⌈ JAMES BULLOUGH LANSING, or JBL, is an American company founded in 1946 by JAMES MARTINI as Lansing Incorporated. Today it belongs to the Harman group, and this one to Samsung. It is one of the most important manufacturers of loudspeakers, Bluetooth speakers and headphones in the world. ⌋

ONE COULD ACTUALLY EXPECT IT - Harman Luxury Group after the success of the vintage series of JBL loudspeakers, first the L100 CLASSIC from 2018, and recently the L82 CLASSIC |PL|, decided to add electronics to them. The occasion for this is unique, because this year JBL celebrates its 75th anniversary.

▌ A LITTLE HISTORY

JBL's roots go back to the 1920s and the explosion of sound films. Its founder, JAMES BULLOUGH LANSING, was born on January 14, 1902 in Macoupin County (Millwood Township), Illinois as James Martini. After his mother's death, in 1924, he moved to Salt Lake City, where he founded LANSING MANUFACTURING COMPANY, which produced car speakers. To enable development of the firm, he moved it to New York in 1927.

⸜ JAMES BULLOUGH LANSING • photo Harman

On October 6, 1927, Jazz Singers premiered, the first Warner Brothers sound film to be incredibly successful. The history of high-class loudspeakers started the same year. Since the sound technologies used so far were quite primitive, the MGM company decided to do something about it. Douglas Shearer, chief sound engineer at Metro-Goldwyn-Mayer, contacted James B. Lansing and together, from 1933 to 1935, they developed the foundations for horn-loaded loudspeakers that became the industry standard. In 1936, the Lansing and Sharer sound system received an award from the Academy of Motion Picture Arts and Sciences.

Everything was going great until the military maneuvers in 1939, in which Ken Decker, Lansing's business partner, chief of Lansing Manufacturing's finances, was killed in an accident. No one else was found to replace him, and in 1941 the company was on the verge of bankruptcy. It survived because Western Electric's ALTEC SERVICE COMPANY (Altec for "all technical") decided to purchase its shares. To this day, it operates as an Altec / Lansing company, and its products are present in recording studios and on stages.

Following the acquisition of Altec, James B. Lansing was asked to remain with the company as vice president of development. After his five-year contract expires, he leaves and in 1946 founds another company - JAMES B. LANSING SOUND Inc., or JBL for short. However, already in 1948 it fell into financial trouble and was bought by the Marquardt Corporation, which in turn was purchased by the tire manufacturer, General Tire Company. The founder of JBL cannot stand the tension and on Tuesday, September 24, 1949, he commits suicide.

Thanks to the high life policy he signed up for, the company not only survived, but became more and more successful. We owe its reactivation to the treasurer, William Thomas, who, after buying part of the shares from Lansing's wife, became the sole owner. In 1969, JBL was purchased by Jervis Corporation, a division of Harman Kardon. As a result of this transaction, Jervis Corporation was renamed Harman International Industries, Incorporated, and ARNOLD WOLF, the creator of the Paragon system, became the president of JBL. It is worth noting that Wolf is also the author of the JBL logo.

JBL loudspeakers have become the basis of many stage sound systems and the heart of the most important recording studios. Along with the development of the home hi-fi market, the manufacturer also began to offer loudspeakers for the home use, and today it even dominates the market of portable systems - from Bluetooth speakers to wireless headphones. Let's add that in March 2017, Harman was bought by the Korean Samsung Electronics.

▌ VINTAGE

JBL IS PART OF A GROUP OF AUDIO COMPANIES, which defined our industry, both in the studio and "home" dimension. With such a long history, it is in a unique position where it can choose any solutions from the past and modify them as desired. The "vintage" trend appeared quite early, although its success was a surprise for the manufacturer..

The aforementioned Paragon system, the "child" of Bruce Scrogin, then the head of JBL International, was called the "Second Project" in the company. It was sold almost exclusively in Japan, and its production ended in 1983. It was decided that a new flagship will be developed and it will be aimed exclusively at that market. One of the country's most famous audio journalists, Keizo Yamanaka, was invited to the consultation. The result was a design that had never been seen before: the DD55000 Project Everest.

⸜ DD55000 Project Everest • photo: JBL

Project Everest was a success: over 500 pairs of these loudspeakers were sold, which was a large number considering the price. It remained in production until 1989, when the smaller K2 model was introduced to the market, later expanded to an entire series. The idea was that it would be a two-way model, reminiscent of Everest in appearance, but with a simpler design. The top model was the K2-S9500, which, along with the smaller K2 S7500, was presented to the press in 1989. In 1993, the smallest model, the K2 S5500, joined them.

At the beginning of the 21st century, in 2003, the K2 S9800 was presented to the world, and a few years later the K2 S9900, both based on the Everest Project. Already in 2002, however, work began on the revitalization of the original. The DD66000 model, planned for the company's 60th anniversary, presented in 2006 was "doomed" to success. It received awards from all over the world, mainly from the Japanese magazine "Stereo Sound", which similarly awarded all its previous incarnations.

In 2018, however, JBL presented something different - supposedly similar, but having a different genesis. Throughout the 2000s, it offered home versions of studio monitors, with new drivers and crossovers, but based on similar assumptions as the originals. At HIGH FIDELITY, we tested a large part of this lineup, including the 4319 CONTROL MONITOR |PL|, 4429 STUDIO MONITOR, and 4306 COMPACT MONITOR |PL|.

In the aforementioned 2018, the American manufacturer, however, at the CES 2018 in Las Vegas, presented something more radical within the concept of "vintage", that is, loudspeakers that are an exact copy of the model from 1970, the L100 Classic. Interestingly, the original L100s were also presented for the first time at CES - in Chicago, but in 1970. Jim Garrett (Senior Director, Product Strategy and Planning, Luxury Audio, Harman) said then that these were not only the best-selling JBL loudspeakers of all time, but - everything points to it - the best-selling loudspeaker of the 70s regardless of the brand.

⸜ The anniversary JBL system: SA750 amplifier and L100 Classic 75 speakers • photo JBL

The American manufacturer decided to discount this success, the more that the "retro" trend was well received in audio, and decided to make another move offering the L82 Classic, smaller and half the price of the L100 Classic. The crowning achievement of this stage - because I assume that there is still more to come - is the system consisting of the JBL L100 Classic 75 speakers and the SA750 integrated amplifier, presented in January this year, with which JBL celebrates its 75th anniversary – congratulations!!!

▌ SA750

The JBL SA750 IS AN INTEGRATED AMPLIFIER with so-called "network functions". What does it mean? - The thing is that it is in fact an all-in-one system. It is a classic amplifier, which has the ability to play audio files with the help of external applications. Moreover, the device is equipped with the widely acclaimed automatic acoustic correction system Dirac Live. So when the manufacturer says: "The design of the SA750 is inspired by the classic JBL SA600 amplifier from the 1960s," he does not mean the device as such, but its style.

The device delivers up to 120 W into an 8 Ω load and 220 W into a 4 Ω load, which in most cases will be at least sufficient. Admittedly, the output doesn’t quite double 4 Ω, but I think that the device will have no problems driving most of the loudspeakers. Although a large number of manufacturers use class D amplifier modules in this type of devices, JBL used a solution from a sister company in its portfolio, namely the Arcam.

It is a class G amplifier ("rail switching"). It allows you to achieve a high output from a small amplifier circuit and does not require large heat sinks, and it is still an analog amplifier. It is, in short, a hybrid amplifier. At low power, it works in class A, when a single power supply works at full speed, and with a higher current consumption, an additional power supply is activated, which provides higher voltage and current, needed to drive the loudspeakers at high signal amplitude. Arcam introduced the G class to its power amplifiers in 2009, and the first device to use it was the AVR600 AV receiver.

⸜ DESIGN When I placed the device on the top shelf of the Finite Elemente rack, above the tube Leben CS600X, it was clear that both were made by people, who like such styles. The SA750 is a very nicely made product, with characteristic knobs that can be used to select inputs, adjust volume and balance between the channels. The knobs are very similar to those used in the Leben. The side panels made of teak wood also match this style. They match the color and grain of the JBL L100 Classic 75 loudspeakers cabinets.

The amplifier is not very big, as it measures 449 x 114 x 327 mm and weighs 12 kg, but it is enough to arouse interest and not overwhelm at the same time. In addition to the stylish elements that I have already mentioned, the brilliantly used JBL logo i.e. an exclamation mark. It acts as a power indicator, usually operated by a LED. In the standby mode, it is red, and when the device is turned on it switches to orange, that is, the same color as the "company’s" color of this manufacturer.

The front is made of brushed aluminum. Immediately noticeable is the division into a square on the left and an elongated part on the left. This was achieved by a simple procedure - the square is positioned in such a way that the brushing lines run vertically and on the other part they run horizontally, so the light refracts on them differently. And there are also characteristic switches that look like large knobs - a feature characteristic of both the 1960s and 1970s, when the successor to the SA600 amplifier, the SA660 model, was launched.

An absolutely modern element, at least in this context, is a large dot-matrix display with two long orange lines. We will read the selected input, volume level, menu settings, as well as song titles and artists streamed via Chromecast or AirPlay 2.

Against this background, the remote control seems not to be well-chosen - it does not look as stylish as the amplifier. It is plastic, fairly simple, and yet not very ergonomic.

⸜ FEATURES The SA750 in its basic function is an integrated amplifier - we have already said that. Let's add that it also features digital inputs, so it can be used as a DAC for external sources. The manufacturer suggests what these could be, describing them as: "Game", "BD" (Blu-ray) and "Sat". However, nothing stands in the way of connecting some nice Compact Disc transport to it.

There are four digital inputs, of which two are coaxial RCAs and two optical TOSLinks. There are also five analog inputs, four of which are located on the rear panel, and one, a 3.5 mm mini-jack, on the front. Next to the latter, there is also a similar headphone amplifier output. One of the inputs on the rear panel is dedicated to turntables, with both MM and MC HO (Moving Magnet and Moving Coil High Output) and MC cartridges. In fact, there are two inputs, separate for each type of cartridge, so you can connect two cartridges (two arms) at the same time.

You can also play audio files to the device, both via an Ethernet cable and wirelessly. The device is equipped with a player compatible with UPnP servers and streaming services. The latter will be controlled by the Arcam Live application, which shows that not only the amplifier has a lot in common with the Arcam’s amp we talked about. On the back, under the Ethernet socket, there is a longitudinal USB socket to which we can connect a thumb drive with files. The SA750 offers full MQA decoding, and there's also Roon Ready function.

For many users, however, more interesting will be an implementation of the Apple's Air Play 2 and Google's Chromecast in the device. The latter allows you to use streaming applications, such as Tidal, from which the signal is sent to the amplifier in resolution up to 24/96. This means that we do not have to run the control application (from Arcam). The problem, however, is that most smartphones only transmit the signal up to 16/48 in this way, and files with higher resolution will be downsampled to this value. Although the manufacturer declares that this is "High-resolution Google Cast", you need a compatible device with the appropriate application.

And finally, there is something one could start this text with, that is the DIRAC LIVE 3. DL is an automatic room acoustics correction system ("Room Acoustics & Room Correction"). It is, let us add, one of the best consumer systems of this type. JBL has a lot of experience with it as it is used in home theater systems in the Synthesis series. Its software includes advanced analysis of the frequency, impulse and phase response of the loudspeakers and the listening room, and then optimizing the sound by applying appropriate corrections to the signal.

To take advantage of the benefits of Dirac Live, we need to measure the acoustics of our room. A calibrated microphone is used for this, which is connected to our computer, on which we previously downloaded the software. The computer and the amplifier must be connected to the same network because they communicate over it.

We put the microphone in several places in the room as indicated by the software. You can start with the measurement in one place, where you are sitting, but the manufacturer points out that the more points we measure, the more precise the correction will be. After starting the measurement, a series of sounds are emitted from the speakers, which go to the microphone and are then analyzed. After taking the measurements on the computer screen, we get a graph with the measurements and the proposed corrections - the target curve.

Importantly, similarly to the Accuphase equalizers, also here the user can modify it, and in the amplifier we can save up to three different results. We can assign them to each of the inputs separately. It's a pretty simple procedure and anyone can do it on their own. However, if you do not feel up to the task, it is worth paying for such a service and asking your dealer to do it for you.

Dirac Live works on Windows 10 and MacOS 10.14+, and on the manufacturer's website you will find information that among the companies that use it are: ARCAM, AudioControl, BRYSTON, DATASAT, EMOTIVA, FOCAL, Integra, JBL, Lexicon, Lucie, miniDSP, MONOPRICE, NAD, ONKYO, Pioneer, quadral+, ROTEL, StormAudio, THETA DIGITAL, WISDOM. Interestingly, the NAD has applied the program to its Master series amplifiers, so there is no need for a computer program - a simple smartphone application will suffice.

I would like to add that in the latest issue of the STEREOPHILE magazine, Kalman Rubinson has published an extensive test of this application used for his multi-channel system (Vol.44 No.10, p. 157-163).

▌ SOUND

⸤ HOW WE LISTENED The SA750 amplifier was tested in the HIGH FIDELITY reference system. It was compared to the Ayon Audio Spheris III preamplifier and the Soulution 710 power amplifier, costing around PLN 300,000. On the other hand, the DAC was compared to the converter section of the Ayon Audio CD-35 HF SACD player. I listened to music through analog and digital inputs, listened to the Tidal streaming service and also transferred files from it via the Chromecast system.

The SA750 was placed on the top shelf of the Finite Elemente Master Reference Pagode Edition MkII rack and was powered by the Harmonix X-DC350M2R Studio Master cable. The signal from the player was led using Crystal Cable Absolute Dream cables. The Harbeth M40.1 was sent to the Harbeth M40.1 using Western Electric cables from the 1940s - that is, from the times when the JBL company was founded.

Listening to analog sources, I always chose the "Direct" switch, which shortened the signal path. It seems to me that it is, above all, a very good amplifier. But I also listened to music with the Dirac Live 3 system, which will come in handy in acoustically challenging rooms.

Recordings used for the test | a selection

⸜ ELLA FITZGERALD, Like Someone in Love, Verve/Esoteric ESSO-90143, SACD/CD (1957/2016): 6 Queens of Jazz Vocal, „MasterSoundWorks”, Esoteric ESSO-90143/8, 6 x SACD/CD (2016).
⸜ FRANK SINATRA, My Way (50th Anniversary Edition), Capitol/UMe USM Japan UICY-15851, “Signature Sinatra”, CD (1969/2019).
⸜ KRAFTWERK, 3-D The Catalogue, KlingKlang | Parlophone 95873424, 7 x CD (2017) .
⸜ PATRICIA BARBER, Companion, Premonition Records 522 9632, CD (1999);
⸜ PETER GABRIEL, So, Realworld/Virgin SAPGCD5, SACD/CD (1987/2003).
⸜ SANTANA, Supernatural, Arista | BMG ‎07822 19080 2, CD (1999).
⸜ LORDE, Solar Power, Universal Music/Tidal, , FLAC MQA 24/44,1 (2021).
⸜ PATRICIA BARBER, Clique, Impex Records/Tidal, , FLAC MQA 32/352,8 (2021).
⸜ ZK Collaboration, Slow Food, „Polish Jazz”, Warner Music Poland | Polskie Nagrania/Tidal, FLAC MQA 24/44,1, singiel (2021).

| 1 | SUPER AUDIO CD/COMPACT DISC

I REMEMBER WELL what a joy I had when listening to the Arcam SA30 amplifier. I was surrounded by it with a warm, dense sound similar to that of tube amplifiers. It was a similar experience also this time. This sound is not 100% identical, there are differences between the two designs - more on that in a moment - but they are several orders smaller than the similarities.

The JBL amplifier sounds indecently downright warm through the analog inputs. ELLA FITZGERALD's voice from the Like Someone in Love was silky, dense and had a good volume. Unlike warm-sounding tube designs, the SA750 does not inflate the sound, it shows phantom images in the right proportions - both within the recording and in the context in which they are played, i.e. in a specific room.

This means that we will get big vocals, but they will not be brought closer to us or enlarged. They will be tangible and silky in themselves, but they will also stick to the "vertical", so to speak, they will be properly fitted into the presentation. So Fitzgerald's voice was not too bloated, but it was still full-bodied and warm. It was similar with the album FRANK SINATRA My Way (50th Anniversary Edition). Released by the "Stereo Sound" magazine, the SACD has a signature similar to the Esoteric (Fitzgerald) label - it is warm and dense.

Although it is easy to fall into the trap of exaggerated warmth, blurring the sound with this type of recordings, the tested amplifier didn’t get caught by it but rather followed its own path. The thing is, this IT IS a warm sound and IT IS a dense sound. And yet there ARE NO most of the problems we usually get with such type of presentation. It is a sound with good resolution and selectivity well suited to its character. In addition, the sound is dynamic, not lethargic.

The resolution helps in discovering subsequent layers of recordings, in distinguishing different types of pressings and releases, and the selectivity does not allow the sounds to form a large "ball". Although the SA750 is not a master of stereo panorama, it does not narrow the presentation. It is just right. With the Dirac Live correction, the edges of the stage are wider, and the depth is a bit greater, but these changes are not significant, and the JBL turns out to be a very good device in this respect.

It is interesting that although warm recordings, such as the mentioned Fitzgerald and Sinatra discs, were not flooded with warmth by the tested device, but only their own warmth was extracted, albums with stronger treble, such as So by PETER GABRIEL, sounded nicer than usual. SANTANA from Supernatural, listened to immediately afterwards, showed that also highly compressed recordings sound nice, dense with JBL, there is no problem with hard attack of the sound.

| 2 | FILES/TIDAL

EVERYTHING THAT I HAVE WRITTEN ABOUT ABOVE, it's warmth, scale, the ability to present everything in a vivid way, will come in handy when we listen to files. Although streaming services have undergone a revolution in terms of sound quality in the last two years, it is still a streamed file. The music played by the SA750 sounded like a warm turntable. And this is probably the key to this device - it is supposed to be a pleasant companion in the afternoons and evenings. For active, dynamic mornings, I would choose something else.

The tonality of both the files player and the amplifier is warm and dense, but in the files player it is even a hair stronger. The high treble is sweet and there is not much of it, so it's hard to call this device "detailed". The new, just released single Slow Food from the ZK Collaboration album, that is to be released soon as a part of the "Polish Jazz" series, was quite energetic and expressive, but it was clear that it was focused mainly in the midrange and the bass.

Exactly - the bass. Already with the aforementioned albums, especially with PATRICA BARBER from Companion and KRAFTWERK from 3-D The Catalog, I heard low, dense and, so to speak, "firm" bass. It was similar with the recordings from Tidal, because the recordings and LORDE from Solar Power, and PATRICIA BARBER from Clique had a low, dense bass base. It was especially audible with the Barber, because the double bass on this album is strong and is an important element of it. The JBL slightly underlined it, lowered it a bit, but did not blur it and did not close it in the "box".

All the recordings I listened to were of a similar nature, that is they were shown in a big, pleasant way. Their dynamics was good, although the CDs and SACDs sounded much more lively and dynamic. What is important, however, is that the SA750 played all files, even the demanding Barber disc, encoded in MQA 32 bits and 352.8 kHz, without any problems.

Casting (Chromecast) fares worse in this comparison. It does not mean - bad, but worse than when playing directly from the player in the SA750 and from an external audio source. The sound is harder with it and not so soft, it is also less resolving. On the other hand, it is more open, with more treble in it, and the midrange is not as warm anymore, so who knows - maybe it will be your favorite way of listening to music from the network. The advantage of this solution is also the fact that after setting the volume in the amplifier, we can adjust (lower) it with the buttons on the smartphone.

| 3 | DIGITAL-TO-ANALOGUE CONVERTER

The DIGITAL-ANALOGUE CONVERTER in the SA750 is similar in terms of tonality to what I heard when sending the signal via Chromecast. It's an open sound with little warmth. It's not that it sounds cold, it doesn't, but that compared with the sound through the analog inputs, the music listened to via the digital input seems to have cooler timbre.

Its advantage is clearer presentation and better controlled bass. This one is not as low and as saturated as with Tidal, we won't get it. But it will have enough power to accurately reproduce both Santana's, Barber's and Deep Purple's albums. If I had to choose, I would choose a classic analog input.

| DIRAC LIVE 3

AT THE TEST DURATION THE THIRD version of Dirac Live was available. It added four additional measurement points to the previous version - to the left and right of the listening position. The measurement itself is simple, although it does take some time. We place a microphone in the spots indicated by the directions displayed on the screen, and in each place the amplifier generates sound, going from the low bass to the high top - three times, after which these three measurements are averaged. The system applies a flat, but descending towards high frequencies characteristic.


In the picture above you can see the measurement of the right channel in the room where I listen to music, and below its corrected version. I encourage you to compare it with the measurement made in the same room by the company AREA OF ELECTROACOUSTIC PROJECTS managed by MARIUSZ ZIELMACHOWICZ (more HERE), as well as with the results of measurements made through the Dirac Live system in the Arcam SA30 amplifier (more HERE |PL|).


And the listening session? Dirac Live changes the sound to a great extent. It zooms in to the foreground and also does something that gives us the impression that there are more sounds in front of us. Reverbs are heard better with it, the bodies of the instruments are larger. The bass is more springy, although it does not seem as fleshy as without it. The most important thing, however, is that the midrange information is presented with it much more clearly - looking at the measurement and the correction introduced by Dirac, it can be confirmed. The treble is much weaker, although I did not have the impression of extinguishing it, but rather of withdrawing it into the background.

Therefore, I introduced my own correction to the curve, lowering the mid-tones a bit, just like it looks normal for me on a daily basis. Then I received a smooth sound - and the Dirac does it brilliantly - but without emphasizing the elements whose main energy is concentrated in the midrange. The music listened to in this way made a great impression, above all with its scale and tangibility.

However, DSP correction is not a universal solution. Having a high-class source with an analog output, be it an expensive CD or a turntable, I would choose listening without the Dirac, with the "Direct" path turned on. The presentation will then be much more relaxed and stress-free. On the other hand, while listening to the sources through the amplifier's digital input, and above all by "casting" the Tidal, I listened, practically without exceptions, with the equalization corrected by me turned on. And it is with this type of source and in acoustically difficult rooms that Dirac Live 3 will turn out to be a killer. In acoustically well-prepared rooms, with a good analog source - not necessarily. But that's what's cool about the SA750 - we have a choice. ♦

▌ SUMMARY

WHAT BRINGS ME TO the following conclusion: I found the SA750 to be a very cool, enjoyable, emotionally engaging amplifier. All the extra features are cool, useful, and Dirac Live 3 will help you master difficult acoustic conditions. Nevertheless, the core of this device to which all these features were added, is an ordinary, classic analog amplifier, which is simply very good.

I also really liked the sound of the files from Tidal, especially the high definition ones. They sounded warm, dense and strong, but neither too close to me nor too closed in. Yes, it is a warm presentation with a center of gravity set quite low, but that's its charm. Along with the way the amplifier sounds they create an engaging, attractive presentation. If we use external digital transport, be it CD or BD or another type, the sound will be more disciplined and open. So you can decide what you like best and choose your preferred source to achieve the sound you want.

The Dirac Live 3 is just an additional feature to me, because nothing about my room’s acoustics bothers me, I like it. In the vast majority of cases, the acoustics of the room are terrible and there it will be a very useful tool, it will be the most important feature of the tested device. As you can see, the SA750 is a versatile proposition for both classic audiophiles and those who spend their lives online.

And the question whether to choose the Arcam SA30 or the JBL SA750 that’s the one you have to answer for yourself. These are almost identical amplifiers, although the JBL seemed to me to sound a bit deeper and warmer. But without a direct comparison, these are just my impressions. So the main factor I think will be the design - a unique one in the case of the SA750.

▌ DESIGN

THE APPEARANCE OF THE SA750 AMPLIFIER is unique and it is the main distinctive element of this design.

⸜ FRONT AND REAR The front is made of an aluminum and it is sort of brushed in two different directions, thanks to which it is optically divided into two parts. On the left you will find the power switch, headphone jack and mini-jack line input, as well as the unique, illuminated JBL logo, which informs you here that the device is turned on.

On the right side there is a dot-matrix LED display, and below it there are four switches that allow user to mute input signal, activate the short direct signal path, choose between the MM and MC phono cartridges, and turn on the Dirac room acoustics correction system. And there are also knobs - on the right, which is atypical, there is an input selector, and on the left, above it, there are ones responsible for adjusting volume and balance. The knobs have a 1970s look. Very similar ones are used by the Leben, and in our country, in the past, by Radmor.

The rear of the device is identical to what we know from the Arcam SA30 amplifier. We have a row of stereo inputs - three line and two phono ones, and a preamplifier output. Above them there are digital inputs - two RCA and two optical ones. On the left side there are two pairs of gold-plated speaker terminals. The latter are of decent quality, while the RCA sockets are of an average one - soldered to the PCB, not gold plated (only the ground connector is gold plated) and made of rolled sheet metal.

Let's add that on the back there are also an Ethernet and USB ports, as well as an RS232 port, which allows user to connect the amp to home automation control systems.

⸜ INSIDE The chassis of the amplifier is made of bent, stiff sheet metal, and it stands on four rubber feet. A look inside and what you might suspect is confirmed: SA750 is almost identical to the SA30 amplifier from Arcam (review HERE).

A different front and top with side panels were bolted to the "chassis" known from the SA30, the WiFi antenna placement was also resolved differently. Here we do not have to screw it on, because it is attached from the inside to the wooden side panels. An in-depth comparison reveals slightly different types of selected components (other manufacturers), but the electronics and mechanics are exactly the same as that of the British amplifier.

| A | The circuits are assembled on two printed circuit boards, largely in the SMD technique. The amplifier section with the power supply is placed on the bottom, and the DAC and files player with the Dirac Live 3 circuit - on the top. After selecting the input, in an integrated circuit, the signal goes to the attenuator. It is a Burr-Brown PGA2311U resistor ladder. Then the signal is amplified in a preamplifier, composed of consecutive integrated circuits, and goes to the power amplifier - this time a discrete circuit (i.e. made of transistors).

The control part consists of bipolar transistors, which are screwed together "back-to-back" and together to small heat sinks, thanks to which the transistors from both signal halves - this is a class G push-pull amplifier - have the same temperature. Which makes a difference! The output transistors, together with the power supply circuits are bolted to a medium-sized, solid heat sink.

There are two complementary pairs of ON Semiconductors in each channel, one per channel, NJL3281D (NPN) and NJL1302D (PNP). They have not three, but five legs, and that's because the chassis also houses a system called Thermal Track. Thanks to it, their gain is not so much dependent on the temperature.

The power supply is based on a large, current-efficient Noratel transformer. The manufacturer states that the amplifier can consume as much as 800 W at the peak! And this is no joke ... It works with four mains ripple suppression capacitors - this is for the power amplifier - and many local voltage stabilizing circuits.

|C| The digital section is mounted on a large PCB, bolted over the amplifier PCB. From the digital inputs, behind which there are coupling transformers, which guard the input impedance, we go to the Burr-Brown PCM9211 digital receiver. The source selector is located in the same circuit. On the other hand, if the signal comes from the analog inputs and we want to send it to the Dirac Live 3 system, we have to convert it to digital. The manufacturer could use the section in PCM9211, but he used a separate, old (from 2003!), but still very good, Burr-Brown PCM4202 chip (24 bits, 216 kHz, with adjustable oversampling 64 or 128 x).

If, on the other hand, we want to use the D/A converter without involvements of the Dirac chip, the digital signal is converted to analog in a tiny, surface-mounted ESS Sabre ES9038K2M chip. In the output of the circuit two National Semiconductors L49723 integrated circuits and a single OP1652 (with FET input) were used.

A wireless communication module and a files player have been plugged into the main digital board. I assume that this is where the Dirac Live 3 settings are saved.

⸜ SUMMARY The SA750 is a solidly built, very good analog amplifier, with a nice digital section. It is almost (sorry for this inconsistency) identical to the Arcam SA30 amplifier, differing only in appearance and small details. ■

Technical specifications (acc. to the manufacturer)

Frequency range: 20 Hz-20 kHz (± 1 dB)
Nominal sensitivity: 1 V
Input impedance: 10 kΩ
Nominal output: 120 W/8 Ω | 220 W/4 Ω (both channels driven)
Maximum input: 6 Vrms
THD + N: 0.002%
S/N: 120 dB (A-weighted, 50 W, ref. 1 V)
Maximum power consumption: 800 W
Dimensions: 449 x 114 x 327 mm (W x H x D)
Weight: 12 kg