Neutron build

[sean k]

Howdy chaps,this is my first post here and I'm coming at ya after having done a neutron and just getting a high frequency oscillator.I've never used LDR/LED stuff before and am thinking I used the wrong LDR's.I used some VT935G's with 10k-50k at 10 lux and a 1M min dark resistance and high bright green led's.Whats a good range thats going to work in the actual circuit?Thats to say whats the resistance without signal and with a hard picked string?
  The first stage works fine as it bypasses the signal and the leds are firing on so that parts doing its bit but I'm guessing I've got all my problems in the filter section and I'll go now and check the wiring and measure the resistances accross the LDR's in on and off states.
      Live from New Zealand!
p.s.Just did Tims T.M.K. the other day and its a superb pedal especially if you want to go off into oscillator mode.Good Oh Tim!

[sean k]

So I went back into the box and found a small part where a signal trace was meeting earth,oops,now it goes and there seems to be the filter effect but without too much sweep or that may be I haven't quite got the settings right yet but what is interesting is that the LED's are on when theres no signal but going off when the signals present.Is this how its supposed to work?
  If this is indeed the case then I would suppose its imperitive to get LDR's with a very low resistance when the LED's conducting.Also it would seem that longer fall times might be better with a shorter rise which is opposite to what I have now.
   I'm also getting some horrid distortion or static when the strings are hit or when the LED's are turning off which I can't understand.
    But I've made progress and I'm definetely happy with that.
           Thanks Lads for replies to come.
                   Sean.

[R.G.]

what is interesting is that the LED's are on when theres no signal but going off when the signals present.Is this how its supposed to work?

Yes. Actually, it works both ways. There is an up/down switch that should convert it from LEDs-on-with-signal to LEDs-off-with-signal.

Unless you found this out by tearing open your light-tight LED/LDR enclosure, then you may be having a problem with light leakage. Those LDRs **must** be enclosed in a light tight enclosure with the LED, or the ambient light from the room lights the LDRs and you get little or no sweep, which is one of your symptoms.

Could also be unsuitable LDRs, but this is not a common problem. The LDRs could also be .......s....l....o....w.... which might do the same thing.