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For Scooter. This is actually his PIFmas present ... or rather, a backup PIFmas present, since his other present didn't work out (it was going to be a new circuit design that didn't work in the PCB stage).



I'll post the new schematic and layout soon, but the circuit has had a pretty major overhaul, including a new smaller envelope circuit with better control, a MOSFET dry path, and a depth control that actually works properly. Mine is very slightly different from Jacob's forthcoming project, mostly just a couple different component values, but Jacob's PCB is also going to have a couple extra options on it. The really big things are that the tremolo mode is back on -- no more volume drop! -- and that it now works with a wider range of photocells instead of requiring the VTL5C1. I used a Silonex 7530 here (the same photocell used in many univibe clones) because it looks awesome.

I'm still filming the demo, which I have to finish tonight before I mail this off to Scooter.

http://www.geofex.com/article_folders/univibe/univtech.htm

Skip down to the list at the bottom, especially #3 about getting the second notch. I'm not sure what schematic the numbering refers to for C7 etc.; does anyone know and could relate them to the harbinger schematic?

New giant box of parts from Small Bear Electronics Day!

Perhaps I will get to open it at some point ... it's currently being used by someone else.



There's a bunch of storage, a ton of LDRs and photocells to test for the Blue Warbler re-design, a ton of pots and resistors ...

And an invoice with an embarrassingly large number next to "total." I've been putting off this order for probably 8 months, though ...

I've spent a lot of time playing with these, and I haven't found a good spot that had as much info as possible in one place. Though they're not the most common LFO these days, I figured some people might have some questions, thoughts, or ideas about using or modifying them. Feel free to jump into the discussion there or here. Here's the thread:

http://www.diystompboxes.com/smfforum/index.php?topic=106566.0

I mean, it sounds pretty good, but something just doesn't seem right about it.

Nothing to do with pedals, but basically this discovery is one of the most important discoveries in physics in decades; it's on par with the Higgs boson to say the least and provides evidence for Inflation Theory, which solves some of the biggest problems in trying to figure out how the Big Bang got so, well, Big.

Here's a NYT article about it:
http://www.nytimes.com/2014/03/18/science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html?ref=science&_r=1

They're both listed as Alpha, I just want to know if they're the same thing.

Bearhug Camp, commissioned by my buddy Keith for his nephew, who is a boy scout. Keith is basically giving him an entire rig -- a 100W Fender head, a 2x12 cabinet with Alnicos, an electric 12 string, and the Bearhug, along with an overdrive not yet determined.



And that is why you always hang up your food when you go camping. He wanted art kind of like Order of the Stick and xkcd combined.

Speaking of Bearhugs, here's one I built to send to Cyrus at Ovnilab for a possible review:


I also sent him an Engineer's Thumb and the Ghost Note (the Afterlife with threshold knob I built a while back), since those were on his "I want to review these" list.

Little Penguin Fuzz



This is an NPN MP38A Fuzz Face with no gain knob for a customer. He only wanted the volume external, but I talked him into some extra controls inside. Pregain, input bass control, bias ( of course), and switches to change the behavior of the pregain pot between Gagan's Easy Face and the Fuller mod. It's insanely loud -- the knob is set above unity. So it can do some legit treble booster settings. It sounded best to me biased pretty cold (6V). This is probably the only fuzz I've ever made that uses the "right" gain buckets and I can't say I'm exactly a fan of that, but it does sound pretty good and it behaves as expected.

And ... the Snow Day OD





I had the day off on Monday due to snow and thought I'd throw together an overdrive to pass the time. Instead I ended up designing a new project and spent the week working on it.

I'll do a project thread with some more info and a demo, but the short description is that it's a FET- and MOSFET-based amp simulation overdrive running on 18V that includes a switchable miniature compressor circuit and soft clipping in a "power tube" section. It has bits of several projects in it; and the really special thing about it (the mini compressor) isn't something I created (though I wish I had).

It sounds quite good. It goes from glassy "almost" cleans to either open or slightly compressed edge of breakup that feels very similar to one of my favorite amps, up to a medium gain compressed sound. It has lots of harmonics without sounding overly clipped, and a very wide dynamic range.

The art is inspired by (and borrows some images from) Calvin & Hobbes strips. The box came from John Lyons. It was pre-marked for three knobs and a switch (or second LED), and I actually designed the project specifically to fill this box ...

I also still need to do a build report for the Britannia from my demo, too, but unfortunately I didn't remember to take pictures before I loaned it to someone.

"Winning" a personal challenge is a funny way to put it, but hey, FAWM puts a little trophy when you hit 14!

FAWM, for those who don't know, is a self-challenge to write 14 songs in the month of February. Despite getting a late start and having a few weeks of feeling bad due to illness, I even finished a few days early in part thanks to some collaboration with my friend Mosno.

I wrote a blog post about the process. I figure most people here have an interest not just in music but in creation, and it also contains some thoughts about balancing a large number of hobbies and interests.

I hope you guys enjoy reading. I'll leave the set list here for anyone who just wants to hear some tunes and aren't so interested in reading my lengthy post. I do want to stress that these are demos, self-recorded and self-mixed, so there are a few rough spots. But I am always open to honest criticisms and suggestions about the songs, because it's always a process.

[cloudset]http://soundcloud.com/jon-patton-3/sets/fawm-2014[/cloudset]

A customer contacted me about doing this. I've never rehoused a danelectro but I figure some other people have and could probably do a good job. PM me and I can put him in touch with you.

You'll also get a kick out of the hack job of JHS's mod to this pedal, which involves sticking a knob an inch away from the footswitch.

I have a white 1590B that I drilled for four pots and either a second LED or a toggle.

I've only had the case for a couple months and I can't figure out what the heck I was planning on putting into it.

My friend Mike Friedman -- who commissioned the Van Gogh mini pedal duo and the mini Engineer's Thumb -- asked for a soldering lesson. Instead of just having him sit around soldering a mesh of wire, I thought this would be more fun.



Rullywowr gave me a little Fo-SHO boost board a while ago, and it was lying on the bench, so I decided we'd build something on that rather than go straight for perfboard. I figured the circuit's biasing and caps were appropriate for several types of transistors, which would add a bit of fun once it was built. I didn't have the schematic in front of me, but I figured it couldn't be too tough to wing it (I did eventually print one out for the schematic reading lesson and realized that I should have used 10M for the base resistors instead of 2M2).

Mike did all the soldering, and considering it was his first time handling a soldering iron, he did a great job -- there weren't any cold joints, bad connections, or anything.

Along the way, I gave him a crash course in understanding the parts of a simple booster, and understanding biasing (and why the pot makes scratchy noises) and did my best to introduce him to the idea of impedance and how it affects things.

Once it was soldered up, we tried different transistors, starting with the MOSFET. Since he asked some questions about germanium transistors, we also tried a germanium transistor (gain 70), then progressively gainier silicon transistors (2222A, 3565, and MPSA13). He settled on the germanium because it was a little warmer, but we taped the other transistors inside the case so he could swap them out.

The we went through the boxing process, using one of Josh's optotron boards. I should have just had him solder the chip directly to the board, since it was sticking up so much, but the lid did fit in the end (just barely).

Finally, I did the letter on the case, since Mike was less confident of his ability to do that part even though it was just his initials.

The base color is Oz Green from Pedal Parts Plus, which is just an awesome finish.

In the end, Mike was really happy with what he ended up with, and I had a good time teaching him. And this is certainly far more robust a box than my first!

For a customer in Norway.

I used one of the tiny 4PDT rotaries I found recently for the tempo divisions -- I just left out dotted 16ths, because who uses those? It's a little awkward that the Taptation exceeds the PT2399's specifications, so there's a lot of gurgle at the longest delay time setting. Seems like a good call on Jacob's part to move the tone control external for the Hamlet+.




The art came out a bit more impressionistic than I'd originally planned, but it's cool enough I think. He specified some ripples and a blue case and let me do whatever I wanted otherwise.

I've had trouble even searching for this information, because I don't know the technical term for these things. It's the little bypass caps between the base and collector (or gate/drain). Same sort of thing that's in op amp feedback loops to "cut" treble.

This might be the most complicated tremolo pedal ever ... Stereo Tap Tempo Tremolo based in part on the Cardinal using essentially every feature of the TAPLFO. I think the only pins I didn't use are the basic tempo LED and the "next multiplier." The stereo switching is kind of cool. I set it up so that it can run in mono (left channel only), left mono in > stereo out, left TRS in > stereo out, and dual mono in > stereo out. The only thing it doesn't do is sum stereo inputs to mono ... except it kinda does because I also added Harmonic and Vibe modes via a DPDT on/off/on switch (it's accomplished a little different than the Cardinal, but similar cutoff frequencies and it sounds pretty awesome), so you could have a different effect in the right channel and cross it over in the vibe mode.

There's also Expression pedal input selectable between the Rate and Multiplier (he wanted the multiplier instead of depth, otherwise I would have used a 3PDT toggle instead of a rotary ... the multiplier is a pain) and sync in/sync out.



The jacks are drilled in the back with exactly enough room to put seven normal right angle plugs next to each other, but something like George L's or straight plugs will fit much easier.

This was for a customer in Switzerland. I hope he's happy with it, it was a HUGE amount of work figuring out all the wiring and switching and I'm not keen on ever building another regardless of price. :p

p.s. I did fix the mistake in the waveform graphic.

New recording interface day!

My Scarlett 18i8 arrived yesterday and I set it up tonight. A pair of Audio Technica mics (2020 and 2021) also arrived, but I decided to try recording direct to one of GrarageBand's amp emulators ("sparkling clean" with a tiny bit of delay and reverb) to test out the preamps, and it sounds pretty good ... in fact I'm not totally sure I could mic my amp well enough to make it sound too much better.


[soundcloud]https://soundcloud.com/jon-patton-3/bbotb-interface-test-scarlett[/soundcloud]

Recorded something with overdubs ... all the guitars here are the Don Q caster, including the bass.
[soundcloud]https://soundcloud.com/jon-patton-3/strattin-around[/soundcloud]

My friends played at the Takoma Park Folk Festival this year, which is actually kind of a big deal in the folk scene in our little corner of the world. They ended up with a board recording of the concert. They started off with like 10 people in seats and by the end of their set every seat was filled and there were a ton of people standing on the lawn.

"There's a Light" is particularly magical. It also has Katie singing lead on one of Joe Scala's best songs, Grounded, which I also cover. (His FAWM recording of that song friggin amazing.)

http://katieandjoe.bandcamp.com/album/live-at-the-takoma-park-folk-festival

It's a free download if you want to pay nothin'.

Also, the drummer and third vocal on this, Mosno, is worth checking out for his own stuff.

Dave Rolo used these in his Twin Peaks (his tap tempo harmonic tremolo), and I finally got around to ordering some. The picture doesn't communicate how small they are. They're about the size of a normal 16mm pot!

http://www.ebay.com/itm/20pc-Rotary-Band-Switches-DC-60V-0-3A-100-500-ohm-2P4T-10-Pins-2-Pole-4-Position-/300881322642?pt=LH_DefaultDomain_0&hash=item460deca292

I have plans for these. Mwa ha ha.

Built this board and put it in a case:


The case had this "cookies and cream vein" finish from Pedal Parts Plus.

So then had to do some "research" for inspiration on the art:


And this is what I ended up with:


Almost stock. I used BC549C for every BJT in the pedal because I have a bunch of them and few 5088s. I've been trying to resist the temptation to mod for the sake of modding lately, but after playing with it a while, I decided to drop the speed limiting resistors to 2.2K. This sacrifices a minimal amount of slow speeds for slightly faster fastest speeds. I also decided to run the LED through the footswitch. There's a 2.2K from the LED's anode to ground, and the cathode connects to ground when switched on. This keeps the LFO running all the time (otherwise it would take a second to go back to oscillating) and also keeps the white LED from being blinding (and saves me from having to use a colored LED in a monochrome pedal ... I won't lie, this was the main reason).

I also socketed R7 thinking I could maybe get a tiny bit more volume, but no dice. Ah well, it's only very slightly below unity on both chorus and vintage, and the chances of me using it in vintage mode or in any situation where I care about the volume drop are pretty small.

No light shield. It's dark in there anyway.

I did have one problem when boxing it up ... I'm not used to board mounted pots, and I had them a little too shallow for the dual gang. The first time I stuck it in there, I ended up with some components compressing and poking through the 3M tape on the back of the pot and shorting out on the dual gang; then I fixed that and ended up with the same thing happening on the volume pot (though this did solve the volume issue ... apparently it was shorting Q2's emitter to ground and nothing else)! Bugger. I finally fixed it by loosening the volume pot's nut by a 1/4 turn. Meh.

EDIT: Oh, one last thing: how is it that no one else has called theirs a punyvibe? It seems like such an obvious pun, but there are no hits in google except a single mention on Circuit Workshop regarding Forrest's puny phase!

I was getting some squeal in a lowrider I just built originating at 6&7 of IC5B. It appeared on the pins, but if I touched the junction of R33/R32 it went away. I started poking around a bit and experimenting and I found I could make it go away with about 33pF of capacitance across IC33, or by shunting the same amount to ground, or adding some capacitance to C21 (but that took more). It still squeals a tiny bit on power up for about 2-3 seconds (obviously only if the second octave down pot is turned up at all). I went and grabbed my old lowrider and noticed that it had a little "peep" on power up, but it didn't last as long, maybe a quarter of a second.

Increasing the capacitance strapped across R33 decreased the amount of time the squeal was audible, but it also cut the volume of the second octave down. I ended up using 150pF, which resulted in perhaps a 1 second squeal with minimal volume loss (which I didn't care about too much ... I boosted R52 on this one anyway so that the whole effect has more output now).

Nothing is wrong with the effect -- it works just fine, tracking is just as good as ever, no magic smoke, etc.

Could anyone venture a guess as to what is (a) causing the squeal (I've swapped the 074 with no change - so it's not a bad op amp) and (b) if perhaps a part went bad that I didn't think of?