Mark Levinson 390s

Basically, all Levinson equipment uses jumpers to set transformer primaries which are compatible with all voltages (visible on left in a picture). However, some of the equipment has also circuitry that monitors mains frequency (a chip on the right in a picture of ML390S).

In such case, even if you set primaries properly, you will get diplay message WRONG AC with a code. Apparently, when you contact Madrigal and give them that code, they will provide you with a new code which when entered through the remote will set the microchip allowing the equipment to operate with a new mains frequency (50Hz vs. 60Hz)
 

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wichers

Member
2009-07-14 7:36 pm
It was a gamble but I've bought a ML390s in the US and did the conversion myself. There was no password code and it was as simple (for someone who studied older electronics, like my father) as moving a jumper to the correct position.

If you look closely at the following picture: http://www.marklevinson.com/image_library/390SOH.jpg you'll see a white jumper block (8 positions) with copper jumpers. On the picture the jumpers are currently set at 110v (starting from the top that's (2/3 and 5/6)) and should measure something like 27 ohm between line and neutral (that's where the voltage cable goes in).

For 220v there only needs to be one jumper between 4 and 5 and this should measure around 98 ohm. For the 240v configuration one jumper should be set to 1 and 2 and should measure 109 ohm.

Cheers,
Alexander
 

wichers

Member
2009-07-14 7:36 pm
Hi Bebo,

Yes that simple. I really thought (reading all the stories) there was going to be a 50/60hz check. I even prepared for this and bought a Willem eprom programmer to start hacking (it's a AT29C010A 128k flash). But to my big surprise there wasn't.

And it sounds great :)

Cheers,
Alexander
 

andmost

Member
2009-12-14 11:26 am
hello, someone can give an help? I purchased an used preamp Mark Levinson 320s from a seller in U.S.A.. I live in Italy . I received the package this morning from ups and before to turn on I set the preamplifer to 230 / 240 volts ( here in Italy the voltage is 230 /240 ).
When I turned on the preamplifier, it asked me a key of 5 numbers or I can't use it !!! I
don't know that code. What do you think I can do?
Thanks for your help,
Andrea