# Isosceles Boost Volume Trouble



## jmsfcx (May 2, 2020)

Hello again! Back with another isosceles boost build. For whatever reason I have the most trouble with this circuit. This time around, I’m having some volume control issues, where if I turn it all the way down, some noise is still coming through like the ground or something isn’t strong enough and when i turn it up, it doesn’t have much gain. I’ve tried everything from changing the pot, checking the values of the pot, touching up connections on both sides of the PCB, cleaning, even changing jacks and nothing. I had something similar happen to me on another board and I just jumped the connections for the volume and set it to full at all times. It didn’t work well with my interface though so I’m trying to add it back. Should I try a a10k?

Thank you!


----------



## Chuck D. Bones (May 3, 2020)

I suggest that you stop changing parts until we find the problem.  Post good photos, ones that are high enough quality that we can inspect solder joints and component values. I also want to see the entire inside of the box, how everything is mounted and interconnected.  Describe the noise.  It is hiss, hum, crackling, radio interference, guitar signal leaking thru?  Measure and report the voltage on pins 6 and 7 of the TL071.  Do the toggle switches do anything?


----------



## jmsfcx (May 3, 2020)

So it’s out of the box as of right now, I just hooked it up real quick to a breadboard to get the voltages. Pin 6 says 17v~ and pin 7 says 28v~. I have changed the chips too I forgot to mention. All of the toggles and eq works. I’m not really getting any hiss or hum or crackling, just low input/output. I made sure all of the resistors and caps were correct value just a bit ago (excluding the LEDR, I’m using a green LED so I lowered the value). I ran it outside of the box too and it’s still the same thing. Pics below.


----------



## Chuck D. Bones (May 3, 2020)

Your voltages are good.
All the R's & C's look correct.
Soldering (the stuff I can see) looks ok.  Maybe touch-up the joints on the LEVEL pot.
Can't see the stomp switch, jacks or marking on the BASS & TREBLE pots.


----------



## jmsfcx (May 4, 2020)

Chuck D. Bones said:


> Your voltages are good.
> All the R's & C's look correct.
> Soldering (the stuff I can see) looks ok.  Maybe touch-up the joints on the LEVEL pot.
> Can't see the stomp switch, jacks or marking on the BASS & TREBLE pots.


good to hear that at least. i went ahead and touched up grounds on the ic sockets and all of the legs on the pots. i’m using the board for the 3dpt. i’m truly stumped on this. photos of the switch, jacks and pot markings. both are c50s.


----------

