Lexicon MC-12 Power supply

pfigg

Member
I'm the original owner of my first generation (non-balanced) Lexicon MC-12 Cinema Processor. I've heard and read that the power supply in these units often fail and need replacement.

I just got off the phone with a rep from Lexicon. He discounted my concerns, stating that (in general) he know's of no vulnerabilities with the power supplies in these units. That's fine, and it was good to hear. OTOH my unit is about 10 years old and I think it's safe to say, considering this thing is essentially "On" 24/7 - the power supply will eventually need to be replaced.

I've been inside the unit to upgrade it. Never had a problem with it. I'm sure I would be able to replace the PS with no problem.

The Lexicon rep. would not give me any information about the PS (part#, etc). There is an authorized service center in my area, and the Lex. rep. instructed me to contact them if my unit was ever in need of service.

I've also heard that the PS in the MC-12 is not a proprietary Lexicon part and a replacement can be purchased from various electronics supply dealers.

I have no idea if this information is accurate. Does anyone have any specific information on a replacement PS, and if so - where I can pick one up? I guess I could call the service center and try to convince them to acquire the part and sell it to me. May be wishful thinking ...

thanks.

-paul.
 
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I know this is an ancient thread, but I found it while searching for a solution to my MC-12b's untimely death.

Sager.com has the OEM power supply...from a company called EOS Power...with the part number LFVLT110-4302.

Ordered mine for under $80, although they haven't told me what the shipping is going to cost.

EOS also has what they call a "Medical" version of this, with model number LFMVLT110-4302...but the specs are identical. Perhaps it is built with a tighter-spec on parts?!

Hope this helps someone else.

Cheers,
John
Detroit
 
I know this is an ancient thread, but I found it while searching for a solution to my MC-12b's untimely death.

Sager.com has the OEM power supply...from a company called EOS Power...with the part number LFVLT110-4302.

Ordered mine for under $80, although they haven't told me what the shipping is going to cost.

EOS also has what they call a "Medical" version of this, with model number LFMVLT110-4302...but the specs are identical. Perhaps it is built with a tighter-spec on parts?!

Hope this helps someone else.

Cheers,
John
Detroit

My MC8 went up in a tiny wiff of smoke and now the red lamp just blinks, was it likely the power supply? I've moved on but it was a pretty adequate 2c pre. Still have it thinking maybe there is affordable hope.
 
part number LFVLT110-4302.

Ordered mine for under $80, although they haven't told me what the shipping is going to cost.
Let us know how this works out with that part number. The same part number but ending in 1 instead of 2 has been suggested elsewhere.
The spec is different on the two... the 2 version is 5 and 16 volt. the 1 version is 5 and 12 volt.
Did you get the number off your actual failed supply or somewhere else?
Thanks
J
 
I have replaced the power portion (not sure exactly what it was) on my MC1. I don't remember the details but it was a well known issue for these units - lots of posts on A'gon

It was rock steady on standby power until I had to unplug the unit and had to cold start it.

The good news it is a cheap and easy fix. I found a shop in Singapore that charged me about $150. (I was living in China at the time so this was a godsend). I am on year 8 of the new unit with no issues.
 
Success!

Finally got it yesterday...I'm too cheap to pay for quick shipping.

Installed it, just got the system reconnected...and it all works perfectly.

Total landed cost, $93.73.

I did get the part number directly off the old one. Didn't even think of searching for the OEM source until Lexicon pissed me off.

Seems to me that companies should always support a box that has their name on it.


Cheers, anyways,
John
Detroit
 
Anyone happen to know where i cn find the xlr ballanced pinout for the mc12?
Common seems to be pin2 hot, but i dont know if this is the case. My Krell amp is this way, trying to make sure its compatable.
 
I'd wager an AK membership it's pin 2 hot. Regardless, it's compatible either way.
 
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Well, I knew this day would come. By the way I am the original poster in this thread ...

Last night I powered down my MC-12 (non-balanced ver.3.14) for an extended period of time in order to remove/service a tape deck. 6 Hours later when I attempted to power up the MC-12 - nothing but the notorious yellow flashing light on the front display panel. I'm guessing the power supply has (finally) failed ...

Can someone please confirm this EOS Power LFVLT110-4302 available from Sager is a suitable replacement? Again I stress my unit is the standard MC-12 (ver.3.14) and not the balanced version. It has come to my attention that my particular model uses a different power supply than the balanced version and/or the newer "HD" models.

I'm weighing a few options:

• Attempt to re-cap the failed PS myself. I've done this before, mostly on tape decks and a projector.
• Remove the failed Power Supply and ship it to an authorized technician for repair. Frankly I don't want to ship the entire unit.

Best case scenario is the Sager OEM will work. If so I'll order it and handle the repair. I just need to know if it is compatible with my particular unit.

I appreciate everyone's help and insight, so thanks again.

-paul.
 
I pulled the Power Supply last evening. Not difficult at all. I was informed by an authorized technician that there is a current compatible replacement. However, they expect me to ship the entire unit to them and probably pay upwards of $500 to connect 2 plugs and tighten 2 screws. No way.

I emailed the Japanese manufacturer. I doubt it's still available. If I cannot convince Lexicon to simply sell me the replacement I may ask around for someone who would be willing to re-cap mine. I can probably do it myself. We'll see ... [-paul.]

Lexicon-Power-Supply.png
 
Just a quick update. My MC-12 is back up and running. I replaced all the clustered electrolytic caps located at the far right in the pic above. I also replaced the centrally located 150uF 400V cap. Total cost was less than $30. I plan to document the process (board characteristics, etc.) and supply a parts list. I will say the most difficult aspect of the repair was the removal of the old caps. There are traces on both sides of the circuit board. I did manage to rip out 2 copper pads. Luckily they were not linked to a trace on the suspect side of the circuit board.

-paul.
 
Just a quick update. My MC-12 is back up and running. I replaced all the clustered electrolytic caps located at the far right in the pic above. I also replaced the centrally located 150uF 400V cap. Total cost was less than $30. I plan to document the process (board characteristics, etc.) and supply a parts list. I will say the most difficult aspect of the repair was the removal of the old caps. There are traces on both sides of the circuit board. I did manage to rip out 2 copper pads. Luckily they were not linked to a trace on the suspect side of the circuit board.

-paul.
Hi Paul,
It's good you got this to work. I'm going to repair mine as well I think. Using the later "EOS" supply looks like it will require a harness modification to work in the older units like yours and mine. As you know Shindengen discontinued these in 2015 and I've been looking for a compatible replacement but in all cases there are modifications to be made or size constraints. If I come up with a mod that will allow the newer EOS supply to work, I will post it.
Thanks,
 
Well, I knew this day would come. By the way I am the original poster in this thread ...

Last night I powered down my MC-12 (non-balanced ver.3.14) for an extended period of time in order to remove/service a tape deck. 6 Hours later when I attempted to power up the MC-12 - nothing but the notorious yellow flashing light on the front display panel. I'm guessing the power supply has (finally) failed ...

Can someone please confirm this EOS Power LFVLT110-4302 available from Sager is a suitable replacement? Again I stress my unit is the standard MC-12 (ver.3.14) and not the balanced version. It has come to my attention that my particular model uses a different power supply than the balanced version and/or the newer "HD" models.

I'm weighing a few options:

• Attempt to re-cap the failed PS myself. I've done this before, mostly on tape decks and a projector.
• Remove the failed Power Supply and ship it to an authorized technician for repair. Frankly I don't want to ship the entire unit.

Best case scenario is the Sager OEM will work. If so I'll order it and handle the repair. I just need to know if it is compatible with my particular unit.

I appreciate everyone's help and insight, so thanks again.

-paul.
How did this information that the standard power supply would not work in the newer mc12hd?
 
How did this information that the standard power supply would not work in the newer mc12hd?
I just finished my older MC12B last night. The newer supply is the EOS, mine is the older Shindengen. I modified a new EOS to retrofit it into my unit, works like a charm. Here are some pics of old vs new with wire harness changes.
Kevin

IMG_4200.JPG
New power supply is on the right
IMG_4157.JPG
The two connectors that connected to the old supply
IMG_4196.JPG
Hardware needed for modification
IMG_4199.JPG
Mounting of standoffs
IMG_4185.JPG IMG_4186.JPG
Removing and inserting wire and lug
IMG_4184.JPG
Completed 12 pin connector
IMG_4181.JPG
Line in connector with leads reversed
IMG_4190.JPGIMG_4192.JPG
Additional info in response to question below. Sorry I didn't put together detailed DIY, but this isn't to elaborate to change, I'll highlight the changes below.

- Use (4) 3/8" M/F standoffs with (4) 3/8" long 4-40 screws for mounting the EOS supply. I used (4) flat washers under the screw head and (4) nuts with integrated lockwashers for mounting to the metal shroud. In the future it makes it easy to remove the supply for service without taking anything else apart.
- Use (1) Molex PN 09-50-8121 12 pin connector to replace the two existing connectors
- Using the pinout from the datasheet you have to rearrange the connections, remove each Molex prong by depressing the small tab with a small screwdriver or Xacto knife enough to release it from the housing and reinsert it in the appropriate 12 pin connector location until it "clicks" in and locks. When you depress the little tab on each connector be careful not to over depress it or it will bend down and no longer "click" in when you reinstall it. If that does happen, simply use and Xacto knife blade to gently lift it up a little before you insert it into the new connector. See images for color code and respective locations.

Red wires, +5.1V
Black wires, Ground or "RTN"
Yellow, +16V
Grey, -5.1V
Blue, -16V

- You have to reverse the line in connections on the connector to accomodate the new supply, the plastic header is reversed. The brown is "Line" blue is "Neutral". The board is labeled, as well as the documentation, for the supply.

The Molex connector is only $.76 at Digikey or at other suppliers, so only a couple of dollars in parts to do this and you mount the new supply. Also, I used the medical version because that's what was in stock, LFMVLT110-4302. Either will work
 
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Nice to see you guys were able to repair the preamps. It sucks that Lexicon is "orphaning" products they could easily help out with. Thiel was only too happy to send out surrounds for 30+ year-old speakers (04a) and even ATI, which bought the remains of B&K bent over backwards to help me fix my Reference 50 pre amp (someone over there found out about a guy that bought the remaining stock of proprietary ICs and called me with the information). Polk Audio, same thing... the guy went to the warehouse to find an ancient (30+ years) NOS part he thought he had seen and again, called back to let me know he had it.

To be such dicks that they won't even tell you where to get an OEM part or at least sell you one at a reasonable markup is unacceptable when they are a high end, low volume manufacturer. Good to know when it's time for me to spend my hard-earned money.
 
I just finished my older MC12B last night. The newer supply is the EOS, mine is the older Shindengen. I modified a new EOS to retrofit it into my unit, works like a charm. Here are some pics of old vs new with wire harness changes.
KevinView attachment 979607 View attachment 979608 View attachment 979609 View attachment 979610 View attachment 979612 View attachment 979613 View attachment 979614
That's great. From what I can see, the differences are the plugs is that right? If you installed a different plug can you supply information as to where you got the new plug, or give a short rundown description of the pictures and what I am seeing? I have the older mc12 non balanced, that I got the numbers from to order the new supply. I also have a newer mc12hdb that I was hoping to fit. I did 2 otjers in the past that were the same, so it is helpful to see this posting to know what I may be up against. Thank you for posting
 
I installed a bunch of MC 12s and the last time I checked most had been replaced. Not because of failures but because more advanced electronics were installed. At the time I thought the MC was a contender for being the best. But a lot has changed since then. We never used Lexicon amps. Mostly QSC in commercial installations. Homes were what ever the customer selected from Yamaha, Marantz, B&K, Crown and Mcintosh .
 
That's great. From what I can see, the differences are the plugs is that right? If you installed a different plug can you supply information as to where you got the new plug, or give a short rundown description of the pictures and what I am seeing? I have the older mc12 non balanced, that I got the numbers from to order the new supply. I also have a newer mc12hdb that I was hoping to fit. I did 2 otjers in the past that were the same, so it is helpful to see this posting to know what I may be up against. Thank you for posting
No problem, I added some details above. Let me know if you have any other questions.
Kevin
 
Hello all. Glad to be here.

I just got an MC-8 that had the power supply replaced (using the one discussed-here). I removed it and I could swear I put everything as it was before. But the fuse blew -I'm hoping nothing else got damaged downstream in the unit.

Any ideas on what could have happened?

Two things that come to mind is that maybe one of the leads going to the on/off switch was not making contact, or that the leads were reversed. I find it hard to believe but it's a possibility.

My first idea is to replace the soldered in fuse and try again.

Many, many thanks in advance.
 
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