Heard the Computer Audio Design GC1

That really was an eye opener wasn't it?  I'm about to pull the trigger on getting one.  It's been the best under 2k tweak I've ever heard.  You can use one on each server, DAC and preamp.

The recommend using one on the earth to the system/power conditioner if you can afford it.  For me, I'm going with the CG1 on the server/integrated DAC as that most probably will be the biggest sound difference in my system.  I already run fairly clean power from dedicated lines to the system.

Not given to overstatement in describing audio gear, I nonetheless have to agree with the OP that this is a must listen product (see below). I came onto it in the ideal way--a friend brought one (the GC1 base model) to my house and I listened to it in my system. Although he was a knowledgeable audiophile and spoke highly of it, I really didn’t expect much. But once it had warmed up (essential), I was amazed at how it improved the sound from my already very high end system. Much deeper, quieter and opened-up soundscape (honestly, made me think of outer space), almost hauntingly so, the sound was cleaner, clearer and the music was just more fully realized. More enchantingly beautiful, I am forced to say. I auditioned it on a Sunday, and ordered one on Monday (also from John Rutan at Audio Connection in NJ). With the two required cables, it comes in at $2,700.  (Pricing structure is $1,995 for the GC1 and $350 each for the two required cables.) Not cheap but in audiophile dollar circles, a very cost effective purchase. Scott (the designer) suggested I hook it up to specific connections on my DAC and preamp (yes, he knew my specific equipment). The GC1 is small enough (sort of a long, rectangular tube shape) to share a shelf on my rack with my server. If you have no dealer nearby, my understanding is that it is 30 day money back, so one can be ordered with no risk. (Note that I have not auditioned similar products to compare.) Also, no deals are allowed--it is only available at retail.

Thanks for sharing. yes, it's an amazing product.  Scott is a genius.  I'm glad that Rutan turned us onto this device. It's a MUST get. I'm calling him in the morning to set up the purchase.  Just one of those rare devices that work.  

I heard these devices at Axpona last year. CAD had a complete system with at least three ground controls, their streamer and their DAC. The system sounded amazing to me - digital but not digital. It was hard to say what was making the magic but I purchased a CAD GC1 in hopes of capturing some of it. 

In my system it did several things
> much more tone color - sounded gray when I removed it
> much better low bass (I have Vandersteeen 5A carbons so when you change the bass it is very audible)
> smoother and quieter without loss of detail, especially with crescendos 

Indispensable devices IMO. I am going to get another one. 

It has improved every system I have been allowed to try it with.

Thanks for sharing.  Where did you purchase it?  I know they only have a small group of trained dealers.