Mp1 with drop out volume problem..help!

[MarshallJMP]

Looks stock to me,don't see any mods or parts that are replaced.

One i thing i noticed,you see that vactrol next (left) to the trimpot (on the second pic),it's that black part with 2 wires coming from the top the pcb.These are very close to each other,try to pull them apart a bit.This vactrol controls the OD1 volume.There's a second one (for OD2) near the V2 tube,i also can see that these wires are also close to each other,so do the same thing here.

[anto84]

Thanks!! Just did what you said to do...

[MarshallJMP]

Ok,well done!

[anto84]

Update: Yesterday I put some contact cleaner oil. Today no pot scrratching ...no jack input problem at all..
NO  MORE   VOLUME  D R O P ! yeahhhh :banana: :banana-dance:

[rnolan]

Excellent  :thumb-up: good to hear  :whoohoo!: MP1 heaven. How are you going with the FX loop ? BTW that pot and jacks could also use a clean. As you work out how best to patch it into your rig, apart from the A/B main outs, you can also get an output signal from the loop send (albeit mono and no chorus) and the headphone out (careful with level, you get allot of level on the phones out) which is stereo and also has the tops wound down a bit (similar to a cab simulator but not as sophisticated), but you can use it for direct recording.

[anto84]

I made a lot of test with the effects loop (which I tend to use only for delay or reverb of my Boss ME5..) comparing the MP1 and the MP1 Classic loops behaviours
Delay level from me5 at 6 on 7 max available; MP1 level knobs at max: MP1 win over Classic loop.
But as I begin to move the MP1 loop level knobs more than a 15% of his course..magic vanishes and the MP1 Classic loop seems more "professional",,,Difficult to explain..

[rnolan]

The classic loop is quite different, like the MP2 it has a stereo parallel loop so you can program the return mix level to mix in FX with the dry signal, with the parallel loops (Classic and MP2) it's best to run the effect at full wet and use the return mix level to balance with the dry signal.
The MP1 loop is mono and serial as in the effect is inserted into the dry signal path and you need to control the mix balance (dry/effect) with the effect's mix setting(s) (and tweak the effect input and output levels to balance with the loop send/return level knob).  The classic and MP2 loops are much better for lots of reasons. Some of the Classic's "enhanced" features (eg stereo parallel loop, cab simulated outs etc) were precursors to the MP2's feature set. I didn't see Classics in Australia, I went from MP1 straight to MP2 when they were released here.
As I said previously, some like the MP1 loop and get it sorted, some don't like it and patch FX in other ways, the most common is probably MP1 A/B out > FX L/R in, FX L/R out > power amp L/R in. (dubbed the 4 cable method (4CM)).

[MarshallJMP]

The classic doesn't have a parallel loop like the MP-2,it's also a serial loop since it doesn't have a mix knob.Just a line /instrument level button.
The idea of the one pot loop level in the MP-1 was quite good but it didn't work out so well in the end.Some effect work pretty good some don't.

[anto84]

So Mp1 and Mp1 classic have a serial loop either.. So why they have a different behaviour?

[tomy]

 :whoohoo!:
Good for you anto