Finally got one of these! It sounds good to me - but I have a couple of issues with it I. Appreciate any help!
- Presets are deleted each time I turn it off. I get the C 1-128 and error 1,2,3. I figured it's the battery. Is the battery mod kit from Marshall JMP Mod shop the way to go?
- If I dial in any chorus (depth), there's a garbled, fizzy sound present. Anyone had this issue before?
- How do I see which firmware version I have? I thought about getting the newest one.
It seems you need a new battery, my kit will work if you want one.
Could be the bias isn't set correctly, mail me so I can tell you what to check.
You see this at startup on the display, it's either 1.36, 1.37, 1.38, 2.00 or 2.01.
Thanks, sent you an email!
It's worth getting the latest EPROM v2.01 from MJMP (if you don't have it already). It's an easy swapout and gives you some additional factory presets and some program save and load to PC via midi capability.
I'm definitely getting the latest eprom. Any other must have mods I should get while I'm at it? I don't think I'm gonna go for anything that radically changes the sound.
The rear jack mod is worth doing as the front jack takes the most ware over time. The noise mods are useful but depends how much noise you have, most noticeable at high gain settings. The MDRT is also a very worthwhile mod but it does change the sound, really opens up the dynamics of the MP-1.
Tnipe
I send you an email, let me know if you got it, I had some problems sending it.
The problem with the chorus is that the bias trimpot is not set correctly, it's at the 1 'o clock position, should be on the 11 'o clock position.
The fix with the trimpot solved the chorus problem. I will be buying some parts from MarshallJMP to fix it up even further O0
Cool :whoohoo!: :thumb-up:
Just an update, I got the noise mod done, rear jack mod, plus an overhaul by an amp tech, great stuff. Invaluable input from MarshallJMP.
But is there a way to get more gain? New tubes? I don't need much gain, but I'm using 10/10 on the overdrive settings on the Tube OD channel, and I'm barely getting an overdriven sound. Not anything close to high gain.
It was kind of like this when I first got it, but suddenly when I changed some settings, it had a bunch of gain! And now it's back to little gain.
With OD1 and OD2 set to 10/10 you should have heaps of gain regardless of tube choice. Some tubes are higher gain than others but what you describe (barely getting an overdriven sound) indicates something isn't working properly. Do you remember what settings you changed to get a bunch of gain? If you re-load the factory presets:LOAD ALL 69 PRESETS:
1. Press the STORE button. lt will light.
2. Press the BANK button and while holding the BANK button down press the number 1 button.
3. The display will read "Presets Loaded" When the display returns to a program number, all 69 factory presets have, been restored.Patch 1 (Marshall) should have lots of gain.There are also trim pots for the gain (see attached).It possible there is an issue with the tubes (one or both), a pair of new known/tested 12AX7s will rule that in/out. There's lots of choices for tubes (see tube section) but a pair of high gain JJs from a reputable supplier (who tests their tubes) are a good start and work well in MP-1. If the issue (low gain) persists then something else is not right.
Could be the tubes or maybe the vactrols, these control the gain. If you look on the left side of the unit you will see 2 small black boxes with 2 wires on top going to the pcb. Make sure these wires don't touch each other.
Thanks guys, I'll check it out. Any suggestions for European tube dealers?
I got a hold of a pair of JJ 12AX7's - but nothing has changed unfortunately. I also did the preset restore, which didn't change anything.
I identified the vactrols I think, and the two wires doesn't touch on either of them.
I noticed while playing around with the trimpots that very little happens when turning the OD2 trimpot. Also if I turn OD2 from 0 to 10.0 in the settings, there's just a little bump in volume, no gain increase really. Can this be relevant? I swapped tubes 1 and 2 just to see if one of them was faulty, but the same result happened.
Thanks again for the help guys. This is getting to be quite a project!
Dumb question; does the battery replacement mod require any soldering?
Quote from: Chip Roberts on June 21, 2021, 10:25:06 AM
Dumb question; does the battery replacement mod require any soldering?
Yes it does. Looks simple enough, but I had a tech take care of it :)
What you can try is to desolder the OD2 wire, it's either brown or yellow, it's shielded wire and it's also the shortest one going from the main to the tubeboard. It's designated letter is "H". This should give you full on OD2 gain.
Dusted off the MP-1 today again. If I max out the gain on 10 on the tube-voicing for both OD1 and OD2, there's not a lot of gain, whereas before the tech did the servicing and some mods there was tons. I'm noticing now that the SS channel is a lot louder than the tube/clean. Can this be an indicator for something maybe?
This sounds similar to what Tommy is experiencing. So question is what did your tech do as in, you had heaps of gain before the work and now you don't :dunno:
could be a tube gone bad.
I swapped out the tubes, and I now how enough gain! :headbanger: Maybe not for a metal player, but for me at least.
There's not a volume difference between the tube and SS voicings.
I remember having more though, before I got it serviced/modded. The problem is still:
If I turn OD2 from 0 to 10, there is just a tiny difference in volume. No difference in gain, doesn't matter where OD1 is set. I played around with the OD2 trimpot, but I can't see it made any difference.
I've tried swapping the tubes with each other, nothing changes.
Also, what does the internal dip switch do, next to trimpot 3? Where do you guys have yours set? Sounds like a line level thing? Currently going into a G-Force, then a Matrix Power amp.
Mmm, the OD2 trimpot settings not making a difference doesn't sound right. MJMP?The switch next to trimpot 3 (SS Alignment) is to switch the MP-1 output level between inst and line level and can be accessed with the lid on. It's only on the earlier models, ADA ditched it later along with the line level rear input. So (as is depicted on the back of the unit) inst level is with the switch toward the front and line level toward the back. It was there so you could plug the MP-1 into a guitar amp input (inst lv) or into a power amp (line lv). I have always set it to line lv as I run into stereo power amp.
Quote from: rnolan on October 27, 2021, 01:02:18 AM
Mmm, the OD2 trimpot settings not making a difference doesn't sound right. MJMP?The switch next to trimpot 3 (SS Alignment) is to switch the MP-1 output level between inst and line level and can be accessed with the lid on. It's only on the earlier models, ADA ditched it later along with the line level rear input. So (as is depicted on the back of the unit) inst level is with the switch toward the front and line level toward the back. It was there so you could plug the MP-1 into a guitar amp input (inst lv) or into a power amp (line lv). I have always set it to line lv as I run into stereo power amp.
Thanks. That's handy. Yeah, there's something weird. Just to clarify, OD-2 doesn't do anything when I change the settings on the front panel, when editing a preset. Just a tiny bit of volume difference from 0-10. When I change OD1 and all the other parameters, things seem to work as it should.
Sounds cool though with no OD2 even. Playing around with it today with a Neunaber Illumine after the MP1, good stuff!
That's not normal, could be a few things, OD2 wire not connected or bad contact. Vactrol, these have 2 wires going over the top to the PCB, sometimes these are shorted together. Bad vactrol or U14 bad (TC9176).
Quote from: MarshallJMP on October 27, 2021, 05:45:37 AM
That's not normal, could be a few things, OD2 wire not connected or bad contact. Vactrol, these have 2 wires going over the top to the PCB, sometimes these are shorted together. Bad vactrol or U14 bad (TC9176).
Thanks! I'll take it to the tech guy again and tell him this :)
If your tech has some questions he can always email me for more info.
Quote from: MarshallJMP on October 28, 2021, 01:50:30 PM
If your tech has some questions he can always email me for more info.
Thanks MarshallJMP! About to drop it off now. I wonder what the problem is, I'll report it here when we get it fixed.
Ok keep us updated!
The tech was not able to figure it out sadly, but I know he's very good at what it does so it must be something weird going on. Still just a few db's of volume when OD2 goes from 1 to 10.
I remember when I first got it, and I had a similar problem. There was not enough gain on the patches, but I was stumbling around in the menus pressing buttons and suddenly all the gain came back. Does anyone know if something like this could be firmware-related?
Never encountered firmware problems with this problem. Why didn't your tech send me an email, I could have give him some things to check out.
Are you sure both tubes are good? OD2 feeds V2, if V2 is suspect, maybe worth checking, just swap the tubes (V1 to V2 and vis versa) and check.
Quote from: MarshallJMP on March 29, 2022, 10:49:51 AM
Never encountered firmware problems with this problem. Why didn't your tech send me an email, I could have give him some things to check out.
He had your info, but seems he never got in touch.
Both tubes have been swapped and replaced...
When you go to SS clean and you raise OD2 you should get more and more compression, does that work?
Quote from: MarshallJMP on March 31, 2022, 01:58:50 PM
When you go to SS clean and you raise OD2 you should get more and more compression, does that work?
Yes, that works.
Do you have any suggestions for me? Thanks again, bothers me a bit that I did all this to my MP-1 and it doesn't work! I'm gonna dust it off again and see if I can get it fixed.
I had a similar issue with an MP-1 that had barely any gain/dist and dialing OD2 had no effect at all.
Solved the issue finally - U3 (VTL5c4/2 Vactrol that controls OD2) was bad.
Check this thread (if you short/hotwire the two lugs of U3 you should get OD2 and it's gain maxed out):
http://adadepot.com/index.php?topic=2830 (http://adadepot.com/index.php?topic=2830)
Quote from: Systematic Chaos on October 28, 2022, 11:17:26 PM
I had a similar issue with an MP-1 that had barely any gain/dist and dialing OD2 had no effect at all.
Solved the issue finally - U3 (VTL5c4/2 Vactrol that controls OD2) was bad.
Check this thread (if you short/hotwire the two lugs of U3 you should get OD2 and it's gain maxed out):
http://adadepot.com/index.php?topic=2830 (http://adadepot.com/index.php?topic=2830)
I'll buy a multimeter and check it! Thanks.