My Rhea's new partner arrives today

Hi Dan,

I can relate so much to your experiences with the BAT vs. Calypso....and the Callisto. I had a BAT 31SE (a phenomenol product) and it too threw a much bigger stage and did a more accurate portrayal of space than the Calypso in my system. But the Calypso allows so much more low level information, subtle queues in the performance, and greater dynamics in the upper frequencies. It is a very tough call to choose and ultimately it comes down to balancing with the rest of your system.

With my preferences being more in the areas of warmth/bloom/3D, the BAT was prefered. But once you hear the subtractive nature of the BAT vs. the Calypso, this lingers in the back of your mind. This all ended up being a moot point as I went with the Callisto which has all of the strengths of both and goes to another level in portrayal of space, dynamics and low-end extension and control.

The Calypso I have heard many times as a reference here is the one owned by A'gon member Jadem6 (JD). He has really maxed out the performance in his unit with tube rolling. I suspect this has much to do with the incredible resolution and openess that I have experienced with this model. I strongly suggest you contact him if you are interested in tube rolling advice. I have done a lot of experimentation of 6922, 12ax7 and EL34 tube rolling in the Callisto and the Io with various Telefunken, Siemens, Mullard, Ei vs. the stock Sovtek and could give you some details here. But I suspect JD's direct experience with your model would be more valuable.

Concerning phono stages, I had an identical experpience with the BAT P10 and the Io. Both were standard models, but for the $1k difference on the used market, the Io was in a completely different league (with stock Sovtek tubes) in the sense of dimensionality, decays, etc. This model loaded up with Telefunkens is pure magic. And in the case here with the Callisto/Io, as for you as with the Calypso/Rhea pair, it is no surprise these are incredibly musical products.

John

Dan,

I can assure you that JD's system does not at all have the digital edge that is prevalent in many other digital-based systems. I believe his Sony unit has gone through a few 3rd-party upgrades so this is not your average Sony unit anyway. The first time I took the Callisto Sig (it had the stock Sovtek tubes at that time) to his home, the sound was not at all forward nor fatiguing.

As for needing to spend a fortune on tubes here, there are many great Mullard and Telefunken pairs out there for less than $100. In fact I have bought quads of these tubes that comes down to $30-40 for each tube and these far exceed the stock Sovtek tubes in terms of resolution, tonal coherency and dynamics. But so far the most quiet 12ax7 I have tried is the Ei and these are only $15-20 a pair! I have 30 or so Tele 12ax7 tubes and none of them are as drop-dead quiet as the Ei's. The Ei's give up a little of the magic to the others in the Callisto & Io but so far, I find them to be the best tube for the Io's input stage. But this is only an issue on the first stage of the Io. I have not played with many Mullards in the Io yet.

JD and another local audiophile were at my home a couple weeks ago and we dropped in a prized pair of BugleBoy 12ax7's in the Callisto. I think we all agreed that the Mullards I had just swapped in replacing the Tele's "locked in" the music like the BugleBoy's had not. With the Mullard, the tonality was more coherent and the sound was more dynamic as well. The Tele's were definitely lacking resolution and presence in the upper frequencies....but I love these things in the Io. You just gotta try each one for yourself in your system.

I just loaned a few pairs to an A'gon member and he ultimately liked the Ei the most in his CAT preamp. If you'd like, I could loan you a pair of the Tele (smooth or ribbed) as well as a pair of Mullard. He ultimately kept the pair of Ei's so I do not have any extra here.

John

Dan,

I have not compared the Tele smooth to the ribbed. Each time I have gotten more Tele's, I have tried them in the Io's input stage hoping they are super quiet like the Ei's, but so far such a quad (or even a pair) of Tele's has not crossed my path. So I have simply replaced the stock tubes with the newly arrived Tele's and enjoyed the improvement with no attention to which type of Tele it is. I guess I will have to do this next time I have an itch to tinker with the tubes. If you are interested, I could loan a pair of each to you.

And one more thing: I have tried the Amperex 6922 in the Callisto and the Io and this tube just does nothing for me. It was lifeless and in fact a bit fatiguing. I always prefered the RAM and Sovtek tubes to this in the ARC LS5 that I ran with for years as well. YMMV. But oh how sweet the Mullard 6922s are in the Callisto and in the CAT amps.

John