@ssriram2791 in your case the 4.4mm path sound the same or higher?
I am sharing some interesting results based on testing completed this morning after your message
I went ahead and performed sound pressure level measurements using SPL meter on Audio-Technica ATH-R70X by connecting it to Cayin C9 (3.5 mm and 4.4 mm outputs) with different line out configurations on Lotoo PAW 6000
LO -> Line Out
LI -> Line In
SE -> Single Ended (3.5 mm)
BAL -> Balanced (4.4 mm)
Here are my conclusions and supporting data below
1. It is quite clear that PAW6000 Line Out gain settings (Low/High) doesn't have any impact on volume levels. If you try to connect PAW6K in preamp mode to C9, then the DAP gain settings have tremendous impact (about 12-14 dBA headroom).
2. Cayin C9 gain settings provide +6 dBA headroom (i.e going from Low to High)
3.
Unfixed LO provides more volume (+6 dBA headroom) than Fixed LO of Lotoo PAW6000 regardless of using 3.5 or 4.4 mm lineouts.
4. Both 3.5 mm and 4.4 mm line outputs from PAW6000 provide the same amount of power (in terms of volume levels) if you use the same outputs (i.e 3.5 mm and 4.4 mm respectively) from C9.
5. Things get more complicated when input output combinations are switched.
SE input/BAL output has +12 dBA headroom over BAL input/SE output. SE input here is Lotoo Paw 3.5 to Cayin 3.5 IC. BAL input here is Lotoo Paw 4.4 to Cayin 4.4 IC.
Conclusion #5 could be attributed to the input sensitivity that I mentioned before in one of my messages
Basically to convert BAL input into SE output you need higher input voltage coming from source. As we know based on the data, both BAL and SE inputs of LOTOO PAW6000 seem to have same input voltage.
1.5 V (SE input/BAL output) vs 3.0 V (BAL input/SE output)
Test Data
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1. 4.4 mm Lotoo PAW6000 Fixed LO 2 Vrms Low Gain --> Cayin C9 LI Low Gain Solid State Class AB (Volume 50) 4.4 mm Input/4.4 mm Output --> 85.8 dBA
2. 4.4 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI Low Gain Solid State Class AB (Volume 50) 4.4 mm Input/4.4 mm Output --> 85.6 dBA
3. 4.4 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 4.4 mm Input/4.4 mm Output --> 92.1 dBA
4. 4.4 mm Lotoo PAW6000 UnFixed LO Volume Maxed Out High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 4.4 mm Input/4.4 mm Output --> 98.7 dBA
5. 3.5 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI Low Gain Solid State Class AB (Volume 50) 3.5 mm Input/3.5 mm Output --> 86.1 dBA
6. 3.5 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 3.5 mm Input/3.5 mm Output --> 92.2 dBA
7. 3.5 mm Lotoo PAW6000 UnFixed LO Volume Maxed Out High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 3.5 mm Input/3.5 mm Output --> 98.6 dBA
8. 3.5 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI Low Gain Solid State Class AB (Volume 50) 3.5 mm Input/4.4 mm Output --> 92.2 dBA
9. 3.5 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 3.5 mm Input/4.4 mm Output --> 98.6 dBA
10. 3.5 mm Lotoo PAW6000 UnFixed LO Volume Maxed Out High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 3.5 mm Input/4.4 mm Output --> 104.4 dBA
11. 4.4 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI Low Gain Solid State Class AB (Volume 50) 4.4 mm Input/3.5 mm Output --> 79.9 dBA
12. 4.4 mm Lotoo PAW6000 Fixed LO 2 Vrms High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 4.4 mm Input/3.5 mm Output --> 86.1 dBA
13. 4.4 mm Lotoo PAW6000 UnFixed LO Volume Maxed Out High Gain --> Cayin C9 LI High Gain Solid State Class AB (Volume 50) 4.4 mm Input/3.5 mm Output --> 92.5 dBA
