The Listening Craft

“A hi-fi system is never finished — only refined through experience.”

Tag: ONGAKU

  • Living with Kondo Audio Note ONGAKU: A Journey into Sonic Purity

    Mature sound, timeless design, and the slow reveal of greatness.
    Image © Kondo Audio Note. Used under fair use for commentary and review purposes.

    Background

    In 1989, Hiroyasu Kondo introduced his all-silver single-ended triode (SET) amplifier to the world. Since then, the ONGAKU has arguably become one of the most famous amplifiers ever made and is still in production today.

    In 1992, Kondo-san published an article in Sound Practices magazine, explaining the ideas behind his design. That article even included the schematic for the ONGAKU.

    Over the years, the ONGAKU has undergone some component changes while keeping the original design more or less intact. One of the most notable changes involves the transformers. When the famous Japanese transformer manufacturer Tango went out of business, Kondo began winding their transformers in-house. Most of the other components (capacitors, resistors, etc.) have also been updated with more modern versions.

    Roughly two years ago, I struck a very tempting deal and acquired a fairly recent version of the ONGAKU brand new. As a seasoned audiophile, this was a dream come true.

    First Impressions

    My first impression was a disaster. I clearly remember the moment we hooked up the ONGAKU and started listening to it. The sound was unbalanced, immature, tense — like a brick wall: no depth, no cohesion, no nothing. Literally, my panic attack kicked in. My brain started listing all the possible negative things at a speed I couldn’t even keep up with.

    After a while, I took a deep breath, calmed myself down, and started repeating to myself: the amplifier and all the tubes are new — let them burn in for at least a couple of hours before listening critically. I clicked on a random playlist, shut the door to my listening room, and left.

    After a couple of hours, I came back to the room for a second time. When I opened the door, even before sitting in the sweet spot, the sound had changed so drastically that I had the biggest hi-fi relief of my life. Although this wasn’t the first or last time I’d experienced a brand-new component sounding terrible out of the box, it was definitely the most high-profile one.

    Over the next hours, days, and weeks, the magic of the ONGAKU unfolded right in front of me. If you can manage to shake off the initial panic, it’s a wonderful journey to experience a component’s burn-in and maturation over time.

    The Sound

    First and foremost, the ONGAKU’s sound is far from the stereotypical tube amplifier sound, while still retaining all the strengths of a SET amplifier. And yes, I’m aware this has been said about many modern tube amps — but the ONGAKU is in a different league than most.

    The ONGAKU truly is a high-end amplifier. It excels at every audiophile parameter you can imagine. It presents an incredible soundstage with pinpoint imaging and separation. The soundstage it creates is one of the most believable I’ve ever experienced. The ONGAKU is a very dynamic amplifier — both micro and macro dynamics are splendid. Tonal balance and timbre are also nearly perfect. You can experience the full harmonic textures and richness of a wooden-bodied instrument like a violin, cello, or double bass. If you mostly listen to acoustic instruments, like I do, once you hear this amplifier, you’ll immediately understand what I mean.

    However, what makes the ONGAKU legendary is not these features alone, but the balance between them. The sound is far from the “dealer sound” you often encounter during demos, which can be very impressive and striking for the first 5–10 minutes. The ONGAKU never overemphasizes anything — the sound is not striking or in-your-face. Treble is silky smooth with texture and harmonics, the midrange is very musical and fluid, and the bass is fast and articulated with texture and detail. The more time you spend with this amplifier, the more layers of sound you discover.

    If you are into wines, you know that what makes a wine great and sought after is its balance. A good, mature wine is complex in flavor, rounded, and layered. That’s also how I would describe the sound of the ONGAKU.

    The Tubes

    My copy of the ONGAKU came with 4 × Gold Lion GZ34s, 2 × Electro-Harmonix 6072s, 2 × Philips JAN 5687s, and 2 × PSVANE 211s. With stock tubes, the ONGAKU sounds good. However, to reach its full potential, you need to replace these tubes with better ones. In my experience, those better ones are always NOS, and some can be very expensive. Always factor in the cost of tubes when budgeting for a tube amplifier.

    PSVANE 211s

    The stock 211 tubes that came with the ONGAKU are made by PSVANE specifically for Kondo. These are not off-the-shelf tubes; they are Kondo-branded.

    They’re modern-sounding, good tubes. If you prefer a dynamic and contemporary tube sound, you don’t need to change them.

    I replaced mine with 1942 JAN GE tubes. The GEs are less dynamic than the stock ones — but in a good way. Their midrange fluidity is incredible, the treble is smooth, and the bass is nicely controlled and detailed. GEs are much more forgiving, especially for sub-par recordings.

    Electro-Harmonix 6072s

    These tubes are my main criticism of Kondo electronics. Almost every Kondo component uses 6072s, and the EH versions are mediocre at best. I really struggle to understand why Kondo continues to ship their gear with them.

    In the ONGAKU, they’re used in the input stage in an SRPP configuration and have a huge impact on the sound.

    They sound grainy. The treble is harsh and lacks harmonic richness. The midrange is stiff. The overall character is not musical.

    I strongly recommend replacing them immediately. The best 6072s I’ve heard are the GE triple-mica black plate variants. They’re not as scarce as some NOS types, but still not easy to find. Any GE black plate will do, but in my experience, the triple-mica version has slightly better treble — tonally, they’re very close.

    Philips JAN 5687s

    The 5687s aren’t as critical as the 6072s, but they still influence the sound. These are generally easier to find.

    The tubes that came with the ONGAKU are good-sounding. They are military-spec NOS Sylvania tubes, branded by Philips.

    The best variant I’ve tried is the NOS Tung-Sol — either black or bronze plates. The black plates might be slightly better, but the two are very close. Either one is a solid choice.

    Gold Lion GZ34s

    These are decent tubes, and there are four of them. GZ34s are among the most common rectifiers, which makes their NOS versions both rare and expensive.

    Here’s the big surprise: these tubes have a huge impact on how the ONGAKU sounds. They completely transform the amplifier.

    The best rectifiers for this position are NOS Mullard GZ34s. The metal-base ones are ideal but are almost impossible to find (or afford). Any NOS Mullard is a major upgrade and well worth the investment.

    The Preamplifier

    Technically, the ONGAKU is an integrated amplifier with an input stage, input selector, and volume control. However, if you check Kondo’s website, you’ll see they categorize it under the “power amplifiers” section. Also, most photos of the ONGAKU online show it paired with a preamplifier — usually the Kondo G-70i.

    Kondo G-70i

    The ONGAKU has an input labeled “direct.” You might expect it to bypass the volume control and input stage — but that’s not the case. It only bypasses the input selector.

    To use the direct input, you need to switch the selector to “direct.” That makes the selector a philosophical one — an input switch that bypasses itself.

    A few months after I bought the ONGAKU, I added the G-70i preamplifier to the system. I wouldn’t even call it an upgrade. In my opinion, it’s mandatory. The G-70i elevates the ONGAKU’s sound by at least a couple of notches.

    As I mentioned, the direct input doesn’t bypass the volume control. So, when using a preamp, the natural instinct is to turn the ONGAKU’s volume all the way up and use the preamp for control. That’s what I did at first. But — and I don’t know why — the sound improves when the volume on the ONGAKU is set a few clicks below maximum. Three to five clicks back seems to be the sweet spot. Modern ONGAKUs use a stepped attenuator, so it’s easy to dial in the exact spot every time.

    The G-70i is a fantastic preamplifier and pairs perfectly with the ONGAKU. This combination alone could easily retire you from the hobby. You could spend the rest of your days with them.

    Kondo G-700i

    A couple of months ago, I found myself in another tempting deal — this time to upgrade from the G-70i to the G-700i. The G-700i is the newest preamplifier in Kondo’s lineup, positioned between the flagship G-1000i and the G-70i.

    A direct quote from Kondo’s website:

    “This unit has been developed as a line preamplifier that combines the rich and mature sound of the G-70 with the expressive power of the flagship model G-1000.”

    I don’t know a better way to describe the sound of the G-700i — but I’ll try.

    It’s not always the case, but when I plugged in the G-700i, the improvements were so obvious that I was impressed from the very first moment. I know my system extremely well — even moving a piece of furniture changes what I hear. I was nervous about replacing the G-70i, because I honestly believed I had already reached the limit of what my system could do. I was wrong.

    The tone and timbre remained the same — which is something I’m particularly sensitive to. But the treble region was the first thing that struck me. The harmonic richness and depth improved dramatically.

    The more I listened, the more I understood what “expressive power” really means. I played Ruggiero Ricci – The Glory of Cremona (Analogphonic Reissue). This record features different pieces played on violins made by Stradivari, Guarneri, and Amati. Hearing the nuances between these fine instruments is challenging — even live. But after upgrading to the G-700i, I could clearly distinguish the character of each violin on this recording for the first time.

    Cabling

    Kondo electronics come with their all-silver ACz-AVOCADO power cord, which is a nice touch — one less cable to worry about. However, you can purchase the ACz-AVOCADO Dual version as an upgrade, and that’s what I did. The Duals bring a significant improvement and are worth the investment.

    In my experience, Kondo electronics sound best with their own cables. These cables are an integral part of the sound. I use Theme-41 RCA cables between my G-700i and ONGAKU, and between my sources and the G-700i.

    These cables are not cheap — but they are essential if you want to hear what Kondo electronics are truly capable of.

    Final Verdict

    The ONGAKU is not just a high-end amplifier — it’s a statement of what refined audio reproduction can be. Its sound is mature, balanced, and deeply expressive in a way that few components ever achieve. It doesn’t try to impress with exaggerated traits. Instead, it offers a presentation so natural, so coherent, that over time it subtly raises your own expectations — not just of equipment, but of music itself.

    Living with the ONGAKU has changed how I listen. It’s helped refine my ear, deepen my understanding of tone and texture, and shift my focus from isolated sonic traits to the totality of musical expression. This isn’t about being more critical — it’s about becoming more sensitive to what truly matters.

  • Blumenhofer Acoustics Corona 4×180 Speakers

    The Speakers That Transformed My Hi-Fi Journey Completely
    Image © Blumenhofer Acoustics. Used under fair use for commentary and review purposes.

    Introduction

    I’ve listened to many hi-fi systems over the decades. Some I liked a lot; others, not so much. The more you listen to different systems, the more your listening abilities evolve. That’s a crucial part of an audiophile’s journey.

    But do we really know what our sound is until we hear it somewhere? In my case, I didn’t — not until I heard these speakers for the first time.

    During a casual trip to a hi-fi dealer with some of my audiophile friends, I stumbled upon Blumenhofer Acoustics speakers. Until that day, I had never even heard of the brand, let alone listened to their speakers. We started in the smaller demo room, where a model from their Genuin series was playing. The system sounded different from anything I’d heard before. I liked certain aspects of the presentation and quickly realized this was an interesting and unique brand.

    Then we moved to the larger demo room, where the Corona 4x180s were set up. The dealer played a random track, and from the very first note, my jaw dropped. I had never experienced sound like that before.

    What struck me immediately was that instead of analyzing the sound or nitpicking technical aspects, I was completely absorbed in the music. Even the cliché demo tracks — the ones we usually dismiss — felt fresh and emotionally engaging.

    To be clear, the setup in that room was far from perfect. The bass was nearly absent, the soundstage wasn’t particularly impressive, and the overall tonal balance was off. But it took me a few songs to even notice these flaws — and once I did, I forgot about them just as quickly and found myself immersed in the music again.

    After we came back from the trip, I couldn’t stop thinking about the experience. For the next ten days, I called my friend and hi-fi mentor every single day. We talked about the speakers — whether it was a good idea to buy them — for almost an hour each time.

    I was hesitant. I didn’t know much about the brand, and the speakers were expensive. But together, we came to the conclusion that what I had experienced might have been one of the most important hi-fi moments of my life.

    And so, I decided to buy that exact pair.

    The Evolution of the Electronics

    A couple of days after the purchase, the speakers were delivered to my house. I immediately set them up in my room and started listening.

    I was nervous — but the magic that had pulled me toward these speakers was still there. With a huge sense of relief, I began fine-tuning their placement.

    I’m obsessive about proper speaker positioning and always spend as much time as needed to dial in a pair. It didn’t take long to realize that these speakers were extremely sensitive to placement. Of course, every speaker responds to positioning, but these were on another level. Move them just a couple of centimeters forward and the bass would vanish completely. Move them a bit further and the bass returned — but now it was boomy. Adjust the toe-in by just a few millimeters and the entire presentation would change.

    And so on, and so on.

    I decided to take careful measurements and document everything. I messed up the setup many times and had to revert to previously known good positions. It took me weeks to get them dialed in — and months to perfect the placement.

    At the time, my amplifier was an Ayre Acoustics AX-5. To this day, I still think it’s one of the best amplifiers in its price class — possibly even above it. It had a very musical, fluid midrange, good bass control, and pleasing timbre. It also paired well with the 4x180s.

    However, after a couple of months, it became clear that these speakers were capable of more. They deserved a better amplifier — perhaps a separate pre/power setup instead of an integrated.

    After some searching, I found an Audio Research 40th Anniversary (REF 40) preamplifier in near-pristine condition — a unit I knew well and had always admired. Around the same time, I came across a Gryphon Mephisto at a reasonable price.

    I decided to buy both — a serious step up to match what the 4x180s could truly deliver.

    At the same time, I also moved away from the “Frankenstein” approach to cabling — mixing different brands — and instead invested in a full loom of In-Akustik cables.

    These cables are what cables should be: they don’t impose a strong sonic signature, yet they offer a perfectly balanced and coherent presentation.

    Once everything was in place, the sound transformed immediately.

    The Mephisto is an absolutely incredible amplifier. Contrary to its extremely masculine appearance, the sound is transparent, balanced, and fluid. Bass control is exceptional, and the overall presentation is deeply musical.

    The REF 40 is arguably the best component Audio Research has ever produced, and it paired beautifully with the Mephisto. This combination significantly elevated my hi-fi game.

    But the more I listened, the more one thought started to bother me. As impressive as the Mephisto is, I began to realize that it was designed primarily for modern, hard-to-drive speaker designs. Its control was phenomenal — but perhaps too much of a good thing?

    The 4x180s are very easy speakers to drive, with relatively high sensitivity (94dB). And over time, it became clear that these speakers were begging for a tube amplifier.

    The ONGAKU

    I’ve written about the ONGAKU in detail in a separate post.

    The ONGAKU’s output transformers have only one secondary winding, designed for 8-ohm loads. There are sonic benefits to using a single secondary, but also a major caveat: most modern speakers — including the 4x180s — have a nominal impedance of 4 ohms. At first glance, that might seem like a serious mismatch.

    However, a speaker’s nominal impedance means very little in practice. Speakers are complex electrical loads, and their impedance varies with frequency. Unless you measure and plot the impedance curve, the nominal figure is almost meaningless.

    In my experience with tube amplifiers and various speakers, even if you have a multi-tapped output transformer, you should always trust your ears over the speaker’s spec sheet.

    Long story short: it was a gamble. But the ONGAKU and the 4x180s turned out to be a match made in heaven.

    The Sound

    First and foremost, the 4x180s can be used with any amplifier that outputs around 8 watts or more — whether solid-state or tube. But after living with them for a while, I’ve come to believe they truly shine with a tube amplifier.

    The 4x180s are a two-way bass-reflex and compression-driver horn hybrid design. The horn can be moved back and forth for time alignment. Blumenhofer Acoustics provides guidance on their website for aligning the drivers by ear. But if you’ve never done it before, it’s hard to know what you’re listening for.

    It took me weeks just to get the horn into a ballpark position, and months to refine it. It was frustrating at first, but once I understood what to listen for, it became fun.

    Is this for everyone? Absolutely not. But if you’re like me — hands-on, patient, and someone who enjoys fine-tuning — it’s well worth the effort. Once the drivers are time-aligned and speaker placement is dialed in, everything clicks.

    The speakers disappear completely — and I mean completely. In total darkness, it’s impossible to localize them. The soundstage is phenomenal: focused, holographic, and emotionally involving.

    The Bass

    The bass performance of these speakers was a game-changer for me. They’re not the deepest or most forceful in sheer output, but the experience of bass is on a different level.

    It’s lightning-fast, with no sluggishness whatsoever. It’s detailed, controlled, and harmonically rich.

    Bass notes from a grand piano or double bass have incredible body, complete with natural overtones and a beautifully realistic decay. You can hear the resonance of the wooden bodies as the sound fades — an unforgettable level of realism.

    The Midrange

    In my opinion, the greatest strength of Blumenhofer speakers lies in the midrange, where about 80% of the music lives. But interestingly, their biggest challenge also resides there.

    These speakers can go mid-forward if not carefully set up. They’re not forgiving in this area. That’s not to say they’re inherently unbalanced — they just require care and precision to get the midrange fully integrated.

    Speaker placement is absolutely critical to achieving a balanced presentation. I’ve set up many speakers throughout my hi-fi journey, and while all are sensitive to placement, these are in a league of their own.

    A few millimeters can make a dramatic difference. Toe-in is essential, and finding the right angle takes patience and experimentation. But once you get it right, everything locks into place.

    The midrange is incredibly lifelike and fluid. Both male and female vocals — as well as solo instruments — sound so convincing, you could swear they’re right in front of you. The depth is equally stunning, whether you’re listening to a jazz trio or a full symphony orchestra.

    The Treble

    The treble region is rich, with ample air and separation. These speakers never sound harsh or aggressive.

    Like the bass, the decay of the highs is impressive — silky smooth, extended, and natural.

    Why the 4x180s?

    Over time, I’ve had the opportunity to listen to several other Blumenhofer Acoustics speakers — including models from the Gioia, Genuin, and Corona lines. Each of them carries the core DNA of the brand: effortless dynamics, horn-loaded immediacy, and a natural, uncolored tonal balance.

    The Gioia 2×10, for example, is a remarkable speaker. It has more scale, more weight in the lower registers, and a physically larger presentation. But it also demands a much larger room to breathe — something my current space simply can’t offer. In the wrong environment, that scale becomes a liability rather than an advantage.

    The 4x180s, on the other hand, get everything right. They don’t show off — they reveal. They don’t impress in the first 30 seconds — they convince you over hours and weeks. Their tonal honesty, midrange richness, spatial accuracy, and speed are simply unmatched — not just within the Blumenhofer range, but in the high-efficiency speaker world more broadly.

    In my view, the 4x180s are the most complete, mature, and musically truthful speakers Blumenhofer has ever made. They are the hidden masterpiece of the lineup — not as visually dramatic as some of their larger siblings, but far more balanced, refined, and emotionally communicative.

    Once properly set up and paired with the right electronics, they don’t just play music — they put the performers in front of you.

    Final Verdict

    Once these speakers are properly dialed in, and system synergy is in place, the result is the most believable and lifelike sound I’ve experienced to date.

    It’s the ultimate “they are here” experience — taken to the extreme.