HK 7300 review and HK AVRx35 questions

Has anyone ever had a chance to critically compare the sound of various HK receiver preamp sections (ie – 235 versus 635)?

I recently acquired an HK AVR 7300 and put it through its paces comparing it to some other gear. I’m trying to achieve that optimal blend of good stereo plus the ability to do home theater as a secondary priority. I tested the following gear:

HK AVR 7300
Rotel RTC-850 (recently acquired here)
Yamaha RX-V795a (my old standby)
Adcom GFA-545 II

All comparisons were made using RTi10s and no subwoofer.

Here were my thoughts:

Yamaha: Neither the preamp or amp section of the Yamaha could keep up with any of the other gear. This was my main receiver amp for the majority of the last 9 years. I’ve critically evaluated it a few times before, but always with a subwoofer. Last year when I had a Rotel RB-970 for an amp, I could really hear the difference running the speakers large, but with a sub, any improvement on stereo using the separate amp was much less apparent. Compared to the other gear listed above it sounds okay, but that’s it. I always envisioned adding an amp based on the one famous review of this piece that says something like “used as a pre/pro I could not hear that the Yamaha was doing anything detrimental to the sound.” Well I can. Too bad, I thought someday I would be happy just running this with a stereo amp, but stereo sound suffered due to the preamp, and the center channel using the yamaha’s amp section now sounds horrific to me.

Rotel – turned out to be a very nice preamp. Very clear and but a little less full sounding than the HK preamp section. I wanted to comtemplate just going 2.0 on this rig, but now I’m more interested in finding an AV receiver that can power the rears.

Adcom – Certainly an improvement over the Yamaha amp section. Matched nicely with both the rotel and HK preamps. Sounded very different than the HK amp section. It made me conclude that the “HK” flavor is more due to the amp section than the preamp section. The mids are more pronounced on the adcom than the HK amps. Bass is also leaner, but I thought I little less muddy than the HK as a result. Highs sounded about the same to me. (Which surprised me from all the things I read about how Adcom butchers the highs). Finally, I don’t know exactly how to explain it, but it almost sounded like during the music there was a hiss or extra noise in the background though, whereas the HK was just clean and clear through and through.

Finally, the HK was very impressive. It has outstanding dynamics and produced the greatest movie sound I’ve ever achieved at home (also using a csi5). But for music, I’m not sure I’m in love with the sound. For jazz or classical, it really sounded great. But when it came to rock, the adcom just had a more present or vibrant sound. I kept thinking that every rock song on the HK sounded as if it was being played inside a giant room lined with black velvet. I’m going to give it some time though. It’s so different I don’t want to make a rash decision. What I’m not so enthralled about is the size of this beast. It’s big.

Which brings me to why I wrote all this. Will the preamp section of the 635, 435, 335 or 235 sound about the same? Because that’s the part of the HK I really liked. Then I can ditch the 7300 and picking up a lesser HK and a 3-channel amp. Maybe an acurus or even the 5-ch emotiva?

Thoughts or comments?