Flatline Compressor Question/Problem

[soggybag]

I just whipped up a Flatline Compressor the other night. I used Ulysses layout in the Gallery. Quick easy build. Everything seems to be working.

I find that when I turn the volume down at a certain point, maybe half way, noise starts increase and it sounds like my amp when there's a grounding issue. Not sure how to describe it. it's not like white noise or a 60 cycle hum. More like a dull deep hum. It isn't there and then it appears when the volume gets down about half way.

Anyone want to recommend a LDR? I have a box full and have trying them out. So far the VTL5C2 seemed to working well. There were some notes recommend a 10K to 20K LDR. I'm guess this refers to the minimum resistance. What about the max resistance? Or does it really matter?

[ulysses]

i have not noticed this issue with my build- have you got another guitar you could try? are you using single coils in a noisy (electrical) room?

if you turn the volume down the pedal will try to increase the volume of the signal to a certain level. maybe its not detecting the frequency of the hum as a volume increase and boosting too high??

i made notes on the writeup about the ldr's to use. i cant remember why, but in my notes i said to use a VTL5C1 or VTL5C3 and did not mention the VTL5C2. maybe the VTL5C2 didn't meet the requirements. also, use a standard red or yellow led, NOT a hi-brite led.

here are the notes i made at the time:
http://www.aronnelson.com/gallery/main.php/v/ulysses/ulysses_layouts/ulysses_jh_flatline_compressor/ulysses_jh_flatline_vero_1_01_p2.gif.html?g2_imageViewsIndex=1

from memory 100k was the maximum resistance, over 100k and it didnt work properly.

cheers

[soggybag]

Thanks for the reaply Ulysses. I printed dand read your notes, they were very useful. I'll try a couple experiments tonight. I'm using a power supply which could be the culprit. I'll give it a test with a battery.