hi, desoldering the pins sounds like an easier cleaner way to do it!
once you've cut the tracks underneath and in front, you will need to
reconnect certain points on the board that originally connected to
each other through the input pins. finding these on the schematic and
reconnecting them will get rid of the distortion and unpredictable
behavior. i was able to get all the sounds to behave normally when
pitched to the original frequency. the pitch knobs now create no
other effects. finding the points can take a while, but as you
reconnect points you'll hear anomalies go away.

my clocks bleed through at lower frequencies as well.

i'll upload a sample soon.

--- In tr-707@yahoogroups.com , "acousmatique" <acousmatique@y...>
wrote:

>
> I finally did it, after months of having my 707 open in the garage.

I had made a

> prototype 555 oscillator, which I tested by applying to the various

gate pins.

> Last weekend I made a small circuit board of eight such oscillators.
>
> This morning I put 100k sealed 1/8" pots along the front of the

unit, just in front

> of the drum buttons. I lifted all of the relevant gate IC pins and

severed the

> traces under those. Severing the traces in front of the IC was

easy. Soldering

> the pins back onto their pads provided some mechanical support.
> Unfortunately, pin 64 - handclap - had broken off of the Gate Array

since I'd

> last tried this a couple of weeks ago. I used a razor to gently

scrape away

> enough of the plastic on the chip to reveal a tiny bit of metal to

solder to. I

> connected the pots to the oscillator board, and ran outputs from it

to the Gate

> Array IC. The outputs were a little tricky, but no so bad. I used

wire-wrap wire,

> which must be like 30-32 AWG. Very fine stuff.
>
> Having gotten all of the pins wired to their oscillators, the 707

does not work

> quite as I had expected. There is some high-frequency noise from

the 555s,

> but that doesn't bother me. My kicks and snares sound nowhere near

as good

> as before I hard wired them. The toms are so loud now that they

overwhelm

> all of the other sounds. I put TWO clock signals to the kick or

snare pins and

> they sound great! I guess I will experiment with the resistor and

cap values on

> the oscillator board a little more. Somehow, the process of

soldering the clock

> outputs had caused the memory of the 707 to be filled with random

drum

> patterns! I spent a few hours exporing the new sounds with these

ghost

> patterns.
>
> Overall sounds great, though I am going to need to tweak the setup

a bit more

> before I consider it ready.
>
> CJ