Author Topic: Slow gear swell effect miserable build  (Read 2457 times)

Esppse

Slow gear swell effect miserable build
« on: October 23, 2018, 01:36:12 PM »
Hey,

For the last 2 days I've been trying to build a swell effect. The first day, I attempted the Boss Slow gear here.

http://www.sabrotone.com/wp-content/uploads/2014/02/SlowGear.gif

I only get sound when I remove the 2SK30A, but no swelling. With the transistor in, there is very low sound. The only part I substitute was is used 2 0.22 elec caps in parallel to make a 0.44 cap, since I did not have a 0.47uf needed at C6.

Today, I built the Paia gator but have some problems.

https://2.bp.blogspot.com/-KNenj2lmCIA/WBMK1V4urGI/AAAAAAAABC8/zhXCHa7ZyesKDBf6LXzaXIhZrUG4PbRNgCLcB/s1600/Paia%2BGator%2B%2528True%2529.png

The gate shuts off too soon, so the high notes have zero sustain, or very short. I put an LPB in front to try to keep the gate open, but that severely distorts the circuit. Is there anything I can do to get this running right?

Thanks

Mark Hammer

Re: Slow gear swell effect miserable build
« Reply #1 on: October 23, 2018, 02:30:30 PM »
I made my Gator using the PAiA layout and a 3080.  Works just fine.  I imagine the blogspot version, using a 13700 could also work fine...but I hate veroboard.  YMMV but I find it far too easy to make mistakes once you go past 8-10 components.

Swell pedals, in general are finicky, and demand compromise in one's playing, since they rely on level-based triggering. (i.e., no subtle picking allowed)

My own preferred swell effect is to set my Line 6 Echo Park to the "Swell" mode, set the delay time to min, no repeats, and turn the mix to all wet.  You get all the benefits of digital triggering and envelope shaping.  Behringer makes an inexpensive clone of the Echo Park.

Paul Marossy

Re: Slow gear swell effect miserable build
« Reply #2 on: October 23, 2018, 02:40:50 PM »
Swell pedals, in general are finicky, and demand compromise in one's playing, since they rely on level-based triggering. (i.e., no subtle picking allowed)

Yes, you definitely have to play a specific way to effectively use a Slow Gear. And the circuit is highly dependent on the FET's characteristics, which is a pain because FETs are highly variable by nature. I would try a few of the same kind, one might make it work fine and others won't, as much.

Esppse

Re: Slow gear swell effect miserable build
« Reply #3 on: October 23, 2018, 04:09:51 PM »
Ahh, yeah I'm willing to adjust my playing for those pedals. It's just that I was hoping to build an analog one, since I have digital multi fx, I'd like an analog variant of the effect.

Is the Gator supposed to distort when played polyphonic? Whenever I hit a chord, even lightly, the circuit starts to breakup, it only stays clean when monophonic, since I believe it's less signal hitting the front.

As for the Slow gear, I've just about given up. I read the comments below, a bunch of people are having problems with that, though it says it's verified. Anyone have success with these 2 Vero layouts?

Paul Marossy

Re: Slow gear swell effect miserable build
« Reply #4 on: October 23, 2018, 05:35:06 PM »
As for the Slow gear, I've just about given up. I read the comments below, a bunch of people are having problems with that, though it says it's verified. Anyone have success with these 2 Vero layouts?

I built mine using the PCB that I got from there (the Topopiccione site) like 10-12 years ago now.

Mark Hammer

Re: Slow gear swell effect miserable build
« Reply #5 on: October 23, 2018, 05:37:46 PM »
Ahh, yeah I'm willing to adjust my playing for those pedals. It's just that I was hoping to build an analog one, since I have digital multi fx, I'd like an analog variant of the effect.

Is the Gator supposed to distort when played polyphonic? Whenever I hit a chord, even lightly, the circuit starts to breakup, it only stays clean when monophonic, since I believe it's less signal hitting the front.

As for the Slow gear, I've just about given up. I read the comments below, a bunch of people are having problems with that, though it says it's verified. Anyone have success with these 2 Vero layouts?
I'd expect my 3080-based unit to do so, more than a 13700-based circuit, since the 3080 doesn't handle input signals >100mv very well/cleanly.  Normally, such circuits would attenuate the input and then boost the output, in order to maintain effect/bypass volume balance.

Paul's advice to install a socket for the FET and try out different ones should be taken seriously.  Just keep in mind that sometimes the same FET number can have different pinouts when made by a different manufacturer.  So ALWAYS verify the pinout via the relevant datasheet.
« Last Edit: October 23, 2018, 05:39:22 PM by Mark Hammer »

Esppse

Re: Slow gear swell effect miserable build
« Reply #6 on: October 23, 2018, 05:55:14 PM »
I tried a bunch of K30a and even a 2n5457 and twisted the legs, the slow gear is a lost cause.

The gator, I swapped the 308 with a TL061, still distorts with chords. No idea why it's clipping. I'm pretty lost on these builds.

Slowpoke101

Re: Slow gear swell effect miserable build
« Reply #7 on: October 23, 2018, 07:49:43 PM »
Slow Gear can be a real pain to get to go correctly. I have built several over the years including the Sabrotone one that you are playing with. It does work and I never found any errors with the layout.

The FET is the key to the effect. FETs are never identical and can vary greatly with their specs. Now you have tried a few different FETs and still no joy. With the FET installed the effect is muted (FET is on) and with the FET out of circuit the effect is fully unmuted. That is good as half the circuit is working and only the envelope follow needs attention.

Put a 2SK30A back in the circuit. Connect up your guitar and amp. Power up the effect (give it at least 5 seconds to get its act together). Turn sensitivity to midrange and measure the voltage across C6 without a signal being applied (don't play the guitar). Make a note of that voltage and now strike a string on the guitar - does the C6 voltage vary? If it does - good, if it doesn't go and look for construction errors around IC1, T4 - T6 areas.

What to do if the voltage on C6 does vary but the effect is still muted? This is now where things get difficult. Vary the trimpot from one extreme to the other to see if it can unmute the effect. Try increasing the value of R7 from 47K to 56K and/or change the 5V6 zener to a 6V2 zener. See what happens and let us know.

I haven't played with the Gator circuit yet but it seems that a construction error (or failed component) would be the most likely problem. Any chance of uploading some detailed pictures of your board (both sides) so we can try to see if there are any problems?



..

Mark Hammer

Re: Slow gear swell effect miserable build
« Reply #8 on: October 23, 2018, 08:09:21 PM »
I tried a bunch of K30a and even a 2n5457 and twisted the legs, the slow gear is a lost cause.

The gator, I swapped the 308 with a TL061, still distorts with chords. No idea why it's clipping. I'm pretty lost on these builds.
The LM308 is not the issue.  It's the CA3080 that distorts easily.

Elijah-Baley

Re: Slow gear swell effect miserable build
« Reply #9 on: October 24, 2018, 04:44:50 AM »
I'm stuck from months with my Sabrotone Slow Gear. I say everything is ok, transistor orientation, I replaced transistor and some caps... even the voltage, but I got just clean sound with any swell or mute. :-[
«There is something even higher than the justice which you have been filled with. There is a human impulse known as mercy, a human act known as forgiveness.»
Elijah Baley in Isaac Asimov's The Cave Of Steel

lars-musik

Re: Slow gear swell effect miserable build
« Reply #10 on: October 24, 2018, 06:24:19 AM »
I need to comment here firstly so the topic comes up in my "new replies" list and secondly because I have been struggeling with these two swell effects (Gator and Slow Gear) on and off for years now! Really a pain in the neck. I once produced a Slow Gear with a minor success (did swell but with a too short attack for my gusto) and have several Gator attemps in my “that-wasn’t it”-drawer. With and without different boosters attached in front of them.

I am sure, you worked through these:
https://www.diystompboxes.com/smfforum/index.php?topic=67428.0

https://www.diystompboxes.com/smfforum/index.php?topic=72027.0


But maybe you'll also find useful information in this zip file. I just quickly packed some Gator related internet finds from back in the day into it.
https://www.dropbox.com/s/btzkfhoexeidank/Gator%20Sammlung.zip?dl=0

The gaussmarkov project that is offline now is also in there as well as some comments from the helpful people that already chimed in here.


To make a lomg story short: I an VERY happy with the EHX Mel9 now for everything that is backward guitar related as it features an attack knob that really works.


PRR

Re: Slow gear swell effect miserable build
« Reply #11 on: October 24, 2018, 05:42:27 PM »
>>  supposed to distort when played polyphonic?
> I'd expect my 3080-based unit to do so, more than a 13700-based circuit, since the 3080 doesn't handle input signals >100mv very well/cleanly.


Often be no difference, '3080 or '13700. They use the same input stage design, the input curvature hewing to basic theory of semiconductor junctions. Yes, the '13700 gang included "linearization diodes", but hardly anybody uses them--- THD is lower to a point and then breaks-up fast and hard. The soft curve without diodes is less annoying for uncontrolled inputs (guitars, as compared to oscillators).
http://www.idea2ic.com/LM13700.html

While that essay says "used the 3080 exactly", modern datasheets show Darlingtons on the PNP current mirrors. Because old-process integrated PNPs were sad things, I suspect the 3080 did this but was omitted in the simple schematic as unimportant detail.
  • SUPPORTER

Esppse

Re: Slow gear swell effect miserable build
« Reply #12 on: October 25, 2018, 11:32:33 AM »
Here are pictures of my first unsuccessful swell, the sabrotone Slow Gear layout.

https://ibb.co/cSRroA
https://ibb.co/h0oRMV
https://ibb.co/jwcWoA
https://ibb.co/mY7aFq
https://ibb.co/hdR2vq
https://ibb.co/nDOFFq
https://ibb.co/bsDt1V
https://ibb.co/gvg2vq

I made one error with a trace cut to the right, but rectified it, but still no sound.

Differences: Trim Pot for sensitivity, 2 0.22uf electric in parallel, since I had no 0.47 elec. (C6)


blackieNYC

Re: Slow gear swell effect miserable build
« Reply #13 on: October 25, 2018, 12:05:44 PM »
Not much help here, but I have an old slow gear that I built from the BYOC kit, and a Gator I built from scratch via guassmarkov. Both are working fine. The Gator is converted to a 13700.
The slow gear really only works with both pots set to about 10:30.   The settings and the playing style required were more particular than I would have imagined. You can find the slow gear schematic that I used if you download the BYOC Lazy Sprocket instructions. No FET measuement was required.
http://29hourmusicpeople.bandcamp.com/
Tapflo filter, Gator, Magnus Modulus +,Meathead, 4049er,Great Destroyer,Scrambler+, para EQ, Azabache, two-loop mix/blend, Slow Gear, Phase Royal, Escobedo PWM, Uglyface, Jawari,Corruptor,Tri-Vibe,Battery Warmers

Paul Marossy

Re: Slow gear swell effect miserable build
« Reply #14 on: October 25, 2018, 12:54:00 PM »
I've made two working Slow Gear clones... y'all must be doing something wrong.  :icon_lol:

Mark Hammer

Re: Slow gear swell effect miserable build
« Reply #15 on: October 25, 2018, 01:50:29 PM »
Behringer used to make a clone of the Slow Gear, though I'm not seeing it in their catalog on their site anymore.

Robbo29

Re: Slow gear swell effect miserable build
« Reply #16 on: January 26, 2021, 09:18:46 PM »
Slow Gear can be a real pain to get to go correctly. I have built several over the years including the Sabrotone one that you are playing with. It does work and I never found any errors with the layout.

The FET is the key to the effect. FETs are never identical and can vary greatly with their specs. Now you have tried a few different FETs and still no joy. With the FET installed the effect is muted (FET is on) and with the FET out of circuit the effect is fully unmuted. That is good as half the circuit is working and only the envelope follow needs attention.

Put a 2SK30A back in the circuit. Connect up your guitar and amp. Power up the effect (give it at least 5 seconds to get its act together). Turn sensitivity to midrange and measure the voltage across C6 without a signal being applied (don't play the guitar). Make a note of that voltage and now strike a string on the guitar - does the C6 voltage vary? If it does - good, if it doesn't go and look for construction errors around IC1, T4 - T6 areas.

What to do if the voltage on C6 does vary but the effect is still muted? This is now where things get difficult. Vary the trimpot from one extreme to the other to see if it can unmute the effect. Try increasing the value of R7 from 47K to 56K and/or change the 5V6 zener to a 6V2 zener. See what happens and let us know.

I haven't played with the Gator circuit yet but it seems that a construction error (or failed component) would be the most likely problem. Any chance of uploading some detailed pictures of your board (both sides) so we can try to see if there are any problems?

Looks like T4 is backwards checking out the photos unless using different transistor...

RickL

Re: Slow gear swell effect miserable build
« Reply #17 on: January 27, 2021, 02:18:44 PM »
If you don't mind trying something a little different, check out the old Morley SAB Sync Attack. You can find a schematic here: https://www.schematicsunlimited.com/m/morley. I've built it and it works.

It has the disadvantage of having to use the attached metal pick, but it triggers perfectly every time, works on single notes or chords, is completely indifferent to your picking strength and has an adjustable  attack time.

I think if you search the forum you'll find a build report by me, but IIRC it wasn't particularly sensitive to the LED/LDR combination used.