I was trying to jam along with youtube so I plugged in my iPad to the "audio in" input of the amp.
Volume of the iPad is cranked to max.
I noticed that the iPad can only be heard when the volume of each channel are turned up.
Problem is, especially in Ultra Gain Channel, the iPad will not be heard until the volume of the channel is set to pretty high (pass 9 o'clock), meanwhile, my guitar sound will be very LOUD that will cover the jamming track and also cause serious air to my neighbour (basically I only hear my guitar and cannot hear the iPad which is connected to the amp throught the "audio in" input).
Solution to the above is very much appreciated.
Regarding your DSL20HR we recommend that you take it back to the dealer so they can check it over for you, as it sounds as the level may be slightly low.