djmiyta
Well-known member
I'm troubleshooting a couple of PT2399 circuits one is the sagan delay the other aleph null special sauce. The Sagan passes only clean signal. and all pt2399 are getting 5.78v. I know the 2399's are supposed to get 5v (the " I know" part is an idiot telling you HE knows something and he just might but clearly it's not these circuits) The wiring for this particular layout is messy and a lot of it. The Special sauce does work but not 100%. and it has all sorts of hiss and beeps and blips and crackle ( I have swapped out the regulator and 2399 3 times with different ones but get the same results voltage and sound wise.
So I'm checking voltages on the Special Sauce and I get higher than expected readings I'll stick the DMM black probe on my DC jack ground lug and measuring that way at my DC jack is 8.84 v. leaving the ground there I measure IC1 pin 1 and have 5.67v measuring the in and out of the regulator in= 8.09v out=5.68v
Now I read somewhere that you should take your readings off the regulator ground and when I do the regulator reads out= 5.05v and in=7.45v. A 1/2 volt give or take ........ is that normal behavior for 2399 circuits? I have built quite a few 2399 circuits with no problem. The chips were same place same order and worked perfectly in other circuits. Quick side note while originally testing with the board powered up one of the pots wires got under the regulator popping it out of the sockets wondering if doing so it fried the chips.
The Sagan Delay the 2399 chips are even higher at 6.47v and I get different readings holding the ground probe in different ground places.
but can someone explain to a 5 year old why having the ground somewhere else will give different readings and IS there a certain place you DO want or need to place the ground ?
And a question from our audience asks are there people out there who are keen enough in electronics that they could look at someones pedal layout and tell if it would work or not just by looking at the layout , I'm asking for a friend of mine. Hey thats a great question I've often wondered that myself from time to time.
I'll patiently wait to hear from Wise Council of the PPCB community as I've got nothing but trustworthy helpful advice here with no fluff thanks to all who roam this forum much appreciated.
So I'm checking voltages on the Special Sauce and I get higher than expected readings I'll stick the DMM black probe on my DC jack ground lug and measuring that way at my DC jack is 8.84 v. leaving the ground there I measure IC1 pin 1 and have 5.67v measuring the in and out of the regulator in= 8.09v out=5.68v
Now I read somewhere that you should take your readings off the regulator ground and when I do the regulator reads out= 5.05v and in=7.45v. A 1/2 volt give or take ........ is that normal behavior for 2399 circuits? I have built quite a few 2399 circuits with no problem. The chips were same place same order and worked perfectly in other circuits. Quick side note while originally testing with the board powered up one of the pots wires got under the regulator popping it out of the sockets wondering if doing so it fried the chips.
The Sagan Delay the 2399 chips are even higher at 6.47v and I get different readings holding the ground probe in different ground places.
but can someone explain to a 5 year old why having the ground somewhere else will give different readings and IS there a certain place you DO want or need to place the ground ?
And a question from our audience asks are there people out there who are keen enough in electronics that they could look at someones pedal layout and tell if it would work or not just by looking at the layout , I'm asking for a friend of mine. Hey thats a great question I've often wondered that myself from time to time.
I'll patiently wait to hear from Wise Council of the PPCB community as I've got nothing but trustworthy helpful advice here with no fluff thanks to all who roam this forum much appreciated.
