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Equipment Review
January 1999

SimAudio Celeste 4150se Amplifier

by John Stafford

Reviewers' Choice Logo
The best of solid state -- bass,
dynamics and plenty of clean
power -- at a real-world price.


Review at a Glance
Sound Great bass, dynamics and clarity are just part of the 4150se’s honest presentation; if your upstream components and speakers are capable, this amp will let you hear all the music there is.
Features Power to drive almost any speaker you can name; inputs for inverted and non-inverted signal; XLRs for balanced connection and an IEC receptacle for power-cord experimenters.
Use Runs cool; rounded heat sinks are safe around little ones.
Value High-power solid-state bruisers don’t commonly sell for $2599 -- or close to it.

Say the name "SimAudio" to a group of audiophiles and they may reply, "Yeah, I think I know who that is -- I think."

Say "Celeste" and they will likely say, "Oh, the amplifier manufacturer!"

The Celeste line of amplifiers gained such a high degree of name recognition that it has also been mistaken for the company name in some circles. In fact, until SoundStage! publisher Doug Schneider visited the SimAudio factory and wrote about the experience, he confessed that he was a little unsure of the line distinctions himself. The fact is, SimAudio is the manufacturer and Celeste is name of only one of the company’s three product lines, each at a different price point. SimAudio is one of the longest-established high-end electronics manufacturers in Canada. In the early 1980s the company began as Sima, and cost-effective, bare-bones performance is what they were known for. Today, with Jean Poulin as president and head of the design team, the company 's name has changed to SimAudio and it caters to every audiophile price bracket with three different brand names.

Stratford is the company’s lowest-priced lineup. However, this doesn't mean cheap by any standard. But it does mean lower prices when compared to the other SimAudio brands. Stratford is mainly targeted toward high-quality home theater. It uses trickle-down technology from the other lines, but in more cost-effective implementations. The Celeste line of amplifiers and preamplifiers (and soon-to-be CD player) are designed to give true high-end performance, but they eschew some of the cosmetic jewelry and sacrifice cost-no-object circuit implementation to bring high performance to the real world. Celeste is bang-for-the-buck stuff -- small sacrifices for incremental gains in cost savings. Next up the ladder is the Moon series. This is where SimAudio pulls out the stops and offers a cutting-edge line of amplifiers, preamplifiers and their first digital product -- the newly released Moon Eclipse CD player ($4999), a top-loading unit that boasts 24-bit/96kHz performance.


In the Celeste line, SimAudio really gained prominence for their 4070 amplifier ($1799) -- a reasonably powerful (70Wpc at 8 ohms), competitively priced amplifier that received much praise for its price: performance ratio. The 4150se is the same basic topology as the 4070, but it's capable of providing far higher power output. The 4150se is a class-AB design that uses Motorola bipolar output transistors and delivers 150Wpc into 8 ohms and 300Wpc into 4 ohms. It can also be bridged into mono operation where it will deliver 600W into 8 ohms. SimAudio boasts of a proprietary power-supply transformer used in both the Celeste and Moon series with exhaustive specifications that can be seen on their website or in their literature.

In addition, SimAudio emphasizes the importance of their "Renaissance Technology," first released in 1993. Their documentation describes it as "a no overall feedback design which uses a very precise differential circuit that employs only one step of local feedback (found in the output stage to maintain low THD). The result is virtually non-existent intermodulation distortion (which is more damaging than harmonic distortion) and an extremely fast amplifier with no phase errors resulting from feedback."

While SimAudio offers a still more powerful amplifier in the Celeste line, the 4250se ($3399 and rated at 250Wpc into 8 ohms, the most powerful amplifier SimAudio makes), it is doubtful whether the majority of listeners will need that extra kick of power. The 4150se is a very powerful amplifier, capable of driving difficult loudspeaker loads -- frankly, more than enough power for most listeners and most speakers. Priced at $2599 USD, the 4150se is not cheap, but it is an amplifier that many can still afford.

The 4150se comes in cleanly finished charcoal-gray chassis -- it does not have the elegant styling of the SimAudio Moon series, but it appears functional and close examination reveals excellent build quality. One particularly attractive and unique feature is the round, extruded-aluminum heat sinks that adorn the sides. The function of the heat sinks is obvious and vital, but they also give the amplifier a sleeker, more diminutive appearance. This means that it will be easier to conceal in a listening room should you wish. I also give these heat sinks the thumbs up in terms of safety as they are not sharp and protruding as on some amplifiers. Being a parent, I note these matters. Some heat sinks seem ready to impale any children or household pets should they happen to get a little too close to the audio system. The effectiveness of the heat sinks prevailed during extended listening sessions where they and the entire amplifier stayed relatively cool to the touch. The original line of Celeste amplifiers when introduced a few years back also had faceplates with rounded sides that matched the heat sinks. While some may have liked that distinctive appearance, I prefer the more traditional rectangular faceplate that is now used. Call me old-fashioned, but I think it makes the amp look more substantial.

simaudio_4150_inside.jpg (58571 bytes)

On the back of the amplifier are two pairs of input RCA jacks (that means four in total) and one pair of XLR jacks, the on/off switch, and the IEC power-cord receptacle. Why four RCA jacks? One pair is for a standard non-phase-inverted signal, and the other for an inverted signal. Certain preamps, mostly tubed units, invert phase, in which case with the 4150se you won’t have to switch the leads at your speakers to add a second phase inversion to cancel the effects of the first. Additionally, you will need to short the pair of RCAs you’re not using. Unfortunately, this aspect of setup wasn't too well explained, and I could envision some listeners not getting their amps set up right at first. I know because I did it, but I quickly realized that something wasn't quite right. Speaker terminals are high-quality WBT connectors, which are some of the best on the market in terms of quality and function. About the only other backside feature of the amplifier is a small reset switch that is used if the amplifier’s protection circuitry is tripped.

The 4150se powers on very quietly with a gentle push of a tiny front-mounted switch. One small beef is that the on/off switch should probably have more resistance when pushed; it is easy to turn on and off quickly without trying if you’re not careful. A small blue light illuminates indicating the powered-up status of the amplifier.


I didn't take long to find out that the 4150se is an extremely fine-sounding amplifier. In short, I found the 4150se to be a high-quality unit with the sonic characteristics that solid state is best known for (tightness and control, great bass performance and extended high frequencies) and then some. In fact, the 4150se is so dynamic, fast, uncolored and clean that it helped when swapping equipment in and out as the amp became quite chameleon-like, making it easier to distinguish between different cables and electronics. In that realm it is also not a terribly forgiving amp, as it showed any harshness or problems up stream in the electronics or downstream to the speakers. While some may want some euphonic cover-up, others want transparency, and in this regard the Celeste 4150se delivers.

Associated Equipment

Loudspeakers – Gershman Avant Garde RX20, Totem Model 1 Signature.

Amplifiers – Arcam Alpha 6 integrated amplifier, Anthem Amp 1 power amp.

Preamplifier – Anthem Pre 1L linestage.

Digital – Primare D20 CD player, Rotel 955AX CD player, Assemblage DAC2 DAC.

Interconnects – Cardas Quadlink 5c.

Speaker cables – Cardas Quadlink 5c, Canare Quadstar speaker cable.

Digital cable – XLO Pro.

Accessories – Blue Circle BC83 PLP power conditioner.

The 4150se has a prodigious bottom end and a very clean presentation. I often go on about the ability of an amp to generate realistic bass at lower volume levels because I have to keep the volume down in the evening until I am sure my daughter is asleep. Many solid-state amplifiers have their best bass only when they play at mid or high volume levels. In fact, I have often found that tube amps will generate better bass at lower volume levels. However, the 4150se was able to deliver smooth and consistent bass at all volumes.

It was convenient that I had a couple of speakers that can be difficult to drive during the review period as they gave the 4150se a chance to flex its muscles. Both the Gershman Acoustics Avant Garde RX20 and the Totem Model 1 Signatures can be a difficult load for a low-powered amplifier. The 4150se handled these speakers with great dexterity. Control of these loudspeakers was more than impressive, allowing them to play very loudly without a hint of stress. To boot, the low-level detail that the 4150se was able to dish out to the Gershman speakers led to some incredible bottom-end detail and ambient information. Misa Criolla [Phillips 420 955-2] is a wonderful live Jose Carreras recording with rich lows and plenty of ambient information. The 4150se presented this recording exceedingly well, displaying an awesome sense of space. With the Totems in use, I was surprised at how much bass came out of the diminutive minimonitors on the re-release of Brothers In Arms from Dire Straits [Vertigo 824 499-2]. On "Ride Across The River," the drumkit and bass track jumped to life with authority and great articulation. With lower-power amplifiers, the bottom end was missing to a degree.

No doubt about it, in my system the 4150se delivered more than sufficient power with great bass presentation. The sound from the bass through the midrange was very detailed and without a trace of unnecessary coloration. This may be a good thing or a bad thing -- you decide. The Celeste 4150se is not one of those sold-state amps that offers tube-like sound, and I don't think that the SimAudio design team had the intention of trying to re-create tubes. The 4150se is lush when the recording warrants it or will exhibit those characteristics when other components in the system do. The result is a midrange that some -- including myself, having been through a number of tube amps -- may find a little lean, perhaps even dry. However, I must say that the 4150se gives a very honest presentation of the music.

On the top end there was plenty of sparkle with a minimum of etch. The 4150se may not be the most pristine of all amplifiers, but it is exceedingly good in its price range -- no traditional solid-state nasties present here. The highs were clean and clear with an easy distinction between brushes and drumsticks on the cymbals and high hats, as in "D&E" from Oscar Peterson’s We Get Requests [Verve 810 047-2], during which the drummer actually changes between the two. Beware of any low-quality components the 4150se is used with, though (that includes CD player, preamplifier and cables). A quick try with a budget preamp did not yield good results -- its character showed through, quickly turning the music hard and badly etched. Moral of the story: Make sure you are feeding the 4150se a quality signal. That does not necessarily mean expensive. The $995 Anthem Pre 1L preamp mated very well with the 4150se.

I’ve use the word clear a fair bit in my description of the 4150se. My suspicion is that the clarity is really produced by the speed of the amp. Fast transients generate good dynamics and clarity. The faster the amp reacts to the changes in the signal, the more clear the music generally sounds. Otherwise, the sound becomes smeared and dull. Take that one step further and you are into dynamics, the ability to the amp to recreate sudden changes in volume like the crash of a cymbal or slap of a drumstick on a snare drum. The two should go hand in hand, and with the Celeste 4150se they do. A good illustration of dynamics and clarity is "Lonesome Road" by Mighty Sam McClain from the JVC XRCD version of Give It Up to Love [JVCXR-0012-2]. The acoustic-guitar work is unbelievably quick with plenty of attack, and Mighty Sam works his own kind of magic.

Imaging was first-rate with good depth and plenty of air around each of the instruments, including vocalists. While air and imaging are not necessarily in the same category in my book (I consider air around instruments to be more a product of good high-frequency reproduction) they help to create that three-dimensional sound that can make high-end audio so rewarding. I have heard systems that image but really only in a two-dimensional way, with the depth and air missing. This kind of system sounds flat and mechanical, whereas the addition of the other two attributes makes the sound more natural with a sense of ease in the presentation. The 4150se renders rock-solid images, provides dimensionality and "breathing space" for instruments and can recreate the sense of hall space and ambience with stunning clarity.


Power, control and grace -- this is one way to sum up the performance of the SimAudio Celeste 4150se amplifier. Not all high-power amplifiers can make music with finesse. At 150Wpc into 8 ohms and powerhouse delivery into 4 ohms, the 4150se can be used with just about any speaker on the market. It’s a very clean-sounding amp with a complete lack of coloration, excellent full-spectrum performance, and able to throw a wide, deep, and rock-solid soundstage. Tube lovers may long for something a little more lush in the midrange, but you can wager that you will likely not get this level of power and control anywhere near this price. You give up one thing for another I guess.

While better solid-state amplifiers do exist, the 4150se lies smack dab where diminishing returns set in strongly. SimAudio's own W-5 is a bit more powerful (175Wpc), but is double the price. Is worth it? In high-end audio every steps towards refinement and perfection costs much more money. A little more articulation here, a touch of refinement there and a wee bit of polishing of the sound can add a lot to the price. The fact is, the SimAudio Celeste 4150se amp gets you almost all of the way there for a reasonable price.

...John Stafford

SimAudio Celeste 4150se Amplifier
$2599 USD
Warranty: Five years parts and labor

3275, 1st Street, Unit 1
St. Hubert, Quebec
Canada J3Y 8Y6
Phone: (450) 445-0032
Fax: (450) 445-6626

E-mail: info@simaudio.com
Website: www.simaudio.com

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