No he is incorrect. Here is a link to the Denon website where they actually list their IR command set for your exact model and there are discrete On and Off commands listed as well as direct input commands for DBS, VDP, etc.

[Link: usa.denon.com]

I wouldn't expect everyone to be able to interpret these commands but here is a brief explanation:

For the AVR3803 there are three system addresses (01000, 00110, 00100)

and a set of tables like this:

SYSTEM ADDRESS(C1 C5) : 0100, EXTENSION BIT(C12,C13) : 11
No. Data (C6 C11) Key Name

1 100000 POWER

System address is what we call device and the bits are backwards, in this case it is 01000 binary or decimal 2. The others are (00110 (really 01100) is decimal 12 and 00100 (00100 either way) is decimal 4)

The individual commands are a little harder. We consider Denon to use an 8-bit key code=OBC=function and it is (C6 C11)and (C12,C13): in this case:

100000 11 but again the bits are backwards so transposing:

11 000001 or 128+64+1= 193

and that is the OBC for power. You can also use the windows calculator pick view|scientific and the radio button for binary enter the ones and zeros then radio button for decimal.

With this information you can use a program like MakeHex and generate the Pronto hex using the Denon.irp protocol.

-Jon