Hi
I have got the SDX all connected up and whilst it passes signal, and it adds a bit of gain, there is no delay effect in any switch or pot position. I have checked all of the resistors and caps (even though I checked them on assembly) but it all seems in order. I spotted another thread which showed voltages around the ICs. Here I have clearly got something wrong. I am getting:
IC3 - PT2399
Pin 7 - 4.57V
Pin 11 - 0.51V
Pin 12 - 4.68V
Pin 13 - 3.16V
Pin 14 - 0.1V
The other voltages are broadly in line with what I have seen tabled elsewhere.
Occasionally it does seem to pass some signal but it's crackles and pops which seems like it's generated by some random noise!
Any ideas would be much appreciated.
Cheers
Steve
Does the other PT2399 have the correct voltages? Have you tried swapping that one into the IC3 position to see if you might have a bad IC?
Quote from: madbean on January 28, 2014, 09:17:57 PM
Does the other PT2399 have the correct voltages? Have you tried swapping that one into the IC3 position to see if you might have a bad IC?
PT2399s are a lot like twinkle lights, easy to get a bad one and then the whole thing doesn't work right.
Thanks for the quick reply. The other 2399 does have the correct voltages and I've done the swapping around. I have even bought two new 2399s, just in case I'd fried the first ones, but they don't seem any different. Having read through a few threads on this topic, it seems the 2399 ICs can be a bit hit and miss in terms of performance. Perhaps I've got 50% failure rate in each batch of 2. I'll leave the one with good values in place and try a bit of methodical swapping around of the others to see if this helps.
Cheers
Steve
Swapped all of my PT2399s arounds and, well, I guess two working PT2399 out of four isn't bad. I wonder what the failure rate in the factory is? I'm now getting repeats and everything seems to be working fine. There is a bit more distortion on the repeats than I expected but that may be down to my lack of familiarity with the pedal and its multitude of switching arrangements. You are so right about twinkle tree lights!
Regards
Steve