This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.
This one was due for a revision/redo. Optical compression with all the knobs from our favorite pedal slingers in Akron. Will fit nicely in a 125B with top mounted jacks.
I only have 1M dark resistance ldr and I can't find 500k nearby. Do you think putting 500k parallel resistor would make it work? Or should I try it with 1M LDR?
One last question, I assume OPA2134 is connected to 18V, right? My problem is that I can't find it neither and I was thinking about putting TL072, but it says that "it is not advisable to run on 18V". What are substitutes od hi quality op amp that can handle this voltage?
Also, my LDR goes to 12M after I placed it in heat shrink tube with the LED. Pedal works great. Perhaps would need to compare with different LDR once I grab one to see if it makes big difference.
I added switchable LED in series with vactrol's LED side. Switching it on has an effect of increasing attack and lowering ratio (blend). Compression only kicks in at later stage. Could not figure how to do that in a transparent way.
Late reply, but may be helpful for someone :) to do it in a transparent way you could use a simple transistor (2222 for example) as a switch for a LED indicator. Connect it to the LDR-driving LED with a reasonable base resistor and do some experiments. I did it in some of my tremolo circuits with great success, so it should be working here as well
I had just bought some, and the circuit sounds good. It's a nicely subtle effect using MPSA18 and 5088s. I may get some 5089s to see how it changes the behavior. I've built the Fat Fuzz Factory and Morning Glory v3 as well from your designs and they all sound good. Thanks for everything!
Hello, I wanted to ask you what type of capacitors are the green ones, the yellow ones and the gray ones, which appear in the diagram. Thank you so much.
I assume LDR is 500k, right?
ReplyDeleteYes, a 500k dark. Specifically a GL5516
DeleteCan't wait to give it a try! Thanks a lot for keeping us busy during this strange time!
DeleteNot much parts... I think is posible to relayout for fit in 1590B..
ReplyDeleteDo one and post a link here, might be helpful to some people.
DeleteI only have some fakes mpsa18 with hfe of 350. 3 of the se would work in the circuit?
ReplyDeleteI would think so. Use sockets though
Deletehey, what's the difference between 5516, 5528, 5537 and 5549 LDR? thanks ��
ReplyDeleteIt's a part number. The difference is the amount of dark resistance
Deletethey have different resistance in the dark
DeleteJandalesands, from my notes the different LDR dark resistance
Delete5516 = 500K
5528 = 1M
5537-1 = 2M
5537-2 = 3M
5549 = 10M
Can we use 7660 not tc1044
ReplyDeleteProbably. Just double check what pins need to be grounded for the 7660.
DeleteI used a ICL7660S in my build with no issues.
DeleteMake sure it is 7660S, 7660 will produce 10kHz hiss. Same goes for cheap fake 1044s from shady corners of Internetz beyond Great Wall.
DeleteHello. This layout has been verified. As to transistors, I tried MPSA18/5089s, MPSA18/5088s and all 5088s. All work.
ReplyDeleteThanks for verifying!
DeleteI only have 1M dark resistance ldr and I can't find 500k nearby. Do you think putting 500k parallel resistor would make it work? Or should I try it with 1M LDR?
ReplyDeleteI would experiment with both options and see which works best.
DeleteOne last question, I assume OPA2134 is connected to 18V, right? My problem is that I can't find it neither and I was thinking about putting TL072, but it says that "it is not advisable to run on 18V". What are substitutes od hi quality op amp that can handle this voltage?
DeleteA TL072 should be fine at 18v. I believe the max voltage for that chip is 36v (or +/-18).
DeleteYour TL072 is a high quality op amp that can fit spot on. Tried this setup: tl072 with BC550s inplace of mpsa18 and works great.
DeleteAlso, my LDR goes to 12M after I placed it in heat shrink tube with the LED. Pedal works great. Perhaps would need to compare with different LDR once I grab one to see if it makes big difference.
DeleteDoes anybody know how to add sidechain input to this one?
ReplyDeleteHi,
ReplyDeleteHow would one do to add a gain reduction indocator led?
Thank you
I added switchable LED in series with vactrol's LED side. Switching it on has an effect of increasing attack and lowering ratio (blend). Compression only kicks in at later stage. Could not figure how to do that in a transparent way.
DeleteThank you. I still hope we could find a solution to have a led indicator work without affecting the sound :)
DeleteLate reply, but may be helpful for someone :) to do it in a transparent way you could use a simple transistor (2222 for example) as a switch for a LED indicator. Connect it to the LDR-driving LED with a reasonable base resistor and do some experiments. I did it in some of my tremolo circuits with great success, so it should be working here as well
DeleteHi!! Is it a problem if I use some 16V electrolytic capacitors ???
ReplyDeleteTheoretically it shouldn't, but I've seen 16v caps blow on a 9v supply. I usually go 35-50v personally.
DeleteWhat kind of caps are the 1uF caps at T8 and F21? They don't look like ceramic, film, or electrolytics.
ReplyDeleteBox film caps. I get them from Tayda
DeleteI had just bought some, and the circuit sounds good. It's a nicely subtle effect using MPSA18 and 5088s. I may get some 5089s to see how it changes the behavior.
DeleteI've built the Fat Fuzz Factory and Morning Glory v3 as well from your designs and they all sound good. Thanks for everything!
What are the additional Ground slots for, down near Out and up near 9v?
ReplyDeleteJust in case you need extras.
DeleteCan i use OPA2132?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteI'm trying to fit this in 21*20. I want to make diagram of yours but can I have your diagrams for capacitors and else?
ReplyDeleteHello, I wanted to ask you what type of capacitors are the green ones, the yellow ones and the gray ones, which appear in the diagram. Thank you so much.
ReplyDelete