Hi
I've performed a few quick measurements with the Topping D90LE
DAC 5V at Max level (USB in, 48kHz, Right Channel)
(ADC: E1DA ADC 4.5V Mono, measured with Virtins Multi Instrument 3.9.6)
"Standard" mode
In "Valve" mode
We see a big 2nd harmonic peak (0.32%), with a more limited 3rd harmonic (0.001%)
In "Transistor" mode
We see a limited 2nd harmonic peak (0.03%), with 3rd harmonic 10 times below (0.003%) - but 3 times higher than in the "Valve" mode.
NB: I can't get more than around 122 dB SINAD.
This is most probably due in part to the low impedance of the E1DA ADC (especially in Mono mode): the output of the D90LE peaks around 4.5Vrms in 5V mode under such a heavy load (around 850 ohm). Or we just reach the limits of the E1DA ADC.
My cabling may also count for a few tenths of dBs.
Every detail counts at such incredibly low distortion and noise levels.
EDIT 2022-06-27:
I re-measured SINAD with a notch filter and it scored at 126.4dB
Full measurement details may be seen in attached pictures.
I've performed a few quick measurements with the Topping D90LE
DAC 5V at Max level (USB in, 48kHz, Right Channel)
(ADC: E1DA ADC 4.5V Mono, measured with Virtins Multi Instrument 3.9.6)
"Standard" mode
In "Valve" mode
We see a big 2nd harmonic peak (0.32%), with a more limited 3rd harmonic (0.001%)
In "Transistor" mode
We see a limited 2nd harmonic peak (0.03%), with 3rd harmonic 10 times below (0.003%) - but 3 times higher than in the "Valve" mode.
NB: I can't get more than around 122 dB SINAD.
This is most probably due in part to the low impedance of the E1DA ADC (especially in Mono mode): the output of the D90LE peaks around 4.5Vrms in 5V mode under such a heavy load (around 850 ohm). Or we just reach the limits of the E1DA ADC.
My cabling may also count for a few tenths of dBs.
Every detail counts at such incredibly low distortion and noise levels.
EDIT 2022-06-27:
I re-measured SINAD with a notch filter and it scored at 126.4dB
Full measurement details may be seen in attached pictures.
Attachments
Last edited: