Picking an amplifier

@kalali - I couldn't find the Krell amp you're talking about.  However, for $1600, you are probably looking at the older KAV stuff from the late 90's.  This is the older D'Agostino stuff and was voiced warm.  It also did not have the detail and attack that the 2002+ generation did.

@shalmaneser - Can you tell us what your source equipment is?  Preamp/processor, CD player?  This may help us guide an amp.  The Anthem is a very nice amp, but it is going to be very fast and high resolution.  It would be well matched to a warmer preamp/processor, such as Marantz or NAD.  You can't go wrong with the Parasound A23 amp, but it will be more forgiving if you have a fast/bright sounding preamp/processor.

I would say there definitely is a difference between DVD and bluray.  On DVD stuff, I can definitely hear the audio is grainy and dirty compared to bluray.  However, your equipment may or may not have enough resolution to reveal this difference.

Wow, that Sony DSP-EP9ES is a really interesting device.  It's also really old and doesn't even support DTS (which is a major limitation in your ability to use media).

I know you want to keep it until it dies, but at this point I would highly recommend you dump it anyways.  Based on your budget, I would say to get the best AVR (audio/video receiver) that you could buy.  It would solve your problem for an amplifier and also give you much better capability to handle current formats.  You can search for "receiver" in audiogon.  Here are a few choices:

Anthem MRX-710 $1,000 - supports all latest bluray audio formats (Dolby True HD / DTS-HD MA).  Sound quality very good for home theater with high detail.

Marantz SR6011 $999 - supports all latest bluray audio formats.  Voiced to be on the warm side.  Probably better for music if you like the warm sonic signature.

Denon AVR-5803 $798 - this is a best of a receiver at 70lbs!  And will have much better sound quality than the above 2 items.  Bigger power supply, better amp boards.  But it is older and does not support HDMI or bluray audio.  It will do Dolby Digital / DTS from COAX digital input.  It will likely sound better than the above two options.

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I would also recommend that you get a very low cost bluray player as a transport and use either HDMI or COAX digital for audio.  Such as Sony BDP-S1700 for $59 from Crutchfield.  If you choose the Denon receiver above, you can use the COAX digital output when playing anything.  The Sony bluray will automatically downconvert bluray audio to normal Dolby Digital / DTS.  This is still SIGNIFICANTLY BETTER than regular compressed DVD audio.  I recommend you get the Blue Jeans Cable Beldon 1694A COAX digital cable at 6 feet for $20.  It's the best for the money.

Let me know your thoughts.