[Whitigir]

Oh i thought GaN was just about making smaller chargers - I imagine that someone is looking into it to see whether it sounds better too - any work on this you're aware of?

You should check this out
https://epc-co.com/epc/Applications/ClassDAudio.aspx

 

[xand]

You should check this out
https://epc-co.com/epc/Applications/ClassDAudio.aspx

Yum. Tiny for the power. Hope it sounds good! Let's also hope it takes 8-10 years though so we can depreciate down the C9 cost haha.

 

[Andykong]

Order placed... couldn’t resist C9.

Curious to see how it will perform with my Diana V2. If it works well, it may replace my current desktop Amp the Broadway Amp. Let's see.

@Andykong 新年快乐！我在珠海渡过我大学的前两年（中大珠海校区），真的是个特别好的地方。希望疫情过去之后可以去珠海拜访你们～

What a coincident, this is my home office stack. The Broadway is a very good amplifier, since you mentioned 1500 mW @ 32 ohms, so I assume we both have the same Balanced version.

You are in US right now? Hopefully we can travel freely by 2022, so stay safe this year, and looking forward to run into each other in the future, who knows, maybe we'll cross path at a CanJam before you come to China again.

The Broadway Amp is known for driving some power-hungry headphones quite well, including the 1266. I think this gives us some hope that C9 should drive power-hungry headphones at least equally well.

On a related note, after using the Broadway Amp, I am really appreciating battery-powered devices, especially powerful amps made portable with batteries. It is just so convenient. I can take it upstairs and use it with my DAP as the source. I can even take it out for a short overnight trip and enjoy the excellent amp on-the-go.

Can't comment on a competitor product other than saying it is a very good amplifier. Michael is a personal friend and we have a lot of social and professional exchanges. One thing you should aware though, Broadway was designed for headphone usage while the single-end Broadway S was recommended for IEM applications. C9, on the other hand, takes IEM as our primary coverage.

 

[Andykong]

Is there any official VRMS specs at 300 ohms @Andykong ?

Based on my calculation, that will be 9.8V

 

[bluestorm1992]

What a coincident, this is my home office stack. The Broadway is a very good amplifier, since you mentioned 1500 mW @ 32 ohms, so I assume we both have the same Balanced version.

You are in US right now? Hopefully we can travel freely by 2022, so stay safe this year, and looking forward to run into each other in the future, who knows, maybe we'll cross path at a CanJam before you come to China again.




Can't comment on a competitor product other than saying it is a very good amplifier. Michael is a personal friend and we have a lot of social and professional exchanges. One thing you should aware though, Broadway was designed for headphone usage while the single-end Broadway S was recommended for IEM applications. C9, on the other hand, takes IEM as our primary coverage.

Yes still stuck in the US; hasn’t been back to China for more than 1 year.

Speaking of the Broadway Amp, have you been able to make some comparisons with C9? And, yes I have the balanced version to drive myV2, but it is way too powerful for IEMs.

Edit: OK I see. I guess it is then up to me to post some impressions here. I am sure both will work great.

 

[Andykong]

Now you just made me want to cancel my purchase. Instead of going half way like this for nothing or merely anything, I rather stay with desktops or portable only, no stacking

If HD800/HD800S is your primary headphone and you want to achieve the best performance per $ invested on amplifier, in regardless of portability, desktop is the way to go. This probably is a bad idea for C9 promotion, but a sincerely advice from an audiophile.

All of that makes sense from both perspectives so it all boils down to individual use case then,. As I said in a private conversation, for me I've always been content to roam around my house with just the DAP on my person, or just listen to the speaker systems or sometimes use the poly/mojo to have the roon access. But in the case of the HD800/S there almost always seems to be a little more that it needs. So, I moved from the C9 as my intended tube amp to an HA-6A desktop. Maybe it's just the big glowing tubes that intrigues me, some guys just can't resist shiny things, or the amount of power (testosterone poisoning) but it seemed the best solution for my head-fi station.

At $500 extra, the HA-6A will outperform C9 significantly with HD800/HD800S, literally to a different level. You make a wise choice IMO.

 

[Bosk]

I am really appreciating battery-powered devices, especially powerful amps made portable with batteries. It is just so convenient. I can take it upstairs and use it with my DAP as the source. I can even take it out for a short overnight trip and enjoy the excellent amp on-the-go.

There must be a lot of us who appreciate high-quality transportable systems. It feels reminiscent of owning an iPad - its hard to be chained to a couch or desk once you can watch & listen anywhere with few restrictions!

If Cayin's calling the C9 a "portable" rather than transportable amp I'd love to meet their concept for a high-end transportable unit. Price might cause coronaries though.

 

[Andykong]

There must be a lot of us who appreciate high-quality transportable systems. It feels reminiscent of owning an iPad - its hard to be chained to a couch or desk once you can watch & listen anywhere with few restrictions!

If Cayin's calling the C9 a "portable" rather than transportable amp I'd love to meet their concept for a high-end transportable unit. Price might cause coronaries though.

From functional point of view, when you listen to the amplifier while you are walking around, waiting or travelling on underground or bus, this is a portable. If the amplifier is designed to move and setup from one place to another place "conveniently" so that you can listen to the same amplifier at different locations, be it office, hotel, from study room to balcony and then bedroom, that is transportable.

The functional perspective provides a rough guideline on the form factor and weight of the gears to be classified as portable or transportable. To me, C9+N6ii is portable, Sony DMP-Z1 is a transportable, but YMMV. I am not surprised if someone consider C9 as "transportable" too. So maybe we can share our view so that we can have a benchmark in our discussion.

Of course, there are always extreme cases, if we use this gentleman as example, he is using a portable system, right?

By the way, miniaturisation is a very high cost concept, so the same processing power, a desktop PC is cheaper than a notebook computer, and a mobile phone that is only 1/10 of the weight of notebook computer will cost even more, per processing power. So a high-end transportable unit is not necessarily more expensive than a high-end portable unit.

 

[Whitigir]

And that is why there is DMP-Z1. Honestly, if the C9 cant drive HD800S well enough, then I don’t see the point of buying the C9. I do have desktop system already Andy, just want to take it on the go. That is why I have been torn between 2 extreme planes, either staying with portable and something powerful enough like the MAX, DMP-Z1, and or sticking to Desktop amp, avoiding Stack.

I sincerely thought C9 would be the game changer since it had so much power

 

[Andykong]

And that is why there is DMP-Z1. Honestly, if the C9 cant drive HD800S well enough, then I don’t see the point of buying the C9. I do have desktop system already Andy, just want to take it on the go. That is why I have been torn between 2 extreme planes, either staying with portable and something powerful enough like the MAX, DMP-Z1, and or sticking to Desktop amp, avoiding Stack.

I sincerely thought C9 would be the game changer since it had so much power

Unfortunately, "so much power" is not the critical success factor to HD800/HD800S, IMHO.

My sincere advice: wait till you have the opportunity to audition the C9 in person, or when there are more user impressions that you can align with. The C9 is a better portable amplifier on many scenario, but high impedance headphone is not one of them. It will sound good and pleasant with HD800/HD800S, but will it qualify as an endgame or game changer with HD800? I am not truly convinced myself, but YMMV.

 

[xand]

... if the C9 cant drive HD800S well enough,

There are other headphones..

Personally I'm pretty sure that for the price I could have gotten a superior amp, albeit not one which is as convenient/transportable, and I liked the demo enough.

 

[Whitigir]

There are other headphones..

Personally I'm pretty sure that for the price I could have gotten a superior amp, albeit not one which is as convenient/transportable, and I liked the demo enough.

That is the problems, I can’t find any other headphones I like , and DMP Z1 drive it nicely. So that is what I am talking about, if Sony can do it, and if the C9 can’t, then why should I stack it up ? The DMP-Z1 runs on batteries and DC-External supplies when needed. Nevertheless, it can drive HD800s in both instances....May be it has enough swing aling and slew bahews ?

It is not the matter of going desktop though, I just want to stay portable.

 

[xand]

That is the problems, I can’t find any other headphones I like , and DMP Z1 drive it nicely. So that is what I am talking about, if Sony can do it, and if the C9 can’t, then why should I stack it up ?

It is not the matter of going desktop though, I just want to stay portable.

Well I picked my current solution because the Z1 has no streaming. If not I might already have the Z1 hahaha.

Also 1kg is better than 2.5 kg(!)

Edit: I did briefly consider a transport to the Z1 but the cost and weight.. Urgh.

Edit 2: what I kinda want now are some "open" customs...

 

[Andykong]

Since we have several C9 users showed up in the thread, I'll start to explain more operational side of C9. Someone has asked whether you can charge while you are listening, so let me started here.

Charging and Protection Circuit

The 18650 is very different from the 3.7V Lithium battery that are commonly find in mobile phone. Overcharge and discharge of lithium-ion batteries will cause permanent damage to the positive and negative electrodes. Excessive discharge leads to the collapse of the negative carbon layer structure, and the collapse will cause the insertion of lithium ions in the charging process; overcharging will cause too much lithium ions to be inserted into the negative carbon structure, causing some of the lithium ions to no longer be released. (Extracted from HERE)

A fully charged 18650 is around 4.2V and a discharged battery should stay at around 3.0V. A deeply discharged cell has fallen below 2.75V, it goes into a sleep mode and the battery is essentially useless.

1. The Battery module and the C9 audio circuit did not share a common ground, so it is likely that there will be potential different between the two grounds. Therefore it is very important to charge the battery with a separate USB charger. Using the USB from connected audio source equipment (such as computer or media player) to charge up the C9 batteries will trigger the short circuit protection, and might even damage the device and/or connected source equipment.
2. In case your C9 (or the battery module) entered protection mode, you need to remove everything and connect C9 or the battery module to a charger, charge it for at least 10 seconds and the device or battery module will revoke from protection mode and resume normal operation.
3. After replacing or dismounting the battery, the battery module enters protective mode, you need to connect the battery module to a charger, charge it for at least 10 seconds, and the battery module will then revoke from protection mode and resume normal operation.
4. Do not charge and playback both C9 and the connected source (let’s assume that is a DAP) at the same time. The four pieces of 18650 batteries are connected as a +8.4V and -8.4V power supply for the amplification circuit, and there is a set of ground line in between and that is connected to the C9 chassis. The charging circuit via USB-C has its own reference Ground connected to the USB socket. Be reminded that these two Ground are completely independent. If C9 and the DAP are charge and play at the same time, the power supply Ground (C9 Chassis) and charging Ground (USB socket) will short circuit by the charging cable and interconnect between C9 and DAP. C9 will enter protected mode. You can revoke C9 from protection mode by disconnecting everything and charge it for 10 second.
5. You can charge and playback C9 at the same time before the batteries is fully charged. 18650 Lithium battery charge control is divided into two phases. The first phase is constant current charging. When the battery voltage is lower than 4.2 V, the charger will charge with a constant current. The second stage is the constant voltage charging stage, when the battery voltage reaches 4.2 V, due to the characteristics of the lithium battery, if the voltage is high, it will be damaged, the charger will fix the voltage at 4.2 V, and the charging current will gradually decrease. Therefore, if you charge and playback at the same time and your charging rate is faster than discharge rate, the 18650 batteries will reach 4.2V eventually. The problem is, when you continue to charge and playback at this moment, C9 power management cannot enter the constant voltage charge stage, this will put C9 into protection mode. You can revoke C9 from protection mode by disconnecting everything and charge it for 10 second. You are advised to disconnect C9 from charging when the fourth battery LED is flashing in these circumstances.
6. If you charge and playback C9 at the same time and your charging rate is slower than discharge rate, your battery will consume slowly. At certain point, the batteries will drop below 3V and triggered the protection circuit to power off the C9. . You can revoke C9 from protection mode by disconnecting everything and charge it for 10 second and charge up the 18650 batteries. Since deep discharge might damage your battery, you are advised to stop your playback and start to charge up C9 when only 1 charging LED remains flashing.
7. Please do not use USB charger from Huawei mobile device to charge up C9. Huawei has it own quick charge protocol that is not compatible with C9.

 

[Whitigir]

How about a conventional way by charging with 18650 dedicated charger, then pull out the batteries and replace for more hours ?