Question about 4.4mm trrs to 3.5mm trs, or 2.5mm trrs to 3.5mm trs

[fxavier]

I am currently using Bose QC35 II for my headphone and considering to buy a DAC dongle for my PC.
There are two DACs on my list, Ibasso DC04 and Hidizs S9 pro. Which Ibasso DC04 have a 4.4mm trrs output and Hidizs S9 pro have 2.5mm trrs and 3.5mm trs output.

Reading from the old articles, I found that trrs output should not convert to trs output because it can damage my amp.
1. So does it mean I shouldn't use either 4.4mm trrs and 2.5mm trrs to my Bose QC35 II (2.5mm trs single-end input)?
2. Should I only use those trrs port to the headphone that can support balanced input?

In case anyone wondering about the 3.5mm trs output on Hidizs S9 pro, I am planning to connect that to my PC speaker.

 

[JustAnandaDourEyedDude]

I am currently using Bose QC35 II for my headphone and considering to buy a DAC dongle for my PC.
There are two DACs on my list, Ibasso DC04 and Hidizs S9 pro. Which Ibasso DC04 have a 4.4mm trrs output and Hidizs S9 pro have 2.5mm trrs and 3.5mm trs output.

Reading from the old articles, I found that trrs output should not convert to trs output because it can damage my amp.
1. So does it mean I shouldn't use either 4.4mm trrs and 2.5mm trrs to my Bose QC35 II (2.5mm trs single-end input)?
2. Should I only use those trrs port to the headphone that can support balanced input?

In case anyone wondering about the 3.5mm trs output on Hidizs S9 pro, I am planning to connect that to my PC speaker.

The answer to both your questions is yes. You have correctly interpreted the relevant posts.

If your QC35 II (which I assume has 3.5mm TRS and not the 2.5mm TRS you mentioned) has a detachable cable with separate connectors at each earpiece, you could replace the cable with a balanced cable that terminates in the two correct male connectors for the QC35 II at one end, and at the other end terminates in either a 4.4mm Pentaconn plug to plug it into the iBasso DC04, or else a 2.5mm TRRS plug to plug the cable into the Hidizs S9 Pro.

If the cable of the QC35 II is not detachable, which is likely the case, then you should not use the iBasso DC04 or the 2.5mm TRRS of the Hidizs S9 Pro with it. You should instead consider buying a USB dongle DAC with 3.5mm TRS output for use with the QC35 II, such as the E1DA 9038D.

You could use either the 3.5mm SE output of the Hidizs S9 Pro or that of a different dongle DAC-amp such as the E1DA 9038D to drive both the QC35 II and your PC speakers (assuming the latter have built-in amps that are independently powered), by using a short splitter cable that outputs two 3.5mm jacks from one 3.5mm plug. Though you may have to adjust volume levels a bit when you go from listening to the headphones versus the speakers. Or use a 3.5mm switch instead of the splitter cable.

 

[fxavier]

The answer to both your questions is yes. You have correctly interpreted the relevant posts.

If your QC35 II (which I assume has 3.5mm TRS and not the 2.5mm TRS you mentioned) has a detachable cable with separate connectors at each earpiece, you could replace the cable with a balanced cable that terminates in the two correct male connectors for the QC35 II at one end, and at the other end terminates in either a 4.4mm Pentaconn plug to plug it into the iBasso DC04, or else a 2.5mm TRRS plug to plug the cable into the Hidizs S9 Pro.

If the cable of the QC35 II is not detachable, which is likely the case, then you should not use the iBasso DC04 or the 2.5mm TRRS of the Hidizs S9 Pro with it. You should instead consider buying a USB dongle DAC with 3.5mm TRS output for use with the QC35 II, such as the E1DA 9038D.

You could use either the 3.5mm SE output of the Hidizs S9 Pro or that of a different dongle DAC-amp such as the E1DA 9038D to drive both the QC35 II and your PC speakers (assuming the latter have built-in amps that are independently powered), by using a short splitter cable that outputs two 3.5mm jacks from one 3.5mm plug. Though you may have to adjust volume levels a bit when you go from listening to the headphones versus the speakers. Or use a 3.5mm switch instead of the splitter cable.

The Bose QC35 II is using detachable 2.5mm input, it can take 2.5mm trrs but only for mic input. I pick Hidizs S9 Pro and IBasso DC04 because I can get them for a decent price (~$60), in this case I guess I will pick Hidizs S9 Pro and just use the 3.5mm trs for both headphone and speaker. The 2.5mm trrs port will be a spare for my future gear that can accept balanced input.

Thank you for your reply!