Nautilus tweaking.

[dwstanford]

I compared my nautilus to a friend's Mu-Tron III from the 70's and it sounded pretty close, but i found that the filter closed a bit slower on the nautilus no matter how i configured it.  Are there any tweaks I can make to change the sensitivity of the filter in this respect?  The best way i can describe it is that while the mutron would say oww, the nautilus would say ooow.  It would remain open longer and wouldnt clamp down quite as hard as it closed.  I know the input gain changes the sensitivity of the filter as well, but even after adjusting the gain on the pedal and the gain of the instrument, I still cant get it to react the same way as the mutron.  I'm wanting to use it specifically with a clavinet to get the sound on stevie wonder's higher ground.  The mutron nails the sound, but i cant quite get it with the nautilus.  It still sounds good, but not the same.  Maybe i am being too picky, but i think it's 90% there and i'm hoping that with a little tweaking, i can get it the rest of the way there.  Any help would be appreciated.

[madbean]

Yes, I think I can make a suggestion. Try fiddling with R15 to control the decay of the filter. Lower values will give you a faster decay, so maybe 33k or 22k there. Or remove it temporarily and hook up a 50k pot as a variable resistor so you can tweak it.

Alternatively, you could lower the value of C9 to 2u2, but I think R15 will be a better way to tackle it.

[dwstanford]

Cool.  I'll give it a try and post my results. 

Thanks Brian.

[garfo]

Anyone tried this mod on R15? I think that replacing a 50k pot is cool.that way we can control the speed of the sweep.This mod es also featured on the MXR Envelope filter and it's really cool.I'll try this mod and put a 10k in series with 50 k pot so that it goes really slow or really fast.

[garfo]

Ye,s, I think I can make a suggestion. Try fiddling with R15 to control the decay of the filter. Lower values will give you a faster decay, so maybe 33k or 22k there. Or remove it temporarily and hook up a 50k pot as a variable resistor so you can tweak it.

Alternatively, you could lower the value of C9 to 2u2, but I think R15 will be a better way to tackle it.

im doing a mod to the gain pot.i want to cross a resistor in parallel but im confused about how to wire it.do you know how it goes,is it from lug 1 to 3?

[dwstanford]

I'm working on this mod currently.  I'll post back with results asap.

[dwstanford]

I did the mod on r15 with a 50k trimmer and that did the trick .  I like being able to adjust the filter a bit more for different sounds as well.  It pretty much nails the mutron filter behavior at about 27 to 31k or so, but i have found some very useful sounds at even lower resistance (15k and up).  Really cool mod.  Thanks Brian and others fo your help.

[hammerheadmusicman]

if you like the range of sounds so much, couldn't you put the pot as an external pot, with a 15k resistor to stop it going below? Then you could dial in the sounds you like?

George

PS It's late and i'm tired, so that may be complete rubbish, disregard if that's the case