pt80 GGG debugging

[wavenator]

TL072CP
P-1   3.02
P-2   0.02
P-3    3.02
P-4    0.00
P-5     6.04
P-6    3.03
P-7    3.03
P-8    1.51


PT2399
P-1   5.03
P-2   2.51
P-3   0.00
P-4   0.00
P-5   2.85
P-6   2.51
P-7   0.10
P-8   0.53
P-9   2.52
P-10    2.52
P-11   0.00
P-12   2.52
P-13   2.52
P-14   2.52
P-15   2.50
P-14   2.52


NE571N

P-1   0.06
P-2   1.82
P-3   1.82
P-4   0.00
P-5   1.45
P-6   1.45
P-7   5.28
P-8   1.82
P-9   0.06
P-10   1.82
P-11   1.82
P-12   6.07
P-13   1.51
P-14   1.48
P-15   5.32
P-16   1.82


MAX1044
                                           CPA0626

P-1   9.15
P-2   8.80( 8.80-8.14)
P-3   0.00
P-4   0.01
P-5   9.15
P-6   8.17
P-7   6.26
P-8   0.01

bypass works
led works
when the effects works, there is a clean sound without any boost at all

[anchovie]

Check the circuit around your MAX1044. It should be doubling your 9v supply voltage.

[solderman]

Same goes for the TL072. The pin 8 should be +9 or was it 12 V ?? well not 1.5 any way. Probably as a consequence of the MAX voltage but looks fishy.

There is a long thread here some where about debugging the PT80. Find it and compare your readings.


//Solderman

[tehfunk]

I just finished my debugging thread a few days back, i had the same problem no doubling of the voltage as it should be by the max 1044. First, as said previously, make sure you have no shorts around the max1044 circuit, and if so repair them. I had a short in mine between legs 1 and 2 IIRC and that actually ruined the chip, but once you have done this, or if there are none... you will need to make sure your max1044 is working in the first place. here's the circuit to test it.
http://www.geofex.com/circuits/+9_to_33.htm
just do the one for +17v, if you're not getting somewhere around there, try another max1044. But, again, before just trying another make sure there are no mistakes in your soldering or pcb because you'll just keep frying them if there is. Good luck, it looks like you're voltages are somewhat ok otherwise, let's hope that you're problem lies solely in this region, but we'll see.

[WLS]

The voltage on the Max1044 or any charge pump infact does not double, or reflect any change at the IC's pins. This is the result after going through a series of rectifiers, and capacitors. To find out if the voltage is correct take a reading right before the circuit enters the regulators.  This is a reading I don't see and is important to the evaluation of the circuit in general.


Bill

[tehfunk]

I agree, but i could tell it wasn't being doubled from many of the voltages on the other chips--yes at the positive side of the second 10 uf capacitor after the max1044 you should be getting around 17v.. but it's pretty clear he's probably not going to be getting that.