We recently upgraded the receiver in a project from a Denon AVR-S730H to a Denon AVR-X3300W.

We were controlling the 730H with a custom android application via IP control (direct connection via Ethernet from android to AVR). Everything we needed for this application has been working great.

Once we switched to the X3300W we lost the ability to control the AVR via IP.

I have been using Putty set up on a windows machine directly connected to the X3300 for testing and here is what I have found.

When I send the 1st command (MV?) I get a response from the AVR. However any command I send after the 1st the AVR will not respond to the command. If I terminate my terminal session in putty and start over I can again send one command such as (MV60) and the AVR will change volume to 60 but if I try and send a second command I get no response from the AVR.

While in this state if I make any changes directly on the AVR such as turn up the volume or change the input I can see the echoed commands in my putty session but at no point can I send a 2nd command.

I did not have this issue with the 730H. I can use the same putty settings and switch from the non working X3300 to the 730H and the 730H will work just fine with no issues.

I have updated the firmware on the X3300 and it made no difference. I have verified the setting on the AVR's and the network settings are identical.

I have tried changing putty from Active to Passive, I have tried withing between New line and ^M when pressing the return key, I have tried toggling on and off implicit CR in every LF and implicit LF in every CR. These setting will either break the overall session or make no difference in the behavior when trying to control the X3300.

Any thoughts?