Orange Squeezer Problem

[DPM309]

Hi, I am new to this board and I have built a couple of Orange Squeezer pedals (GCC not MadBean) and am having problems with one of them.  After a few hours, it quit working.  Voltages were off on Q1 an 2 and IC1.  Swapped them out and it would not work until I replaced Q1.  Put it back on my pedal board, and after an hour or so, it quit again.  Went over the board, soldered connections, etc with a fine tooth comb and could not find any problems.  I am using a 1 spot 9V DC adaptor that reads about 9.5 VDC and was wondering if this could be causing the transistors to burn out.  The other 2 I build are not experiencing this problem.  Any suggestions?  GCC does not have a forum like this so that is why I am here asking questions.

Thanks,

Dan

[jkokura]

It depends on the transistors you are using and since you didn't specify, I can't tell you whether it's the case. If your transistors are max rated for 8.5 or 9V, than feeding it 9.5V for a while may kill it. Chances are high however, that what's actually happening is that you have some sort of short of problem on your PCB, or in your wiring.

Could we ask you to share some more details? perhaps pictures of the board and a link to the project docs you've used? Posted voltages would help too.

Jacob

[DPM309]

I am using NTE457 instead of 2N5457 which according to the NTE site, are direct substitutes and are rated at 25V.  The one thing I did notice when looking at both datasheets side by side is that the pinouts look different - DSG for the NTE and SGD for the 2N5457.  I used these same transistors for the other 2 I built and have had no problems with them.  Here are the latest voltages (Expected voltage in parenthesis):  IC1 P1 and 2 - 1.4V (8.3v), P3 and 4 - 0V (0V), P5 - 1.8V (4.7V), P6 - 2.3V (4.8V), P7 - 2.6V (4.8V), and P8 - 9.5V (8.8V).  Q1, Drain - 9.5V (8.V), Source 2.9V - (4.0V), Gate - 2.4V (2.4V).  Q2, Drain - 1.1V (2.1 to 2.6V), Source - 2.3V (2.6V), and Gate - 0V (0.6V).  Here is a link to GCC page for the OSC: http://www.generalguitargadgets.com/pdf/ggg_osq_instruct.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d&phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I will go back and recheck the PCB and connections in the meantime.

Thanks,

Dan

[jkokura]

Try flipping your trannies so the pinout is correct, swapping the correct lugs and such. Once that's done it will tell you what's what.

Jacob

[DPM309]

I installed a new IC and 2 transistors (flipped the leads) and the unit is now running just like it did last time I replaced these.  I will bench test for a few days to see if this will do the trick.  Could having the leads switched on the trannies cause them to fail and take out the IC?  I installed dip sockets for the IC and trannies so that I can change out easier next time.

Thanks,

Dan