Joule 150A MKII versus Atma-sphere Preamps

Currently have a Joule 150A MKII that works fantastically well with my CAT JL2 and Music Reference RM9 Special Edition; bot are single-ended RCA only. I will be getting a Atma-sphere OTL amp in a little while which I'm told is generally best with balanced connection. My question is both general to the Joule versus the Atma MP1/3s and also regarding the need for running balanced with the Atma-amp versus using very high quality RCA ICs.
Isn't running differential balanced the raison d'etre of Atma-Sphere amps & preamps?
I question how much difference you would hear running the Atma amp balanced versus unbalanced, although there would definitely be less noise, hum and hiss if you ran balanced. The tonality would not change appreciably, IMO.

I run an Atma-Sphere MP-1 preamp balanced with Pass Labs amps and the combo is very, very quiet.
I do think it is the raison d'etre, but I'm not sure I could hear a difference based on the "quieter" potential of balanced operation. My system is pretty darn quiet. My quandry is that I don't want to own two preamps if I don't have to. I notice that many reviews of the Atma amps are actually using single-ended preamps, which makes me think it is fine, on the other hand you hear about the special "synergy" between the Atma pres and amps. I guess there is really only way to find out....
As I understand it, the basis for balanced designs comes from studio equipment. Unlike home use where 1-2 meters is typical for interconnect, studios often run 10-30 meters so noise rejection becomes critical. So balanced may measure lower noise, even in a home system, but is it audible? I wish someone would run a reliable test on this.

Another point, a few years ago I ask Jud about a balanced version of the Joule preamp. He said to make it truly balanced would require another gain stage and he did not believe that would be worthwhile (increased complexity in the circuit). He also mentioned the unlikelihood of noise with good quality interconnects of moderate length.

04-26-08: Pryso
So balanced may measure lower noise, even in a home system, but is it audible?
When I have experimented with gear that offered both balanced and single ended operation, I can say without hesitation that the balanced option was always audibly quieter.
I thought the goal of "balanced" cables was to keep the shield separate from the "-" wire. In many RCA's the shield is connected to the "-" so that the noise collected by the shield may become a part of the amplified signal. Doesn't a "balanced" cable drain the noise collected by the drain wire and connect it directly to chassis earth ground, bypassing the "-" wire, hence never giving it the opportunity to pollute the amplifed signal. Am I misunderstanding this?
My other issue beside design approach is whether or not the MP-3 is as inherently good a preamp as the Joule 150A MKII. I love the Joule after having experimented with CAT,Lamm, and Placette Active. So quiet or not, I just don't know if the MP-3 is as a good a preamp, but again, I guess I just won't know till I get one in my system.
The MP-3 will be different. I'll put money on it. It'll be more neutral and less romantic than the Joule.

Now, you may consider this as not being better than the Joule, and others would argue that the neutrality makes the MP-3 better. Who's to say what's better? It's a matter of preference.

Let me know if I'm right after you hear it.
I've been a long time user of MP3/AS30. Prior to the MP3 I had a AI M3(single ended) as my preamp running to the AS30.
The combo worked fine with no issues. The MP3 was a sgnificant stepup but I suspect that's because the MP3 is a better preamp and not because it's balanced. If you like the Joule there shouldn't be any issues running it single ended with the AS amp.
Thanks Franks, I'm coming to that conclusion. I want to enjoy some M-60s without having to carry two preamps. I've spoken to a few folks who have made me comfortable with the idea that the Joule will work very well indeed, even if unbalanced. Thank you for keeping me from going over the deep end. But there is a ARC Ref 1 on sale....
I agree with Tvad as I have run my PSE HL-1 in both modes and the Balanced always seem to have a lower noise floor and offered more resolution;also when I last talked with Ralph he recommended using Mogami cable which I did and think it is excellant;also will not break the bank.