coincidental that the tube to become the reference was also Amperex: the 7062 PQ pinched waist. I knew nothing about this tube before but it gets great respect from me now. Surprisingly the tube that was in virtually last place was the Sovtek 6H30 tube. Just as a few tubes were able to take the WV to top-end performance, a few, most notably the 6H30, let none of the WV’s capability through.


With the 7062s in the line stage and the Amperex 6922 PQ’s in the WV’s phono stage, I played for a few nights with various PS tubes. I was not surprised to learn that the Amperex Bugle Boy rectifier tube had clarity and dynamics compared to the other 3 rectifier tubes I had on hand for this evaluation. But with this tube came added energy that was causing some fatigue and forwardness. I hoped this was more of an issue of exposing flaws in the other PS tubes. Evaluating many tubes in 2 of the other 3 PS sockets allowed me to find a combination of PS tubes that worked incredibly well with the Amperex rectifier tube. I now had a nice refinement over the stock PS tubes in terms of midrange smoothness, dynamics and treble clarity. The WV’s cover was sealed for good as I was done with the tube evaluation process, i.e., until another WV owner reported the success of the 5814 tube in the line stage.


Curiosity got the best of me. I tried 3 different pairs of the 5814. None of them came remotely close to the 7062. And so that indeed ended the tube evaluations. One interesting note was that I changed the ECC99 tube in the APL Denon player with a 7062 and I was stunned by the benefits. People pay $10k in digital gear updates to achieve what this tube does in the APL player. But this too is a different topic. The 7062 tube is special.


Throughout the tube evaluation process, I had one primary thing on my mind: I wanted to recover some of the 3-dimensionality midrange magic that was so inherently strong with the Callisto Sig and somewhat lacking with the Bent. Ultimately I feel that I have achieved most of this in the WV primarily due to the 7062. Ideally, I would like a little more authority in the fundamental of the midrange tones. But I am also aware that the midrange smearing is gone. And the follow-on tones are now rendered beautifully. Perhaps the colorations from before added to the sense of what I liked about the Callisto Sig with its strengths clearly coming through in the bottom half of the range. As outstanding as the Callisto Sig had been for me, the WV is altogether in a whole different league of performance. No doubt the latest Callisto version addresses some of the shortcomings for which the WV excels.


As I was assembling my notes from the last 2-3 months for this report, I wanted to try the Bent one last time this week. It had been 2 months since I last had it in the system. A CD getting lots of play here has been the Mike and the Mechanics, “Beggar on a Gold Beach”. This recording is outstanding with great detail and decays. Synthesizer chords and vocals carry on forever and ever. After playing a few tracks 2-3 times and the system powered on for nearly 3 hours, I put the Bent into the system.


The differences between the WV and the Bent are greater now than before due to the WV custom tube set. But the Bent continues to be an unbeatable value here. Frequency response between the two is nearly identical. The Bent renders the decays that very very few line stages can match. But the emphasis here is the decay of the fundamental. It sounds wonderful and with the focus more in the mids, it can be seductive. But a return to the WV and now the decays that fade are those from the fundamental AND the harmonics. It gives a sense of far greater dynamics but I think it is more to do with the notes’ loudness levels lasting longer as the tones shift to the higher frequencies. And this gives each sound that more distinct dimensional signature as it decays in one direction across the room or to the rear for a longer period of time and if there is nothing stopping it. The Bent and WV have nearly identical bass extension but with the Bent, there is a bit of bass “thumpyness” vs. more control with the WV.


I tried another favorite CD, Vangelis “Reprise”. There is a wonderful piano track here. A friend of mine who heard this many times here always commented that something was wrong even though it sounded good. With the WV, I understand what he meant. Now there is evidence that the piano contains strings. You can so easily hear this as if it were a harp. A jump to the Bent and the sound is beautiful, but there is no presence of vibrating strings. And the harp that is playing in the background is much overwhelmed by the piano. A final return to the WV and the result is layers upon layers of harmonic structured details with the decays seeing no boundaries. This is absolutely phenomenal.


With the WV loaded with the custom tube set, I have bottom-to-top resolution and dynamic contrasts like never before. And there is this new experience of depth with sounds so beautifully placed throughout the region behind the speakers. But the most significant benefit is this attribute of purity. I never caught onto the constant use of “transparency” so often used by reviewers. Perhaps this is what this new experience refers to but I have owned some of the preamps and amps that got high praise of transparency. And the WV is in such a different performance level than those that I will continue to be cautious of the use of transparency.


Not only has this retest confirmed to me the incredible performance of the WV, but I have greater respect for the Bent as well. That top-tiered TVC’s are selling for a few hundred to a few thousand $$ makes them an unbeatable choice for someone not willing or not quite ready to jump in to the costly arena of the great active preamps.


I commend Mr. Elliot for his efforts to not rush the WV’s design and delivery schedule. What I have enjoyed for several months is a result of that process. I never had the opportunity to own his previous top models, but I feel mighty fortunate to own the WV. And for the price, I cannot imagine anything out there coming close. To pay $8k for a line stage at this performance level is a bargain with all the $15-20k line stages coming out now. And here we have a full function preamp whose phono stage, even with SUTs, significantly outperforming phono stages I have owned that cost from $4-8k. This too is another topic. When you think of the added cost of another power cord and interconnect for separate phono and line stages, the WV’s value is even more apparent. And add to this the possibility of custom design work and modifications, which is unheard of with all the top preamp manufacturers out there, the WV customer has more options than ever before.


As with the SP-10 and LS5/PH2 that I owned for 8 years each, I suspect I will own the WV far longer. It really is this good.

 
 

Electrical Specifications


Line Stage Gain: Depends on tube type. Some tubes (but not all) below. (gain is shown in dB, bilance in to bilance out / RCA in to RCA out):

-6414, 6829,7062: 33dB/25dB

-12AV7: 29dB/21dB

-6922, 6922(WA), 7308, 8223, CV5231, CV5354, CV5358, CCa, CV2492, CV2493, CV8065, CV10320, ECC86, ECC88, E88CC, E88CC/01, ECC868, E188CC, E288CC, 6N1P, 6829, 7062/E180CC: 28dB/20dB

-12AV7, 12AY7, 12BH7, 5965, 6414, 6913: 26dB/18dB

-6CG7, 6GM8, ECC86, ECC99: 24dB/16dB

-12AV7/5963/ECC82, 12AU7A/6680/7730, 12AU7WA/6189, 6067, 6680, 7489, B529, ECC82, ECC802S, & more types: 20dB/12dB

-6H30Pi (AKA “6N30”): 18dB/10dB

Input impedence: 100K ohm (higher is ALWAYS better, never accept a line stage with less than 50K)

Line Stage Output Impedance: This is not a fixed number, it varies according to the tubetype used. You can assume it never goes higher than 5k ohm, and is closer to 3k typically. This is plenty good for driving cables with no more than 1200pF capacitance and power amps with no less than 50K ohm imput impedance (higher is always better).

Signal To Noise: -91dB (14uV noise) below 0,5V output reference, IHF weighted, 20Hz-20KHz, volume control at minimum.

Crosstalk: Greater than 68dB canne separation, 20-20KHz

Power requirements: Avaible in 100V (87 to 118Vac), 115V (100 to 136Vac), and 230V (200 to 270Vac), all 50/60Hz. 75W


Physical Specifications


Dimensions:

Audio chassis: 19” (48cm) wide x 17,5” (45cm) fore-to-aft x 5,5” (14cm) tall; allow at least 2” (5cm) at rear for interconnects and at least 4” (10cm) above for ventilation.

Power supplì chassis: 10” (25cm) wide x 10,5” (26cm) fore-to-aft x 5,5” (14cm) tall; allow 4” (10cm) at rear for interconnects.

Weight:

Audio chassis: 30Ibs (14kg).

Power supplì chassis: 8Ibs (3,6kg).

Shipping weigt approx. 65Ibs (30kg) in wood crate.