Hey guys, I hope everyone had a great weekend! Those pics sure helped But I am having a little problem..... No presense control.
I currently have it wired exactly like Normsters layout. I measured the pot and all resistors (out of the circuit) and they are all in spec. I even tried both positive and negative jack connections without success.
If anybody has any ideas on how to trouble shoot this circuit please help!!!
Last edited by keithrick on Wed Jun 28, 2006 7:06 pm, edited 1 time in total.
Having trouble tracing the wires. Looks like a red wire goes from the PI and feedback resistor to head toward the presence pot, but a purple wire attaches to the pot. Am I missing something?
Wife: How many amps do you need?
Me: Just one more...
It's kinda hard to tell, Bob. The reverb pot is a B2M for sure and it looks like the same number on both pots. (513?) You may be on to something.
Keith, it's also hard to tell if the cap is a .68uF (good) or a .1uF (bad) and if it's wired across the wiper. The cap should be a 1uF electrolytic with the plus side going to the wiper and ground side of the pot. It's also OK to use a .68uF poly according to Dogears. (Of course, Gil's pics show a .1uF Tantalum so who knows.)
Hi guys
I can't quite make out the pot value either but I agree 2 Meg will definately not work.
Regading the cap value in the hand drawn diagram,I think Billy has simply
written the wrong value--I am sure we will all forgive him after all he has done for us!
Take a look at picture# ods_124067.jpg it clearly shows a 1uF tantalum.
mlp-mx6 wrote:Having trouble tracing the wires. Looks like a red wire goes from the PI and feedback resistor to head toward the presence pot, but a purple wire attaches to the pot. Am I missing something?
OK, I was assuming the Presence was the last pot in the line - clearly it is not. So your presence pot looks okay, except I cannot tell from the picture what is attached to the center lug on the pot. It looks like the red wire is on the right lug, and the cap is on the left lug, but I cannot tell what is attached to the center lug. The center lug should be tied to the left lug - where the cap is.
I'm sorry - you probably have this right. I just can't quite tell from the picture.
Wife: How many amps do you need?
Me: Just one more...
Hi Keith,
This a long shot but,you might try and touch up the solder joint on the phase inverter tube.I had the same problem with mine and found when I re-did those points on the tube and board I had a precense control.
thanks
Chris
That Orange Drop looks the same as the .1uf on the board. If so, you need to put in a 1uf electrolytic asap. The knee of the .1 is really high and that would explain things.
I'd use the electrolytic (or tantalum) for historical accuracy anyway!
keithrick wrote:My problem is probably the .1 cap! I will replace and and check my solder joints, hopefully that is my problem! Thanks again for the advice everyone!
You may want to get a .82uf if you get the .68 to try. I just go with the 1uf myself.... But, there is a noticeable difference between .68, .82, and 1uf. If you are tinkering, do it right You can always tack the .68 acorss the .1 to make .78.......
keithrick wrote:Wow, Just checking in thanks for all the replys! Sorry the pics weren't as clear as they should have been!
-The cap is a .1 I am going to get some new caps today, .68 and 1.0Uf! Duh!
-The pot is the 2k and it measures 2.14K.
- the .1 cap is connected to both the left and center lugs as in Normsters layout.
My problem is probably the .1 cap! I will replace and and check my solder joints, hopefully that is my problem! Thanks again for the advice everyone!
But I am having a little problem..... No presense control.
I am going to get some new caps today, .68 and 1.0Uf! Duh! 