List Price: $18,000

Review by

James Darby


My Beyond Frontiers Audio trek began in Denver at the Rocky Mountain Audio Fest. I was sitting outside, enjoying the clean mountain air and resting my feet when a tall, lanky gentle walked past, did a double take and said in a thick Eastern European accent, “James Darby! You are James Darby – Stereomojo!” I replied that I was upon which he said he had been looking for me the entire show. He then told me that I MUST come to his room because he has an amplifier that I must hear. He was talking so fast and with so much exuberance that I really couldn’t follow everything he was saying, except “You must come!” He told me the room number and I told him I would visit. He thanked me profusely and went on his way. I noted that the room was on the same floor as the room in which I was staying, so I made a note to visit it on my way back to the room at the end of the day.

Later, I was meeting in the lobby with the 4 other Stereomojo staffers attending the show, comparing notes. All of a sudden the same tall, lanky guy that sounded as if he was ex-KGB accosted us. “You MUST come,” he repeated.

What the heck, I thought, why don’t we all go? So all of us followed the guy whose name I came to know as Bosko. When we entered the room, there was only one pair of large speakers, an integrated amp and a disk player in sharp contrast the equipment packed rooms we’re used to seeing. We were introduced to another Eastern European gentleman whose name I couldn’t pronounce at first - Zdenko Zivkovic. We learned that Zdenko was the designer of the original Sonic Frontiers preamp that, back in the 90s was a state of the art component, one that still brings good money on the used market. "The goal is to build the best preamplifier available making absolutely no compromises", was their statement. Zivkovic also designed other famous brands such as Magnum Dynalab.


We handed our Stereomojo Ultimate Evaluation Disk to Bosko, the disk we’ve heard many hundreds of times on as many systems. The moment the music started, we all exchanged glances signifying that we were all hearing something way out of the ordinary. As the next few tracks flew by, we couldn't contain ourselves anymore and began talking about what we were hearing – something the likes of which none of us had heard thus far, and the show was almost over. The mood in the room was joyous and almost euphoric. We moved, we danced, we sang. My friend Clement Perry of StereoTimes came in. He tried to remain a bit aloof with a poker face, but a minute after he sat down next to me, “One Foot in the Blues” by Johnny Adams started playing from our disk. I asked Clement if he had heard of Johnny Adams. He looked at me as if I were nuts and commenced singing along with Adams in a very nice sounding bluesy voice. We all laughed, but continued acting like American Idol contestants for much of the tune. We just were told that VIDEO of that moment was shot by someone from BFA. You can view it here!

In our Show Report, we named the Beyond Frontiers Audio (BFA) as “BEST SOUND AT SHOW”, commenting “This was easily the biggest (pleasant) surprise at the show. This Serbian company has created one of the most exciting systems we've ever heard. We don't know if it was the speakers or the integrated amp/DAC that most contributed, but the musicality we've noted throughout these awards was here in spades, hearts, diamonds AND clubs. The music just permeated our hearts, souls, brains and bodies. Big grins were plastered on everyone's faces. With each cut of the Stereomojo Ultimate Stereo Evaluation Disc, we found ourselves saying, "Now THAT'S the way this is SUPPOSED to sound!" Highs, mids and deep bass inspired us to not only do a little bootie shaking, but we even ended up breaking into a sing-a-long session. Classical music burst forth in such a way that we wanted to do some air conducting. Talk about immersive. We stayed way too long in this room and hated to leave.”

Not long after, I was sent the new BFA Tulip integrated amp for its world’s first review. The old Sonic Frontiers philosophy still stands, to build the best amplifier available making absolutely no compromises. The name Beyond Frontiers is a direct reference to the old Sonic Frontiers, this time going beyond the former Sonic Frontiers. The Tulip is indeed an all out assault on the state of the art. Here are some of the amp’s features:

- VFD display by Noritake – Japan,
- Inputs include 4 LINE level, 2 digital COAX (S/PDIF) and 1 USB port,
- Click-less (in sound path) (Takamishawa-Japan) Shunt Relay Volume Control - Patent Pending,
- Built-in 24bit/192kHz resampling Cirrus Logic & Burr-Brown DAC (all audio data always plays on 24bit/192kHz),

- Mundorf M-CAP® Supreme Silver / Gold / Oil (2x) and MLytic® HC (4x) 47000uF/80Vdc Mundorf electrolytes,
- Tubes are JJ Tesla 1x ECC83S and 1x E88CC Gold pins, cryogenically treated,
- Amplifier is 100% tube gain without any type of feedback,
- Dual-mono amp, current output driver with Sanken bipolar transistors,
- Pure silver Mundorf and Kimber wire PTFE insulation,
- WBT Speaker Output posts and Cardas Rhodium input RCA’s, Neutrik USB port,
- Toroidal 1600W dual primary power transformer,
- 2 x 200W/8 Ohm, 2 x 400W/4 Ohm, capable to drive speakers down to 2 Ohm,
- Swedish air-craft quality aluminum chassis panels and unique constant temperature heat-sinks,
- Full aluminum remote control, in house patented remote protocol.

Designer and company owner Zdenko Zivkovic told me that this amp is “the sum total of all I have learned in all my years, the culmination of everything I know”.

The Tulip is a hybrid design, meaning the preamp section is tube based while the amplifier section is solid state, for many the best possible combination with the preamp providing the qualities that only tubes can impart while the solid state provides much more power at a much lower cost than a full tubular power amp could.
At 17” x 8” x 14” and a hefty 112 lbs, the Tulip is certainly not built like a flower.

The front of the amp features a vacuum florescent display that puts on a bit of a show when power is turned on. The first thing you see is the BFA logo and motto “Together to Sound”. Next, as the amp warms up and does a complete internal check, you see display that tells you the number of hours on your tubes. If there’s another amp that provides that info, we don’t know about it. In operation mode the Selected Input is displayed on the left side, “LINE 1” or whichever input you used last – it remembers. The upper right side displays the relative dB level of the output signal, “-46dB” while the lower right side displays the volume position in a range from 00 to 96 steps.

The status LED will flash Blue for 10 sec. upon the AC cord connection. Once the LED stops flashing it changes color to Green. You press the “STAND BY” button to turn ON the Amp. The Green LED light changes to Blue again, to indicate that the unit is in a working state. A Red LED will indicate an error, but that never happened.
The VFD is easily visible from across the room and does not emit too much light like many LEDs do. The whole display can also be turned off via the remote. YES! Thank you Zdenko!

Beneath the display are 6 small buttons. The first pair on the left, vertically aligned is for changing sources. The next, standby and mute. On the right the two buttons are volume up/down. Simple, elegant and effective. All of those functions and more are also available via the metal remote. In fact, one the amp is set up, I never had to touch it again, other than to make gear changes.

The tri-colored LED on the Front Panel indicates the operating mode. When the LED is Green, the unit is in Off/Standby. When the LED is Blue, the unit is in On/Operate mode. When the LED is Red, the unit is in MUTE mode.

Around back we find RCA inputs for lines 1 -4, coax inputs 1 & 2 if you want to run your CD, DVD or transport through the Tulip’s DAC and a USB jack. On the bottom are true WBT (not fakes) 5-way posts for left and right speakers. On the bottom right it says, “Designed in Canada, Made In Serbia”.

That’s right folks; this state-of-the-art product is made in Serbia. Without question, the build quality, design and appearance is worthy of a S-O-T-A product. What’s missing though are any balanced/XLRs inputs or outputs, a little disappointing in a product of this price.

The remote has a button labeled “CF” for coefficient of attenuation. What that means is that you can adjust each input’s level to match so that when you change inputs the volume level stays the same; no loud, startling volume jumps or too soft listening. Perfect for comparing sources or recordings on different devices. One device you can’t compare via the Tulip alone is a turntable. No phono section. You can, of course, use a phono preamp.





Before we jump into the heart of the review, I have to mention something I usually don't talk about unless it is unusual, especially if it's unusally bad.  Shipping packages.

We've seen a lot of damage to incoming review samples,especially carboard boxes, even triple boxed and well designed. UPS and FEDEX are brutal. The Tulip does not come tripled boxed in carboard; it arrived in a custom fitted, steel edged heavey wooden crate held together by 8 inch screws. Extraordinary time and expense to build that puppy.




I’m not sure of this company motto; "TOGETHER TO SOUND". Sounds like a translation of something wonderful in the Serbian language. If it means that the Tulip is dead quiet at full output with no music playing, then it’s accurate.

Since Zdenko had told me that amp was the culmination of everything he has learned in 11 years, I had to ask him what some of that knowledge was that he incorporated in the Tulip. Here’s what he had to say, remembering that English is not his first language:

“Tulip have only two tubes, first is ECC83 which amplify audio signal after total passive volume control. Audio signal after passive volume control is amplified with that tube up to 115V pick - pick. Then another tube (ECC88; 6922) will reference that signal to virtual ground. Then that signal will be amplified (no gain, just current - power) with solid-state current amplifiers with 10 Sanken transistors per channel.


Volume control is done with self-latching relays and acting as a fully passive volume control. All that means that audio signal is amplified only with one tube, NOT any type of feedback. Having no feedback mean also fully preserved DYNAMIC and content of the music.

Compared to, let’s say POWER 2 from Sonic Frontiers, one of the best tube amplifiers ever made. Difference is:

Number of "small" tubes 8 compared to 2 tubes in Tulip,
No 8 output tubes, no two huge output transformers.
Power 2 can deliver 110W on 4 or 8R.
Tulip have 190W on 8R, 360W on 4 R and not any output tubes to be replaced after few years.

Power 2 have positive and negative feedback and damping factor of 50 what is the best ever achieved with standard tube design,

Tulip have none of the feedback circuit and infinite damping factor. Power 2 need 8 "small" tubes to amplified audio signal in 3 stages, that also mean 8 or 4 times more distortion compared to only one tube as gain stage in Tulip and second as output tube which is DC connected to current amplifier.

Audio signal path is 3 to 4 time simpler than in any other tube design. But heart of all is black box on tube gain board which allowing all this happened on the best way possible for audio signal”.


He went on to say, “As we all know, all existing transformers due to hysteresis of the core has a loss of up to 5% between the primary and secondary windings.

What is lost?

Primarily it’s the odd and even order harmonics from the second up to the eighth. Because they are such low level they cannot magnetize the core of the transformer and can not go through the transformer. Then harmonics will be replaced with distortion of tube circuit, especially OP tubes.

Depend of tubes used in OP stage, Amplifier will have dominant even or odd order distortion which almost doesn't have any relation with sound.
To decrease distortion and loses in OP stage and transformer negative feedback must be used to "repair" audio signal. That will make amplifier more listenable, but with much less dynamic and with strong influence of newly generated distortion That's how all tube amplifiers with OP transformer work, and therefore the reason why I have no output tubes or transformers in audio line”.

But what about the solid-state power amp section? Anything interesting there, I asked.

“About solid state amplifiers. Solid state amplifiers by default generates unpleasant odd order distortion. Then the amplified audio signal which comes from the amplifier becomes also dominant in really unpleasant odd order distortion. That new distortion will be superimposed to original audio signal,
cover some of mid and high frequencies and make sound like its listen through metal curtain.

Almost any solid state design must use negative feedback to repair damage by solid state circuit itself and to control gain of overall circuit. But negative feedback will also kill the dynamics. My solution: My design has 100% gain amplified with tubes without damaging signal or generating even order distortion (no need for feedback), then its DC connected to current amplifier capable of driving almost any load. (1R) Current amplifiers will give power to audio signal amplified with only one tube gain stage, having no phase shift and without "seeing" load. As less as possible gain stages, grounding for unit done right, top of the line parts, DC connected tube gain stage and current amplifiers and 11 years of dreaming and hard work result with Tulip integrated amplifier”.



I used four different pairs of speakers with the big BFA, my Vaughn Cabernets, best speaker of 2009, the Italian speakers that we heard in Denver with the amp, the Von Schweikert VR-33s, our Best Speaker Value of the Year for 2010, and the Evolution MMMiniTwo’s that are in for another world’s first review.
After 100 hours of burn in, things started with using the standard analog inputs fed by the Eastern Electric DAC, another Stereomojo award winner, and the Qsonix 205 music server with digital out processing by Wadia, also a Product of the Year. Cables were my top-of-the-line Kimber Selects. The BFA let me hear the characteristics of each of the four speakers, adding no particular sound of its own. Its level of transparency is unsurpassed by anything we’ve yet heard. The tubes in the preamps section add no obvious sound of their own, but impart a staggering 3-dimensional image of soloists, orchestras, jazz ensembles and everything else that passed through it. Remarkably, the amp sounds neither tube-like nor solid state, but reproduces the benefits of both with none of the detractions.

The sensitivity of the four speakers varies widely from the easy to drive Cabernet’s to the 86 db, power-soaking Evolutions. The BFA never complained or strained and just went about its job of producing one of the most musical presentations on record (or CD). It’s fast, producing transients without dulling any edges or sounding the least bit blunted. Recorded things that ring, pluck, whack or thump did so impeccably. It also held onto those same qualities like a pit bull, allowing each instrument to trail off into the deathly black background without cutting them off prematurely. We all know how unpleasant premature termination is, right?

Speaking of backgrounds, the soundstage is big, deep, wide and tall, but not exaggerated. And it adapts to the soundstage of the recording, never insisting on its own interpretation. I’ve mentioned that one quality to which I am particularly sensitive is ambience and/or reverb. That comes from in studios where adding just the right amount, depth and timing of reverb is as much of an art as the music. Reverb is also very difficult to reproduce since it is very dense bit-wise and requires a lot of transparency and lack of distortion to render fully. Here are some visual examples of what ambience/reverb can sound like:

The Tulip’s tulip is fully rendered like the top picture above with beautiful echoes, waves, early and late reflections full density in the long, sustained trails. Outstanding!



The second phase of this review sees the bypassing of the EE DAC and going straight from the Qsonix to the BFA via USB. Now we all know by now that USB is limited in bandwidth and resolution to 24/96, right? To hear full hi-res such as 24/192 one must have a source that will play them and a DAC that will process such high bitrates natively (many say they have 24/192 chips but downsample to 24/96). Well, the Qsonix does output whatever resolution that’s playing via its USB (or the 2 SP/DIFs) and the Tulip does play back those files in full resolution via USB – they have crashed through the barrier of the 24/96 USB limitation! In addition, the Tulip upsamples everything else lower than 24/192 to full 24/192 as well, even regular CD quality. More on that part in a moment.

Playing albums from Reference Recording’s catalogue of HRx files at 24/172 was simply sublime. Again, the tulip showed no signs of strain or loss of transparency; in fact, just the opposite. Solo piano on Joel Fan’sWest of the Sun (HR-119 HRx ) was stunning in its realistic portrayal of a concert grand with all of its rarely heard overtones going well beyond 20KHz and all the little nuances of the combination of wood, steel and felt that a real piano produces. This is certainly one of the best recordings, especially in hi-res, of a solo piano in existence and the BFA handled it flawlessly.

The recent Grammy Award winning Britten's Orchestra with Michael Stern and the Kansas City Symphony (HR-120 HRx) showcased the BFA’s amazing dynamic range from the quietest passages to the most bombastic the recording had to offer. Detail was abundant throughout with no trace of edginess or harshness or the “hyper detail” we hear often in some pricier components – or cheaper ones for that matter that just boost the high end to give the impression of real detail. My notes are proliferated with words like “natural, musical, rhythm, speed, realistic”.





We’ve examined the BFA’s performance without its internal DAC and its USB DAC with high-resolution material. But the amp also upsamples everything to 24/192 whether you like it or not. There is no bypass or adjustment available. Now if you’ve read many of my reviews, you know that I don’t especially like the sound of music that has be upsampled at all, much less as extremely as 24/192. That’s one thing I like about the EE DAC, it just takes whatever resolution it sees and plays it with no manipulation of the sample rate – it’s what called NOS or non-oversampling. Me like. Changing the native sample rate involves many algorithms, filters and other mathematical alterations of the original. Me no like. As we saw with the PS Audio Perfect Wave system, you have to choose the right filter from a list of many and play with the sample rate to achieve successful upsampled sound. I still preferred the native sample rates on most recordings.

So, the BFA started in the hole as far as my preferences go. The first tunes were ones with which I am very familiar, the tracks on the Stereomojo Ultimate Disk. After all, it was those that we all listened to in Denver and loved. Right there a core preference of non-upsampling DACs became suspect, right? After all, the Best Sound At Show was the product of upsampling to 24/192. Hmmm….

Most of the cuts on our disk are outstanding quality – that’s why they’re there. Rather than running through each one, let me surmise by saying the BFA’s DAC sounding surprisingly good after all its machinations and number crunching. Yes, for most there was a noticeable improvement; extended range enhanced high end, more solid midrange and bass as well. The dryness and lack of ambient detail that I’d heard with previous upsamplers was not as apparent and most times non-existent. It short, more musical and realistic.

The problems occurred as I explored lesser more standard recordings with average recording quality or some even below that – though I don’t have many of those. I do keep one CD that is among the worst sound quality I’ve ever heard: the band Chase self-titled debut. Imagine four Maynard Fergusons playing hot horn charts in back of an average male vocal with rock drums and bass. A couple of the cuts are pretty fun, but the sound quality if that of a bad 128 bitrate mp3. Could the BFA transform this miserable recording into something at least listenable? No. Not even close. It was worse.

Track after track, from super quality to everything less over every genre from rock to opera, one thing became clear; the better the recording, the better the BFA’s oversampling works. The vast majority of the 1,600 or so CDs I have on the Qsonix are superior quality, but some aren’t. There’s some party music from the 50’s and 60’s, some 70’s, 80’s and 90’s rock like Foreigner and Boston. I should mention that not all rock from those periods are bad recordings; listen to Alan Parsons, Queen and many more I could mention. Amazing.


Listen to the intro of The Hollies’ Long Cool Woman (in a black dress) from 1971 and tell me what you think.

I listened to hundreds of tracks. Even some high quality mp3’s. Those that were the best rose to the surface with the upsampling while others sunk like the Titanic.

I know. You want to know how the BFA’s DAC compared to the Eastern Electric. Here you go. The EE was better with standard material, equal with high quality CD’s (though it varied from CD to CD, but I’m calling it a tie) and not quite as good with high-resolution files. That is actually a compliment to the BFA because the EE is an amazing DAC, especially since I’ve rolled a rare and expensive SIEMENS SILVER PLATE 12AU7 NOS circa 1959 into it. Wicked good!

My ultimate judgment of a high-end component is its ability to reproduce musical content without having to strain to listen to it. The more you have to lean forward, squint your eyes or mentally focus on any aspect of the music to hear it clearly, the further away from the ultimate you get. In fact, the ultimate musical experience is not listening to the system at all, but having the system immerse you in the music in all its detail and emotion with no effort on your part at all. Does that make sense?
With that standard, the BFA Tulip is most decidedly an ultra high-end amplifier, integrated or not.




The Beyond Frontiers Tulip Hybrid Integrated Amplifier’s designer Zdenko Zivkovic set a very high bar for himself and the amp – the best in the world with no compromises in build or sound quality. No expense was spared – even sending parts to Canada and back to Serbia for cryogenic treatment. The best materials and parts with the most efficient circuitry with noise and vibration suppression.

Is the Tulip the best on the planet? Unlike other reviewers, I’ll be honest and say that I have not heard every integrated amp on the planet (neither have they), but I can say I have not heard anything at any price that is better. The BFA’s ability to portray music in a lifelike, highly musical and neutral manner is unsurpassed. Its degree of transparency, clearness, dynamics and lack of distortion is about as good as it gets. Most importantly perhaps, it conveys the emotion of the music in a way seldom heard at any price. It rocks, it simmers, it can bring tears to your eyes – or more accurately, it can allow the music to bring tears to your eyes. And you never have to strain to hear the most minute instrumental line or vocal background. Music is full of nuance and so is the BFA.

The BFA is unique in that it does high-res music up to 24/192 over USB.

The only downsides are (one) that it lacks balanced circuits. The DarTZeel for comparison has one pair of balanced inputs, but costs considerably more. A phono stage is a DarTZeel option where the BFA has none. The BFA is the only Hybrid integrated amp to include a 24/192 DAC, they tell us.

The second downside is that the DAC upsamples everything to 24/192 with mixed results. If your collection is mostly high quality recordings like classical, jazz or any genre with high quality sonics, the BFA is the perfect choice. But there are many who pay much less attention to the recording quality than the musical content. It used to be that the two were seldom found in one recording, but that is changing rapidly.

The BFA Tulip is a reference qualityamplifier, integrated or not. It has luxuary touches, like telling you how many hours are on the tubes, a full-function matching metal remote, the ability to match all inputs levels and more. But it doesn't waste money on excessive casework just for appearance sake; it appears that every dime was efficiently spent building a machine that has one purpose - to be the best on the planet.


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