Who can convert single ended to balanced?


Fellow Audiogners, please advise me as to who I should contact to convert two stereo single ended Thiel 3.5 equalizers, to two mono balanced Thiel 3.5 equalizers. While I'm having this work done, are there any other upgrades that I should consider? As always, thanks in advance.
unsound
Swampwalker, I'm waiting for a response from Thiel. My memory is vague on this, but, I think they declined to do it in the past. Thanks anyway.
Wasn't there a company, I think it was JPS, that made a modification for the Thiel 3.5 EQ box called the Golden Flute? You might contact them--not sure if it's the same company as the one that makes cables now, but worth a try.