Building Mark Levinson 38 preamp chassis from scratch

Hi. If you have a main PCB that you like to use, just to let you know that I built a few new sets of front control and remote PCB.

I will have two complete sets to sell, including the hard to find HP/Agilent optical encoder for the volume control

The kit includes:
-Main front PCB and small standby button PCB with needed cable to main PCB
-Remote PCB with battery holder and button caps that will match the upcoming remote plate.
-NEW This year: Rear remote PCB with 2 flat cables to connect to the REC OUT outputs on the main PCB
-HP Optical encoder (volume) with needed cable and connector
-EMI entry AC Filter
-AC selection jumpers for 120V or 220V operation as needed.
-CD documentations, manuals, pictures, parts list, etc.
-LM380 code upgrade EPROM.

You need to provide the Neutrik Connectors and the 2 pairs of Cardas RCA connectors for the REC OUT connectors on the back.

Send me a email for the details.
Thanks...
 
This is the biggest PCB run I ever did, ouf :dead:. It will also be the last batch of PCB for the ML38 interface. After that I won't have any parts left. So, the is the last chance.

Bye...
 

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Here the first prototype of the small PCB that fits on the back of the preamp. It has thte RJ12 and RJ45 Master & slave connectors, the IR remote, 1/8 jack and both pairs of REC OUT RCA outputs. Pretty close to the original. A real pain to assemble, very small PCB traces, a lot of jumpers and the Cardas RCA are tough to solder. But a very nice look once done :D
 

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Hi. Good question and not easy to answer. My own ML38S modified to ML380S is using MUR860 diodes. But doing my research on the ML380 original upgrade kit, I'm pretty sure that ML use originaly MRP10B diode . This diode is the little brother (smaller rating) of the MRP15B they use in their top transport ML31.5.

I like the MUR860, but I really like to try also the MRP10B. I didn't have the time yet to do so. I just completed the small mounting PCB. The price of these small diode is so low that you may try both and decide which one you prefer. Bye...
 
Hi everyone. I'm ready to place an order for the nice ML38 preamp rear plate, see images in this thread.

The new 2007 version rear plate has the holes for the small PCB (Master/Slave Interface PCB) on the back. As you can see it will give your ML38 kit a perfect fit and finish.

As stated for the first batch, these plates are made of aluminium, images are hi-res 700 scratch resistant process, holes are all laser pre-drilled. Fit and finish are outstanding, as good, if not better than the original. Take note that the posted images are in lower resolution and are not showing the great look of the final plate.

For the guys that bought the last kits in 2007 with the new remote design (with button with studs), I will also provide a remote front plate. This plate is an exact replica of the original but with mechanical specs to accept the new remote and button choice.

I will accept offer, then request a price for the needed quantity. Me and a friend we may order 15 rear plates to start with. If we can get to 20 plates we may get even a better price.

Note that will be the last order of this plate, this is your last chance to get it. Last batch ordered price was around 65$, if I remembered correctly.

Let me know if you are interested with the rear AND/OR remote plates. I plan to place the order within a maximum of 2 weeks.
 

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Mark Levinson n.38 fault

Hi,

I am a newbie on the forum.

I was changing main voltage to adapt an US unit to EU but something went wrong. Not sure the fault is really related to my work that at the end was only to modify the jumpers in order to put in series the two primaries of the transformer ...

In any case now I am in some trouble I have not schematics and no big experience in troubleshooting.

Any help or suggestion will be welcome.

Regards

Linus
 
I have a 36 DAC that I've had since '97 when I bought the display unit from the store I worked as service manager at. The DAC analog boards are very similar to the 38. Well the 36 gave up the ghost the other day so I put it on the bench and found beaucoup capacitors either leaking or open. I ordered long-life, low impedance "FR" Panasonics for most of the values, Nichicons for a couple of values and UCC for the 6800uf/ 35v snap-ins. My question for you all is how do you get the old snap-ins out without pulling out the plated through holes??? I have a nice temp-controlled soldering station and a nice temp-controlled vacuum desoldering gun but the original capacitors tabs are crimped really tight to the board. I've been soldering professionally for 40+ years but this one has me stumped. I am guessing that my 380S capacitors are not too long before failure and I can't imagine trying to get those 6800uf out of a four-layer board!!
Thanks in advance!
 
Thanks Willcycle,
That is good to know about the 380s. The 36 DAC used snap-in capacitors and the legs were crimped on to the bottom of the PC board making them all but impossible to get out without damaging the board. All of the other caps came out easily. I have the 36 DAC re-capped except for the nearly three dozen 10uf/50v electrolytics that I forgot to put on my Mouser order.:headbash: I did remember to get new MUR860 and MSR860 diodes to upgrade the power supply.

Thanks again!

p.s. human powered cycle or motorized cycle?