@amirm : Thanks Amirm for the great measurements!
Did you measure the output impedances of RCA and XLR?
Based on the info what I got from the manufacturer by email, the output impedances are 100 Ohm on both. (but they never published these data officially)
Can you please confirm this?
Many...
Many thanks for your confirmation!
I guess I can feed from the same +/- 15V battery PSU the both circuits without any problem. I think the reason of doubling (separated) the 78/7915 pairs is just reaching higher decoupling between the two stage of amplifiers (in PSU point of view).
But in this...
The matching of D400EX output and A90 / A90 Discrete input should be fine theoretically, because the ratio of output/input impedances is more than x8/x10 times.
Based on the given data from Mandy@SMSL:
"The output impedance of D400ex rca and xlr are 100Ω.
m400 and d2 are same, rca is 100Ω,xlr is...
Is there anybody here who has the schematics of the used Audiophonics buffer stage/PCB?
I'd like to modify mine to feed the +/-15V PSU from battery...
As I see there are two pairs of onboard 7815/7915 regulators. One pair for the buffer's OPA, another pair for the +/-VOP of the 1ET400S - I just...
Oh! Looks so smart!
So simplified: The default setting is 230V but if the output voltage isn't enough then it select automatically the 110V mode for the transformers.
Am I right?
I don't find any AC input voltage switch on my D2, so it can handle 100-240V AC, but it have toroidal transformers inside...
How can switch automatically the right voltage for the transformers???
I never saw similar before...
Any idea???
Hi,
It has totally different analog (buffer/driver) stage after the DAC output. The PSU is also different, but both are very good.
I didn't realize any notable others...
Can I connect directly a headphones with 40 ohms impedance from the outputs of the Pre90?
As I remember the output impedance is around 40 ohm.
Am I right?
Thanks!
I didn't hear the RME ADI-2 yet, but AFAIK there is no hardware volume control on it nor LeedH Processing too.
Yes, when the volume is set to 100% in D90 or M500 (or every DAC which has simple digital volume control the given I2S signal entering the DAC chip is bit-perfect, so their SQ is the...
The D90 doesn't have real - high quality hardware volume control what is required on their level. I as an audio equipment developer know that well. Every standard and simple digital volume control (what is in the D90 too) has many many problems which are degrading the sound quality.
In the past...
Are you kidding? The pre-amp mode is just a joke in the D90. It's a crappy standard digital way - I don't want to use that at all.
The Lumin's LeedH digital method is an ultimate version of the digital attenuators which doesn't causes any loss in dynamic range.
Yes, I'm pretty sure. This method working successfully with the SMSL M500.
Lumin U1 Mini (USB output, MQA passthrough or digital out, Tidal MQA source - Enabled and used LeedH Volume Control) -> SMSL M500 (Detected MQA up to 352kHz from Tidal) -> NuForce Ref.18 Monoblocks
Hi All,
I purchased finally my Topping D90 MQA. It has already the latest v1.24 FW version on board.
The USB source is a Lumin U1 Mini.
I'd like to use the LEEDH digital volume control of the Lumin because I don't have any preamp in the chain.
Unfortunately there is no MQA transmission when the...