question: connecting MP1 to various heads

[Chamai]

Hey all

Need some help!

right now i run my MP1 through the return on my JCM 2000. I get a great sound, but the volume control won't work on my JCM 2000. it seems like it's on full blast. I can only adjust my volume through my MP1

If i connect my MP1 through my Dual Rectifier or my JCM 900, It will allow me to adjust the volume.

Anyone know why?

[El Chiguete]

Is my understanding that the poweramp sections on an amp ar technicly allways at 100% full volume and all that the Mater Volume knob does is just adjust how much of the preamp signal goes to the poweramp section... so with the examples that you are saying what it meens for me is that on the JCM 2000 the return in the loop is after the Master Volume and on the others is not OR that loop of the JCM 2000 is in pararell and the others are in series and that would meen that the one in pararell allways has a dry signal comming thru and you have to adjust the volume of the wet effects going in to get them in the volume that you want compared to the dry signal.

But lets wait for the real peaople that know what they are talking about in this forum to speak.

[MarshallJMP]

Just checked the schematics and it's a serial loop which is placed after the master volume knobs.So for this amp it's normal.
It's depends from amp to amp,some have a master before the loop some after the loop.
Now this will work fine as long you can set the volume on the mp-1.Now you can lower the volume also by setting the loop level switch to +4. (the difference between -10 and +4 is that if -10 is 100% +4 is only 30%).

hope this helps you out.

[Chamai]

appreciate the quick response guys.

my jcm 2000 is the only marshall i have left. i really love el34 power sections.

i didn't like the fact that the treble, mid, bass controls were still usable when i hooked my mp1 to it.

[El Chiguete]

I played thru a JCM800 and I was surprised about that too, my tech told me to put all the knobs at 10 because that way they let pass all the signal (allmost like if they werent there allthough even at 10 they still affect even a little bit the signal) and adjust from there, I ended up just turning down the presence I think that time.

[MarshallJMP]

Even with the controls fully open you won't get a flat response and the presence isn't part of the tonestack but a part of the power amp and it's active (works in the feedbackloop).

[Chamai]

after running the ada through the jcm 2000, i no longer use my jcm2000 as a stand alone head.

now running my mp1 and stiletto in stereo.

now i need a marshall cab so my setup looks cleaner. serious GAS.

[Dante]

That's why I call it CRACK Gear  ;D

Keep going, the rabbit hole is DEEEEEP

[rnolan]

At the back of the new ADA APP1 manual is a section on how to set various amp eqs so they are "flatish", Marshall being one of them, when I first read the settings I was quite surprised, worth a read, attached..

[MarshallJMP]

Just did a check on the marshall settings and they come close to a flat setting,just a small dip in the 800Hz range.