Ars Sonum Gran Filarmonia

Tube Integrated Amplifier

List Price: $10,950 (with Cardas Clear Beyond Power Cord)


Malcolm Gomes


When Spaniard Ricardo Hernandez of Ars Sonum took the bull by the horns and contacted Bobby Palkovich of Merlin Music all those years ago, little did he realize that it would be the start of a collaboration that would bring to North America the Filarmonia, a real jewel of a tube integrated amplifier that would gain such a loyal following, customers would be willing pay up and wait many months to get their hands on it.

At its relatively modest price of $4,000 (which then rose steadily due to inflation), the Filarmonia offered a level of craftsmanship and performance that made it one of the truly great bargains in the world of high-end audio. There was general agreement that the Filarmonia was a soul mate of Bobby’s own speakers. The two had so much of synergy many audiophiles regarded them as a match made in audio heaven.

For all its virtues, the Filarmonia had one limitation, it offered just 30 watts per channel and although this was more than enough for most applications involving smaller listening rooms and relatively efficient, easy to drive speakers, it was known to run out of juice when hooked up to power hungry, inefficient speakers or when it was required to deliver high sound pressure levels in larger rooms.

There were many who opined that Ars Sonum would do well to introduce a more powerful tube integrated amplifier with the same impeccable craftsmanship, build quality and sonic characteristics of the Filarmonia but with a lot more power. Ricardo answered those requests in a very emphatic manner with the introduction of the Gran Filarmonia, which is the subject of this review.

Ars Sonum fans who would have been quite satisfied if the Gran offered the same sound quality as its predecessor but with more power, will be glad to know that Ricardo went one better. While maintaining the basic sonic signature of the Filarmonia, the bigger, more powerful sibling reaches new heights in many aspects that make it very deserving of the ‘Gran’ moniker.  In designing the Gran, it is obvious that Ricardo has learned from and applied many of the lessons he learned when designing and building the Filarmonia. 


Like its sibling, the Gran is individually hand crafted by Ricardo one at a time and employs very high quality parts and materials. Also like its sibling, the Gran uses hand matched JJ E34L output tubes but doubles the number to 8 tubes. The front-end tubes are meticulously selected and the Gran has four compared to the Filarmonia’s three. Another carryover is the number of line level inputs but with two outputs instead of one – monitor and tape. The Gran has an upgraded ELMA precision rotary switch input selector and DACT 24-step volume control. The coupling capacitors have been upgraded to the copper/Teflon V-CAP CuTf series. In my experience, copper rather than aluminum foil capacitors make a very audible difference. To my ears they make music sound a lot more real.   

The excellent Cardas speaker terminals on the Gran are the same as what adorn the Filarmonia. The power cord on the Gran has been upgraded to the Cardas Clear Beyond as opposed to the Cardas Clear of the Filarmonia. This cable retails for near $1,000 on its own, so it is a significant contribution. We recently published the first review of the Cardas Clear Beyond speaker cables if you are curious.


The Gran uses a special screen grid regulated pentode circuit and a low 6dB of feedback and a DC coupled inter-stage configuration. This design reduces the number of capacitors in the signal path. The big, chunky output and power transformers are designed by Ricardo and made exclusively for Ars Sonum.

Technically speaking, the Gran has an input sensitivity of 300mV a frequency response of 5 Hz to 80 kHz at minus 3 dB. The signal to noise ratio is better than 90 dB and the power output is 60 watts RMS per channel at 8 ohms. The Gran delivers 40 of those watts in pure Class A with less than 0.5% distortion.

The build quality of the Gran is truly impeccable. The high level of craftsmanship is very obvious. You can’t help by marvel at the attention to detail that Ricardo has lavished on this amp. This kind of fit and finish is only possible when the component is made one at a time at the hands of an artisan at the top of this game.

Relative to its size, the Gran comes in a surprisingly large and quite unwieldy (for one person to carry) carton with oodles of packing material around it which secures the amplifier so snugly, it should survive even unusually rough handling during shipment as it makes its way from its cradle in Spain to any destination worldwide.  



The set-up of the Gran was simple and straightforward with the tubes very clearly labeled to be totally idiot proof when placing the right tube into the right socket on the amplifier. The bias on the Gran is set automatically and cannot be fine tuned by the user. The review sample I received was totally burnt in but since it was fitted with a completely new set of tubes, I further burnt it in for another 100 hours before reviewing the Gran.

I used various sources for the review including a Sooloos 5 system, a Bryston BCD-1, a Bryston BDP-1, and an iMac running the latest Amarra software. I also employed music files of various resolutions all the way up to 24/192.


The music I used for the audition included Susannah McCorkle – Let’s face the music, Nikolai Rimsky-Korsakov – Scheherazade, The Definitive Simon & Garfunkle, Boz Scaggs - Dig, Cantate Domino (Oscar’s Motet Choir), Eva Cassidy – Somewhere and Jazz at the Pawnshop.

Like its predecessor, the Gran runs hot enough to warm a small listening room on a cool winter evening. I am hardly surprised that Ricardo decided not to have the tubes enclosed in a cabinet. Proper ventilation and placement is a must to avoid any problems caused by overheating.

The very first thing about the Gran that impressed me was the fact that it has very deftly managed to side step the negatives that plague many tube amplifiers while retaining most of the positives that we have come to expect from glowing tubes. It has none of the signature euphonic sound or flabby bass that plague many mid and budget priced tube amplifiers. On the contrary, it has the kind of bandwidth, bass depth & control and dynamics that I have heard on some very pricey tube separates. The Gran delivers midrange magic to die for. The incredible texture, layering and resolution that this amp is capable of needs to be heard to be believed! In fact the Gran is the first tube integrated amp I have auditioned at this price point, that combines so many of the advantages of both, the best solid state and the best of tube amps, with so few of the disadvantages.  

The sound reproduction was so pure, relaxed and smooth; it was very easy to give in to the temptation of increasing the volume ever higher because even at high SPLs there was surprisingly little compression and smearing. While listening to the Gran with a few audiophile friends, we did not realize how loud the sound was till one of my friends sitting besides me tried to tell me something and he had to literally shout really loudly for me to hear him. That’s when it dawned on all of us how incredibly loud the sound really was and how we were unaware of it because the sound was still so pure, relaxed and effortless even at very high SPLs. This also reminded me of the fact that when we feel that the sound is too loud, often times it is the high distortion levels in the sound that makes us reach that conclusion rather than the loudness.

One of my favorite albums of all time is Rimsky-Korsakov – Scheherazade, which has few equals when it comes to music with richness and grandeur combined with the subtlest nuances. While listening to ‘The Young Prince and Princess’, what got my attention was the rendition of the harp. Through the Gran I could hear each string separately as it was plucked even when the notes followed each other very closely. Also, the fragile nature of the sound of a harp came through with an incredibly delicate touch. I have heard some obscenely priced tube and solid state amplifiers that did not accomplish this as well as the Gran.  

The Gran is particularly deft at reproducing vocals, especially female vocals. When listening to Susannah McCorkle’s ‘Let’s hear the music and dance’, I found this femme fatale’s voice rendered not just with scary realism but also with an incredibly sexy and seductive touch. The Gran reproduces voices so accurately; it allows you to detect how the singer uses breathing techniques to optimize their vocal talents.

I could just not get over how realistically the Gran allowed my brain to recreate the incredibly sultry image as Don McLean paints a romantic picture on a sonic canvas as he gently croons ‘If I only had a match’. I could very easily envision the mood of the scene complete with late night street lighting, mist hanging in the air and cigarette smoke wafting into nothingness.

Another aspect of the Gran that is easy to discern is the clarity with which the lyrics are deciphered. This is very evident. There have been many instances in thr past when listening to vocal tracks, especially harmonies, where I had to Google the lyrics to find out what the words were. When I listened to the same tracks via the Gran, the lyrics came through clear as day, easily decipherable and therefore making the listening experience so much more fatigue free and enjoyable. One such instance is when listening to Scarborough Fair by Simon and Garfunkel. Not only were the words of both Simon and Garfunkel easy to decipher even when their voices harmonized together, but the delicate arrangements of the multitude of instruments on this track also came through with greater finesse and panache than some amplifiers I’ve heard costing twice as much.

With a library of over 72,000 tracks, I was able to throw all kinds of music at the Gran and in every case I was rewarded with a relaxed, effortless presentation, even with complicated musical passages.

Dynamic contrasts can be a challenge for amps with limited power output. A good case in point is ‘Killer’ by Seal. This is a very dynamic track that is particularly good at making even some killer systems lose their composure. Not so with the Gran. The whole track was reproduced with aplomb and poise not unlike an actress' perfectly coiffed head of hair with nary a strand out of place, like Evangeline Lilly over there.  

The sound stage created by the Gran was as wide, tall and deep as they come and so well defined, I could detect musicians’ movements be they side to side or from one point on the stage to another. The Gran also has all the PRaT that you will ever need and the dynamic contrast is truly sublime. There is also a very uncommon continuity from top to bottom across the whole audible frequency spectrum. Ok, you stop looking at Evangeline now.

Major factors that allow us to detect if the sound is live or recorded include the dynamic range, the way the leading edges are rendered, the air around the instruments and the reproduction of harmonics. Few systems today come even close to live music in these four areas. While the Gran may not be exactly SOTA, it comes closest to getting these four factors right amongst all similarly priced tube integrated and separates I have heard.

I also give full marks to the Gran when it comes to connecting you emotionally to the music. I have heard many fine amps that do everything right but still come out sounding very mechanical. No so with the Gran. Try listening to emotional ballads like Stimela on it and don’t be surprise if Hugh Masekela succeeds in making tears well up in your eyes.  

At close to $11,000, the Gran is around twice the price of its smaller sibling and this is not exactly pocket change. This raises the question; is it worth the money? Suffice to say that the Gran is the first integrated tube amp I’ve heard that destroys many separates, tube and solid state, at the same price point. Heck, it even gives separates that cost a lot more a real run for their money, but to answer the question of whether it is worth the money, you have to listen to it and make that judgment yourself.



If I were to be picky, I can name a few elements that I would like to see different on the Gran. The first is the absence of a remote control. Unlike a CD, when listening to computer-based music, the songs are not volume matched and so with many songs I felt the need to walk up to the Gran to adjust the volume. This interruption adversely affected the mood of the audition. However, I was told that Ricardo was unwilling to accept the tradeoff reduced sound quality for remote control convenience. I am not sure if I buy that argument as I have heard many integrated amps that have managed to offer the convenience of a remote control while still maintaining very impressive performance characteristics.

The other element that I found wanting is that the volume control had only 24 steps. This being the case, in many instances, I was not able to get to the exact volume level that I wanted and so had to compromise.

The review sample of the Gran generated an audible transformer buzz that I could hear from the sweet spot of my listening room. This is totally mechanical and is generated at the amplifier with none of it manifesting at the speakers. However it was not loud enough to be of much consequence once the music began playing even if the volume level is low or when listening to the quiet passages of music with very wide dynamic range. Once the fasteners securing the transformers were tightened, this buzz went away.  

The Gran is also a bit quirky in its break-in modus operandi. According to Ars Sonum, during the first 50 hours, you need to run the amp for 3 hours before turning it off for an hour before running it for another 3 hours etc. Apparently this is required to help cure the paint on the transformer laminations. I was also told that total stable operation is only reached after 500 hours of break-in, which is on the high side, even for a tube amplifier.  

The Gran has a particularly good affinity with the Merlin VSM MXM speakers, with Cardas Clear Beyond speaker cables connecting them. Together, they synergized to a level that is delivered truly sublime sonic performance. I tried the Gran with a few other speakers and cables and experienced a significant drop-off in the level of synergy. If you already own Merlin Speakers and are looking to acquire the Gran to drive them, that decision is a no brainer. On the other hand if you plan to marry the Gran to other speakers, it would behoove you to hear them together before pulling the trigger. It is not that the Gran does not play well with other speakers but rather, it plays better with certain speakers than others so if you plan to hitch them to other speakers, especially if they present difficult loads to drive, I would strongly advise you to try before you buy.

The Gran is covered by a two-year warranty that does not include the tubes, which are rated to work for around 4,000 hours. If you buy and use the Gran in North America, the warranty is covered by Merlin Music. Given the great customer service provided by Bobby Palkovich of Merlin Music, it is reassuring to know that Gran customers would enjoy the same standard of courteous and friendly service. 

If you are in the market for a tube integrated amplifier or separates and have a budget of around $10,000 to $14,000, and if you have or plan to buy speakers that are an easy load, I would strongly urge you to put the the Ars Sonum Gran Filarmonia on your shortlist. We never stop emphasizing how important it is to carefully match amps to speakers in terms of sensitivity as well as impedance. The Gran Filarmonia has enough grunt and drive to overcome some mistakes, but why buy hard to drive speakers in the first place!? If you have questions, just write Bobby Palkovich at Merlin Music. He's an honest guy. He will tell you if this amp will work with your speakers.

On the other hand, if you own or plan to acquire Merlin Music Speakers, you would be hard pressed to find an integrated tube amplifier in the $11,000 price range that would dance with them the way the Gran can.  I know that anyone with a budget of over $10,000 would seriously consider separates, but don’t be surprised if, after comparing separates in this price range to the Gran, you end up taking the bull by the horns and preferring this beautiful Spanish option. Ole!

Associated equipment:

CD Player - Bryston BCD-1 (SS)

Digital Player – Bryston BDP-1

Turntable - Technics SL-1200Mk2 (direct drive) with Goldring 1042GX cartridge

Music server - Sooloos 5 complete 3-piece system, iMac (latest) with Amarra 2.3 and Decibel media players 

Preamp – Bryston BP26 with MPS2 Power Supply

Power Amp – Ayre V3

Phono Stage - Bryston BP-1.5

Speakers – Merlin Music VSM – Master with Master BAM and RCs

Speaker Cables - Cardas Clear Beyond

Power Cords - LessLoss Signature

Interconnects - Cardas Clear

Headphones – Sennheiser HD 600

Digital - Transparent Reference (digital co-axial), Cardas (USB), Analysis Plus (Toslink)

Stands and Racks

Black Diamond Racing (The Shelf for Sources and LM series) 

Black Diamond Racing cones 

Shelfs are placed on a bed of pure silicone sand and equipment placed on the shelf via the cones

Review Equipment is not provided with any tweaks or enhancers

DAC – Calyx Femto DAC

Power Conditioner -  Isotek Sigma II



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