Converting Mark Levinson gear from 240V to 120V

Can anyone assist me in converting an ML 23.5 from 240 Volt to 120 Volt? I see a series of blade connections where the power wires converge with 2 jumpers. I'm sure it's a matter of moving/adding/removing these jumpers.

I also have an ML 30.5, 31.5 and 38S. These look like they have to go back to Madrigal for some surgery to make the change, but if you know how to do this, any help would be of great assistance.
i have the same problem as you have and i wrote madrigal to ask for their help.
they told me that they will only do it at their factory in connecticut for about $150 per piece or you can have it done by a dealer in your country outside the us.
since i live in hong kong and am moving back to the us, i wanted to have the job done properly and tested so if i have it done in hong kong, i won't know if they did it properly by testing it. then again i don't want to be shipping all my mark reference components to get it done either, the 33's are quite heavy to ship. i asked madrigal to send someone for a field job but they said that they don't do that.
i don't want to run the equipment on step down converters. it looks like i will have the dealer here do it and take a chance. the dealer here atleast does field jobs. let me know what you do.
As far as I know, most of the power transformers used in audio-gear assumed to work on both 240 and 120V. Most of them have an extra output set that even no manufacturer can get rid of. Manufacturers to hide this fact from illiterate consumer can make money without extraneous part and labor investment. Madrigal in this case can be on my "Crook list" charging $150+....
I do suspect that Madrigal speculating on these piece-of-cace issues since they largely deal with Europe and less-likely will they use different transformer.

The bottom line is that if voltage is measured accross each of output windings of power transformer at the same input AC voltage they will be different in relation of 2:1(120V terminals v.s. 240V terminals. It lies in the simple ideal transformer formula:
Vin/Vout = Nin/Nout where N is the number of solenoidal winds and V is input and output voltage respectively.

If it's just a matter of re-plugging different wires from the same transformer it can only take 10...15min depending on skills of technician.
Why not run a dedicated 240V line from your electrical box? Simpler and the equipment would probably run better anyway.
Send it to Madrigal, please. That is what they recommend (if it was safe or easy, the procedure would be in the owner's manual). Poking around in power supplies of hefty SS amps is deceptively dangerous.

Respectfully, and with no offense to anyone, I would not trust any advice on this matter unless it's from a qualified technician.
When I worked at a ML dealership I was told by the ML rep. that it was done to protect the dealers and distributers from "gray market" goods. Not to mention the safety issues. I can understand this after feeding my family by selling hifi gear. When you spend hours with someone educating them about a piece of gear and then they buy it from an overstocked dealer, it hurts. I have been out of retail for four years and don't miss it at all. I do miss many of the music and equipment nuts that I became friends with though. All in all, it was a great way to make a living.
Hifi I agree with you they should buy from you, if
you spend time teaching them,I would love to go
to a dealership where there is a salesman like you.
Unfortunately and sad, there are not that many salesman
who knows, How to treat costumer, Not trying to hijack
this thread.Agon is my best dealer.
I've converted my 20.6s from 110v to 230v. It's was not done at the factory though (too expensive including shipping and not forgetting a 6 weeks waiting time) but by my trusted hifi technician. The circuit is at the front of the unit (you'll have to open the cover). He did some measurements, swapped the jumpers as well as flip a switch from "low" to "high".'s been more than 1 1/2mths now and no problem encountered. The conversion should be similar to the 23.5. Just look around...happy listening!! Cheers.
I second the option of running two/three dedicated 240V lines into your listening room instead. I've heard from several people that their system sounded better running 220V-240V. And it can be done for less than $300.