I've got no clue, but i need to know one thing. Where did you get that lamp in your system? I've been looking for something like that for a long time.
I believe Albert Porter is intimately familiar with both of these units. He owns the IO and has demoed the Rhea.
He's currently in Europe doing several shows. His shedule is posted here somewhere, perhaps you could arrange to run into him. If not, you may have to wait a couple of weeks until he gets home. I don't know if he has the time to keep up with A'gon threads as much as he normally does.
Well, the Zyx 1000's main difference to my former Benz and Lyra:
Good as they were, after some listening I started to rate my records a la "good sounding"," bad sounding" etc.
With the Zyx this stopped, the music is always the priority and I don't think about the quality of my records.
I think, it is a good cartridge.
Sorry to be off topic. I've got a Tizio lamp too. I added a base to it, so it becomes a floorstanding. The light now "hangs" over my turntable. Any modern furniture store will most likely carry it. Another place online is called "Design within Reach". If you have an Architect friend, they can get one for you with a designer discount.
Thomas, I'm glad to see you're still considering an Aesthetix phono stage for your system. I've not listened to the Aesthetix Rhea in my own system in direct comparison to my Aesthetix Io Signature, so I'm going to pass on trying to offer any specific thoughts regarding your first question.
As to your second, I posed this same question to Jim White, the designer of Aesthetix, when I was purchasing my Io. His reply to me as to what he heard was very direct:
The Signature provides the following benefits:
Hope this helps some in your pursuit of your ultimate answer.
I have an IO Sig in my system now (single power-supply) and auditioned Rhea for a couple of days last spring. The IO sig is in another league. I have followed Albert Porter's advice and replaced the 12ax7's with selected low-noise telefunkens. However even with the stock tubes I would say that there is a huge difference between the two. The sense of space and ease that the IO provides is really something. I am running it through a CAT ultimate (also re-tubed with vintage mullard and telefunkens).