Quote:
Originally Posted by
CHRIS650 
I current have AVR 745, which was the top of the line back then.
Looking to upgrade. So many people around here say that 3600 is better 3650. Why?
I don't care about the analogue pre-out or in. What are differences between 3600 and 3650?
I do like the switched power out on the 3600, I use it to control my DVD players, power woofer, etc.
The 3600's amplifier section is more robust, with a larger power supply and greater secondary capacitance. Though less
muscular, the 3650 still shares the same amplifier topology as the 3600, which has been relatively unchanged for SEVERAL generations within the 1/2/3 series.
The bridge III ipod dock (which allows audio, images, and HD video playback from ipod/iphones) is included with the 3600, but optional with the 3650.
The 3600 offers more analog inputs, a 6/8 channel direct input, 8 channel pre-outs, more digital inputs, a LOW amp switched outlet, an A-Bus multizone connection (but requires an A-bus 24VDC power adapter unlike previous generation HKs), and an IR carrier output (to connect an IR blaster)
The 3650 did add several features over the 3600;
Network Playback + Internet Radio
USB playback (MP3/WMA)
2 additional HDMI inputs (with one conveniently on front panel)
Audio return for HDMI
RS-232 control support (though HCG support has no definitive info for the control codes as of yet)
A 12VDC trigger output (but no switched outlet)
DPLIIz support (still 7.1, but ability to re-assign SB amps as front height channels)
Both are HDMI 1.4a and support 3D
With HDMI the industry standard, the additional HDMI ports are likely welcome in favor of the extra digital and analog inputs. The same can be said of the 3600 vs its predecessor.
Also, with increasing popularity of 'smart' TVs, the 3650's HDMI audio return channel makes things easier with a single HDMI connection between the (compatible) TV and receiver even when using the TV as the audio source.
Note: Both the 3600, and even more so the 3650, would be a BIG step down from the 745's power amplifiers. The 7550HD (discontinued, but refurbs are available from HK) would be the comparable replacement/successor to the 745 and is even slightly more powerful. Both flagship HK
7 series models.
The 3600 and 3650 also have less audio processing capability, with a much less sophisticated EQ system than the 745 and 7550 and inability to post-process/layer Logic 7 onto 5.1 multichannel streams. The 745/7550 support TWO independent subwoofer outputs.
The 7550 offers the power of the 745 with the newer functionality of the 3600 and 3650. Despite being a couple years old, several of the new features for the 3650 trickled down from the 7550 - e.g. Network+Internet Radio, USB playback, RS-232, etc. The 7550 can also view still images over the network and USB connections which the 3650 does not.
Like the 3600, the 7550HD features Dolby Volume, and 4 HDMI 1.4a inputs with 3D and DTS-HD/True-HD decoding but no HDMI audio return. The Bridge dock (II) is also included.
Hope this helps