Hypex Nilai gain

[Vhond]

Hi everyone,

Can someone explain how the gain is implemented in the Nilai power amplifiers?
The amplifier has built-in preamp providing three levels of gain (12, 22 and 28 dB).
You can adjust it using a switch. But HOW is this sensitivitylevel built in?

Thanks for explaining me

 

[NTK]

Below is the input buffer schematic from the Hypex NC500 evaluation board factsheet. The gain of the buffer is set by the values of Rf (R10 and R12 in the schematic) and Rg (R11 in the schematic), or can be set by Rg only if Rf is fixed.
For unity gain for the input buffer, Rg can be set to ∞ (= removed = open circuit/no connection), giving a gain of 0 dB (= 1X) for the input buffer.
The total amplifier gain is the input buffer gain (in dB) plus the amplifier power stage gain (which is fixed in the design and not adjustable).

https://www.hypex.nl/media/9a/9b/da/1646119649/NC500_Evaluation_01xx-R2.pdf

 

[Vhond]

Thx, so all is managed by 'only' resistors??

 

[NTK]

Thx, so all is managed by 'only' resistors??

Most likely — the J200 jumper in the Nilai (my guess) is used to select the value of Rg: Open = unity input buffer gain/open circuit; 1-2 = mid gain/higher Rg value; 2-3 = high gain/lower Rg value.
Doesn't need to be more complicated.

 

[Vhond]

Some additional question:

What would be the best jumpersetting for connection with a Bryston BP25 preamp (using XLR)
(measurements I could find: https://www.stereophile.com/content/bryston-bp25-mc-preamplifier-measurements
and speakers with
Impedance: 4 Ω
Bandwidth: 30 Hz – 31 kHz
Efficiency: 89 dB

??

 

[Vhond]

Finally I found this topic: https://audiosciencereview.com/foru...rstanding-gain-on-power-amp.11309/post-322641

Very interesting!