Soundtank Chorus Mods

[bass_econo]

Does anyone have a schematic or known mods for this pedal?  I'm still a n00b so I would appreciate any help anyone can offer.  I like the pedal pretty much but I can't leave anything alone.

Here's the thing I know what I would want from it but I don't know how to describe it really.  Right now it has a nice chorus to me but seems to be a dry kind of flat sound to it.  I would want to try to get a wet sort of round sound out of it.  Not sure if that makes much since, but to me (in my mind) it would almost be come feedback mixed in.  Maybe some minor clipping? But not any kind of fuzz.

Anyway, thanks in advance for the help.

[Mark Hammer]

The Soundtank line represents reasonable value-for-money but the chassis don't provide much opportunity for doing the sorts of mods that are desirable in a chorus - namely those that are externally switchable, not just component changes on the board.

On the other hand, you're desire for a "wetter" sound suggests to me that you really want to shift the delay range over a bit, and that's something you can do on the board.  After carefully opening it up, you should see a chip in there labelled either MN3101 or MN3102.  It may be another but there is a 95% chance it will be one of these two.  Snuggled up right against that chip should be a small-value capacitor, probably something in the range of 500pf or less.  If you increase its value the delay time will be shifted over by a proportional amount.  So, for example, if it was currently sweeping between 5 and 12msec and used a 220pf capacitor, adding another 100pf on top of that would shift the range by 45% so that it would sweep from about 7.3msec to about 17msec.  That would give it a thicker, wetter, chorus sound.  It would also increase the amount of "wobble" that chorusses are prone to, so you'd probably need to trim back on the depth control a little more than you are accustomed to.

My advice would be to identify the relevant solder pads on the copper side and, with your guitar plugged in, touch the leads of different small-value caps to the pads to find out what additional capacitance would get the sort of sound you're aiming for.

[bass_econo]

Thanks Mark that sounds exactly what I am looking for.  I will try that tonight.  I did sort of the same thing (touching different value components) with a junk pastrami overdrive I have.  

I'm trying to learn but right now I am just addding and replacing components based on things I find on the net.  So thanks for the help.

[Mark Hammer]

De nada mi amigo.

There is a broad range of acceptable delay times for producing chorus sounds, and every one of them appeals to *somebody* or to some application.  Only a few commercial pedals provide some means for tuning the delay range the chorus operates in, and if you don't have one of those you may find the chorus flavour isn't your favourite.  Fortunately, tweaking delay range is made very easy by the clock circuits typically used in these pedals.

Although the John Hollis Zombie chorus is nothing special as designs go (well, it is elegantly simple), one of the things that people really like about it is the mode control, which simply shifts the delay range over to provide a different sound and feel.  Like a little gravy drizzled over one's mashed potatoes, it is simple and easy to do, and brings so much pleasure.