Slow Gear Built

[RickL]

I used the layout at GGG which works fine except the outlines are reversed for all the transistors. Just point them the opposite way and it will work. It fired up perfectly from the start, I didn't even have to fiddle with the trim pot much. Centred is just about right for it and you don't have to be too fussy.

Both controls work perfectly but I seem to remember more fade in time with my original one. I'll dig it out sometime and compare the two, I'm probably remembering wrong. It tracks quite well but it wants a little silence between notes. Without the silence it won't trigger reliably on the next note (no fade in).

The flip flop bypass works perfectly, but as the build notes say it's the old style where the LED only flashes when you hit the switch. It doesn't stay on to indicate status.

I still think the PAiA Gator is every bit as good but it's nice to have a working layout for the Slow Gear if that's the one you absolutely must have.

[Ry]

That's great!  Getting something like that working on the first power up is a really good feeling.  Do you know how it compares with the EH microsynth attack delay function?  I have a microsynth that I like quite a bit, but it tends to add a lot of 'dirt' to the signal in most settings.

[RickL]

I don't have a microsynth so I don't know how they compare. This unit is very clean. I didn't notice any distortion in the sound nor any particular background hiss. It seems to work slightly better on single notes but I can't say that chords actually cause any problems. The sound of the attack being removed might just be more apparent on single notes.

[smccusker]

I would like to build one of these, but why on earth does it have so many components?
Couldn't you make a really simple one using an LED+LDR combo, and somethign similar to the nurse quacky circuit, where the led lights up as you play?

[Mark Hammer]

why on earth does it have so many components?

Take away all the stuff related to switching, and actually it doesn't have all that much, given what it does.

A good third of the components involved (all that stuff built up around the op-amp) is for deriving a full-wave rectified envelope signal with good ripple control.  Another third is the attenuation and input/output buffers, and the remaining third is the switching.  In part, the amount of envelope circuitry needed is a function of using an FET for attenuation.  The FET responds quickly to fluctuations (as it ought to), which means that the envelope signal needs to be as smooth and ripple free as can be achieved (and needed, given the application).  

You may be correct in suggesting that use of an optoisolator may reduce the component requirements, since LDRs can be selected to introduce enough lag that it mimics a well-smoothed rectifier circuit, at least for the rise times needed.

[jmasciswannabe]

I built the slow gear off of zero the hero's site. he has some component changes and a smaller layout. I combined this circuit with a rebote 2 circuit so i could try to get a reverse delayesque type of sound. Boxed it up in a hammond box and voila! Good times!

[Paul Marossy]

I built the slow gear off of zero the hero's site.

So did I. I tried and tried to get mine to work, and it never did. What FET did you use?!

[dr]

.....I wish I could get a clear schematic for the EH Attack Decay-I played through one of those a long time ago;man, that thing sounded much better than the Slow Gear.....now I'm messing with the Dano Reverse Delay....looks like it has a PT2395 in it.....

[RickL]

Since this has drifted a bit I'll contribute again. For my money the best tracking of the attack delay units I've tried is the old Morley Pick Percussion pedal (big chrome beast with an attached metal pick). It tracks absolutely flawlessly no matter how fast you pick since it always knows when a new note or chord has started. The pedal also lets you control the attack time while you're playing. It's kind of nice to have a fairly short attack time on single notes but a longer attack on chords or short attack on short notes and longer on held notes.

It would be nice to have this feature on the Slow Gear (the metal pick). I experimented a bit when I got my first Slow Gear by running a wire with the hot signal to a metal pick which shorted the signal to ground every time the pick touched the strings. It didn't work too bad but I had to insulate the pick where my fingers touched it to avoid buzzing (the Morley pick isn't insulated). I wonder if a resistor or capacitor in series with the pick might help or experimenting with where the hot signal is tapped. Any suggestions Mark before I go in blind?

[jmasciswannabe]

paul - i am pretty sure i used the 2sk30a....it was a real adventure to get both the slow gear and the rebote 2 in one box...i dont want to open it! and speaking of sites, I love your's too man! I was sad to read that you were going to concentrate more on playing (though that's totally understandable!!)

[Zero the hero]

Congrats Rick!
The layout in my site is smaller cause i removed the bypass circuitry. Also, some component values changed, nothing dramatic, though.
I used both 2SK30A and BC264 by tweaking some components.
jmasciswannabe, thanks for having built it from my site, that's another build report and feedback I can trust!

[jmasciswannabe]

ya man, its a great build....I am trying to get around to that ring modulator, too! I feel sorry for those poor oranges...

Take Care!

[Paul Marossy]

Thanks jmasciswannabe. I guess I am going to have to get a 2SK30A. I've tried a ton of other FETs, and I couldn't get any of them to work. I suspect that I may have a bad cap or something. I'm going to pull this one out of my pile of failed circuits sometime and see if I can get it to actually work.  

[Mark Hammer]

If one has a bit of cash to spend, and is not averse to digital, the Line 6 Echo Park delay pedal does both types of slow attack effects.  One of the patches/programs called "Swell" has a slow volume increase on the delay portion.  If you pan the pedal so that it is ONLY wet signal, and set it for the shortest possible delay, and no regen, you can use it like a Slow Gear, albeit with a slight lag in the note, which occurs normally with a slow attack unit anyways.

The same unit also does true reverse.  Here, no artificial envelope is imposed on the notes.  Rather, you get a very slow attack from those notes held a little longer, and then played back in reverse.  With the other approach, the notes all have the same attack time, regardless of what you played, and come out in the same order they were fed in.

Neither of these is inherently better than the other, and both have their limitations as far as incorporating them into your planning and playing.  Nice to be able to choose betwen them in one box.

Rick,

If I could make a suggestion, it would be to have some means to not only fade in the volume, but also have a 1-pole lowpass that "opened up" as the attack swelled.  Not exactly sure how that could be easily implemented in the SG-1.  Chances are, not bloody likely, and certainly not with the existing layout.

To some extent, the inefficiency of human ears to high end at lower amplitudes mimics part of what a VCLPF would do in this instance.  I'm just not sure how much, though. A better analog simulation of reverse-tape sounds ought to be achievable if the note gets brighter as it swells.  Since SG-type units are working with a note in real time, the problem then becomes one of artificially creating brightness in the note/chord as the harmonics in the one you actually plucked die out.  My guess is that this would necessitate some sort of voltage-controlled distortion that would crank up the overdrive as the plucked note died out, and mixed in some of the upper mids and treble with the "reversed" note, to mimic something that ends with a crisp tone.  Obviously, this is a whole lot more complicated.   :cry:  )

(NOTE: For novice onlookers/lurkers, typically a plucked note has the most harmonic content immediately after it is plucked, with the harmonics disappearing quickly thereafter.  Making it sound more "backwards" means reversing that sequence.)

[Baran Ismen]

I used the layout at GGG which works fine except the outlines are reversed for all the transistors. Just point them the opposite way and it will work. It fired up perfectly from the start, I didn't even have to fiddle with the trim pot much. Centred is just about right for it and you don't have to be too fussy.

Both controls work perfectly but I seem to remember more fade in time with my original one. I'll dig it out sometime and compare the two, I'm probably remembering wrong. It tracks quite well but it wants a little silence between notes. Without the silence it won't trigger reliably on the next note (no fade in).

The flip flop bypass works perfectly, but as the build notes say it's the old style where the LED only flashes when you hit the switch. It doesn't stay on to indicate status.

I still think the PAiA Gator is every bit as good but it's nice to have a working layout for the Slow Gear if that's the one you absolutely must have.

You mean this project all transistor are flipped?

http://generalguitargadgets.com/wp-content/uploads/ggg_sgo_sc.pdf

[ElectricDruid]

You mean this project all transistor are flipped?

http://generalguitargadgets.com/wp-content/uploads/ggg_sgo_sc.pdf

Ermm...Baran? That was posted in 2005!

They talk about the flip-flop bypass, which that current GGG project doesn't include, so I doubt it's the same as they used back then.

[Baran Ismen]

You mean this project all transistor are flipped?

http://generalguitargadgets.com/wp-content/uploads/ggg_sgo_sc.pdf

Ermm...Baran? That was posted in 2005!

They talk about the flip-flop bypass, which that current GGG project doesn't include, so I doubt it's the same as they used back then.

Now that's a dead horse yeah, didn't notice that its that old!

My SG-1 doesn't seem to work as it should actually -swell effect doesn't rise from zero, instead bleeds a small amount of volume on picking and rises- I was checking solutions for that. I think it has to do with the trim pot, even tho I set it many times and used a multi-turn one for better sensitivity. I'll go over it again