Hi Mike,
Here are some responses to your post and answers to your questions about my system I may have glossed over:
1. I really don't have an agenda but admit I've had very positive experiences with several class D amps I own. I bought my 1st class D amp (a classDaudio SDS-440CS) when my previous class A/B Aragon 4004 MKII broke down due to leaking caps in the power supply.
My system is used equally for 2-ch music and as a 5.1 surround system for HT. My main speakers are an older pair of Magnepan 2.7qr panels. I use a Magnepan CC3 as a center channel, Infinity in-ceiling speakers as rear surrounds and an Audio Kinesis Debra distributed bass array system as subs. This consists of 4 67lb subs that contain 10" drivers and are all driven by a separate 1,000 watt class A/B amp. I previously used all class A/B amps but have transitioned over the past few years and currently use all class D amps to drive my 5 channels: a pair of D-Sonic M3-600-M mono-blocks to drive the 2.7qrs, an Emerald Physics EP-102 stereo amp bridged to mono for the CC3 and the classDaudio SDS-440CS stereo amp for the rear surrounds.
While these class D amps are from different companies and use different power modules, they have similar sonic qualities:neutral, very good dynamics, very low noise floors with smooth but very detailed mid-range and treble response that avoids harshness. However, I have to resist claiming all class D amps sound the same due to my limited sample size.
2. I don't believe class D is inherently better than traditional hi-end tube and class A amps. I have a great deal of respect for the sound of many traditional hi-end tube and class A amps.
While I've never used tube or class A amps in my system, I have listened to several hi-end traditional tube and class A amps at audio showrooms and friends' homes and find most sound very good. I've never been able to directly compare very good examples of tube, class A and class D amps to one another since I've yet to find an audio dealer that carries all 3 types. These dealers typically don't carry good examples of class D because they're usually sold internet direct and bypass dealers. I've had to rely on professional audio reviewers opinions for information on how the better class D amps compare to the better traditional hi-end traditional tube and class A amps.
Since you have the excellent, but notoriously hard to drive, Apogee Diva speakers I thought you might want to read this 6Moons review of the D-Sonic M2-1500-M mono-blocks. They drive a smaller pair of Apogee Duettas as part of the review. If you need a cooler running pair of amps than your big Krells, you might want to audition these in your system:
http://www.6moons.com/audioreviews/dsonic/1.html
3. I do believe, based on my personal experience, that good mid level class D amps are inherently better than good mid level class A/B amps. This is the one blanket statement I am confident is true. Now that I've used class D amps for a few years, I can honestly state that I cannot think of a single advantage that my former class A/B amp can claim. The validation of my blanket statement is that absolutely no one on this thread has identified even 1 advantage of class A/B amps, either.
My switch from class A/B to class D was all upside with absolutely no downside.
4. The Oppo 105 is a high quality component that is very versatile.
Yes, the Oppo has a menu for selecting the sub crossover frequency from 40 to 250hz in 10hz increments.
The Oppo also has a menu for configuring your speakers and their volume level. There's a tone generator that allows you to cycle through each channel Each speaker/channel can be set as either 'Large' that has no bass augmentation from the sub or 'Small' that does augment the bass via the sub. Each speaker/channel's volume is adjustable from -10db to +10db in .5db increments.
No class has a monopoly on good ,
Tim
Here are some responses to your post and answers to your questions about my system I may have glossed over:
1. I really don't have an agenda but admit I've had very positive experiences with several class D amps I own. I bought my 1st class D amp (a classDaudio SDS-440CS) when my previous class A/B Aragon 4004 MKII broke down due to leaking caps in the power supply.
My system is used equally for 2-ch music and as a 5.1 surround system for HT. My main speakers are an older pair of Magnepan 2.7qr panels. I use a Magnepan CC3 as a center channel, Infinity in-ceiling speakers as rear surrounds and an Audio Kinesis Debra distributed bass array system as subs. This consists of 4 67lb subs that contain 10" drivers and are all driven by a separate 1,000 watt class A/B amp. I previously used all class A/B amps but have transitioned over the past few years and currently use all class D amps to drive my 5 channels: a pair of D-Sonic M3-600-M mono-blocks to drive the 2.7qrs, an Emerald Physics EP-102 stereo amp bridged to mono for the CC3 and the classDaudio SDS-440CS stereo amp for the rear surrounds.
While these class D amps are from different companies and use different power modules, they have similar sonic qualities:neutral, very good dynamics, very low noise floors with smooth but very detailed mid-range and treble response that avoids harshness. However, I have to resist claiming all class D amps sound the same due to my limited sample size.
2. I don't believe class D is inherently better than traditional hi-end tube and class A amps. I have a great deal of respect for the sound of many traditional hi-end tube and class A amps.
While I've never used tube or class A amps in my system, I have listened to several hi-end traditional tube and class A amps at audio showrooms and friends' homes and find most sound very good. I've never been able to directly compare very good examples of tube, class A and class D amps to one another since I've yet to find an audio dealer that carries all 3 types. These dealers typically don't carry good examples of class D because they're usually sold internet direct and bypass dealers. I've had to rely on professional audio reviewers opinions for information on how the better class D amps compare to the better traditional hi-end traditional tube and class A amps.
Since you have the excellent, but notoriously hard to drive, Apogee Diva speakers I thought you might want to read this 6Moons review of the D-Sonic M2-1500-M mono-blocks. They drive a smaller pair of Apogee Duettas as part of the review. If you need a cooler running pair of amps than your big Krells, you might want to audition these in your system:
http://www.6moons.com/audioreviews/dsonic/1.html
3. I do believe, based on my personal experience, that good mid level class D amps are inherently better than good mid level class A/B amps. This is the one blanket statement I am confident is true. Now that I've used class D amps for a few years, I can honestly state that I cannot think of a single advantage that my former class A/B amp can claim. The validation of my blanket statement is that absolutely no one on this thread has identified even 1 advantage of class A/B amps, either.
My switch from class A/B to class D was all upside with absolutely no downside.
4. The Oppo 105 is a high quality component that is very versatile.
Yes, the Oppo has a menu for selecting the sub crossover frequency from 40 to 250hz in 10hz increments.
The Oppo also has a menu for configuring your speakers and their volume level. There's a tone generator that allows you to cycle through each channel Each speaker/channel can be set as either 'Large' that has no bass augmentation from the sub or 'Small' that does augment the bass via the sub. Each speaker/channel's volume is adjustable from -10db to +10db in .5db increments.
No class has a monopoly on good ,
Tim