Let me chip in with a couple of observations on the IO Sig. I have had mine for about a month (I am second owner of this unit 18 months old bought here on the Gon)and it superceded a hot rodded Sonic Frontiers Phono 1 SE with Amperex Bugle Boys. My speakers are 89db sensitive with ribbon tweeters that love to let you hear any tube noise going!
Both phono stages are in the sytem for direct comparison.
When I first powered up the IO Sig the tube noise became a big issue for me compared to what I was used to with the SF using a .25mv output ZYX UNIverse and a .15mv output Kondo IO-j. The SF has a 62db gain but is totally quiet even with the lowest output carts and no tube rush to speak of (function of the FET gain stage). With the IO, I found that I had to notch the gain jumpers back to 60db to reduce the tube noise and with subbing in various NOS Raytheons, NOS Brimars and regular electro-harmonix the noise issue basically went away. I concluded there was a noisy Sovtek somewhere and maybe just removing and replacing tubes cleaned up the tube socket connections. I also put on a top notch Granite silver power cord 10awg (with ferrite) and that seemed tame the noise a bit as well. I also found with the really low output Kondo, a 1:10 Tribute transformer that sounded horrible with the SF is just great with the IO and absolutely no ground hum whatsoever, which can be a challenge with some phono stages.
I can't fault the IO in any way with 1 power supply and if Jim says 2 are better, I am not sure my ears would be up to it even! My SF is competitive with most expensive phonos out there, but the IO just takes everything to a new level and it is the top of the food chain, putting pressure on the rest of my equipment to keep up. In comparison to the SF, the IO is more open, relaxed and dynamic all at the same time, the SF sounds a little closed down and veiled in comparison. It is also worth noting that background noise is also a function of appropriate loading to match cart impedance.
I have spoken to Jim White when the initial noise issue first depressed me and he was incredibly responsive both email and later by phone when I needed some info. I recently decided to send the units back to Jim for a tune up as they were used and even though I am a second owner, no warranty and living in Canada, Aesthetix have been wonderful in supporting me. My next decision is whether to get the Callisto to replace my SF Line 3 SE and the only concern (besides the cost) is if the heat will be much greater in my closed listening room.
Steve
Both phono stages are in the sytem for direct comparison.
When I first powered up the IO Sig the tube noise became a big issue for me compared to what I was used to with the SF using a .25mv output ZYX UNIverse and a .15mv output Kondo IO-j. The SF has a 62db gain but is totally quiet even with the lowest output carts and no tube rush to speak of (function of the FET gain stage). With the IO, I found that I had to notch the gain jumpers back to 60db to reduce the tube noise and with subbing in various NOS Raytheons, NOS Brimars and regular electro-harmonix the noise issue basically went away. I concluded there was a noisy Sovtek somewhere and maybe just removing and replacing tubes cleaned up the tube socket connections. I also put on a top notch Granite silver power cord 10awg (with ferrite) and that seemed tame the noise a bit as well. I also found with the really low output Kondo, a 1:10 Tribute transformer that sounded horrible with the SF is just great with the IO and absolutely no ground hum whatsoever, which can be a challenge with some phono stages.
I can't fault the IO in any way with 1 power supply and if Jim says 2 are better, I am not sure my ears would be up to it even! My SF is competitive with most expensive phonos out there, but the IO just takes everything to a new level and it is the top of the food chain, putting pressure on the rest of my equipment to keep up. In comparison to the SF, the IO is more open, relaxed and dynamic all at the same time, the SF sounds a little closed down and veiled in comparison. It is also worth noting that background noise is also a function of appropriate loading to match cart impedance.
I have spoken to Jim White when the initial noise issue first depressed me and he was incredibly responsive both email and later by phone when I needed some info. I recently decided to send the units back to Jim for a tune up as they were used and even though I am a second owner, no warranty and living in Canada, Aesthetix have been wonderful in supporting me. My next decision is whether to get the Callisto to replace my SF Line 3 SE and the only concern (besides the cost) is if the heat will be much greater in my closed listening room.
Steve