MXR Green delay modded to digital, slight problem.

[Chris Goodson]

I got an MXR Green delay in a trade for some work that has one the modded boards that were being sold on eBay a few years ago.  This mod was to replace the chip in it that is no longer available (mn something or other), you know the one if you are familiar with these and other old delays.
 
Anyhow, it works fairly well, except when I turn the delay pot past about 1'oclock the repeats start getting an extra sort of distorted sound with them.  I was hoping maybe someone familiar with delays could help point me in the direction of a cure for this.
In the past, I've noticed with analog delays that if you adjust the delay time too long you will get this sort of sound.

So I played around with the trim pots to no avail (I really hate fiddling with these when I don't know what they are doing but that distorted sound annoys me).  Could somebody give me a general idea of what these pots do?  There are four of them, two seem to affect the repeats, one seems to affect the delay time (but not in the way I'm used too) and the other doesn't seem to do anything.

Where the distortion starts is well past what this pedal would originally do in terms of delay time.  A possibility I considered is that maybe I need a different value for the delay trim pot..? 

I would just contact the guys who did this mod, but I don't have any idea who they are.

[redeffect]

I still see these boards on ebay(PT2399 mod). Go there and search MXR analog delay. You should get all the info you are looking for. Please do yourself a favor, and refrain from playing around with those trimpots till you know their functions. I know how tempting this is; I learned the hard way!