[Nostoi]

Since there's no mention of it elsewhere, this is a thread for the Japanese Bakoon HDA-5210MK4 headphone amplifier. Note this amp is built and designed by Akira Nagai, the founder of Bakoon, rather than the South Korean division of Bakoon which makes the widely known Amp-13r, etc. Bakoon Japan now trades under the brand SCL (SATRI Circuit Laboratory). You can read more about this dispute here.

Retail price is ¥419,000

I have just received the HDA-5210MK4 and will be posting impressions on this thread for anyone interested (especially in comparison to the HPA-21).

In the meantime, some information (taken from here):

Sound with different dimensions and depth!​

MK4 equipped with a newly developed IC​

Description
It is a new model equipped with a further evolution MK4 circuit from HDA-5210MK3, which was developed to sound headphones with the highest sound quality. The new Hibiki-iC has been added to the SATRI-IC, which has increased the thickness and reality of the sound than the MK3. The rising when the power was turned on was also faster. It also has a high -impedance current output. By driving the headphones in current, the distortion is reduced compared to the voltage drive, and it is possible to play more precise. Many headphones have few swells in the impedance frequency characteristics, and if they use these headphones for current output, it is possible to hear a lot of information that can not be obtained by voltage driving.

HDA-5210MK4 has a SATRI-LINK current input assuming that it is combined with the company's preamplifier and D/A converter. In addition, a good result can be obtained in combination with a non -company pup or D/A converter, etc., with a voltage input of one system. The gain of the amplifier can be controlled with a 23 -step attenea and can be changed continuously to 20dB. Unlike the normal volume control, there is no deterioration of S/N even if the volume is lowered.

Voltage output adapts to headphones with an impedance up to about 100Ω. Since the current output is driven by a very high impedance, the headphones are driven, so the sound distortion is low, and the frequency characteristics vary depending on the impedance curve of the headphone, so adapt to almost all headphones. The current output gain can be switched with the Current Gain switch according to the headphone. In addition, current output and voltage output can be used simultaneously. In that case, the output current of the current output is the current flowing to the headphone connected to the voltage output. Therefore, the output current of the current output reflects the personality of the headphone connected to the voltage output. Therefore, the sound changes depending on the headphone connected to the voltage output.

The rising is very fast, dynamic, powerful bass, presence, deep, vast, silence background and sound field. It is a sound that sets it apart from many headphone amplifiers. The overwhelming sense of realism, resolution, surprisingly natural playback sounds and live sounds with depth are not tired even if you listen to it for a long time. You can't let go if you listen to it once more comfortable than you might imagine.
SPEC

input	Voltage input: (RCA) x 1, current entry (SATRI-LINK): bncx1
output	Voltage output: Standard headphone jack X1, current output: standard headphone jack X1
Frequency characteristic	20kHz/-0.03db, 100kHz/-0.17db
Headphone impedance	33Ω
Conforming impedance	8-600Ω
Maximum output	Voltage output: 1000MW Current output: 500MW
gain	4.5 times
power supply	100V, 120V, 220V, 240V/50, 60Hz
Outer size	78mm (H) x 235mm (W) x 295mm (d)
weight	2.9kg

*Bacoon Products change the logo and name to SCL (SATRI CIRCUIT LABORATORY). please note that.

 

[Nostoi]

 

[jjss]

Look forward to your impressions and review

 

[jjss]

This headphone amp looks promising. Over the years I've found that the Sony signature series sound (e.g. DMP-Z1, NW-WM1Z) is what I'm looking for, resolving with lots of details and yet "musical", presents a sense of realism of tonality, timbre, and space! This is what the DMP + u18t gives me! Right now I'm in the hunt to find what other headphone amp, esp those from JP, would deliver such sound or close to it, esp to drive my other headphones like the planar! Your review definitely helps my investigation .. TIA

 

[Nostoi]

This headphone amp looks promising. Over the years I've found that the Sony signature series sound (e.g. DMP-Z1, NW-WM1Z) is what I'm looking for, resolving with lots of details and yet "musical", presents a sense of realism of tonality, timbre, and space! This is what the DMP + u18t gives me! Right now I'm in the hunt to find what other headphone amp, esp those from JP, would deliver such sound or close to it, esp to drive my other headphones like the planar! Your review definitely helps my investigation .. TIA

I will begin to offer impressions later today, but for context the Bakoon amps with current output are designed for planar headphones. Indeed, I bought the 5210MK4 especially to drive my Kennerton Thror/Rognir because I was so impressed with this pairing on the HPA-21. The voltage output on these amps is generally designed for dynamic drivers, but one would not really buy a Bakoon amp to drive dynamic headphones (although there's plenty of dynamic headphones like the TH900/HD800s that do pair exceptionally well).

I've only heard the DMP-Z1 briefly, but the Bakoon tuning generally departs from Sony's slightly liquid/smooth/warm tuning. The overall presentation is markedly more resolving and transparent while still being highly musical. The Bakoon presentation is also characterised by a wide sense of space with excellent layering/imaging/detail.

What planar headphones do you have out of interest?

 

[Nostoi]

First brief impressions of Bakoon HDA-5210MK4:

1. Build: The HDA-5210MK4 is a fairly compact (A4 size) though quite a chunky amp. It's probably somewhat bigger than it looks in photos. You can see difference in size between HPA-21 and HDA-5210 below (and also HPA-01M for the giggles). HPA-21 is notably more compact. Build is tank-like. Everything feels immensely robust and solid, from the output ports to the enclosure itself. Indeed, the enclosure has an interesting sort of texture which is not unpleasant to the touch. In terms of design, I'm a fan, though I can see it being a bit of a niche aesthetic.

2. Usage: You can read more on the specs here, but a couple of points. The volume knob - controlled by a metal film attenuator - is a 23-step control. This means, it "clicks" with each step rather than rotating in one smooth motion. In practice it works exceptionally well with planar headphones, though this is not the amp for IEMs. Incidentally, the volume knob has a very satisfying tactility. I believe it's made from bakelite. While there is a notable resistance to each gain step, it's satisfying in hand.

3. Power: You'll notice the specs say 500MW for current output. I wasn't quite sure this was right, given the HPA-21 is 1W. I looked into this and got the following reply:

"As Bakoon Products founder Mr.Nagai said that 1W current output for a headphone is too much for a headphones, it would be breaking headphones.
He doubts 1W. Please note that Bakoon Products is original SATRI-IC company who provided SATRI circuit as OEM to Bakoon international in Korea. But no more providing.
Mr. Nagai develops all SATRI systems. Thus, I believe current output 500mW is correct number."

In practice, I can confirm that 500mW is more than enough power. On both my Thror and Rognir, I am seldom moving beyond 12pm on the dial. I cannot speak for other planar headphones, but for Kennerton headphones there is an abundance of headroom.

4. Sound: Let's get to the goods - how does it sound? Some context, I fell in love with the HPA-21 & Thror/Rognir pairing. It was the best headphone pairing I'd heard in terms of pure synergy. There are some combos you hear together and you know they were meant for each other; that was the HPA-21 Thror/Rognir pairing. I'm pleased to say with the HDA-5210MK4 this synergy is even greater. Indeed, everything is greater on the HDA-5210MK4. This is truly a remarkable amplifier on a number of levels:

1. The timbre of the HDA-5210MK4 is neutral/linear but incredibly musical. I have a leaning toward this sort of presentation - precise, highly resolving, fast, musical - but I've never heard it articulated with greater coherence than in the HDA-5210. I would not exactly describe this amp as "smooth" if you take smooth to be rolled off and "lush". The presentation on the HDA-5210 is highly resolving, transparent, and very revealing - and yet, absolutely not dry or clinical.
2. The timbre itself has the most accurate sense of realism I've heard in an amp. By "realism" I mean the amp produces the timbre of individual instruments in a lifelike way, capturing what is unique about a given instrument/tone (including the voice).
3. The sense of authority and dynamics are staggering. This amp has a serious sense of "grunt," which is present on both low and high volume. Some amps come alive when pushed; the HDA-5210 already sounds excellent at low volumes.
4. Detail retrieval, speed, imaging, and layering are notably excellent. I had thought the HPA-21 was impressive in terms of keeping pace with complex music, but the HDA-5210 is on another level (spoiler alert).
5. The overall presentation also has a very holographic sense of space without being overly diffused. Presentation is immerse and expansive while retaining total coherence.

5. Pairings. As above, I only bought this amp to use with Thror/Rognir. I did try on some other headphones using the voltage mode, and they sounded very good, but this is not what this is amp is for. Both the Thror and Rognir pair majestically well with this amp. With the Rognir, you get a very punchy/exciting presentation with sublime layering, outstanding extension, and top-tier dynamics. Bass is thunderous and immensely quick. With the Thror, you get a reference presentation with greater linearity than the Rognir. Detail retrieval and imaging are immerse and precise; the HDA-5210 also gives the Thror a controlled but extremely layered bass.

6. Vs. HPA-21: How does it compare to the much venerated HPA-21? I connected the HPA-21 to a Hugo 2 and the HDA-5210MK4 to a Qutest to even out the odds. The HPA-21 remains an outstanding desktop amp (and also trans-portable amp given it runs on batteries), but the HDA-5210 is in a different tier. Compared to the HDA-5210MK4, the HPA-21 sounds more laid-back, with less authority, and less definition and less resolve. The HDA-5210 has much better control over the overall presentation: everything sounds tighter, crisper, with much better definition. Details pop out effortlessly and both macro/micro dynamics are articulated with more clarity on the HDA-5210MK4. In addition, comparing the two I notice some kind of grainy quality in the HPA-21. On the HDA-5210, there is an absolute clarity even at high volumes with badly produced music. Beyond this, these two amps do share the same tonality/timbre, so if you like the HPA-21, then you will love the HDA-5210.

In sum, kudos and congrats to Akira Nagai on the design and implementation of an excellent amp! I also want to give a shout out to Pat at War Audio in Australia. I ordered this amp on Thursday (28th) and it arrived today. Excellent to deal with more generally.

This one is a keeper for sure.

 

[jjss]

I will begin to offer impressions later today, but for context the Bakoon amps with current output are designed for planar headphones. Indeed, I bought the 5210MK4 especially to drive my Kennerton Thror/Rognir because I was so impressed with this pairing on the HPA-21. The voltage output on these amps is generally designed for dynamic drivers, but one would not really buy a Bakoon amp to drive dynamic headphones (although there's plenty of dynamic headphones like the TH900/HD800s that do pair exceptionally well).

I've only heard the DMP-Z1 briefly, but the Bakoon tuning generally departs from Sony's slightly liquid/smooth/warm tuning. The overall presentation is markedly more resolving and transparent while still being highly musical. The Bakoon presentation is also characterised by a wide sense of space with excellent layering/imaging/detail.

What planar headphones do you have out of interest?

I have the LCD-4, and have recently read an excellent review of CRBN by Bob Katz and it seems that according to him its even better than LCD-5, but the CRBN is electrostatic, and if I go go for it would need to save to buy ..

 

[jjss]

First brief impressions of Bakoon HDA-5210MK4:

1. Build: The HDA-5210MK4 is a fairly compact (A4 size) though quite a chunky amp. It's probably somewhat bigger than it looks in photos. You can see difference in size between HPA-21 and HDA-5210 below (and also HPA-01M for the giggles). HPA-21 is notably more compact. Build is tank-like. Everything feels immensely robust and solid, from the output ports to the enclosure itself. Indeed, the enclosure has an interesting sort of texture which is not unpleasant to the touch. In terms of design, I'm a fan, though I can see it being a bit of a niche aesthetic.

2. Usage: You can read more on the specs here, but a couple of points. The volume knob - controlled by a metal film attenuator - is a 23-step control. This means, it "clicks" with each step rather than rotating in one smooth motion. In practice it works exceptionally well with planar headphones, though this is not the amp for IEMs. Incidentally, the volume knob has a very satisfying tactility. I believe it's made from bakelite. While there is a notable resistance to each gain step, it's satisfying in hand.

3. Power: You'll notice the specs say 500MW for current output. I wasn't quite sure this was right, given the HPA-21 is 1W. I looked into this and got the following reply:

"As Bakoon Products founder Mr.Nagai said that 1W current output for a headphone is too much for a headphones, it would be breaking headphones.
He doubts 1W. Please note that Bakoon Products is original SATRI-IC company who provided SATRI circuit as OEM to Bakoon international in Korea. But no more providing.
Mr. Nagai develops all SATRI systems. Thus, I believe current output 500mW is correct number."

In practice, I can confirm that 500mW is more than enough power. On both my Thror and Rognir, I am seldom moving beyond 12pm on the dial. I cannot speak for other planar headphones, but for Kennerton headphones there is an abundance of headroom.

4. Sound: Let's get to the goods - how does it sound? Some context, I fell in love with the HPA-21 & Thror/Rognir pairing. It was the best headphone pairing I'd heard in terms of pure synergy. There are some combos you hear together and you know they were meant for each other; that was the HPA-21 Thror/Rognir pairing. I'm pleased to say with the HDA-5210MK4 this synergy is even greater. Indeed, everything is greater on the HDA-5210MK4. This is truly a remarkable amplifier on a number of levels:

1. The timbre of the HDA-5210MK4 is neutral/linear but incredibly musical. I have a leaning toward this sort of presentation - precise, highly resolving, fast, musical - but I've never heard it articulated with greater coherence than in the HDA-5210. I would not exactly describe this amp as "smooth" if you take smooth to be rolled off and "lush". The presentation on the HDA-5210 is highly resolving, transparent, and very revealing - and yet, absolutely not dry or clinical.
2. The timbre itself has the most accurate sense of realism I've heard in an amp. By "realism" I mean the amp produces the timbre of individual instruments in a lifelike way, capturing what is unique about a given instrument/tone (including the voice).
3. The sense of authority and dynamics are staggering. This amp has a serious sense of "grunt," which is present on both low and high volume. Some amps come alive when pushed; the HDA-5210 already sounds excellent at low volumes.
4. Detail retrieval, speed, imaging, and layering are notably excellent. I had thought the HPA-21 was impressive in terms of keeping pace with complex music, but the HDA-5210 is on another level (spoiler alert).
5. The overall presentation also has a very holographic sense of space without being overly diffused. Presentation is immerse and expansive while retaining total coherence.

5. Pairings. As above, I only bought this amp to use with Thror/Rognir. I did try on some other headphones using the voltage mode, and they sounded very good, but this is not what this is amp is for. Both the Thror and Rognir pair majestically well with this amp. With the Rognir, you get a very punchy/exciting presentation with sublime layering, outstanding extension, and top-tier dynamics. Bass is thunderous and immensely quick. With the Thror, you get a reference presentation with greater linearity than the Rognir. Detail retrieval and imaging are immerse and precise; the HDA-5210 also gives the Thror a controlled but extremely layered bass.

6. Vs. HPA-21: How does it compare to the much venerated HPA-21? I connected the HPA-21 to a Hugo 2 and the HDA-5210MK4 to a Qutest to even out the odds. The HPA-21 remains an outstanding desktop amp (and also trans-portable amp given it runs on batteries), but the HDA-5210 is in a different tier. Compared to the HDA-5210MK4, the HPA-21 sounds more laid-back, with less authority, and less definition and less resolve. The HDA-5210 has much better control over the overall presentation: everything sounds tighter, crisper, with much better definition. Details pop out effortlessly and both macro/micro dynamics are articulated with more clarity on the HDA-5210MK4. In addition, comparing the two I notice some kind of grainy quality in the HPA-21. On the HDA-5210, there is an absolute clarity even at high volumes with badly produced music. Beyond this, these two amps do share the same tonality/timbre, so if you like the HPA-21, then you will love the HDA-5210.

In sum, kudos and congrats to Akira Nagai on the design and implementation of an excellent amp! I also want to give a shout out to Pat at War Audio in Australia. I ordered this amp on Thursday (28th) and it arrived today. Excellent to deal with more generally.

This one is a keeper for sure.

Thanks for your effort and appreciated ..

 

[Nostoi]

I have the LCD-4, and have recently read an excellent review of CRBN by Bob Katz and it seems that according to him its even better than LCD-5, but the CRBN is electrostatic, and if I go go for it would need to save to buy ..

The HPA-21 was built around LCD-3, so I would expect LCD-4/5 to pair well with the HDA-5210. CRBN, of course, another route.

 

[eskamobob1]

The HPA-21 was built around LCD-3, so I would expect LCD-4/5 to pair well with the HDA-5210. CRBN, of course, another route.

Just a heads up, lcd-4 is a realy best to run. It need similar sound synergy to 3 but an entierly different power profile

 

[paradoxper]

Nice to see these receiving more coverage. I recall the HPA-21 from Tyll that generated my interest and spawned me to Kevin Gilmore's Transconductance and earlier to the CFA2 and today the CFA3 as current drive is simply sublime.

It would be interesting if you could get a comparison of the 13R or 23R as not many have heard all of these.

 

[Nostoi]

Nice to see these receiving more coverage. I recall the HPA-21 from Tyll that generated my interest and spawned me to Kevin Gilmore's Transconductance and earlier to the CFA2 and today the CFA3 as current drive is simply sublime.

It would be interesting if you could get a comparison of the 13R or 23R as not many have heard all of these.

I would love to do a direct comparison with 13R and 23R (especially 13R) though sadly they're hard to find in Austria. I feel @eskamobob1 would be ideally placed to offer this comparison if he's able to demo/secure the HDA-5210MK4.

And indeed, once you go current drive, there's no turning back.

 

[eskamobob1]

Nice to see these receiving more coverage. I recall the HPA-21 from Tyll that generated my interest and spawned me to Kevin Gilmore's Transconductance and earlier to the CFA2 and today the CFA3 as current drive is simply sublime.

It would be interesting if you could get a comparison of the 13R or 23R as not many have heard all of these.

Just a heads up, current amplification and current drive output aren't the same thing. Cfa3, 13r, all queststyle CMA amps, and a slew of others are current based amplification but are rectified to voltage drive output. An easy way to check this is to throw a dynamic can on the amp and see if it sounds all sorts of jacked up.

True current drive output required an effectively infinite OI (for example the HPA-21 has an OI > 1,000,000 ohms on the current out), so it seriously messes with dynamics. In the case of hd800s, adx5000, T1.2, and a few others this does some truly amazing things. Unfortunately with stuff like focals and ZMFs it turns into a nasty bloatty spike fest.

All that said, I would seriously love to get my hands on one of these to try it. I am a massive current drive believer in general so something at a higher level than hpa21 but maintaining the crazy time domain accuracy of current drive is super appealing to me

 

[paradoxper]

Just a heads up, current amplification and current drive output aren't the same thing. Cfa3, 13r, all queststyle CMA amps, and a slew of others are current based amplification but are rectified to voltage drive output. An easy way to check this is to throw a dynamic can on the amp and see if it sounds all sorts of jacked up.

True current drive output required an effectively infinite OI (for example the HPA-21 has an OI > 1,000,000 ohms on the current out), so it seriously messes with dynamics. In the case of hd800s, adx5000, T1.2, and a few others this does some truly amazing things. Unfortunately with stuff like focals and ZMFs it turns into a nasty bloatty spike fest.

All that said, I would seriously love to get my hands on one of these to try it. I am a massive current drive believer in general so something at a higher level than hpa21 but maintaining the crazy time domain accuracy of current drive is super appealing to me

You misunderstood the lineage context of CFA2 and CFA3 from the Transconductance.

 

[eskamobob1]

You misunderstood the lineage context of CFA2 and CFA3 from the Transconductance.

Whoops! I thought cfa3 was current amplification. Is it classic voltage amplification?