Neptune+

[lincolnic]

I'm not sure if this actually deserves a "+" in the name, but I threw a couple of mods onto the Neptune, so that's how I've been thinking of it since. Bought the board in the last group buy (April 2012?), populated it sometime in the fall, and finally boxed it up right before the end of the year. I had an issue with the switch popping, and my thanks goes to midwayfair, culturejam, and LaceSensor for teaching me a bit about the circuit and how to deal with that.

Okay, so the mods - nothing fancy, but I think they're useful. When I saw in the build doc that R17 set the overall range of delay times, and that the stock minimum was ~200 ms, I knew that I'd want a shorter option for something slapback-y. I wired up a DPDT instead of R17 to select between two resistors - that's the Short/Long switch on the left. "Long" is the stock 18k, and I have 10k on the other side for a shorter setting. I may replace that with an even smaller resistor at some point; it gets close to the slapback I'm imagining, but not quite there.

As for the second mod, I used eldanko's mod from his Dory Deluxe build to switch the momentary between the stock warp option and infinite repeats. I was pleasantly surprised by how long you can let it oscillate before it gets painfully loud.

If I was going to build another one, I might try messing with R18 to slow down the modulation a bit...maybe I'd replace it with a trimmer to experiment a bit more. I probably won't build another soon, though - so much wiring! This pedal has made me seriously consider using ribbon cable in the future. Contrary to the gutshot here, it actually looks a little neater in person. There's actually plenty of clearance between the 1M resistor on the switch and the enclosure wall, but in the photo it looks like they're touching. Same goes for the bottom left corner of the PCB. Must've just been a bad angle. I think that yellow input wire was originally meant to go underneath the PCB, but I'm not sure why it ended up on the top...I probably just ran out of patience and wanted to play with my new delay already!

I have to say, even though the wiring was a pain, this pedal made me appreciate the DIY experience that much more. It's a nice confidence boost when you know that you couldn't buy the same pedal in a store.

But enough talk - have at you!

[whitebread47]

Looks good, man!  Is that the powdercoat blue from Mammoth?  Love that color.

Good to know on R17, as I built one recently for a bass player who rarely goes over about 150ms.  So I'll try dropping that value down to 8.2k or so and go from there.

[midwayfair]

This is a great set of mods for this pedal! I Love the Neptune. So many cool sounds available with the momentary.

I have 10k on the other side for a shorter setting. I may replace that with an even smaller resistor at some point; it gets close to the slapback I'm imagining, but not quite there.

Check the datasheet - there's a chart that gives you the times for the resistance of that R17 resistor.
http://www.datasheetcatalog.org/datasheet/PrincetonTechnologyCorporation/mXyzsyzt.pdf

10k is a little long -- that's 150ms, not much less than the 18K, really.

Good to know on R17, as I built one recently for a bass player who rarely goes over about 150ms.  So I'll try dropping that value down to 8.2k or so and go from there.

25K repeats pot + say, 2.7K R17 would give you about 60-300ms. However, the warp will have much less effect below 200ms, which is the reason for CJ's original value.

[lincolnic]

Looks good, man!  Is that the powdercoat blue from Mammoth?  Love that color.

Good to know on R17, as I built one recently for a bass player who rarely goes over about 150ms.  So I'll try dropping that value down to 8.2k or so and go from there.

Yep, it's a Mammoth finish. I like this color because it looks straight out of the 50s.

25K repeats pot + say, 2.7K R17 would give you about 60-300ms. However, the warp will have much less effect below 200ms, which is the reason for CJ's original value.

Thanks, Jon! I wasn't aware of the chart in the datasheet. In my mind, I figured (almost) half the resistance would give me (almost) half the delay time. I might go for 4.7k instead. Mainly because I have a spare 4.7k resistor lying around, but also because I think ~80 ms of delay time (what looks like the minimum for 4.7k) would be a bit more useful than 60 ms.

[nzCdog]

Nice build!  Time for a demo methinks

[eldanko]

Lovely work good sir!

[lincolnic]

Thanks, guys. I'm not really set up to do any kind of demo videos, but maybe some audio isn't totally out of the question.

[culturejam]

Nice build!

Yeah, 18K is a bit much for the minimum, but as midway pointed out, I originally set it there because the delay "stretching" effect is very minimal at short times (and also to eek out a bit more max delay time on the other end of things).

I've since discovered that I prefer 2K2 as the minimum, and I use a 100K time pot with a 270K resistor in parallel. That gives very short times up to about 900ms on the other end. With C14 at 47n (you could even go a bit higher), even the longest times are nearly noise-free, albeit quite dark.

[lincolnic]

Nice build!

Yeah, 18K is a bit much for the minimum, but as midway pointed out, I originally set it there because the delay "stretching" effect is very minimal at short times (and also to eek out a bit more max delay time on the other end of things).

I've since discovered that I prefer 2K2 as the minimum, and I use a 100K time pot with a 270K resistor in parallel. That gives very short times up to about 900ms on the other end. With C14 at 47n (you could even go a bit higher), even the longest times are nearly noise-free, albeit quite dark.

Thanks a lot - nice circuit! I'm really pleased with the sound.

I wish I'd known about your preferred values before I started building; that sounds like a great range of delay times. If I build another one, I'll build it to those specs for sure.

[culturejam]

I wish I'd known about your preferred values before I started building; that sounds like a great range of delay times.

It's trivial to pull the the Delay pot and replace it with 100K. And just solder the resistor right on the pot lugs. To avoid desoldering anything, just add the 2K2 in parallel with the 18K on the board. That would give you 1.92K, which is close enough.

[lincolnic]

It's trivial to pull the the Delay pot and replace it with 100K. And just solder the resistor right on the pot lugs. To avoid desoldering anything, just add the 2K2 in parallel with the 18K on the board. That would give you 1.92K, which is close enough.

Yeah, I know. I just get lazy. 

Next time I order parts I'll be sure to throw these in.

[spaceboss]

Those are nice useful additions. Slapback delay makes the world go round.