MP-1 mod for more bass

[Axemane]

Not really a complaint , but if I could change anything about the MP-1 it would be the low end freq. I have a couple of ideas but I don't know which would be best, cheapest , etc. Any help would be appreciated.

1. MDRT   

2. Changing the EQ freq of the bass with component changes or a trim pot

3. Adding a resonance knob to the TS100s




Taken from the 3.666 mod -

The "Bass" EQ Circuit is optimzed to
include what I call the "Bass Warp"
control. This is simply a trimpot that
allows you to raise or lower the target
frequency of the MP-1 Bass EQ
Control to better match the resonant
frequency of your cab. Simply put, it
gives you the ability to optimize the
"thump" frequency of your 4x12 making
the bass response sickly tight.

Can I do just this mod to my MP-1 and get a resonance/focus type low end or would there be other component changes as well. I don't want my  MP-1 to sound like a Mesa, but I sure would like some more low end chunk.

Which components could/should I change to tweak the low end ?

Thanks,

Axemane

[DesmoBob]

2. Changing the EQ freq of the bass with component changes or a trim pot
.
.
.
Can I do just this mod to my MP-1 and get a resonance/focus type low end or would there be other component changes as well. I don't want my  MP-1 to sound like a Mesa, but I sure would like some more low end chunk.

I had thought about this too, but never got around to asking about it.

Sorry for slight hijack :-* ...My idea was to go one step further in order to accommodate situations with frequent swapping of cabs (e.g., using the venue's house cab, then later using own cab in band practice). Instead of an internal trimpot, I was thinking of running (shielded?) wires from the empty R165 pads to a regular pot mounted on the back panel. This way, the frequency could be tweaked on the fly without having to unrack & open the MP-1 each time. Feasible?

[Axemane]

Yes a trim pot mounted outside would be even better ! 

I just want to be able to get a much fuller low end that is tight and chunky. A resonance depth knob on my power amp might help, but I really think the tone stack (bass) needs to be altered.

My sound now is really good but I think the lows can be shifted lower to do what I am aiming for. Maybe lows and lower mids need a little tweaking.

[MarshallJMP]

An external pot is possible and it would be best to use shielded wire (2 wire + shield).2 wires go to the pot and the shield goes to the ground.

[Axemane]

MarshallJMP -

So is the "Bass Warp" control mod what I need ? would any caps or resistors need to be changed  to shift the bass freq  or does the bass warp trim pot cover this ?

[GuitarBuilder]

Maybe this is a dumb question, but wouldn't an external EQ in the effects loop accomplish what you want?

[Peter H. Boer]

Doesn't the MOD4 MK2 also include a change to the tone centers?

Is this tone mod also doable on a stock MP-1 without doing the rest of the MOD4 MK2?

[MarshallJMP]

The bass warp is actually part of the mod3.666 but can be done to any mp-1.It just shifts the bass freq.

[Axemane]

Eq in the loop, yes. I don't think the lows in the MP-1 are low enough , if that makes sense.

So MarshallJMP - What exactly would I need to do for the Bass Warp trimpot mod (as per the 3.666 mod) , just the trim pot or all of the cap changes etc ?

Thanks

[rnolan]

The easiest option is the one GB suggests (not that the others are a bad idea) but a decent external mono eq in the FX loop works just fine (you'd want one optimised for guitar frequencies like the Boogie (5 band ??), or a decent stereo (analogue) eq after the MP1 (check some of Els posts, he's been playing with this), or if you use a small desk to patch you system together, you can turn up the channel bass (which is what I tend to do with MP2 although it has a room eq adjustment which is quite useful and a built in graphic (9 band)).

There are other posts about lowering the bass centre freq though, IIRC it was well covered in those and the mod wasn't hard ?

[MarshallJMP]

Just the trimpot,the rest changes the mid and treble circuit.

[Axemane]

Thanks MarshallJMP !

I'm going to try this soon. I think this trimpot mod with the EQ in the loop should do the trick or at least get me closer .

[rnolan]

Maybe just try EQ in the loop first (unless you really want to do the trim pot (which isn't a bad idea)), if you set the ADA bass to 0 you can then just adjust with the eq in loop (though loop must be "In" for the patch).

[MarshallJMP]

ok let me know if i can help.