3TM mod MP-1 preamp turns off by itself

[Hamer95USA]

  Hey guys,

I had to use my ADA Depot 3TM mod MP-1 preamp as a backup rig for my Marshall 6101 combo amp since I didn't properly repair the speaker cable.  :(  I turned on the preamp and while I played it onstage, it turned off and then turned itself back on again while playing onstage. Very embarassing to say the least. I was like "WTF?!!"  How would l fix this problem? Any information or suggestions would be greatly appreciated.

Guitar George

[rnolan]

Hey George, well that sucks  :facepalm: Does it have the MDRT, I assume that's part of the 3TM mod ?

[MarshallJMP]

If it has the original tranny this can happen if you get a voltage drop on the power line.

[Hamer95USA]

  Hey rnolan,

No, it doesn't have the MDRT transformer.

Hey MarshallJMP,

It does have the original transformer. Is there anything that I can try to do that will fix the issue? Replace the transformer? Contact ADA? They're back in business and will do repairs for their gear.

Guitar George

[MarshallJMP]

Can you take a pic of the inside near the transformer?

[rnolan]

Hey George, the MDRT is a very good idea as it's a much better transformer, and even more so as the 3TM has an additional tube so will draw more power (a feature of the MDRT is more and better power available (http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm)).
For power surges (which it's sounding like ?), you can use a power conditioner (Furman seems to get the nod around here) or use a computer uninterruptible power supply (UPS). I use a 1kva UPS with my MP2 rig as we typically run off a generator and the MP2 shits itself when the voltage drops, display goes hieroglyphics and I have to power cycle it to get going again (really great in the middle of a solo NOT  :facepalm: ). The Furmans are quite expensive here in Oz >$500 AUD, The UPS cost me $160 but down side is the battery in the UPS will go eventually.

Cheers R

[Hamer95USA]

  Hey rnolan,

I had the 3TM mod MP-1 preamp mounted in a rack and connected to a Furman PL-Plus power conditioner when the preamp decided to power off/power on by itself.

Hey MarshallJMP,

I'll post a few pictures later on. I remember buying this preamp off of kurtstuff about 10 years ago. Do you think that I would need to replace the lithium battery?

Guitar George

[rnolan]

Hey George, mm sounds like the MDRT may be the fix you need, lets see what MJMP comes back with after you get some pics.

The batteries are very old now (if it's original battery) and are definitely due for a change (CR2032) but I don't know/think it would cause a power cycle ? My understanding is they still work with dead battery but wont hold presets when turned off as the battery powers the ram when turned off. We were posting about this a while ago and quite a few MP1 members were needing to replace batteries. However, it would be good if it's that simple as that's a cheap and cheerful change but does require solder  :thumb-up:

[MarshallJMP]

Ok post them here or email them (or both) so i can have a look.

Battery has got nothing to do with it,if there's something wrong there you will loose your presets but it won't give a brown out.
A safe voltage is 2.7V or above.(a new one is 3.3V)

Did you got anymore troubles with it,or did it happen just one?

[Hamer95USA]

Hey guys,

I brought my 3TM mod MP-1 preamp to my amp tech. He told me tested it and there's an issue with the MIDI board which makes it shut off after being turned on for a period of time. Any recommendation on where to find a MIDI board?

                                                                                                                                            Guitar George

[MarshallJMP]

If your tech knows what the problem is why doesn't he fix it? Don't see the need to find a another midi board?

[Hamer95USA]

  Is there anyone in the northern California area that can fix the problem with my 3TM mod MP-1 preamp or do I need to send it to someone here who can fix it?

                                                                                                                                        Guitar George

[Hamer95USA]

  Hey MarshallJMP,

If I send it out to you in Belgium, can you fix the issue? I can't find a tech here in California that would know how to fix it and Todd Langner passed away a few years ago.

                                                                                                                                            Guitar George

[MarshallJMP]

Yes you can but maybe we should some other things first? Besides the 3TM is anything else been done to it?

[Hamer95USA]

Nothing else has been done to it.

                                                                                                                                                 Guitar George