Advice on LDR/LED setup for Phase II

[mybud]

Greetings all: First forum post after receiving my initial PedalPCB order.

I'm about to build the Phase II and just wanted to confirm that the LDR/LED setup is flush to the board as opposed to raised off the board with the LDRs surrounding the LED in a kind of 'floral' arrangement.

My artistic skills amount to exactly zero, so I can't help with a diagram for visualising 'the flower.' I'm thinking LED at the centre raised off the board and LDRs arranged to bend close to it.

I'd appreciate it if anyone can assist. Seems logical to insert these parts flush but don't want to discover my mistake after it's done and difficult to rectify.

Thanks in advance, all.

 

[Betty Wont]

Either way will work fine. I personally lay the LDR flush because it is easier and cleaner looking. For compensation one of the trimpots is a fine adjustment to the brightness of the LED.

 

[Paradox916]

I’m still in the middle of building one myself but here is how I did it... and I believe it’s a common approach to this circuit

 

[Jonnytexas]

I did mine like Paradox. Sounds great.

 

[mybud]

Thanks, all, for the prompt responses. Much appreciated.

 

[mybud]

Happy to say this build (my first from PedalPCB) worked first time. I had to wait a fair length of time for the boards to arrive (very nice BTW) and then discovered that 1/8W resistors were required (perhaps the BoM could be updated in time?), then that the 220uF cap I had was too big for the board, and finally that I had too few 072s. A quick visit to my local this morning and these frustrating shortages were resolved. I had to come up with a kludge for the rate pot (wired an A100k with 33k in parallel to get approx. 25k). After all these minor issues, I built it today and am very pleased with the sound, authentic 1970s vibe with its own character as befits its origin as a Mutron Phasor. I fiddled with the trimmers to taste and think I'm on the right track sound-wise. I get the brightness one but the other has to do with the depth setting, I'm presuming. Any advice appreciated as ever. Next up, the Minnow ...

 

[danfrank]

I find when adjusting the two trimpots:
Set depth control to max
Set feedback to min
Set rate to like 9-10 o'clock. You want the rate slow so you can observe the LED but not so slow that you fall asleep while waiting for it to cycle.

For the offset trimpot (10k) I adjust so the LED goes very dim but not completely off. Do this in a dark room. Don't look directly at the LED as the center of your vision is mainly sensitive to colors and not levels of darkness, look off to the side of the LED just a bit.
Set the brightness trimmer (1k) about half way, that's a good start. Again, do this in darkness. The object is that you want the LED to take advantage of the resistance slope of the LDR, where the LDR is around 10k ohms when LED is bright and +200k ohms when the LED gets dark.
I find the most important setting is the offset, you don't want the LED to go completely off.
Hope this helps

 

[mybud]

Thanks for the swift response and detailed setup instructions. I’ll post the finished article, all boxed up in its drab retro glory, in due course. Thanks again.

 

[mybud]

Thanks again for the valued assistance. As promised awhile back, here's the finished article.