[elton7033]

After purchasing the world smallest full balance portable headphone amp with a 4pin XLR the MASS-Kobo 424 last month I have addicted to MASS-Kobo clean , powerful yet detail sound signature, in less then 3 week time I had say goodbye to some of my portable audio gear and save up 648000yen to say hello to its bigger brother the model 394 II. Since I have just received the amp 2-3 days I will be spending sometime before I finish writing up this short review. I will be comparing to my old headphone amp the Luxman P700/P1u/P200 and the Bryston BHA1, so far the 394II have no problem driving all my headphone from the easiest to drive the SONY R10 to the hardest of all the AKG K1000.
Let me first list out my gear for this review:
PC Foobar (ASIO optical out Audioquest Carbon optical) for digital music to
SACD Player Luxman D08 (SACD also used)->Crystal Cable References Diamond XLR->MASS-Kobo 394 II
->Crystal Cable References Diamond RCA->Luxman P1u/P200
Headphone: Sony R10/Focal Utopia/Audio Technica L3000/L5000/Senn HD800/AKG K1000/Final Sonorous X

I have also have a chances to audit the older 394 before I purchase the 394II, although MASS-Kobo official claim that there are no different between the circuits of the two except the input gain switch on the 394 is fixed either for +4db(studio version) or -10db(home audio Version), I can clearly feel that the 394II have a bunch more power then the 394(-10db ver) and a slight different signature tuning. I was using the Abyss 1266 (non phi) and the Grado RS1 for the testing, however here comes a disclaimer since I do not own both headphone, so I cannot really do justice on how they perform on the amp, however both seems to be driven to a very good standard, wgere the Abyss 1266 sound abit smaller on the same volume level to the 394II. the 394 have somehow a much warmer signature to the 394II which makes the original 394 somewhat sounds like a Class A amp with lots of power there, where the 394II have a more cold and monitor sound then the 394. The 394II really sounds more like its flagship the 1mil yen over the model 406 however the 406 is still clearly a better amp although I have only heard once at Fujiya Avic Headphone Fest. I think the 394II is a very good alternative for people who like the 406 but dont want to cash out so much money on a headphone amp.

After the first day of listening, i can say its a very good match to eventually all headphone, may be not my Senns HD800 as the P1u tame it very well, but a very good match with the R10 and the Utopia...then the blue power LED lamp start to fail and goes dimmer as the amp goes hot, although these does not effects the amp performances at all, it remind me the Rudistor RP303 my friend have a few years ago and somehow these hand designed and crafted top of the line amps sometimes does have a bit trouble, just like a handbuild supercar or my KGSShv which blown up at 2016 right after headphone show although MASS-Kobo quickly try to come and fix the amp so the review will continues after the LED is fixed.

 

[Zhanming057]

I'm a big fan - it's one of the best solid state amps and extremely portable for a high-power desktop system.

Yeah, I used to run two of these in a monoblock

 

[elton7033]

I'm a big fan - it's one of the best solid state amps and extremely portable for a high-power desktop system.

Yeah, I used to run two of these in a monoblock

how do you run it in monoblock? do you only plug in one 3pin XLR per amp from in put to output?

 

[Focux]

just realised my audio store back home has this haha..

https://store.jaben.com/products/mass-kobo-headphone-amplifier-model-424

 

[elton7033]

just realised my audio store back home has this haha..

https://store.jaben.com/products/mass-kobo-headphone-amplifier-model-424

The 394II really is one of the best high power solid states headphone amp you can find in the market at the moment which in my opinion worth the money.
The 424/428 is no doubt a good portable amp but for its price you can have other very attractive opinion like the chord hugo2. The only reason why people are buying Masskobo 404/424/428 are it’s possibily the only choice for people who want to just have one portable amp and being able to drive anything balance from sensitive UIEM to HD800S and forget about a desktop setup. I only bought it because Sony WM1Z are being under power when driving my Fitear Titan. But by the end of the day, I realized that it’s not that portable at all and portable will never be able to replace full-size desktop amp that’s why I got the 394II.

 

[JR WEST 5489]

The 394II really is one of the best high power solid states headphone amp you can find in the market at the moment which in my opinion worth the money.
The 424/428 is no doubt a good portable amp but for its price you can have other very attractive opinion like the chord hugo2. The only reason why people are buying Masskobo 404/424/428 are it’s possibily the only choice for people who want to just have one portable amp and being able to drive anything balance from sensitive UIEM to HD800S and forget about a desktop setup. I only bought it because Sony WM1Z are being under power when driving my Fitear Titan. But by the end of the day, I realized that it’s not that portable at all and portable will never be able to replace full-size desktop amp that’s why I got the 394II.

Thx for Elton to let me try and own this good amp.

 

[John Massaria]

 

[LoveKnight]

Well I am sorry to dig this thread up just because I am searching for my next desktop amplifier and considering two amps from Japan. First is Bakoon HDA-5210MK4 with untrusted winding resistance Attenator option (natural sound more neutral and suitable for classical music and this is my taste of music too) and second is Mass Kobo model 433 (Combining the sound quality that inherits the lineage of the higher model models 406 and 394 with the output circuit of the model 402 used by the Japanese broadcasting station NHK, it will deliver you a nice sound of course with a reduced cost and lack power to drive hardcore headphones as Suvasra, Abyss, ...). My two headphones are dynamics such as Sennheiser HD650 and Denon D9200, maybe a Final Audio D8000 pro if I am interested in near future. Both amplifiers have reputation and quality about driving these cans so I need some helps (if you guys would) to decide. This will be my last headphone amplifier for a long time and then in the future when I am better with economy I will move to a Stax headphone combo. Thanks for your supporting.

One more thing I know someone in Japan can help my buy Mass Kobo directly in the webpage so the model 433 is a little cheaper than Bakoon HDA-5210MK4 according to money in my case. However because Mass Kobo is made to order so I could wait for months to really touch it compare to Bakoon is about 1 month.

 

[TheMiddleSky]

Well I am sorry to dig this thread up just because I am searching for my next desktop amplifier and considering two amps from Japan. First is Bakoon HDA-5210MK4 with untrusted winding resistance Attenator option (natural sound more neutral and suitable for classical music and this is my taste of music too) and second is Mass Kobo model 433 (Combining the sound quality that inherits the lineage of the higher model models 406 and 394 with the output circuit of the model 402 used by the Japanese broadcasting station NHK, it will deliver you a nice sound of course with a reduced cost and lack power to drive hardcore headphones as Suvasra, Abyss, ...). My two headphones are dynamics such as Sennheiser HD650 and Denon D9200, maybe a Final Audio D8000 pro if I am interested in near future. Both amplifiers have reputation and quality about driving these cans so I need some helps (if you guys would) to decide. This will be my last headphone amplifier for a long time and then in the future when I am better with economy I will move to a Stax headphone combo. Thanks for your supporting.

One more thing I know someone in Japan can help my buy Mass Kobo directly in the webpage so the model 433 is a little cheaper than Bakoon HDA-5210MK4 according to money in my case. However because Mass Kobo is made to order so I could wait for months to really touch it compare to Bakoon is about 1 month.

Note: I never heard Bakoon 5210Mk4 or Mass Kobo 433 my self. However, I'm familiar with most of Bakoon Japan products (included their dac, pre amp, monoblock amp, and their various headphone amps). Personally I also own Bakoon Japan PRE7610Mk3. I also familiar with many Mass Kobo products (394, 393, 404, and 465) and met Masuda-san for 3-4 times as well in various audio event (before covid era).

If I may help a little, in general, Bakoon Japan is all about being organic, balance with sweetness character, full body sound, that has good clean impact, and "natural" soundstage presentation (not super wide, have excellent depth and height).

Mass Kobo, on the other hand, deliver fast, Neutral-Bright character that excel in clarity, detail, "clean cut" impact, fast decay, and more to spacious and intense type of sound.

Their basic house sound simply really different.

 

[LoveKnight]

Thank you for your reply. After reading your comments I decide to buy both and will compare them in this post. However it will take me about a year so please be patient ha ha.

 

[Nostoi]

Thank you for your reply. After reading your comments I decide to buy both and will compare them in this post. However it will take me about a year so please be patient ha ha.

I can slightly chip in here - I just received the Mass Kobo 428 and would agree with what @TheMiddleSky says above: the Mass Kobo tuning is fast, clean, transparent, linear/bright, and quite forward. Some people might find it quite fatiguing. For a portable amp, the 428 is very impressive. The Bakoon Japan sound - esp. 5210MK4 - is linear/warm with a *slightly* smoother sound, but nevertheless very incisive on a technical front. It offers a more "robust" presentation. Both of these amps would pair very nicely with Final Audio D8000 pro, I think.

To my ears, they compliment each other very well and also reinforce my conviction that there is something fundamentally special about Japanese amps.

I'm also very curious to hear 433, so do let me know if you track one down.

 

[LucasKA]

After a long research for the end game amp and considering many others like Pass Lab, Audio-GD, Luxman, Ferro, I had settled on Mass Kobo 394II and was lucky enough to find one for sale in Singapore at a more affordable price.

I can say that I am really really happy with it, its clean, powerful and delivers the detail and works well with most of my headphones. It hides its virtue well that it become un-noticeable.

I will be curious to hear Bakoon or Audio-GD next but will give it a few years.

 

[Ricco275]

Hello,
I own a Pass Labs HPA1 and I’m happy with it. Currently owning HD660S2 and Arya stealth. The latter will be replaced by Meze Elite next week.
I have just bought a Okto dac8 which is amazing.
My problem is the Okto is balanced only and the Pass is SE only.
I’m torn which component to change.
I use the Okto with my integrated amp for loudspeakers now.
The Okto has also a decent headphone out.
I was trying to understand if there could be an amp with balanced input within the 4k euro budget new or 3k second hand that could satisfy me more than the pass.
So far my Pass HPA1 is dedicated to my LP12 turntable and it works wonders.
Other option would be to keep the Pass and add a balanced head amp not too expensive, like the GSX mini second hand.
I hope someone in this thread can help me out with some insights and experience. Thanks a lot.

 

[LucasKA]

Hi I would suggest to look into the following, they all have balance input and with Balance/SE output, but all with different sound signature, depend on what you are looking for. I was in similar boat earlier and these are my top candidates with top reviews. I went for a Mass Kobo 394II for its reputation and was not disappointed.

Benchmark HPA4
Ferrum OOR
Audio-GD HE9/Master 9/19 (Good for Planar)
Mass Kobo 394/433
Luxman P750/700
GSX or CFA3

If you don't mind older technology and want something cheaper that will work well with Planar:
Monolith Liquid Gold X

 

[Ricco275]

Hi I would suggest to look into the following, they all have balance input and with Balance/SE output, but all with different sound signature, depend on what you are looking for. I was in similar boat earlier and these are my top candidates with top reviews. I went for a Mass Kobo 394II for its reputation and was not disappointed.

Benchmark HPA4
Ferrum OOR
Audio-GD HE9/Master 9/19 (Good for Planar)
Mass Kobo 394/433
Luxman P750/700
GSX or CFA3

If you don't mind older technology and want something cheaper that will work well with Planar:
Monolith Liquid Gold X

thank you! It matches my list except ferrum and luxman which I didn’t know.

Which one in your opinion are superior to Pass Labs HPA1?

As a sound signature I like neutral and dynamic, not warm laidback.