Cayin C9: Dual Nutube, Fully Balanced Class A/AB Portable HeadAmp

[fuhransahis]

@Andykong a question if I might - the manual shows that in Pre mode the C9 was tested with a 4.2V input in High gain and 8.4V in Low, would there be any issue in using a higher voltage (around 7V) for input when in High gain mode? Not sure if these specs were just how it was tested or if they are the recommended max figures.

 

[Andykong]

N6ii Titanium will be competing against AK SE180 I think ?

This is interesting as a Known Lixurious brand has brought itself down a few levels to compete to Cayin, or Cayin has brought itself up a few levels to compete against AK. Could be both

However, it is very interesting to see the direction this hobby is heading toward

I have shared my hard feeling regarding the global shortage of electronic and electrical components. With that in mind, supply chain might become the biggest battlefield. Company with strong engineering but weak supply chain will suffer.

Unfortunately, supply chain of Chinese boutique brands is quite often the weaker link in their system.

 

[Andykong]

Hmm, I listened for about 1 1/2 hours last night on tube mode and it was quite warm.. hopefully that’s normal. I’ve had lots of tube amps in the past in 2 channel so I know they can run quite hot.

For classical tube amplifier, the heat from the vacuum tube is substantial. The Nutube in C9 uses LED to replace the filament, so it basically run cold, the extra heat of tube mode is originated by extra current required by Nutube over the alternative Solid State timbre circuit, so it does run warmer but the different is not as significant as normal vacuum tube vs solid state amplifier.

 

[Andykong]

Finding the Cayin case solves the fry an egg issue, unless you need to fry an egg than that is a good thing.

There is something well done going on here with how Cayin designed that case. No leather here, the black material must be an excellent conductor of energy. Seems it is allowing the heat sink metal of the case to dissipate the heat at a rate that keeps up with its generation on the surface of the C9s housing. I think this is just material science and attention to detail at work here.

Yes a lot cooler touching the case vs the C9.
What I do not know is how much heat is reduced by the case providing separation from vs dissipating heat, likely both going on here.

Yeah, I would think the case would insulate some thermal between the C9 body and the outer leather itself ?

Whitigir is correct, the case makes the C9 more "practical" because you are not touching the metal chassis directly, so you can hold it in your hand comfortably when you playback. The temperature of the the C9 chassis will increase slightly when it is operated inside the case, but only by a few degree C, it should well within the recommended operation condition of C9. Be reminded that the components are build to last much higher temperature than we feel comfortable to touch. For example, 50°C is consider burning hot when you touch the equipment chassis, but 50°C is well-acceptable for PCB and electronic components.

 

[Andykong]

You could save some $s and go with a Lotoo PAW6000 it sounds great with the C9 has a true line out, easy to use software, it will even flip the screen so it is facing the right way when sitting on top the C9.

If someone has the C9, LPGT and the PAW and compared them we could find out if there is a big improvement.

Likewise a comparison between the N6ii A02 to the PAW6K or LPGT these are the only three DAP options with a true line out, (I think).

L&P products may still qualify as true line out, with these the DAPs volume control is still in the chain so not sure.

On the P6Pro volume control is relay based with all relays on (I think) in line out mode when you engage it. I can say it sounds great as a source with the C9.
I have heard an opinion that it was the best combination for a DAP with C9 available today.

Anyone please feel free to correct any of this if my assumptions are incorrect.

These are the only three DAP options with a true line out? I assume you are referring to balanced line out. For the record, Cayin N8, N6ii(E02) and N6ii (A02) offers unamplified dedicated line out, so we have three entries under one brand already.

Both R8 and new R6 from HiBy also offer DAP with true balanced line out.

The XLR5 output of AK Kann Cube also offered true balanced line out, but you need to make the right cable for that purpose.

Not sure about other models, I'll be grateful if someone can compile a complete list and I'll pin this to the bottom of the opening post of this thread.

 

[Andykong]

Geez.. this C9 continues to amaze me. Listening to this and even a YouTube mp3 sounds fantastic,



PS... I’ll consult the manual tomorrow but can the C9 be used while charging from an external battery or does the power need to be off?

Officially we don't recommend charge and playback at the same time because you might defeat the overcharging protection circuit when you do that. Other then that, short-term charging and playback under a well-ventilation condition is not a problem. When I run in my C9, I'll charge and playback at the same time occasionally, with that I set an alarm clock in my mobile phone to alert me after 60-90 minutes, depends on the battery status indicator, and I'll stop charging when the fourth LED start to blink. Last but not least, your amplifier will run hotter when you charge and playback at the same time, so ventilation is very important.

If you are not listening to headphone when you charge your C9, please turn off the C9 during charging. C9 is a pure analog device, there is no boot time delay so there is no point to keep it running when you are not using it.

 

[Andykong]

@Andykong a question if I might - the manual shows that in Pre mode the C9 was tested with a 4.2V input in High gain and 8.4V in Low, would there be any issue in using a higher voltage (around 7V) for input when in High gain mode? Not sure if these specs were just how it was tested or if they are the recommended max figures.

I believe you are referring to the figures in Input Sensitivity of the specification table. That figures might server different purpose from what you anticipated.

First of all, C9 is a headphone amplifier with split-voltage power supply, the 4x18650 batteries provides stable, rapid transient response, low internal resistance bipolar voltage to C9 without needing DC to DC regulation circuit. That's why the C9 can offer maximum rated output at high or low gain, at Class A or Class AB.

However, while C9 is capable of delivering the same maximum rated power output in regardless of High or Low gain setting, it does required a higher input level in order to deliver that power output, and that's where input sensitivity kicks in. Let's take a look at the table:

For balanced line in, if you set C9 to High Gain, then your line input must be rated at 3.0V (or above) otherwise C9 cannot deliver the maximum rated output power as specified. Likewise, if you set C9 to Low Gain, then your line input must be rated at 6.0V (or above). For instance, if your balanced line is rated at 4V, you need to set the amplifier to High Gain IF YOU NEED full power output of C9.

Similarly, for balanced Preamp input, if you set C9 to High Gain, then your line preamp must be rated at 3.0V (or above). If you set C9 to Low Gain, then your Preamp input must be rated at 6.0V (or above). This is less of a problem relatively because preamp should have voltage gain, so 6V is very common and you can stick with low gain even when you need all the power of C9.

What happen if we use 4.4V balanced line input or 7V balanced preamp input to C9 when we set C9 to high gain? That's quite OK, you can reach full power at a earlier volume setting, but if you continue to turn up the volume after that, you might end up with higher distortion, so as long as you use the volume control of C9 (or your source in case of Pre-amp input mode), you are perfectly OK.

 

[Andykong]

And the Fantasy. I like how the Fantasy looks better.

Yeah the Fantasy looks real nice. We should ask @Andykong to prioritize us C9 users in the tour!

There is still a lot of opening in the tour, so whoever joined the tour with C9 in his equipment list, the chance is very good.

Just in case other readers are not family with this top, Cayin is planning a tour on our Fantasy IEM. If you are interested in checking out our latest Beryllium-plated single DD IEM, please sign up HERE.

 

[RTodd]

These are the only three DAP options with a true line out? I assume you are referring to balanced line out. For the record, Cayin N8, N6ii(E02) and N6ii (A02) offers unamplified dedicated line out, so we have three entries under one brand already.

Both R8 and new R6 from HiBy also offer DAP with true balanced line out.

The XLR5 output of AK Kann Cube also offered true balanced line out, but you need to make the right cable for that purpose.

Not sure about other models, I'll be grateful if someone can compile a complete list and I'll pin this to the bottom of the opening post of this thread.

Hello Andy,

Sorry about leaving out Cayin products trying to clarify what true line out options there are and what qualifies a DAP or source to be included as true line out.

When using line out on the DAP/source if the answer to both of these questions is yes, does that qualify as true line out?
Or is there a third question?

First is the volume control off the DAP/source no longer in the output circuit?

Second is the amplification circuit of the DAP/source no longer in the output circuit?

There is potentially a third question, related to the gain setting of the DAP/source if that setting only raises/lowers the voltage level would having that setting “not” disqualify the DAP/source from meeting the true line out classification?

The third question may be;

Third does the gain setting of the DAP/source only effect the voltage level of the output?

If we can clarify the questions I think we will have a black and white answer that could be used to create a list of DAP/sources, or at least clarify what to look for when choosing a DAP/source to best pair with an amplifier.

 

[elira]

Is the C9 good for full size headphones or just for IEMs?

 

[bluestorm1992]

Is the C9 good for full size headphones or just for IEMs?

Full size friendly too. People here have paired it with Diana V2, ZMF VC, HD800s, various ATH models, and so on.

 

[elira]

I’ve just ordered a C9, I hope it lives up to the expectations. I’ve had bad experiences with portable amps, in specific the WA11 and the Romi BX2(+). The C9 seems to have great features and I like the replaceable batteries. Let’s see how it goes.

 

[Nostoi]

Is the C9 good for full size headphones or just for IEMs?

Yes, sir. Closed back fiend here and it responds marvellously to them all, from the modest MSR7B to the lofty ZMF VC and all in-between.

 

[Nostoi]

I’ve just ordered a C9, I hope it lives up to the expectations. I’ve had bad experiences with portable amps, in specific the WA11 and the Romi BX2(+). The C9 seems to have great features and I like the replaceable batteries. Let’s see how it goes.

I had the BX2 Plus and never had any issues with it - great amp, in fact. But the build quality on the C9 is in a different league.

 

[Andykong]

Hello Andy,

Sorry about leaving out Cayin products trying to clarify what true line out options there are and what qualifies a DAP or source to be included as true line out.

When using line out on the DAP/source if the answer to both of these questions is yes, does that qualify as true line out?
Or is there a third question?

First is the volume control off the DAP/source no longer in the output circuit?

Second is the amplification circuit of the DAP/source no longer in the output circuit?

There is potentially a third question, related to the gain setting of the DAP/source if that setting only raises/lowers the voltage level would having that setting “not” disqualify the DAP/source from meeting the true line out classification?

The third question may be;

Third does the gain setting of the DAP/source only effect the voltage level of the output?

If we can clarify the questions I think we will have a black and white answer that could be used to create a list of DAP/sources, or at least clarify what to look for when choosing a DAP/ source to best pair with an amplifier.

I can only comment on Cayin's approach to line out, for obvious reason.

To certain extend, there won't be any black and white answer because there is no standard in DAP line out, everyone is doing their own version of line out. Line out in home audio has a fairly standardize practise, I prefer to stick with that standard if possible.

In home audio, line out is fixed level un-amplified output from your source: CD player, DAC, phono amp, ... etc. Single-ended line out should be 2V to 2.2V, Balanced line out should be 4V - 4.4V. There shouldn't be any "gain" control in line out because they are supposed to be unamplified signal. There shouldn't be volume control because they are supposed to be fixed level signal.

Cayin implements the line out of our DAP under the same principles. Unless we stated the line out as shared line out or shared output with phone out, it will be fixed level un-amplified output from the DAC circuit (buffered output from LPF). The only feature that we added to our line out was choice of L, M, L level. In order to allow our DAP to pair with headphone amplifier with very high gain, we have attenuated our line output level to around 50% and 75% of the standard line output level.

If you have following our previous discussion along on this subject (HERE), you probably aware that there are a lot of "variation" of line out from DAP. C9 is flexible enough to work with most of them satisfactory, but if you are searching for an ideal line out source for C9, I'll suggested you start with something that is UNAMPLIFIED (i.e., no gain in the signal) and FIXED LEVEL. (i.e., no volume control).