[DaYooper]

It is also interesting that you can try Cayin N8 with Korg Tube SE as a Preamplifier into a C9 with Tube input stage for a power Amp !! Korg and Korg.

Or...any iBasso with amp9

 

[eskamobob1]

No gunna lie. I still just dont get it. They say pre-in mode just sets volume on the amp to max. How is that any different than just turning the dial up?

 

[Whitigir]

No gunna lie. I still just dont get it. They say pre-in mode just sets volume on the amp to max. How is that any different than just turning the dial up?

This one Bypass the Volume control functions on C9, or set to 0db attenuation

You can also utilize the volume control on C9 if you so preferred . Just do not enable Pre button on the side. It does the same thing, just that now you have 2 volume to control instead of one

 

[eskamobob1]

This one Bypass the Volume control functions on C9, or set to 0db attenuation

You can also utilize the volume control on C9 if you so preferred . Just do not enable Pre button on the side. It does the same thing, just that now you have 2 volume to control instead of one

I just don't get why that is desirable over having 2 vol control

 

[Whitigir]

oh well, while the Pre-In and the Pre feature is actually exciting to have. I was having a lot of fun to toy around, but I would gladly be doing real “line out” into C9 any given time. There is a much more defined soundstage and imaging compared to the Pre-in features from phones out. Beside, the Line Out has a much more blacker back-ground. This alone is a winner. I am glad to have Max as a source for the C9

 

[newworld666]

Unfortunately I won't buy this amp as I intended to use it with an HEDDphone ..
I could temporarily find a way with the Centrance M8V2. It includes a DAC, so a different concept, but it's an intermediate way between moderate power amps (less than 2x1.4W) like this C9, the BX2/Less plus or the new iFi Diablo and the best I could get with a 2x6W THX887 amp.

But ! As I am a regular IER-Z1R user, I am a bit surprised that the C9 could be an improvement compared to the WM1A, as I couldn't catch till now any significant improvements with any external amps I used (out of any of my daps R6pro, M11, Kann Alpha, WM1A, Win10 +SMSL M500).

With the HEDDphone, for sure, it's very easy to catch amazing improvements in low and ultra low frequencies as it becomes "clear" in this range with impressive fast impacts with or without passing through a 2x6W THX amp, though measurements (with a non pro system like miniDSP ears) doesn't show any noticeable difference in response curves (nearly flat from 20hz to 20kzh), I would say clearly the amp makes a difference to move the AMT drivers, but for IER-Z1R ??? .

If there is an improvement with such IEM, in which area can it be eared ? I think frequency response won't change at all, so ne need to measure, but where should I get some improvements that a simple 2x6W THX887 doesn't offer me compared to my WM1A ? Are my 60yo ears already out of the race ?

 

[Whitigir]

Unfortunately I won't buy this amp as I intended to use it with an HEDDphone ..
I could temporarily find a way with the Centrance M8V2. It includes a DAC, so a different concept, but it's an intermediate way between moderate power amps (less than 2x1.4W) like this C9, the BX2/Less plus or the new iFi Diablo and the best I could get with a 2x6W THX887 amp.

But ! As I am a regular IER-Z1R user, I am a bit surprised that the C9 could be an improvement compared to the WM1A, as I couldn't catch till now any significant improvements with any external amps I used (out of any of my daps R6pro, M11, Kann Alpha, WM1A, Win10 +SMSL M500).

With the HEDDphone, for sure, it's very easy to catch amazing improvements in low and ultra low frequencies as it becomes "clear" in this range with impressive fast impacts with or without passing through a 2x6W THX amp, though measurements (with a non pro system like miniDSP ears) doesn't show any noticeable difference in response curves (nearly flat from 20hz to 20kzh), I would say clearly the amp makes a difference to move the AMT drivers, but for IER-Z1R ??? .

If there is an improvement with such IEM, in which area can it be eared ? I think frequency response won't change at all, so ne need to measure, but where should I get some improvements that a simple 2x6W THX887 doesn't offer me compared to my WM1A ? Are my 60yo ears already out of the race ?

I am not much a stacking person , but this is good ! Dynamic, imaging, resolutions are all a notch up.

 

[twister6]

Unfortunately I won't buy this amp as I intended to use it with an HEDDphone ..
I could temporarily find a way with the Centrance M8V2. It includes a DAC, so a different concept, but it's an intermediate way between moderate power amps (less than 2x1.4W) like this C9, the BX2/Less plus or the new iFi Diablo and the best I could get with a 2x6W THX887 amp.

But ! As I am a regular IER-Z1R user, I am a bit surprised that the C9 could be an improvement compared to the WM1A, as I couldn't catch till now any significant improvements with any external amps I used (out of any of my daps R6pro, M11, Kann Alpha, WM1A, Win10 +SMSL M500).

With the HEDDphone, for sure, it's very easy to catch amazing improvements in low and ultra low frequencies as it becomes "clear" in this range with impressive fast impacts with or without passing through a 2x6W THX amp, though measurements (with a non pro system like miniDSP ears) doesn't show any noticeable difference in response curves (nearly flat from 20hz to 20kzh), I would say clearly the amp makes a difference to move the AMT drivers, but for IER-Z1R ??? .

If there is an improvement with such IEM, in which area can it be eared ? I think frequency response won't change at all, so ne need to measure, but where should I get some improvements that a simple 2x6W THX887 doesn't offer me compared to my WM1A ? Are my 60yo ears already out of the race ?

I only tested IER-Z1R briefly 3 yrs ago at CanJam NYC, and WM1Z didn't have sufficient power to drive it properly, treble was quite splashy. Z1R is a lower sensitivity IEM that scales up with more power. WM1A/Z DAPs are rated at only 30mW (@32ohm, 3.5mm SE) and 125mW (@32ohm, 4.4mm BAL). Just to put it in a perspective of comparison, C9 offers 700mW (@32ohm, 3.5mm SE) and 2600mW (@32ohm, 4.4mm BAL). Of course, there is a lot more than just power, you are also dealing with tonality of ss vs tube, class A vs class AB, etc. Thus, I'm curious why you are surprised that C9 would drive Z1R better than WM1A?

 

[lumdicks]

I only tested IER-Z1R briefly 3 yrs ago at CanJam NYC, and WM1Z didn't have sufficient power to drive it properly, treble was quite splashy. Z1R is a lower sensitivity IEM that scales up with more power. WM1A/Z DAPs are rated at only 30mW (@32ohm, 3.5mm SE) and 125mW (@32ohm, 4.4mm BAL). Just to put it in a perspective of comparison, C9 offers 700mW (@32ohm, 3.5mm SE) and 2600mW (@32ohm, 4.4mm BAL). Of course, there is a lot more than just power, you are also dealing with tonality of ss vs tube, class A vs class AB, etc. Thus, I'm curious why you are surprised that C9 would drive Z1R better than WM1A?

I have WM1A, C9 and Z1R, and I agree every words above.

 

[Whitigir]

I have WM1A, C9 and Z1R, and I agree every words above.

Substantial improvements with C9, not just little

 

[lumdicks]

Substantial improvements with C9, not just little

Overall control, imaging, dynamics and high low extension are just in different league with any standalone DAP.

 

[Andykong]

​

Dual input mode: LINE input vs PRE-amp input

The Dual input mode in C9 is designed to widen the choice of front-end, not to serve as an alternative sound signature for the same DAP, but we are not surprised that this will also work out. When something is done right, it will enable a lot of possibilities.

When I wrote the C9 introduction, the first thing I put down was a brief summary of Cayin’s history: “We have developed over 400 products to date, ranging from CD players to speakers, all of which provide the same high-quality benchmark, but our amplifiers have been particularly well-received within the audio community.” We come with a long history in design and manufacturing audio amplifiers before we venture into headphone amplifier, and it’s just natural that when we want to develop a reference grade portable headphone amplifier, we refer to our experience in speaker amplifier design. If you ask an audiophile what is your options when you want to upgrade your amplifier? One of the answers that will come up very often is to upgrade from integrated amplifier to Pre-amp/Power Amp configuration. We know Pre/Power design is superior over integrated amplifier, so why can’t we implement a Pre/Power design in our flagship portable headphone amplifier? We have the expertise and experience, some of our integrated amp has pre-amp output (e.g., HA-1AMK2), and some of our high-power integrated amplifier has a pre-amp input to turn the amplifier into a pure power amplifier, and we decided to take the later route when we design the C9: to provide a PRE-amp input mode (aka. Pure power amp. mode) on top of integrated amplifier approach.

Pre-amp input in CS-150A, our latest high-power tube integrated amplifier​

So what exactly is a pre-amp? The explanation from Wiki is very user-friendly so I’ll quote that here for our reference:

A preamplifier (preamp or "pre") is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier and a loudspeaker. Without this, the final signal would be noisy or distorted. …… In an audio system, they are typically used to amplify signals from analog sensors to line level. The second amplifier is typically a power amplifier (power amp). The preamplifier provides voltage gain (e.g., from 10 mV to 1 V) but no significant current gain. The power amplifier provides the higher current necessary to drive loudspeakers.

While the level of voltage gain varied from brand to brand, and from model to model, but the idea is well-explained. To summarize, line output is a fixed level un-amplified output. In DAP, the common practice is to take the LPF output after DAC as-is, a more delicate implementation will add a line driver or a buffer to make sure the impedance and output level can reach the de facto level (2V single-ended, 4V or 4.4V balanced). A pre-amp output is a variable level output (i.e., volume controlled) with voltage gain. There shouldn’t be any current gain from preamp output. The headphone amplifier circuit in DAP will amplifier the signal at voltage and current, so that we can drive our headphone satisfactory. Most, if not all, headphone amplifier, portable or desktop, is an integrated amplifier for headphone application, so it will combine volume control, voltage gain and current gain in one box.

PRE-amp vs Line input mode with maximum volume.

When C9 operates in PRE-amp input mode, it is basically functioning as a power amplifier with volume control disable (set to 0dB attenuation) and all amplification circuit operate in full capacity. Theoretically if you use maximum volume in Line input mode and let your DAP control the volume, the signal processing will be the same as PRE-amp input mode, but my personal impression prefers PRE-amp input mode because I get better amplification control, the sound is tight and focused, and the music is more lively. It’s like a water supply system with 5 water taps installed in different location. Theoretically if I turn all water taps to fully open position, the water supply is in its full capacity, but will that be 100% equivalent to water supply when all water taps are removed? Ultimately, this is up to C9 users to experience the difference between the two input modes if you have an appropriate source that offer comparable Line out and Pre-out (e.g, A02, or line out/Pre out of DACs such as Cayin iDAC-6MK2)

It is important to understand the definition of Line output and Pre-amp output. There are DAP that offers Line Out "mode" but the signal will go through the headphone amplifier circuit. There are desktop DAC that offers Pre-amp "mode" but in fact it is only a digital attenuator. Up to this point, the C9 implementation is very straight forward: you should use line output with C9 Line input mode, and pre-amp output with C9 Pre-amp input mode. The problem is, there isn’t any “portable” preamp source among DAP except A02 unless you want to use C9 as the headphone output of your desktop preamplifier. So what happen is we want to use to make good use of the Dual input mode of C9?

From here on, our discussion will go beyond the original design and product definition of Cayin, so everything is in my personal opinion. I'll summarize the options for quick reference before I go into details:

1. Line output from DAP or desktop DAC: use LINE input mode of C9, this is the default setting to use C9;
2. Pre-amp output from DAP, DAC and Pre-amplifier: use PRE-amp input mode of C9; this is an alternative setting to use C9;
3. Phone output if your DAP don't have line out option: use PRE-amp input mode of C9. It might or might not work, depends on the level of current gain, but worth trying because you don't have other options;
4. Pseudo Line out or Line out mode: try both line out mode to C9 LINE input and phone out to C9 PRE-amp input;
5. Variable Line Out: use LINE input mode of C9 with digital volume set to maximum or maintain at a higher level.
6. Pseudo Pre-amp Output or Pre-amp mode: similar to (4), try both line out to C9 LINE input and Pre-amp mode to C9 PRE-amp input, theoretically, LINE out option is the default C9 setting and it should be superior

Phone out as Pre-out?

If your DAP don’t have line out option, that will limited your option to upgrade your system though an outboard headphone amplifier, using phone out as pre-out is probably the best bet. Theoretically, that should be better than turning the volume to maximum and use it as line out because you are operating your DAP at a lower distortion level and SNR. On the other hand, since pre-amp output is by definition voltage gain without current gain from line out, so phone output with smaller current gain will likely perform better than phone output with higher current gain; a phone out with lower output will likely work better then phone out with beefy output. The Sony WM1Z and WM1A probably is one of the best example of this scenario, please refer to Headphonic C9 review (https://headfonics.com/cayin-c9-review/3/) for more detail about this combination.

Pseudo Line out or Line out mode?

Now this is a funny terms but this is as close as what I can think of from audiophile point of view. Take A01 and T01 audio motherboard as example, the 3.5mm line out of these two audio motherboards are line level outputs that meet all the description we stated earlier on, but the balanced line out are fixed level output shared with phone out. In other word, when you set the 4.4mm output of these two audio motherboard to line out, the DAP will set a fixed level (4.4V) output from headphone output, this will functionally perform as a line out, but since the audio signal has gone through both voltage gain and current gain in the headphone amplification circuit, I’ll describe it as a pseudo line out in order to differentiate it from the “real” balanced line out of E02 and N8. You can use Pseudo line out with LINE input mode of C9, but in my humble opinion, since the signal has gone through the same headphone amplification circuit as phone out, so you might as well compare the phone out of these DAP to C9 in PRE-amp input mode against pseudo line out to LINE input mode and judge the final performance with our own earphones and headphones.

Some DAPs didn’t specify clearly that whether their line out is un-amped clean line out, or pseudo line out that didn't bypass the headphone amplification circuit, in these cases, you have to test and compare the two input modes of C9 and select your preferred connection. Don’t make any assumptions if you are uncertain, there is no cost to try it out when you have C9, and you should always trust your ear.

Variable Line Out?

This is a line output stage with digital volume control in DAC chipset. Electrically this is line out signal as long as there is no voltage gain or current gain after LPF. My personal choice is to set the digital volume to maximum and connect to C9 in Line input mode. This should preserve all the dynamic range of your DAC output and pass it to C9 amplifier with minimum lost. There is one added advantage of have an extra digital volume in the signal path: if you run into a very sensitive IEM and the C9 is overpowered (according to your impression), then you can lower the digital volume to provide more room for C9. I have tried Andromeda with N6ii + A02 line out + C9 in Balanced low gain and it works OK (background is not completely dark) but YMMV.

​

Pseudo Pre-amp Output or Pre-amp mode

Some desktop DAC offers Pre-amp "mode" but in fact it is only a digital attenuator that lower the output level of DAC line out, there is no voltage gain in the pre-amp function, only attenuation. To certain extend this is desktop version of Variable line out in DAP, just a different name to fit into different scenario and user groups. The original Cayin iDAC-6 is an example of this, and we have included a proper pre-amplifier circuit when we update to iDAC-6 MK2. From functional point of view, you can use PRE-amp input mode in this scenario, but the result will unlikely superior over Line out from DAC to C9 in Line input mode because the attenuated signal from Pre-amp mode might lower the dynamic range or even resolution of the source signal, especially when you need to turn the volume all the way down to below 50% output level.

It is very important to follow the steps carefully when you switch from Line input mode to Pre-amp input mode, I hereby copy the complete paragraphs from User Guide for your reference.
--------------------
Since C9 is a very powerful headphone amplifier, so we must take appropriate precaution to make sure the PRE-amp input mode will not be activated “accidentally” or before the user has prepared his system properly.

The following 2-steps secure procedure will switch the C9 headphone amplifier form LINE input mode to PRE-amp input mode:

1. Turn down the volume control of C9, set the input MODE switch to PRE
2. Connect your PRE-amp music source to one of the input connector, we recommend you to turn down the volume of your source equipment at this point.
3. Connect your earphone or headphone to one of the output connector
4. PRESS and HOLD the Pre-amp Input Activator for 3 seconds.
5. You’ll hear a click sound when the switching kicks in, and the Pre input indicator will light up
6. The C9 is now operated in PRE-amp input mode. You can turn up the volume at the pre-amp music source (the volume control of C9 is disabled).
7. When input and/or output devices is disconnected, or when C9 is restarted, the amplifier will “deactivate” PRE-amp input mode and switch back to LINE input mode automatically despite the setting of input MODE switch, that’s why we remind you to turn down the volume of C9 before you use PRE-amp input mode.
8. When you change your music source or headphone, you need to activate PRE-amp input mode again by repeating step (4)

WARNING:

The PRE-amp input mode is designed to work with audio source device with Pre-amp output, or in technical terms, a variable voltage output with a user-controllable volume. You MUST NOT connect the Line Out of DAP, DAC or whatever source equipment without a Pre-amp output to C9 in PRE-amp input mode.

 

[Whitigir]

@Andykong while you are here, could you tell me more of how the C9 be able to utilize Amplified signals from PhonesOut to be PreAmp signals ? Does it have additional circuitry for that ?

 

[Andykong]

oh well, while the Pre-In and the Pre feature is actually exciting to have. I was having a lot of fun to toy around, but I would gladly be doing real “line out” into C9 any given time. There is a much more defined soundstage and imaging compared to the Pre-in features from phones out. Beside, the Line Out has a much more blacker back-ground. This alone is a winner. I am glad to have Max as a source for the C9

If you have other DAPs around, try again, maybe it works differently.

Max is properly not a good source to compare the Line input mode vs phone out to PRE-amp input mode of C9 because the Phone out of Max is relatively more powerful when compare to other DAP. When the current gain of the headphone amplifier circuit is substantial, it can't "stimulate" a preamp output.

For the same reason, Cayin N8 phone out is not a good choice if you want ot compare Line out vs phone out to Preamp input.

Looks like my Chinese New Year holiday will start a few days later, as usual.

 

[Whitigir]

Overall control, imaging, dynamics and high low extension are just in different league with any standalone DAP.

Yes! I can vouch for this, even Max won’t drive IER Z1R as well as C9 and Max stacked up