Liquid Mercury Tap Phaser - LDR version

[MAO]

01/31/2016
After many, many hours I've finally settled on 9203 LDRs and 3mm yellow diffused LEDs, with the LDRs angled over the top of the LEDs, then each LDR/LED/LDR combo covered with shrink tube. See post dated 01/31/2016 for additional details

12/15/2015 Verified!

Will report back in a few days with a couple of LED/LDR combinations. I fired it up with Tayda LDRs and 5mm yellow LEDs, sounded pretty good and quiet.

I'm also going to test out the other 4 available modulation shapes - Ramp Up, Ramp Down, Sweep and Lumps (not shown on schematic or in the build doc)


I modified Alex's layout to accommodate LDRs and replaced the dip switches with an external DPDT on/off/on to select the number of swept stages.

Proceed with caution as I have made a bunch of changes to Alex's original layout (fantastic work Alex!). I have checked it against the schematic and it seems fine, but another pair of eyes would be helpful.

Schematic

midwayfair (Jon Patton) suggested NSL-7532s and Red superbright LEDs as noted here:

DIYSB

I'm going to try Tayda LDRs and GL5516s as I already have them, but I'm sure Jon's suggestion will turn out best.


not yet verified


Copper side for cuts




         

[Chris60601]

While I ABSOLUTELY admire anyone that tackles projects that are as mammoth as this, one has to simply ask; when does one make the call and say, yanno - maybe it would be better to just do up a PCB.

Again, don't get me wrong, seeing projects of this caliber is what helps to keep this site going, its 2nd gen if you will. Is anyone actually building these ginormous projects? and then, what sort of enclosure does one use within reason? does something like this fit into a 1590BB?

In any event, truly amazing work Alex and Mao, AMAZING.

[MAO]

Thanks Chris6001,

Hopefully there are a few other vero-maniacs out there.

Maybe there should be a huge-vero folder for posting these types?  

No doubt, PCBs probably make more sense when the circuits are this complicated. But for me, I always feel a little guilty afterwards, like I somehow cheated.

I used to etch my pcbs back in the day, but ever since discovering tagboards, there's been no looking back.

The largest veros I have built so far are the Craig Anderton layouts I've posted, most fit in a 1590BB, a couple I put in a 125BB.  

I'm not sure this one is going to fit in those enclosures, it may need a 1790 which I've used on a few dual effects, but never with a single vero. This may be a 1st!

I'll report back after I verify and box it up.

[rocket88]

The problem is some of these massive boards done have pcb's, as they're gone. If someone with pcb talents wanted/could/would tackle making a new pcb for it for the community we could get some made.

Wink, wink, nudge, nudge.

[Chris60601]

LOL - I bet a person might try it if there was easy access to a schematic, one would think. Just sayin

[rocket88]

diysb or official 

the second link should also have a few other crazy builds on it that we have veros for. i know who ever might be crazy enough to tackle designing some nice pcbs for them, will definitely have many thanks and be an awesome guy.

[MAO]

There is a newer version on madbeanpedals::forum

[MAO]

Verified!

[MAO]

I replaced the 4 position Shape switch with a 10k pot, allowing for all 8 available wave shapes.

I'm getting the dreaded ticking with the Ramp Up, Ramp Down and Square Waves. Somewhat with the Random shape too. Backing off the Depth control reduces the ticking.

Not sure if the Square Wave ticking was there prior with the Shape switch.

The other shapes are tick free.  

Any ideas on getting rid of the ticking?  

[MAO]

LDRs tried: Tayda, GL5516, and Small Bear's 9203 & 7532.

Also tried all LED colors, 3mm & 5mm diffused and superbrights.

I settled with 3mm yellow diffused and the 9203 LDRs. I also increased the bias trimmer to 30k and have it turned back a good bit.  

I was unable to completely eliminate the ticking with the square wave, without weakening the other shapes in turn.  but found a decent compromise.

I added a 10n cap to ground between the bias trimmer and the LEDs which is engaged only when the square wave is selected. I slightly modified the board and used the unused side of the 2P4T rotary to switch in this cap when the square wave is selected.

The square wave still ticks with the depth on full, but with the 10n switched in, I just have to back off the depth a tad for the ticking to greatly diminish.

I have to admit, there where a few time I wished I had had a pcb and the VTL5C3/2s


   

[scimitar]

8 would just like to thank you, Alex and David Rolo for this fantastic circuit, I have just built it including writing my own Taplfo chip and it worked first time. Need to spend a little more time with it to fully confirm but seems to live up to its demo so far.

[MAO]

Cool, great timing as I literally sold mine last Saturday.  

I was debating whether or not to build another one since it's such a monster. Plus, I couldn't get rid of the ticking in the Square Wave mode.  

Does yours tick?

Also, which LDRs and LEDs did you use?

Mike

[scimitar]

Sadly yes it does tick on the square wave, not yet tried anything to reduce it, will look at your switchable capacitor option as I have a pole free on the rotary switch. I used yellow LEDs and GL55 series LDRS (not sure which ones as I ordered a lot from ebay and they came unlabelled - they are tricky to measure but I think I chose the ones with the highest off resistance) not done any experimentation (yet).