the preamplifier built in the ayon cd5 is great?

Afc, thanks for the comments and complement. I appreciate the added info!

Perhaps the info I learned from my time writing up the Cambridge Audio Azur 840C applies. When I worked with that pre I was surprised that at times I had to push it's vol. control to about 85% of total output. That concerned me, but as I discussed with the situation with Cambridge they reassured me about it. The volume control was truly linear. A typical one is not, and you will get the majority of increase "front loaded", but as you continue to elevate it the amount of rise in level tails off.

Conversely, with the Cambridge, even though you have to take 85% of the volume control to reach the theoretical same point, as you increase from there, the increases are quite dramatic and the unit actually has more than enough left in it for elevated listening levels. I was told that one can push it to Max output and won't harm it one bit. We are so used to "front-loaded" attenuators that it scares us when we use a linear level control, as though something is horribly wrong.

Though I did not ask the same question regarding the Ayon player I suspect it might operate similarly. To need 75% of the level output might not be a big deal if the unit ramps up in a linear fashion. The next 5-10 digital steps may blow the lid off the level. I am no longer concerned about being within 15 digital steps from "Max" volume with the CD-5 for my listening.

Do you find a fair bit of difference in level needed for the Zu versus the Aliante? The monitor I can see being a bit underpowered at nominal 6 Ohms, 88 dB, and being pushed by 30wpc. I can definitely see why the CD-5 would need its level taken to 75% of capacity. I have also needed this type of level when using the Kingsound King ESLs, which are very inefficient. But when I put the 4 Ohm, 95 or so dB Legacy Focus SE in to the system the CD-5 only needs to be taken to about halfway on the level. Profound difference.

I'm not surprised at all about the resultant "...better soundstage and imaging" experience with the CD-5 and the Ear. I have also experienced the "exploded" soundstage and hyper-detail with the CD-5 into the VAC Signature Preamplifier MkII, and it's a very intriguing, captivating sound. I can see why some would prefer it over the "direct to amp" setup.

I find the amp is important in the attempt to use the CD-5 direct. I might not be satisfied with the CD-5 into a lower powered SET amp, even with the 8v output from the CD-5. I have to have my big power, minimum 200wpc to get the dynamics I want, at least with larger, multi-driver full range speakers and panels. :)

Thanks for the reassuring comments. I was very concerned that as I pushed the volume on the CD5 that I was going to badly overdrive the amplifier. It does seem quite linear rather than front loaded. At low volumes, you don't get much bump from the CD5 volume control. As you get to about -40 though, it really starts to take off.

Fair bit of difference between the Zu and Aliante? No. HUGE difference. The Aliantes, you have to push them. The Zu's don't require a big shove, but they really, really start to sing when you open them up big time. The imaging and soundstage just explode as you push the volume on them. The Aliantes, they just kind of get louder.

I think what you experienced with the VAC, I'm getting a similar thing with the EAR. I'm sure you're familiar with that unit. Does it stack up similarly to the VAC?

Not so sure about the need for a high powered amp with the CD5. It really cranks with the 30 wpc Mastersound and the Essence speakers. Less efficient speakers, yes, maybe. But I notice essentially zero difference between the Mastersound and the Rowland 102 with regards to dynamics. The Mastersound has tremendous headroom that the Rowland doesn't seem to match, and with a six ohm load, that's a 150 wpc amplifier.

I read a thread recently in the amp/preamp forum about solid state amps increasing their power output as the speaker load decreases. Makes sense. But the author laid something out with tube amps that was the polar opposite of that- something akin to tube amps increasing their output as resistance INCREASES. I didn't touch that one, since I don't understand the concept. Is that a true concept?

How is the heat issue and lifespan of the 8 tubes in the CD-5 ?

Tosses a fair amount of heat. Not like an amp, but it definitely gets warm over the vents. Ayon claims the tube life is 5000-10,000 hours.

Afc, the EAR components are also very good sonically, from what I have heard at shows. I have not compared them in my room.

Here are some articles which discuss basic differences between SS and Tube amps:

http://www.soundstage.com/gettingtechnical/gettingtechnical200405.htm

The Second site has a lot to do with guitar amps,etc. but I found the answer to #2 to be clear:

http://aga.rru.com/FAQs/technical.html#pwrvsvol

Regarding the heat from tubes, I would not put the CD-5 into a closed shelving unit, but it does not throw so much heat that a room would be adversely influenced.