# Clock noise Cataclysm Delay



## jeromekolinka (Feb 13, 2019)

Hi everyone, 
I've just finished building the cataclysm delay (musikding component selection), plugged it this morning and i've got some pretty strong "clock noises" on the verge to auto oscillation instead of repeats... Bypass signal is ok, as is the dry signal when the effect is on... Can someone help me? It's my first delay, i've only build od's and fuzz's until now... Thx!


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## zgrav (Feb 13, 2019)

are you getting signal repeats as well as clock noise?  or just clock noise?   if you are not getting signal repeats check the circuit diagram in the build document and look at the parts between the dry signal and the delay chip to make sure your dry signal is reaching the PT2399.    also, does the speed and number of repeats of the clock noise change when you rotate the delay and repeat pots?


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## jeromekolinka (Feb 13, 2019)

Thx ! Yes, speed and number of repeats change when I rotate the knobs... only clock noise... I'll check the signal flow tomorrow... Could it be a problem with the Tl072 or the transistor ?


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## zgrav (Feb 13, 2019)

Did you use a socket for the TL072?  If so, it is easy enough to replace it with another TL072 and see if it makes a difference.  If your dry signal is OK when the effect is on, your voltage regulator (transistor) is probably OK.   Your most likely problem will be a bad solder on a part, a short in the audio path from too much solder, or an electrolytic capacitor put in the wrong way.  If those all look OK, double check your work to make sure you used the right values for the parts on the board.  Also take a good loot at any parts you had to unsolder and resolder/replace when you were building it since connections between the traces can get damaged when that happens.


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## jeromekolinka (Feb 14, 2019)

After checking the circuit this afternoon, it happens that the signal is repeated, but very degraded (i'm an avid user of old analog delays, and it's not degraded in that way! >
) with clock noises in the background, and the repeat knob seems to be very sensitive, with auto oscillation soon in the sweeping of the knob... It reminds me if a badly biased bbd delay...


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## zgrav (Feb 14, 2019)

if you have the PT2399 in a socket, try another one if you have it.  check carefully to make sure you have the right parts installed in the paths and controllers.  right part value for the echo pot?  seems like it should have move control over few to many repeats before oscillating.


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