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ADA Preamps => MP-2 => Topic started by: Hanneman213 on March 27, 2018, 07:09:02 AM

Title: Delay and Bumb Noise - Bank Changes
Post by: Hanneman213 on March 27, 2018, 07:09:02 AM
Can any improvements or modifications be applied to reduce the delay when bank changes ? Clean sound comes like a ''fade in'' in a very short time. Also I have a bumb like sound when I change my bank from Crunch to clean.
Title: Re: Delay and Bumb Noise - Bank Changes
Post by: Hanneman213 on March 27, 2018, 07:14:54 AM
Ops. I did not realized that below topic is about my concern.I will read it first. Sorry.
Title: Re: Delay and Bumb Noise - Bank Changes
Post by: rnolan on March 28, 2018, 06:36:52 AM
Hey Hanneman213, there's 2 bits to this (if I understand correctly):
Delay between patch changes - the last EPROM for MP2 is v1.41 (http://www.marshalljmpmodshop.net/miscellaneous_parts_and_replacement_tubes.htm).  If your MP2 isn't v1.41 (displays when you turn it on) then this EPROM will make your patch changes faster (it was a problem in the early models (which I bought BTW)).  But you also have to go into the System Edit menu, scroll (left arrow, 3 clicks) around until you find Program Change Speed, set it to Fast (default is Normal) BTW this is not available in the original EPROM, it was issued as a (very needed) update.
Now the pop/bump is another thing, I get it as well going from crunch/dist to clean, I get a pop if I'm still playing across the change (letting a chord ring etc).  But my recollection is I didn't used to get it, it's come in over time (as I haven't changed anything in the patches). I get around it by making sure I make a space (in playing) while I change the patch, not ideal but works for now.  I'm wondering if it's the compressor circuit/IC as I have that only on my clean patch but not on my rhythm/dirty patch(s).
Title: Re: Delay and Bumb Noise - Bank Changes
Post by: Hanneman213 on March 31, 2018, 12:50:07 PM
Yes Mine is V 1.41.Today I made my all crunch settings all same in volume and Od And increased some mids and trebs in leads. It really improved the transition between banks.
I also modded the resistor 611.Finally I found 3.0 mohms resistor. It finished the chatter, okay but, you know we all need long sustains after we bend. My hiss/noise cuts in threshold 16 and I stop there. Maybe I close the gate in leads. I will look at the situation.
Title: Re: Delay and Bumb Noise - Bank Changes
Post by: rnolan on March 31, 2018, 09:02:18 PM
IIRC I used to run my gate on 25 and fader. You can look into doing the MP2 noise mod, 21 caps and R913 (which is under one of the tubes).  MJMP has a kit that includes all the components you need.  2 of my MPs have been modded, 2 are still stock. Have a look at the instructions, if you do the test point measurement, if it's just under 190v (eg 187v) then R913 is probably ok. If R913 it's more than 190, R913 should be replaced.

That you had to change R611 means it's an early unit as this was already changed in all the later ones.