Vintage TS9 problem with low drive after installing IC socket

[strato2009]

thanks for the advice!
I agree, I shouldn't even have desoldered one leg of the 51pf, but I thought it would tell something.
So I have a few questions as my knowledge is very limited:
1. how do I check if the 51pf or 220nf caps are bad with a multimeter that doesn't have capacitator measuring setting? If the 220nf would be bust, would it affect the amount of drive? I think that's what I should be considering, everything that affects the drive pot.

2. I suppose the back of the pots are supposed  conducting to the enclosure (they weren't conducting to any of the pots legs)?

3.how do I check the mentioned continuity accross the feedback loop? I did the diode setting reading accross the diodes on the drive circuit, gave me readings around 600-700 which I suppose is OK?

4.The pedal was functioning perfectly before I installed the chip socket. To me the first thing that comes to mind is that I burned something, but if this is the case, which parts around the socket affect the drive?

thanks

I think you're easter-egging, my friend     If you have a vintage effect, why change parts that don't need to be changed?  Is it still vintage then?  You're going to change the cap, and maybe more but - you KNOW the cap, etc. is bad??   

That cap is just working as a filter in the feedback loop, it has little to do with actual volume!  It may help reduce some harshness in the sound, is all.  It is so tiny that you may not even hear the frequencies it affects.  If it is not burned to a short (test with meter!), then it is fine.

***  If the back of your pot has continuity with any of the 3 terminals of the pot, then it grounding out IS a problem.

You could check for continuity across the feedback loop, making sure the drive pot is set in the middle or so, so it won't represent a short to your meter.   You could make sure that 4.7k resistor IS connected to ground at one end...and that the cap above it isn't shorted, altho unlikely.  Most problems come from US soldering etc, so that has to be looked at over and over.

Once settled that the feedback loop is ok....could your problem be further along?  I would AUDIO PROBE that area, at this point. Each pin, carefully.  FIRST thing that is suspicious are the controls....the output of that opamp goes to the tone control - if THAT pot were bad, could it create a big load on the circuit?   Keep it simple, you don't have to rebuild the effect starting at that part of the circuit!!     

[duck_arse]

 

...... and the rest were in the middle

this is not allowed. please post the voltage readings on each pin, as they appear on your meter.

power off, remove the IC from the socket, and set the meter to ohms. probe each adjoining pair of pins on the socket. is there any chance those exposed leads on the clipping diodes are touching and shorting?

and can you post some picture of what you have in your hands, the one that doesn't work. the working build in the photo needs no troubleshoots.

also, welcome to the forum.

[strato2009]

...... and the rest were in the middle

this is not allowed. please post the voltage readings on each pin, as they appear on your meter.

power off, remove the IC from the socket, and set the meter to ohms. probe each adjoining pair of pins on the socket. is there any chance those exposed leads on the clipping diodes are touching and shorting?

and can you post some picture of what you have in your hands, the one that doesn't work. the working build in the photo needs no troubleshoots.

also, welcome to the forum.

I will post pics and the voltages soon.
The opamps should be fine since I had three different on the socket and none worked.

[strato2009]

Thanks for all the help guys. I'm so glad it works now, turns out there was a corroded contact with one of the capacitors outside the drive circuit that I didn't see before. Now it works and sounds great.

Thanks for all the effort and time taken for helping me out on this one!

best regards from Finland

[GibsonGM]

You're welcome, Strato, enjoy!  I thought there would be a simple reason for the trouble, and there was!   

Next time, you will know that even if it seems funny, we have to check all the solder joints!