[Andykong]

So is the C9 in stock at US dealer yet ? I wonder when it will start shipping.

Spoiler

I am still thinking a D9 (DAC-9) will go together nicely with C9, just as long as it sport 4-5 18650. Desktop normally run 12V-20V. So I don’t see it being a limitations at all. May be current consumptions and heat dissipation, but I am sure Cayin can be creative and work up something

Not to mention the new Gan-Fet technology, and the possibility to hook external DC voltage directly, aka external LPSU. I see a huge market to go with C9

Still haven't seen any expected time frame when I'll be able to put all the watts on my head though.

If it helps - my order left China yesterday (to my dealer), expected arrival at dealer is next Friday.

I'm in Singapore.

To answer similar questions at that same time: we have send out C9 to international dealer already, if they have an confirmed order with us, the package is out. However the actual delivery date might be different because of logistic arrangement, waiting period at custom office, and local freight control to lithium battery powered device. We can't keep track of the dates because some of them are FOB transactions. Your local dealer will know better then me.

 

[Nostoi]

Suddenly HD800 is all over the thread, I'll try to response them in one post.

Did I vastly limited the applications for the C9? A lot of people don’t just search any further? I don't really think so, but if this really happened, I'll continue without hesitation. To be honest, I have shared similar thoughts previously (e.g. HERE), I am pretty consistent in steering people away from using HD800 for portable.

To me, using HD800 with battery powered portable amplifier is workable, some portable amp are better then others for this scenario, but please accept the reality that there are limitation you can't solve by more money. If you only listen to "simple"music, with one of two instrument that does not required a lot of dynamic (bot macro or micro),

First of all, those who try to work out the power requirement of HD800 based on electrical engineering principles and specification, I can tell that you know nothing about HD800, or the real game of headphone/amplifier synergy. The reality is, the formula only tell you how much power you need to make is sound loud, but that is not our requirements, right? We want to hear it sing, not to hear how loud it can go.

The biggest problem with battery powered headphone amplifier and HD800 (or 300ohm headphones in general) is insufficient voltage swing. The impedance ranges of HD800 swing between 340 and 650 ohms (HERE), to handle this kind of impedance swing, you amplifier must have very respectable voltage swing. So what kind of voltage swing can you achieve if your amplifier is powered by one 3.7V lithium battery? Sure you incorporate DC to DC regulation circuit to boost the voltage to 10V, 20V, 30V, but experience amplifier builders will tells you that there are procs and cons in using booster circuit, especially when you are going for 20x or 30x voltage gain. The biggest question is, can the booster circuit response fast enough? will it compromise the transient of the playback? In desktop implementation, we can install arrays of capacitors as buffer to support short-term power requirement, the capacitors are not expensive, nor are they difficult to implement, but they need space to start with, something that portable headphone amplifier are lacking.

To certain extend, the power supply of C9 starts at a much better off situation. The four 18650 lithium batteries are connected as a ±8.4V (i.e., 16.8V) battery power supply, this is significantly higher than the commonly used 3.7V USB rechargeable lithium battery. We don't incorporate any DC to DC regulation circuit in our power line, making sure the power supply is direct, extremely fast responding and noise-free.

Yes, we are better than many portable alternatives, but still, when compare to ±24V power supply with a dozen of 20000 uF electrolytic capacitors (just make up some numbers for comparison purpose, please don't take it specifically), C9 is in a very disadvantage position.

There are other factors that makes HD800 or HD800S difficult on portable environment than other 250 ohms or 300ohms headphones, for example, its unique sound signature, huge soundstage, and music genre that are frequently associated with them, ... just to name a few. These I don't want to turn this thread into a HD800 mix and match thread, so I'll stop here. I hope I have make my point: the problem is not whether C9 has enough output power to drive HD800 to 96dB, its the voltage swing that matters, and low-voltage battery powered amplifier has a congenital defect on this issue.

Thank you; very much appreciate your candid and honest response on this thread. The fixation on driving the HD800/S via a portable amp - and when cycling no less - seems rather strange to me, to put it politely.

 

[DaYooper]

Suddenly HD800 is all over the thread, I'll try to response them in one post.

Did I vastly limited the applications for the C9? A lot of people don’t just search any further? I don't really think so, but if this really happened, I'll continue without hesitation. To be honest, I have shared similar thoughts previously (e.g. HERE), I am pretty consistent in steering people away from using HD800 for portable.

To me, using HD800 with battery powered portable amplifier is workable, some portable amp are better then others for this scenario, but please accept the reality that there are limitation you can't solve by more money. If you only listen to "simple"music, with one of two instrument that does not required a lot of dynamic (bot macro or micro),

First of all, those who try to work out the power requirement of HD800 based on electrical engineering principles and specification, I can tell that you know nothing about HD800, or the real game of headphone/amplifier synergy. The reality is, the formula only tell you how much power you need to make is sound loud, but that is not our requirements, right? We want to hear it sing, not to hear how loud it can go.

The biggest problem with battery powered headphone amplifier and HD800 (or 300ohm headphones in general) is insufficient voltage swing. The impedance ranges of HD800 swing between 340 and 650 ohms (HERE), to handle this kind of impedance swing, you amplifier must have very respectable voltage swing. So what kind of voltage swing can you achieve if your amplifier is powered by one 3.7V lithium battery? Sure you incorporate DC to DC regulation circuit to boost the voltage to 10V, 20V, 30V, but experience amplifier builders will tells you that there are procs and cons in using booster circuit, especially when you are going for 20x or 30x voltage gain. The biggest question is, can the booster circuit response fast enough? will it compromise the transient of the playback? In desktop implementation, we can install arrays of capacitors as buffer to support short-term power requirement, the capacitors are not expensive, nor are they difficult to implement, but they need space to start with, something that portable headphone amplifier are lacking.

To certain extend, the power supply of C9 starts at a much better off situation. The four 18650 lithium batteries are connected as a ±8.4V (i.e., 16.8V) battery power supply, this is significantly higher than the commonly used 3.7V USB rechargeable lithium battery. We don't incorporate any DC to DC regulation circuit in our power line, making sure the power supply is direct, extremely fast responding and noise-free.

Yes, we are better than many portable alternatives, but still, when compare to ±24V power supply with a dozen of 20000 uF electrolytic capacitors (just make up some numbers for comparison purpose, please don't take it specifically), C9 is in a very disadvantage position.

There are other factors that makes HD800 or HD800S difficult on portable environment than other 250 ohms or 300ohms headphones, for example, its unique sound signature, huge soundstage, and music genre that are frequently associated with them, ... just to name a few. These I don't want to turn this thread into a HD800 mix and match thread, so I'll stop here. I hope I have make my point: the problem is not whether C9 has enough output power to drive HD800 to 96dB, its the voltage swing that matters, and low-voltage battery powered amplifier has a congenital defect on this issue.

That clears things up for me, and politely. Thanks.

 

[xand]

To certain extend, the power supply of C9 starts at a much better off situation. The four 18650 lithium batteries are connected as a ±8.4V (i.e., 16.8V) battery power supply, this is significantly higher than the commonly used 3.7V USB rechargeable lithium battery. We don't incorporate any DC to DC regulation circuit in our power line, making sure the power supply is direct, extremely fast responding and noise-free.

Yes, we are better than many portable alternatives, but still, when compare to ±24V power supply with a dozen of 20000 uF electrolytic capacitors (just make up some numbers for comparison purpose, please don't take it specifically), C9 is in a very disadvantage position.

There are other factors that makes HD800 or HD800S difficult on portable environment than other 250 ohms or 300ohms headphones, for example, its unique sound signature, huge soundstage, and music genre that are frequently associated with them, ... just to name a few. These I don't want to turn this thread into a HD800 mix and match thread, so I'll stop here. I hope I have make my point: the problem is not whether C9 has enough output power to drive HD800 to 96dB, its the voltage swing that matters, and low-voltage battery powered amplifier has a congenital defect on this issue.

Emphasis mine, above.

I think you're saying that more voltage swing is always better - if so, are you saying that a desktop is always better?

Or are you saying that for SOME headphones, the C9 is as good as a desktop (i.e. actually there is a sufficient voltage swing depending on headphone)?

If you're saying the desktop is always better then.. okay? Not sure that's been the point of the discussion around the HD800, though.

If you're saying that for SOME headphones, the C9 is as good as a desktop, then the question for the HD800 is which side of the line it falls on, and with respect your argument is a straw man fallacy - https://en.wikipedia.org/wiki/Straw_man. You're of course right that the cited measurements/calculations are primarily based on the possible volume in decibels, but a headphone amplifier is all about what voltage and current the amplifier can deliver anyway?

Your choice of voltage as the reason is quite interesting because voltage tends to be linked to the dB SPL target. Using a lower sensitivity number than from Stereophile (I used the minimum sensitivity from https://reference-audio-analyzer.pro/en/report/hp/sennheiser-hd-800.php#rw2) - 96 dB SPL/V, the question should be whether, at all relevant impedence values, there is sufficient power, voltage, and current? Happily, the voltage doesn't change much, and the power seems to be something the C9 is capable of: As long as the dB SPL target is 115, if we use that minimum sensitivity number (96 dB SPL/V), whether the impedence is 1 or 700, the required voltage is below 9 V.

If we use the Stereophile reported sensitivity number (102 dB SPL/V), which is what Sennheiser itself publishes (https://www.bhphotovideo.com/lit_files/150621.pdf) and a dB SPL target of 115, the voltage required is even lower - always below 4.5V.

Try it out yourself, https://www.headphonesty.com/headphone-power-calculator/. (Note that I also tried to find a efficiency number - which should be in dB(1mW)), but it seems elusive).

I'm very happy to be corrected, by the way - by Andy or anyone else. I may very well be misunderstanding or have missed something. For example, trying to calculate what voltage swing is required using the method above might be wrong - by all means please describe how the required voltage swing (to determine whether the headphone can be driven by a certain amp) might be calculated?

While I agree that using HD800 while cycling is... an interesting use case - one far more common use case is being able to listen to the HD800 all around a house (depending, for example, on the furniture in each room, whether it is nice outside on the balcony or in a garden chair, and how quiet it happens to be at the relevant time) - and surely you can agree this scenario is where something like a C9 has an advantage, even over something like the Sony DMP-Z1 (which is 2.5kg), or heaven forbid an amp which requires a mains plug.

 

[DaYooper]

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.

 

[xand]

To change the topic a little, is it safe to say that the Utopia can be driven well by the C9?

 

[xand]

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.

No no, you need the HA-300B. Obviously.

 

[DaYooper]

No no, you need the HA-300B. Obviously.

Maybe, but the $1500 will soothe my disappointment for a while.

 

[Whitigir]

Doesn’t seem that Cayin started shipment of C9 until today. It is gonna be a while to wait....and I thought release date was 20th instead of 30th LOL

 

[jonstatt]

I think you're saying that more voltage swing is always better - if so, are you saying that a desktop is always better?

Or are you saying that for SOME headphones, the C9 is as good as a desktop (i.e. actually there is a sufficient voltage swing depending on headphone)?

I'm very happy to be corrected, by the way - by Andy or anyone else. I may very well be misunderstanding or have missed something. For example, trying to calculate what voltage swing is required using the method above might be wrong - by all means please describe how the required voltage swing (to determine whether the headphone can be driven by a certain amp) might be calculated?

I think Andy is being misunderstood. He didn't say the voltage wasn't sufficient. I think he is saying its the speed at which the voltage can swing from one point to another. The bigger the voltage required the more rapidly the swing needed. At battery power you are at a disadvantage especially if you are boosting output voltage above the battery voltage itself. @Andykong I believe you were referring actually to the slew rate

The C9 will potentially sound as good as desktop amps for headphones and iems intended for portable use. I.e. less demanding such as an Audeze 4z vs a 4.

The HD800 varies in impedance substantially across its frequency range. The calculator and stats are based on the output and drive at one frequency point typically.

 

[xand]

I think Andy is being misunderstood. He didn't say the voltage wasn't sufficient. He said its the speed at which the voltage can swing from one point to another. The bigger the voltage required the more rapidly the swing needed. At battery power you are at a disadvantage especially if you are boosting output voltage above the battery voltage itself. @Andykong I believe you were referring actually to the slew rate

The C9 will potentially sound as good as desktop amps for headphones and iems intended for portable use. I.e. less demanding such as an Audeze 4z vs a 4.

The HD800 varies in impedance substantially across its frequency range. The calculator and stats are based on the output and drive at one frequency point typically.

Thanks - assuming that's so, apart from simply seeing if a demo sounds good, is there any generally available method to calculate the slew rate requirement (or to determine the slew rate specification of an amplifier)? I did try a quick Google but nothing seemed on point.

I should mention that generally the impedence and sensitivity are available for each frequency (and I used the minimum sensitivity, as that was the "hardest" tests based on the algorithms the calculator was using).

Edit: reading a bit more about slew rate it doesn't seem to be power source dependent as much as component dependent see for example - it's simply an op amp spec: https://www.ti.com/product/TLV2774

 

[jonstatt]

Thanks - assuming that's so, apart from simply seeing if a demo sounds good, is there any generally available method to calculate the slew rate requirement (or to determine the slew rate specification of an amplifier)? I did try a quick Google but nothing seemed on point.

I should mention that generally the impedence and sensitivity are available for each frequency (and I used the minimum sensitivity, as that was the "hardest" tests based on the algorithms the calculator was using).

Edit: reading a bit more about slew rate it doesn't seem to be power source dependent as much as component dependent see for example - it's simply an op amp spec: https://www.ti.com/product/TLV2774

That's because TI are quoting it in relation to their op amp chipsets. A better article is this
https://mynewmicrophone.com/what-is-amplifier-slew-rate-does-it-affect-performance/

In portable amplifiers the effect on transients in particular should be noted because typically a portable amp is running much nearer its limits compared to a power amplifier for a surround sound system.

 

[xand]

Thanks - so perhaps headphone amp manufacturers should also be reporting the number - and that way maybe it'll be possible to figure out based on comparisons amongst various amps for a specific headphone, what the headphone "requires"?

Andy is that what you meant?

Any chance of specs for say the C9 and the iHA-6?

 

[DarginMahkum]

A new video on Facebook:

https://fb.watch/3oJnFsuhBG/

 

[cheznous]

Any reputable dealers in the UK that will be selling this?
I normally buy from Hifonix but they are not dealers for Cayin.