PT80 repeats are too soft - need help

[jasonsmusicgear]

I finished the PT80 project from GGG but the repeated notes are not loud enough.  I basically have to play one note and then listen for the repeat.  If I play more than one or two notes, the repeat is lost in the mix.  Please help me debug this.  Below are my voltages, pictures, and links to the schematic.

Schematic and layout are here http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=125&Itemid=26
I used the layout that included the MAX1044.  I am using my DIY power supply which supplies 8.9v in.
The only changes I made were log pots instead of linear because thats all I had and I also used 2 18k resistors in series to make the 36k resistors. (2 of these)



Voltages:

PT2399
1= 5.0
2= 2.5
3= 0
4= 0
5= -.8
6= 2.5
7= 0.7
8= 0.7
9 through 16= 2.5

NE570N
1= 1.6
2= 1.6
3= 1.6
4= 0
5= 1.8
6= 0.1
7= 6.8
8= 1.8
9= 1.8
10= 6.1
11= 1.8
12= 1.8
13= 12.4
14= 1.8
15= 1.8
16= 1.1

TL072
1= 6.2
2= 6.2
3= 6.2
4= 0
5= 3.1
6= 6.2
7= 6.2
8= 12.4

MAX1044
1= 8.9
2= 4.3
3= 0
4= .2
5= 8.9
6= 3.6
7= 4.2
8= 0.3


From the topic below I determined that pin 5 of the PT2399 is probably wrong and pin 6 of the NE570N is probably wrong.
http://www.diystompboxes.com/smfforum/index.php?topic=52689.msg398691#msg398691

Also my 2n5088 voltages are .5, .5, and 12.4.  Isn't the base supposed to be .5 volt higher than the emitter?

Any help is appreciated
Jason

[miqbal]

A glance from the PT-80 schematic:
1. MAX1044: pin1 and pin 8 are connected, i.e, same voltage, wrong trace?, measurement error?
2. NE570: pin 6 and pin 7 are also connected, i.e, same voltage, another wrong trace?, measurement error?

[Andre]

I really don't mean to pi#ss you off, but I think your soldering may be the cause of your problem with this circuit.
When you take a look at the solderside of your board, you will see quite a number of joints that look like this:
       ___
      /     \
     |       |
___\     /___

A big round blob of solder.
There's hardly any or sometimes maybe no connection between the solder and the copper.
Your solder joints should look more like this :
        __
        | |
       /   \
___/     \___

Here the solder has amalgamated(I used an online translator for this word  ) nicely with the copper.

When soldering you should try to heat both the copper and the part you're soldering at the same time for about a second or so
and then apply just as much solder as necessary to create a solder joint as shown above.

It also helps to clean your PCB just before soldering.
Even after a few days after you made a PCB, there will be some oxidation on the PCB which prevents good soldering.

André

[miqbal]

A glance from the PT-80 schematic:
1. MAX1044: pin1 and pin 8 are connected, i.e, same voltage, wrong trace?, measurement error?
2. NE570: pin 6 and pin 7 are also connected, i.e, same voltage, another wrong trace?, measurement error?

WOoow, eagle eyes, Andre, it could explain why Pin 1 and Pin 8 of MAX1044 don't have same voltage reading (although in the sama rail).

Resolder them!! Let the solder flow

[jasonsmusicgear]

Thanks guys, this PCB did sit quite a while before soldering it and I never even thought about cleaning it again.  I was having a hard time getting the solder to stick to the board on this one, but I thought my iron was the problem.  I will check all the solders tonight.

Jason