Voltage gain k4040

I’m sorry, I want to know the voltage gain of the K4040
velleman.eu/products/view/?id=19149

Because I want to use the k4040 in multiamplification.
The configuration would be:
TUBES PRE : LUXMAN CL-38U ebay.com:80/itm/ws/eBayISAPI … rid=229466
TUBES AMP for middle/treble frequencies : VELLEMAN K4040
TRANSISTOR AMP for bass frequencies: YAMAHA P3500S yamahaproaudio.com/global/en … ations.jsp

What is the K4040’ voltage gain ?
The configuration is good?

Thank you so much!
Fausto
Italy

Inputs sensitivity is 1Vrms for 90Wrms out in 8 ohm
90Wrms in 8 ohm equals 27Vrms
Gain: 27

(For 4 ohm: gain = 19)