[Bosk]

The Nutubes takes about 20 minutes to really dishes out it whole performances

Its very difficult to gauge one component from a piece of equipment's effect on performance, but are you able to comment on the character of nutubes compared with the sterotypical sound of real tubes? Very curious to know how close they come to the real thing.

 

[Whitigir]

Its very difficult to gauge one component from a piece of equipment's effect on performance, but are you able to comment on the character of nutubes compared with the sterotypical sound of real tubes? Very curious to know how close they come to the real thing.

Sweet and fluid vocal, mid. It had vivid textures and the complexity...I would say that it has a faster transient than classic tubes, but still carry the tubes characteristic in the lower bass. Somehow it also has very dynamic mid bass as well. That could be due to many things and I think one of the reason is that it is input tube stage, rather than output. It is fair to say that the Nutubes is a hybrid between solid and classic tubes in the C9. The soundstage is less expansive than SS, also it is more intimidating than SS

this is by matching with a very neutral source , the MAX

if you ask me to judge the tier level of C9 tubes implementations, I would say that it is a very sophisticated highend sounding for a tube amplifiers

 

[normie610]

Sweet and fluid vocal, mid. It had vivid textures and the complexity...I would say that it has a faster transient than classic tubes, but still carry the tubes characteristic in the lower bass. Somehow it also has very dynamic mid bass as well. That could be due to many things and I think one of the reason is that it is input tube stage, rather than output. It is fair to say that the Nutubes is a hybrid between solid and classic tubes in the C9. The soundstage is less expansive than SS, also it is more intimidating than SS

this is by matching with a very neutral source , the MAX

if you ask me to judge the tier level of C9 tubes implementations, I would say that it is a very sophisticated highend sounding for a tube amplifiers

Congrats! Now you have the perfect setup for audiophile on a bike! Glad the C9 work out for you man

 

[Whitigir]

Congrats! Now you have the perfect setup for audiophile on a bike! Glad the C9 work out for you man

Except that it get pretty warmed up. Probably not a good idea to run class A, tubes, and keeping it inside the backpack lol

 

[normie610]

Except that it get pretty warmed up. Probably not a good idea to run class A, tubes, and keeping it inside the backpack lol

Hahahaha....yes I forgot that class A can run pretty hot. Is there a major sound difference between A and AB tube?

 

[Bosk]

Except that it get pretty warmed up. Probably not a good idea to run class A, tubes, and keeping it inside the backpack lol

My old ALO CDM was the same, in fact it was pretty effective to use as a hot water bottle when listening in bed.

 

[Whitigir]

Eventhough I have the C9 warmed up by a lot when using Tube, Class A, Balanced all around. I am very happy because I know that it is dissipating the heat very effectively through it small chassis

Alien Eyes for the night !

 

[bluestorm1992]

Eventhough I have the C9 warmed up by a lot when using Tube, Class A, Balanced all around. I am very happy because I know that it is dissipating the heat very effectively through it small chassis

Alien Eyes for the night !

More thoughts and impressions please!

 

[Bosk]

Eventhough I have the C9 warmed up by a lot when using Tube, Class A, Balanced all around. I am very happy because I know that it is dissipating the heat very effectively through it small chassis

Alien Eyes for the night !

It sounds superficial but Korg should work on tweaking the illumination color if the technology allows it. Nothing beats warm orange tube glow on a cold winter's night, except a real fire which I suppose it has the psychological effect of representing.

 

[Zambu]

Can we at some point get a picture of @Whitigir riding his bike with C9+MAX+HD800

 

[jmills8]

Can we at some point get a picture of @Whitigir riding his bike with C9+MAX+HD800

Or riding a unicorn.

 

[Andykong]

Another thing to keep in mind, my ATH-R70x is 3.5mm terminated, not balanced. So, I was running C9 in low gain with a volume set to 50% from SE output. If I would to run it off the BAL output, volume would have been much lower since:

Spoiler

Since Twister6 has raised an interested topic regarding volume would have been much lower if run it off the BAL output (or maybe high gain will also cause similar effect), I'll take this opportunity to explain the volume and gain control of C9 in detail. This is one of the critical designs that facilitate C9 to work well with both IEMs and headphones and the implementation is way more complicated than we anticipated in the very beginning.

Gain Control, Volume Control and Input Sensitivity

The C9 volume control is divided into two parts. The front-end control is a high quality 4-channels ALPS potentiometer, this will provide a firm, reliable and familiar rotation control experience to our users. The back end of the volume control system is a PAIR of low distortion 130 steps resistance ladder stereo electronic volume, MUSES72320, this is a very high quality volume control chip, it is more sophisticated that then PGA2311A used in N8 DAP. The PGA2311A has internal op-amp that can’t be bypass and that will introduce a small amount of background noise and its own tonal characteristic to the circuit. The MUSES72320 integrated with our discrete headphone amplifier circuit completely, instead of relying on internal Op-Amp. Each MUSES72320 is equivalent to 4 potentiometers in one chip: 2 for stereo volume and 2 for stereo gain, we need to install a pair of them for fully balanced implementation.

​

Although it comes with its own gain circuit, we want to further enhance the gain control of C9, so we have added a preliminary gain control circuit before the MUSES72320 electronic volume control, and use a MCU to select between internal gain circuit and our own gain circuit according to the volume level setting. For the record, we have two MCU in C9, one for volume/gain control, and the other in Power management circuit.

The ALPS + 2xMUSES72320 in C9 delivers a volume control system that is very precise, highly linear, and extremely flexible so that you'll have enough "room" to adjust your volume from highly sensitive IEM to full size headphones. During the critical volume range (~63dB to -5dB), we offer 0.5dB attenuation per step, and that span across from slightly before 9 o'clock position to 4 o'clock position of the ALPS volume knob, roughly speaking.

​

Take Alex's little experiment for example. When you change from single-ended mode to balanced mode, the output power will indeed increase significantly, 4 times more at 150+ Ohms, or more than 3 times below 150 Ohm. However the volume position will not go down linearly to 1/3 or 1/4 of original position. That's because power vs dB is a logarithmic function, not a linear function. To quantify the dB vs power relationship, 4 times more power will increase volume by 6dB (check WiKi for detail explanation), and in C9 volume control, that will be 12 steps, or from 12 o'clock (61/130) to 11:15 o'clock (49/30)

Another factor that affects the relationship between gain control and output power is input level. We have documented that in the input sensitivity section of our specification table.

​

If you are in Line input mode, C9 can deliver the stated output power in low gain IF your front-end can meet the output level as stated in the Input Sensitivity of our specification table, that’s why didn’t list high or low gain setting as an variable in power rating. For instance, you only need 1.5V Single-ended and 3.0V Balanced in high gain for C9 to deliver the rated output power, but if you switch to low gain, you need 3.0V Single-ended and 6V balanced for C9 to deliver the same maximum rated output power. Similarly, if you are using PRE-amp input mode and your preamp (or phone out) offers adequate output level (e.g., 8.4V from A02), you can achieve maximum output power at low gain.

The question is, do you need the extra power provided by high gain even when your output level does not meet the requirement as stated in the input sensitivity table? This is more a headroom issue, so you can consider high gain as extra 6dB headroom at difficult load rather than how many watts is needed to produce 100dB loudness at 1 kHz. On the other hand, headroom is a personal requirement because it also depends on music genre, dynamic range of music passage and/or person preference in music presentation. In my person experience, if the sensitivity of my headphone is not too low (e.g, enough sound pressure before 3 o'clock position), then I should have enough headroom even at low gain. For your reference, from 3 o'clock position (step 109/130) to max volume is roughly 13dB. I prefer to stay in low gain all the way because low gain offers slightly better dynamic range and SNR over high gain (again, check the specification table for the exact different at different mode).

 

[Andykong]

Then your IC will also be very important

Thanks for the early impressions. Maybe BX2 has a more of amplifications stages, but as Andy said, it may not have enough swing voltage/slew rate coming off the batteries ? So , C9 is a good choice here, low gain and 50% is enough.

Alex was comparing to volume knob position which, in the case of C9, is dictated by a volume setting table we set arbitrarily to accommodate the IEM and headphone market at the same time. We can alter the volume setting table to produce the same output at 20% instead of 50% volume setting, that will change the user impression completely, rating C9 as a very powerful amplifier, but then we can't offer enough adjustment for sensitive IEM.

 

[Andykong]

Holy Cow!!! He arrived !!!!

Here is how I stacked him up and I chose Max as my line out over other players after the auditioning

And a Pelican Case to carry this stack with me anywhere I would love to.

The stack still allows removable battery tray
The stack allows Max to be slipped out of his Case
The stack allows removable solution for each piece if needed
The Stack allows laying Max face down without worry as there is a case

The Stack solution can be purchased by Walgreen or DrugMart in the Picture hanging isle

You will notice that I arranged my Pelican Case carefully to keep both the player and stack in place including the Interconnect. The explanation is that this is my “EndGame” IC, the Furutech doesn’t like to be inserted and removed too many times. So I carefully Matched up the other DAPS that I have on hands and chose the best to let it stays this way. They are officially “Married”

What made this stack stands out with Max as a source ? Well, Soundstage, clarity and airiness, details, imaging are much better than other DAPs!!!

You may ask why am I using stock cables outlet on Hd800s, well because my main is the HD800S-Anniversary and so she stays home with the best cables I have had

Amazing.

You use Pelican 1170, that certainly will provide ample space for your stack, I was hoping that 1120 can work for me, but 7.3" seems very tight even when I use L-shape 4.4mm connectors. I use a "softer" L-connector cable when I travel, I'll switch to the Sommer Excelsior Blue Water with Plussound Gold Plated 4.4mm connector at home/office, and Cayin stock cable at shows and events. Can't have the luxury to "marry" a cable with C9, good for you.

I attached some pads so I can also flip around the C9 and navigate the Max screen. It doesn’t look all that bad

I am looking for round rubber feet like this, couldn't find it so far, only the circular but flat "bumper" feet available locally.

 

[Andykong]

Cayin's Chinese New Year Holiday Announcement

The Chinese New Year is around the corner, all teams in Cayin will be having their yearly holiday starting from this Sunday.

Holiday period: 7 Feb 2021 to 20 Feb 2021

We'll resume office operation on 21 Feb 2021

All members of Cayin wish everyone an amazing Year of the Ox.