--- In tr-707@yahoogroups.com , "djdsl_tru" <dsl_tru@h...> wrote:

>
> Finally.. im getting around to working on this mod.
> Im in the process of building the 555 timers.
> It seems those of you using the 100k pots in the cicuit were finding
> that they would go too high to be useful, I'm starting with 50k pots,
> I suspect it will take some fine tuning to get them optimized.

It's the pots and the capacitors also which determine the frequencies. Since
the pots are just picking a voltage from between +v and ground, the actual
resistance ralue is not too crucial. I just used 100k pots because I have them,
and they are small. I did try various caps beforehand, but I don't have a great
selection of values yet.

> What's a good point on the board to power the 555's with

There are many possibilities. I used a RAM IC with pin 28 for +v, and pin 14
for ground. If there's a convenient chip location, you can quickly dl a
datasheet for that IC and see what its supply pins are.

> It's great to see that you guys have done such great jobs with your
> 707's. Hopefully i'll have some new info to share before im done.

Modifying my 707 has been a lot of fun. I am looking forward to my next one! It
will go in a new case, since there are more mods I want to do than I can fit in
there. Take your time and enjoy!

CJ