MASS-Kobo Headphone Amp. model404
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Zhanming057
500+ Head-Fier
You don't have to, but the additional grounding is helpful in controlling the not insignificant noise floor that these amps have. It's a problem with the 404, 424 and 428 - keep in mind that all three are effectively the same amp - and separating out the ground helps. On the 404 there is support for using the 3.5mm as a balanced ground with AK DAP's, it looks like the same option is available on the 424 with the WM1A/Z. I seem to also get some small soundstage benefits from using the 3.5mm connection on the 404 in addition to the 2.5mm TRRS.
Former 404 and 394 owner here. The 404/424 is one of the better value propositions among strong portable solid states. The massive amount of power from the XLR jack means that you can just about drive any headphone on the market and have a good time, if you're not too fussy with the minutiae of how they perform. The problem is that on the 404 the "IEM" 2.5mm jack is too weak for many high end IEM's, and the XLR jack is relatively noisy for sensitive cans. Some thoughts about the 404/424 and its main competitors:
404/424: Powerful, good with really hard to drive cans, the 2.5mm output is ideal for IEMs such as the Tia Fourte. Good with the HD800S and really good with the Mysphere 3.2. Has a real XLR jack, replaceable batteries last for 6/4 hours but performance decreases as the batteries discharge. For critical listening on the 404 I swap out the AA's whenever the low power LED comes on. Overall, the 404 is probably your best bet for a collection of both big cans and hard-to-drive IEMs (LCDi4), and if you don't want to deal with the size of the Broadway.
WA11: Clean, quiet, extremely composed but is too strong, even on low gain, for sensitive IEMs. Great with portable cans such as the Diana Phi and Stellia. USB-C charging and has an internal DAC that isn't horrible. Supports charge and listen with little perceivable performance loss. No XLR out though. A modern portable amp with some comforts and advantages over the 404. I want to travel with the Diana Phi's and I bought a WA11 over the 424. If I wanted to push the Utopia or Mysphere into that role, I would have chosen the 424.
Xi Broadway: extremely powerful, will sound objectively good with the 1266 phi and LCD4. Less composed than the WA11, without the Mass Kobo's hotter treble. A highly dynamic signature with great punch and a comforting amount of treble rolloff. Requires a balanced portable DAC and only has XLR out. Too powerful for any IEM this side of the LCDi4. Huge and something like 2.5 pounds. Too big for a practical travel option for me, although I know people who swear by it.
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Mimouille
Headphoneus Supremus
Thanks a lot man. I want to buy an amp only for my Spiral Ear SE6 which is a 130ohm impedance IEM, so fairly hard to drive and mostly silent with all sources. It works well with WM1Z but could scale. So what would be the best option to put between WM1Z and SE6? I should have a test of the Broadway soon and want to try Mass Kobo 428 as 4.4 is more convenient for me. But maybe Wa11 would be easier.
jmills8
Previously known as bmiamihk, jmills2
Really sounds nice at home and on the go. Cowon PL, TH900 , MK.
lithiumnk
500+ Head-Fier
Source: Ak SP 1000cu
Headphones/iem: Audeze Lcd i4, AT ADX5000, Hyla TE5T
This is the cable from creator cables hong kong. Its a 10 wire pure silver with 8 wire for 2.5mm(R+R-L+L-) & 2 wire for 3.5mm(ground). I had purchased my amp from jaben hong kong (with IC cable).
Check out this post : Post #58
It drives lcdi4 with ease. It has a gain switch (low-high gain). With iems i have set it to low gain.
1. Background becomes pitch black.
2. Soundstage depth & width, imaging & layering improves.
3. The transient response & tonality improves
4. The bass notes gets more extension & definition.
5. The mids have more body, overall resolution has improved especially when multiple vocalists are involved. Its easier to differentiate them with precise imaging.
6. The overall output (power) increases which is really helpful in driving LCD i4.
With adx5000 which is 420ohms, high gain works perfectly & my volume pot is near 9oclock on majority of tracks. Since sp1000cu is on warmer side the synergy with adx5000(bright) & kobo 424(neutral) is near perfect for me. The trebles are super extended, coherent, speed & transients are one of the best in dynamic HP. The transparency is too good. There is no perceivable noise floor, the sound comes from a super black bckgrnd. There is no harshness in my setup at all.
I believe its all about synergy of components & for someone like me choosing right components becomes a very difficult task as majority of my purchases are blind.
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lithiumnk
500+ Head-Fier
He travels a lot but he always answers on FB messenger in my experience.
Mimouille
Headphoneus Supremus
Thanks a lot, sounds like what I need.Source: Ak SP 1000cu
Headphones/iem: Audeze Lcd i4, AT ADX5000, Hyla TE5T
This is the cable from creator cables hong kong. Its a 10 wire pure silver with 8 wire for 2.5mm(R+R-L+L-) & 2 wire for 3.5mm(ground). I had purchased my amp from jaben hong kong (with IC cable).
Check out this post : Post #58
It drives lcdi4 with ease. It has a gain switch (low-high gain). With iems i have set it to low gain.
1. Background becomes pitch black.
2. Soundstage depth & width, imaging & layering improves.
3. The transient response & tonality improves
4. The bass notes gets more extension & definition.
5. The mids have more body, overall resolution has improved especially when multiple vocalists are involved. Its easier to differentiate them with precise imaging.
6. The overall output (power) increases which is really helpful in driving LCD i4.
With adx5000 which is 420ohms, high gain works perfectly & my volume pot is near 9oclock on majority of tracks. Since sp1000cu is on warmer side the synergy with adx5000(bright) & kobo 424(neutral) is near perfect for me. The trebles are super extended, coherent, speed & transients are one of the best in dynamic HP. The transparency is too good. There is no perceivable noise floor, the sound comes from a super black bckgrnd. There is no harshness in my setup at all.
I believe its all about synergy of components & for someone like me choosing right components becomes a very difficult task as majority of my purchases are blind.
lithiumnk
500+ Head-Fier
I had the same question for my sp1000cu.
His response to this was--- "Perhaps most cable manufacturers do not understand the importance of connecting the ground.They are connecting only TRRS.If you do not connect the ground is unable to demonstrate the performance up to the maximum amplitude to occur."
Yes the same answe came after a long explanation from him and he have also mentioned another way to connect the ground using the 3.5mm to 3.5mm with only the ground cable connected if left and right is connected might cost damage to both the amp and player.
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Since some Headfier have try to contact me though PM and ask me to explain what Mr. Masuda the founder of mass-kobo told me about ground connection in the 404/424/428 I guess I should translate the Japanese message into English for everyone as reference.
"It basically says to eliminate background noise and to use the full potential of the amp is necessary to connect the ground, but sadly in portable-world there are a lot of cable company out there making balance interconnection cable without ground being connected. In order to fully explain this it is necessary to use a lot of diaphragms to explain and knowledge in electronic engineering is needed to understand therefore I won’t go into it with full details.
We need to understand that balance amp amplify signals base on the ground. When connected unbalance, even the ground isn’t connected nothing will be transmitted, however when connected in full balance even the ground is not connected there will be signals being transmitted.
Most DAP have output which is designed for headphone or earphone and not designed for line out, because it is specific made to accommodate output to earphone or headphone only, most earphone jack/balance connector in modern DAP does not have ground connected, however in order to connect with amp correctly, is necessary for the reference potential from the DAP being the same. However even the amp is not connected with the ground, the amp will still have sound coming from the output but it will be easily effected by noise and large distortion will occurs.
In order to prevent this is necessary for the cable to either have a shield cable so noise will not enter the circuit between the player and the amp or else connecting the ground is the only method.
If you don’t have a cable with shield cable to connect both then you need another wire connected from ground to ground.
A lot of overseas customers have question about using the same power charging pack(li battery pack) as power supply will create lots of noise but most have been solve after the ground being connected. Noise happen because both grounds are connected through the power pack and the USB cables and the high frequency switch noise of the power pack will affect the signals therefore become noisy. However connecting DAP with balance amp using ground as well will not eliminate all noise but will eliminate most of it and made it not a problem to most user.
About your question if you have already made a 4.4cable with out ground connection then there is another way of connecting the ground. That’s connecting a cable of 3.5 to3.5 with only the ground being connected from the unbalanced output from the 404/424/428 to the unbalanced output of your DAP so the ground could be connected. The only thing which user should take caution of is not to connect the unbalanced ground cable with any signal otherwise the power of 424 will be outputted into the player and cause damage to both.
And we also suggest user to turn the volume of there DAP to full volume when connecting our balance amp, this is due to digital volume unlike analog volume the sound quality will be affected by volume, our amp are designed to be work with DAP being full volume and can withstand the power of it. Digital volumes not change the volume by altering the voltage but use digital processing to lower the volume therefore the signals wave will not be 100% similar to the file which is playing, in order to achieve the same sound signal with the file from your DAP is necessary to find the position where the sound signal have not been alternated, however, there is alot of DAP out there so is hard to say that max volume works for every single player out there but user who use the Sony WM1 series and AK380/SP1000/AK family can try full volume indeed or line out indeed. "
"It basically says to eliminate background noise and to use the full potential of the amp is necessary to connect the ground, but sadly in portable-world there are a lot of cable company out there making balance interconnection cable without ground being connected. In order to fully explain this it is necessary to use a lot of diaphragms to explain and knowledge in electronic engineering is needed to understand therefore I won’t go into it with full details.
We need to understand that balance amp amplify signals base on the ground. When connected unbalance, even the ground isn’t connected nothing will be transmitted, however when connected in full balance even the ground is not connected there will be signals being transmitted.
Most DAP have output which is designed for headphone or earphone and not designed for line out, because it is specific made to accommodate output to earphone or headphone only, most earphone jack/balance connector in modern DAP does not have ground connected, however in order to connect with amp correctly, is necessary for the reference potential from the DAP being the same. However even the amp is not connected with the ground, the amp will still have sound coming from the output but it will be easily effected by noise and large distortion will occurs.
In order to prevent this is necessary for the cable to either have a shield cable so noise will not enter the circuit between the player and the amp or else connecting the ground is the only method.
If you don’t have a cable with shield cable to connect both then you need another wire connected from ground to ground.
A lot of overseas customers have question about using the same power charging pack(li battery pack) as power supply will create lots of noise but most have been solve after the ground being connected. Noise happen because both grounds are connected through the power pack and the USB cables and the high frequency switch noise of the power pack will affect the signals therefore become noisy. However connecting DAP with balance amp using ground as well will not eliminate all noise but will eliminate most of it and made it not a problem to most user.
About your question if you have already made a 4.4cable with out ground connection then there is another way of connecting the ground. That’s connecting a cable of 3.5 to3.5 with only the ground being connected from the unbalanced output from the 404/424/428 to the unbalanced output of your DAP so the ground could be connected. The only thing which user should take caution of is not to connect the unbalanced ground cable with any signal otherwise the power of 424 will be outputted into the player and cause damage to both.
And we also suggest user to turn the volume of there DAP to full volume when connecting our balance amp, this is due to digital volume unlike analog volume the sound quality will be affected by volume, our amp are designed to be work with DAP being full volume and can withstand the power of it. Digital volumes not change the volume by altering the voltage but use digital processing to lower the volume therefore the signals wave will not be 100% similar to the file which is playing, in order to achieve the same sound signal with the file from your DAP is necessary to find the position where the sound signal have not been alternated, however, there is alot of DAP out there so is hard to say that max volume works for every single player out there but user who use the Sony WM1 series and AK380/SP1000/AK family can try full volume indeed or line out indeed. "
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I am selling my Masskobo 424 with interconnection cable at headfi for a great price please have a look and feel free to send me pm if interested.
lithiumnk
500+ Head-Fier
Have you found an upgrade to 424 or just selling it?
Have you tried changing the opamps?
Sorry, I am curious about your decision.
Is nothing wrong with the amp it’s very good sounding indeed however is too heavy for me to bring it around to use it as portable and at home I just purchase a Masskobo 394II so I no longer need the 424.i rather just use my Sony Wm1z directly is already too heavy lol
lithiumnk
500+ Head-Fier
Congratulations
Have you compared 394II with the likes of Luxman p750u, Head amp Gsxmk2, benchmark hpa4, XIAudio formula S etc.? I am in the market for a new SS to replace my v281 which is very good but with ADX5000 I have started to realise its weakness(treble).
Any suggestions
Thanks
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Zhanming057
500+ Head-Fier
For the ADX5000 I would say that the 394 is the best of the bunch with the HPA4 coming in second being even more neutral and a bit less exciting. The Fomula S is heavily optimized for the 1266 phi and works best with low sensitivity cans. The P750u is nice but huge and a bit overpriced in anything but the 100v config.
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