Death CLaw delay problem!!??

[Spenzerleehorton]

Hi All,

I have just built the Death claw delay and i'm getting delay with the ghost switch one way but when i switch to the other way i don't get any delay?
I also don't get feedback to oscillate?
and the other weird ting is that when i take out IC2 and only have IC3 in there the delay is much longer than with both IC2 and IC3 in?
Voltages are all pretty close to what they should be, i'm a bit stumped, could anyone help please?

[madbean]

Audio probe the junction of C12 and R15 to see if you have output from the Q3 buffer. If not, there could be a problem wit, or around, that transistor.

[madbean]

BTW: the reason you get more delay time when you remove one of the PT2399 is because of how the delay time is controlled which is by current on pin6. When you have two of them there are two ways to control delay time. The first is to use a dual-ganged pot, one for pin6 on each device. The second is to use a single ganged pot with a constant current drain on both devices. The Deathklaw uses the second option. When you remove one PT2399 you halve the current drain which doubles the delay time.

[Spenzerleehorton]

what about the delay not feeding back and oscillating? i specifically wanted to build this for this function, along with another one to feed two amps.

[madbean]

Well, without more information on your build I don't have a recommendation yet. You said you get delay with the one setting on the Ghost switch - do you get any feedback at all with that setting or does it not work at all? If you are getting feedback but not oscillation that is an easy fix - lower the values of R24.

[Spenzerleehorton]

yes i'm getting feedback but no enough for oscillation, so lower R24, perfect will give that a try, thank you.

also i will look at the source of Q3 and see if i get signal with switch both ways.

[Spenzerleehorton]

yeah i've tried adjusting r24 down to 5.1k but it doesn't feedback just the repeats it seems to feedback other material?
sounds like a reverb or feedback in the distance, i wanted the repeats to keep repeating so i could then play with the delay time so it sort of spazes out, i have an old digital copy cat somewhere and i remember it did this quite nicely but unfortunately was very noisy.
still havent figured out the switch yet but will keep fiddling.

[Spenzerleehorton]

couple more things, i found c22 was 100nf so ive changed that for 22nf, now adjusting R24 doesnt seem to do anything, the feedback does about 16 repeats but fades pretty fast and doesnt feedback and ive lowered r24 to 2k?

Im only using one chip so to get the longer delay settings and having a green LED doesnt seem to do anything?

any ideas?

[Spenzerleehorton]

this effect is a total loss at the moment!!!
i have removed Q3 and the surrounding caps and resistors along with switch as advised on pdf as i just want a simple delay pedal.
there seems to be signal both sides of R7 and signal at one leg of R13.
But apart from that i don't see any signal getting to IC2 or IC3?
Voltages look ok on both IC2 and IC3 apart from pin 7 on IC2 which is 1.7v.

bit stuck on how to progress with this one?