[SyntichSenna]

I have Iphone 15 pro max and beyerdynamic DT770 PRO 80ohm, can I drive this headphones with this dac in normal mode ? I am planning to buy IEMs or some portable headphones in the future , any suggestions ?

 

[991 Carrera 4S]

Voltage swing determine how loud the headphone can get. However, don't forget KA17, even when powered by external Type C source, still operates on a 5V USB power rail. Generally the quickest way is to flip the USB power rail into +5V / -5V rail which that amp section can work to generate a voltage swing between that. But since some power will be wasted to generate the + / - voltage rail, you won't be getting the whole +5V / -5V but less. Most of the time manufacturers will instead opt to split 5V into +2.5V / -2.5V as it is easier to do when you don't need to up-convert the voltage, hence why you typically see less than 2V of output on USB audio devices and especially dongles. Anything more than +5V / -5V will increase noise and circuit size too much that likely won't worth the effort nor fit inside a dongle sized device due to the limitation of USB power. That why if you really need a lot of voltage swing, better look for a battery powered DAC/amp instead.

But how does FiiO KA17 achieve 4.5 V_rms = 12.7 V_P-P (4.4mm, desktop mode, high gain) then?

 

[ClieOS]

But how does FiiO KA17 achieve 4.5 V_rms = 12.7 V_P-P (4.4mm, desktop mode, high gain) then?

Perhaps I should be more clear - I am not saying it isn't possible to up-convert the power rail above +5V / -5V, but the higher it goes, the more difficult it will be. to keep the circuit in reasonable size/complexity to maintain a clean power. The way FiiO partially solves this issue is by introducing a second power source via a Type C port, but that's still limited to 5V nonetheless. If you look at FiiO old E12 series of portable amps, the best way to get a bigger and cleaner voltage swing is by stacking up multiple Li-ion batteries to get a higher starting voltage (11.1V = 3 x 3.7V, so three Li-ion batteries in series)). Another example is Mojo, which used a 7.4V ( 2 x 3.7V) battery pack. There is a reason why a higher starting voltage is generally preferred over an up-converting voltage because, at some point, the latter is much more difficult to get a good result than just stacking up batteries. The point is, it is not whether it is possible to do so or not, but what kind of design makes the best sense to the targeted audience.

 

[jsmiller58]

deleted

 

[FiiO]

I have Iphone 15 pro max and beyerdynamic DT770 PRO 80ohm, can I drive this headphones with this dac in normal mode ? I am planning to buy IEMs or some portable headphones in the future , any suggestions ?

Dear friend,

Hi,
1. Yes. And according to the feedback from other users, the iPhone 15 could work with KA17 desktop mode as well. (But the battery of iPhone15 will lose faster at that time.)
2. As for other IEMs to pair with KA17, maybe other users here could share their experience with you. You could also have a try in the local store if possible.

Best regards

 

[sofastreamer]

I have Iphone 15 pro max and beyerdynamic DT770 PRO 80ohm, can I drive this headphones with this dac in normal mode ? I am planning to buy IEMs or some portable headphones in the future , any suggestions ?

it might be better to ask about iem suggestions in the Introductions, Help and Recommendations Subforum. your beyers arent hard to drive by the way. depending on the volume you listen to even the Apple dongle could drive them. The KA17 might be better sounding regarding dynamics, tightness and soundstage tho.

 

[SyntichSenna]

Thank you guys

 

[Fantomax]

After several tests to understand the reason for strong EMI noise when the KA17 is current powered, I found that the problem lies in the structure of the Shozy P20, which is an all-metal planar IEM. I tried all possible tests, even changing the cables (the data cable is the ddHiFi TC09S so the best possible) and there is no EMI with the other resin IEMs... this isn't nice because if I touch the jack handle it disappears, discharging with my body.
The only way to solve it is to use a power bank: no EMI.
The P20 sounds so good and warm... they pair amazingly with the KA17!

 

[Osaris]

After several tests to understand the reason for strong EMI noise when the KA17 is current powered, I found that the problem lies in the structure of the Shozy P20, which is an all-metal planar IEM. I tried all possible tests, even changing the cables (the data cable is the ddHiFi TC09S so the best possible) and there is no EMI with the other resin IEMs... this isn't nice because if I touch the jack handle it disappears, discharging with my body.
The only way to solve it is to use a power bank: no EMI.
The P20 sounds so good and warm... they pair amazingly with the KA17!

I have the p20 as well, I will test to see if I can find the same issue.

 

[Osaris]

I have the p20 as well, I will test to see if I can find the same issue.

After several tests to understand the reason for strong EMI noise when the KA17 is current powered, I found that the problem lies in the structure of the Shozy P20, which is an all-metal planar IEM. I tried all possible tests, even changing the cables (the data cable is the ddHiFi TC09S so the best possible) and there is no EMI with the other resin IEMs... this isn't nice because if I touch the jack handle it disappears, discharging with my body.
The only way to solve it is to use a power bank: no EMI.
The P20 sounds so good and warm... they pair amazingly with the KA17!

What cable are you using? is it balanced or SE?

 

[Fantomax]

What cable are you using? is it balanced or SE?

It's a 4.4 balanced cable, but I tested also 3.5 SE and there was even much background noise... It can be completely solved with a power bank. I ordered a nice Remax 5.000mAh with direct plug on AE, but I'll receive it in 1 month (hopefully). So, I'm currently using the power bank that I already have with a long cable. Not very practical as you can see, but just for the moment.
The TC09S is strongly recommended, mainly because of its shielding features, despite much shorter than TC05.

 

[GroovyAudio]

I noticed with the original cable that the sound will randomly stop, especially when I move the dongle a little bit. The trick with reverse cable swapping works, but temporary, so I decided to upgrade the cable.
Today I received DD ddHiFi TC05 Type C to Type C Data Cable to try it with my KA17 and I'm very happy to report no more disconnection or sound stopping. The original cable is not very good unfortunately. @FiiO please make better cables for your future dongles. I mean you guys put high quality silver plated cables on your iems but your dongles get the short end of the stick...
Back to the TC05, no sound improvements over the original cable if anyone is interested. A/B tests they sound the same to me, but that's my opinion. Reviews from my local store are saying that there is better sound with this cable, but I can't notice anything different over the original. All in all I recommend this cable with the KA17. If you guys have the cash to spare you could try the TC09S cable that is better quality although at a higher price. For now I'm happy with TC05.

 

[jsmiller58]

I noticed with the original cable that the sound will randomly stop, especially when I move the dongle a little bit. The trick with reverse cable swapping works, but temporary, so I decided to upgrade the cable.
Today I received DD ddHiFi TC05 Type C to Type C Data Cable to try it with my KA17 and I'm very happy to report no more disconnection or sound stopping. The original cable is not very good unfortunately. @FiiO please make better cables for your future dongles. I mean you guys put high quality silver plated cables on your iems but your dongles get the short end of the stick...
Back to the TC05, no sound improvements over the original cable if anyone is interested. A/B tests they sound the same to me, but that's my opinion. Reviews from my local store are saying that there is better sound with this cable, but I can't notice anything different over the original. All in all I recommend this cable with the KA17. If you guys have the cash to spare you could try the TC09S cable that is better quality although at a higher price. For now I'm happy with TC05.

Thank you, the frequent cut outs had also been puzzling me! I’ll try other cables!

 

[xxxstarmanxxx]

Thank you, the frequent cut outs had also been puzzling me! I’ll try other cables!

Same here with the ka17 - swapped mine over with the cable that came with my earlier ka3 - no problems since

 

[zilax002]

USB cables are gonna make zero difference as long as they work and don't have disconnect issues, folks.

Anything saying more premium USB cables "sound better" is pure snake oil, folks. We're talking about digital signal here. This isn't even like talking about headphone cables which at least is an analog signal that can actually be affected in some way (in some circumstances) by the quality of the cable.

For digital, the cable either works and is compliant with relevant protocols or it's not. That's it. That's the whole story.

There's zero quality difference between a $200 gold plated HDMI cable and a $10 one as long as they're both compliant with HDCP protocol and using the same HDMI standard.

Same with USB.

Between two cables that work the only factor is durability and aesthetics.

I use the braided cable from the Qudelix 5K with my KA17. It feels nice and is more flexible than other cables. There's no other difference between other USB-C cables.