Could use some help with a tough match

FYI (and to the best of my knowledge), the earlier single ended Threshold amps are cap coupled. The later e series fully balanced Threshold amps are DC coupled. Some earler Threshold amps were upgraded to "e" series with balanced inputs, but are still cap coupled. Most tube pres are not DC coupled (the only ones I'm aware of are Atmasphere and Sonic Frontiers). Adding balanced inputs to your Threshold amps might help with long cable runs, but will other wise just add needless complexity. You might have more (though not necessarily better) tube pre options sticking with your single ended Threshold amp. On the other hand upgrading to newer fully balanced Threshold amps might offer better tube pre options, albeit at a cost. My previous recommendations for Audio Research and Sonic Frontiers comes from an ex Threshold tech with lots of expereince and feed back from Threshold customers. The c-j thought just seems to make sense. Why pay for expensive fully balanced operation if you won't use it. The really high end c-j pres output impedance might be cause for concern though.

Thank you Unsound. Excellent post, you have helped me crystalize my way forward. I will leave the Thresholds unbalanced because frankly I firmly believe they match up well with my speakers so will look for a single ended ARC, Sonic Frontiers or c-j preamp but welcome other suggestions. I looked at the ARC 3 but once again would be paying for technology ( balanced operations) I won't use. Any recommendations on a good ARC, Sonic Frontiers, or c-j models? I don't mind if its a few years old but I really want a quality unit. It will be the heart of my system so a class A component is essential ( quiet, big soundstage and dynamics ). I will start researching again but if anyone has a slam dunk recommendation I would appreciate your input.
Thanks,
Don

Don, if you are looking for a great single-ended preamp, I suggest that you do some research on this Shindo Monbrisson. They are a rare find on the used market.

FWIW, I have no connection with the seller.

Cheers,
John

I have use a few different preamps from Space Tech Labs http://www.space-tech-lab.com/ with S series Threshold and Fote #4 + #6 amps with very good results. Custom built to match the rest of your gear.