Hi everyone,
continuing with my recent obsession I spent most of my Saturday designing the simplest (within reason) and smallest true-lowpass envelope controlled filter I could think of. It uses a single NSL-32 vactrol to control a Sallen-Key lowpass. The other resistor of the Sallen-Key is contains a range pot. This pot sets the total range from wher to where the filter goes and also at what frequency the maximum Q occurs. Since only one resistor varies with the envelope, the Q factor changes along the sweep and reaches its highest value when both resistors are equal. The maximum Q of 21.7 can be shifted between 245 and 1468 Hz using the Range pot, providing some variability in the sound. The changing Q gives the effect a somewhat vocal timbre, especially at lower Range settings.
The rest is fairly standard as seen before in many other envelope filters. The Volume control is a set-and-forget trim pot since the other settings hardly affect the output volume. This is sort of the little brother to the Funkkontakt:
http://www.diystompboxes.com/smfforum/index.php?topic=118966.msg1109620#msg1109620
The schematic:
(https://s8.postimg.org/hrjqnqpw1/Quackmire.png) (https://postimg.org/image/hrjqnqpw1/)
The sound:
http://www.aronnelson.com/DIYFiles/up/Quackmire.mp3
I also drafted a 12x15 strip-board layout, which should just about fit into a 1590A enclosure. I will post this as soon as I have checked and verified it.
I called it The Quackmire because the objective to have a true resonant lowpass with only one control element that fits into a 1590A enclosure but is flexible enough to allow some individuality in setting the sounds proved to be quite the quagmire.
Mod suggestions:
For a less aggressive sound I suggest increasing C5 to 500pF or 1nF. For a more aggressive sound increase C4 to 1µF. The Range pot can be a linear type if you do not have a rev log, although rev log has a slightly better control characteristic in this position. The Range pot can be made a trim pot or fixed resistor (combined with R7) to further reduce complexity. Change the charge cap C10 for slower or faster attack and decay. Low values (1µF-2.2µF) will giver a more synth-like sound. Q1 can probably be any high-gain NPN BJT, like 2N5088 or 2N5089, although I did not check. Just try whatever you have, this is not a demanding role for any BJT.
As always: Let me know if you find errors or bad design choices or if you have suggestions for improvements or questions.
Have fun,
Andy
Very nice, Andy - quite a bit of quack for a simple one, too!! Thanks for posting it :)
That sounds super. Can you explain a bit the necessity of D1 and D3?
Sweet. Nice sound . Is the bass active or passive?
Nice low parts count too.
You might be able to save a part if you if you make R6 a pot.
What size is D3 please.
Great job.
Hey guys, thanks for the kind words!
QuoteCan you explain a bit the necessity of D1 and D3?
D1 and D3 are used for biasing:
D1 together with R2 and R3 tries to keep the Base of Q1 at one LED drop above (supply voltage - one LED drop)/2, i.e. at 5.2V (for a 9V supply, assuming the LED drops 1.4 V). I did that because the Emitter of Q1 is DC coupled to the input of the filter op-amp IC1b. Since we want to keep the op-amp around 1/2 supply voltage and the Emitter of Q1 sits 1 Si-diode drop (0.7 V) below the Base the LED provides just the right shift.
D3 is a bit simpler: It biases the envelope follower op-amp IC1a to 1 LED drop above ground, together with R10. This way the envelope starts just below the conducting threshold of the yellow diode in LDR1, for best sensitivity. Props for this idea go to Jack Orman, who used it in his Dr. Quack for the same reason. You may find that the envelope section of The Quackmire bears an uncanny resemblance to that of the Dr. Quack / Doctor Q.
QuoteIs the bass active or passive?
Cort B4 fretless with stock pickups (Bartolini license MK1) but with the original active preamp yanked out. Best modification ever. Sounded like utter crap with the preamp and now sounds absolutely fantastic purely passive. I only used the neck pickup for this (as I mostly do).
QuoteYou might be able to save a part if you if you make R6 a pot.
Which one?
QuoteWhat size is D3 please.
All LED's are 3mm. But that should not matter (much) to their functionality, should it?
Cheers,
Andy
Giggity!
(http://images.uncyclomedia.co/uncyclopedia/en/d/d0/Edmund_grindal.png)
Quote from: Fancy Lime on November 11, 2017, 06:43:26 PM
D1 and D3 are used for biasing:
D1 together with R2 and R3 tries to keep the Base of Q1 at one LED drop above (supply voltage - one LED drop)/2, i.e. at 5.2V (for a 9V supply, assuming the LED drops 1.4 V). I did that because the Emitter of Q1 is DC coupled to the input of the filter op-amp IC1b. Since we want to keep the op-amp around 1/2 supply voltage and the Emitter of Q1 sits 1 Si-diode drop (0.7 V) below the Base the LED provides just the right shift.
D3 is a bit simpler: It biases the envelope follower op-amp IC1a to 1 LED drop above ground, together with R10. This way the envelope starts just below the conducting threshold of the yellow diode in LDR1, for best sensitivity. Props for this idea go to Jack Orman, who used it in his Dr. Quack for the same reason. You may find that the envelope section of The Quackmire bears an uncanny resemblance to that of the Dr. Quack / Doctor Q.
Awesome. Thanks for taking the time to explain!
Same bass as I have.
I also note theres no decoupling cap between the input buffer and the filter.
I guess theres no need.
I know all of jack squat about vactrols. I have one labeled VTL5C1, is this an equivalent?
How do you think this circuit would sound with guitar?
Quote from: Kipper4 on November 12, 2017, 03:39:10 AM
Same bass as I have.
I also note theres no decoupling cap between the input buffer and the filter.
I guess theres no need.
's'right. DC coupling the two stages saves some parts and for some reason seems to have more headroom and sound better than with separate biasing. It also means that Q1 works in a double role as an audio buffer as well as a bias buffer and therefore must itself be biased 1 Si-diode drop above V 1/2 (so that the Emitter is at V1/2), which is what D1 does.
Quote from: thermionix on November 12, 2017, 03:57:13 AM
I know all of jack squat about vactrols. I have one labeled VTL5C1, is this an equivalent?
How do you think this circuit would sound with guitar?
The filter is designed for the characteristics of the NSL-32's I have, which have an Off Resistance of >10MΩ and an On Resistance of 1kΩ. The VTL5C1 seems to go to even lower On Resistance, which means that the filter sweep will go higher. So, yeah, you can use it, it would actually be better than the NSL-32. You might want to adjust R6, R7, C4 and C5 to adjust the sound to the vactrol and your personal preference but I don't think it is necessary. Here is the datasheet:
http://logosfoundation.org/instrum_gwr/playerpiano/Optor_VTL5C1_87223.pdf
To calculate the response of the filter to component changes I like this tool:
http://sim.okawa-denshi.jp/en/OPseikiLowkeisan.htm
For guitar use it should be fine too. It may sound a tad aggressive as it is now because the pick attack frequencies are amplified a lot. Increasing C5 to 500p or 1n would make it a bit rounder and less peaky. Also I personally like fast attack and decay for bass but slower attack and decay for the typical funky rhythm guitar autowah sound. Try increasing the charge cap C10 from 10 to 22µF, I think that may sound better with guitar. You can socket this cap for extra flexibility.
Cheers,
Andy
I get "internal server error" when I try to download the circuit???
Sounds pretty good, especially while you keep riding the envelope. It's got a clean wide bandwidth sound.
I'd try to clean-up the sound right at the end of the tail of the envelope, it cuts off/out a little quick. (Maybe decrease R6 (1M)?)
Many moons ago I played around with envelope filters in the DSP domain. I started by writing a VST plug-in for the MXR envelope filter. What I found is second order filters for the envelope detection filter sounded better. (If there was a secret that would be it.) If you look at the MXR envelope filter it actually has a second order filter for the envelope. The vactrols kind of give you a second time constant by nature.
For the circuit,
- I'd put in a larger R3 and remove D1.
- Also D4 doesn't do anything. You normally put this diode in when there is a cap between the opamp and D4. This gives you a voltage doubler; IIRC the MXR has this.
Hi Rob,
thanks for the input!
Quote from: Rob Strand on November 12, 2017, 02:44:07 PM
Sounds pretty good, especially while you keep riding the envelope. It's got a clean wide bandwidth sound.
I'd try to clean-up the sound right at the end of the tail of the envelope, it cuts off/out a little quick. (Maybe decrease R6 (1M)?)
Do you mean that the release/decay is too fast? That is actually a feature, not a bug. I added R13 after originally leaving it out because I found the decay too long. Matter of taste. I like when I can return the filter to zero by quick muting and have to willfully stay on top of the envelope rather than the envelope making me cruise along the crest automatically. Increasing R13 to 100k or 330k will give longer decay times. For guitar use I would recommend longer decay times. One may even want to change the charge cap C10 to 22µF for guitar. Decreasing R6 would set the starting point of the filter higher. Also an option that probably makes more sense for guitar than for base. I should probably write a more extensive Mod Guide for this thing one of these days.
QuoteMany moons ago I played around with envelope filters in the DSP domain. I started by writing a VST plug-in for the MXR envelope filter. What I found is second order filters for the envelope detection filter sounded better. (If there was a secret that would be it.) If you look at the MXR envelope filter it actually has a second order filter for the envelope. The vactrols kind of give you a second time constant by nature.
By "second order filter for the envelope detection" I assume you mean double the R12 C10 arrangement? I did this sort of thing on OTA based envelope filters, where it does indeed help smooth out ripples in the envelope. I also tried it with vactrol based filters. However, I found that when using vactrols and relatively "large" charge caps (C10=10µF), I could not hear a difference so I left it out. But for faster control elements you are definitely right. The more flexible solution if you want a smooth sound even at very short attack and release times is to use a precision full wave rectifier with an over-sized de-glitching cap (which effectively works like the first pole of the seconfd order filter you mentioned) instead of a half wave rectifier.
QuoteFor the circuit,
- I'd put in a larger R3 and remove D1.
- Also D4 doesn't do anything. You normally put this diode in when there is a cap between the opamp and D4. This gives you a voltage doubler; IIRC the MXR has this.
The R2-D1-R3 biasing is a result of me being to lazy to get my multimeter out. But you are right of course, removing D1 and adjusting the R2/R3 ratio until the Emitter of Q1 is at V 1/2 works exactly the same with one less part.
And finally: Yepp, D4 is indeed pointless and shall be removed for the next version. Can't believe I missed that. Rookie mistake. Might be a good idea to reroute it to the op-amp feedback to keep reverse leakage from eating away charge on the negative swing, although the effect will probably be minimal. We'll see.
Thanks and cheers,
Andy
QuoteDo you mean that the release/decay is too fast?
No, it's not the general fast attack. That's fine.
QuoteI added R13 after originally leaving it out because I found the decay too long. Matter of taste. I like when I can return the filter to zero by quick muting and have to willfully stay on top of the envelope rather than the envelope making me cruise along the crest automatically.
Yep, I understand you here 100%. (I do the same thing.)
QuoteIncreasing R13 to 100k or 330k will give longer decay times.
Agreed, and it goes against what you want.
So the general fast decay isn't the issue. As you play, the envelope filter will shape the envelope/fiter, as normal. However when you let the note ring out (eg. on your sample at say 0:14, 0:32, 0:51) you get to hear the full sweep of the filter. The "issue" is when the filter gets near the end of its "trajectory". To me the rate at that point is a tad too fast (not bad). I think the reason is because R33 is connected to ground, this makes the discharge of the cap aim towards 0V. However, the circuit stops at 1.5 to 1.7 due to the the Vactrol LED. So the cap doesn't get a chance to discharge naturally to zero and the filter sweep just stops. The time slope of the cap voltage at 1.7V discharging to 0V is higher than a cap at 1.7V discharging to say 0.6V. If the ground side R13 (not the cap) is moved to D3 then the cap will discharge towards 1.7V and it will slow down the discharge; this will probably be too slow. Maybe 0.6V will help, basically a silicon diode connected like you have D3.
The other thing that's going on is as the vactrol gets near cut off the resistance goes up. Eventually it will rise to a point where the parallel resistance R6 will dominate and the filter cut-off will settle to it's lowest point. The presence of R6 also slows the filter sweep rate at the end of the sweep. So I was thinking as a quick hack you could see what decreasing R6 sounded like. It's not the same as playing with the discharge slope as changing R6 will raise the final cut-off frequency. Both aspects affect the final sound.
QuoteBy "second order filter for the envelope detection" I assume you mean double the R12 C10 arrangement? I did this sort of thing on OTA based envelope filters, where it does indeed help smooth out ripples in the envelope. I also tried it with vactrol based filters. However, I found that when using vactrols and relatively "large" charge caps (C10=10µF), I could not hear a difference so I left it out. But for faster control elements you are definitely right.
Yes, the vactols give the extra filtering for free. It's also hidden as it's part of the vactrols behaviour. When you take it away by using an OTA something is missing!
Hi Rob,
ah, now I see. You want to make it "land more gently". I'll try move the R13 bottom from ground to the R10-D3 junction and see what happens. It should as you say slow the draining shortly before touch down.
R6 is near the useful limit at 1M. Making it smaller means that the filter idles above the fundamental frequencies of the lower register on bass. Which also sounds good, but takes away some of the "flashy quack" so I decided to go with 1M. Changing R6 to a 1M or 2M5 pot would make an additional "floor" control very similar in effect (but very different in execution) to what I implemented in the Funkkontakt envelope filter.
Andy
QuoteYou want to make it "land more gently".
Yes, that's it.
QuoteR6 is near the useful limit at 1M. Making it smaller means that the filter idles above the fundamental frequencies of the lower register on bass. Which also sounds good, but takes away some of the "flashy quack" so I decided to go with 1M.
Yes it's a fine line playing with these things and you don't want to upset the goodness in what you already have.
Hi Rob,
I had a minute to try to get the gentler touch down. Adding a diode works but as it turns out, so does turning up the Sensitivity a smidge. Then I listened to the sound sample again (later realizing it should have done that earlier) at the points you mentioned (0:14, 0:32, 0:51) and realized that you probably thought that I let the notes ring out when in fact I muted them. When letting notes ring out the filter follows the envelope nicely to zero without any abrupt drop.
Once at it I also played with the charge cap C10 as Rich (Kipper4) suggested elsewhere. Turns out 1µ, 4µ7 and 22µ all provide very cool and quite different sounds. That in itself is not surprising but I was mildly surprised that they all sounded so good without any additional changes. Although the original goal was to keep it as simple as possible, I think an additional Mode switch between the 3 caps (synth, fast, slow) is warranted, considering the benefits. And it should still fit into a 1590A, although it's getting tight now.
Cheers,
Andy
Quote from: StephenGiles on November 12, 2017, 07:45:21 AM
I get "internal server error" when I try to download the circuit???
Downloaded OK today - how strange!!
Alrighty,
removed the unnecessary D4 and added a Mode switch, making it much more versatile (but you can just as well leave it as well as C10 and C12 out and only use your preferred value for C11). It is a bit of a challenge to fit it all in a 1590A enclosure with the extra switch but it is doable. I'll post pictures of my build one of these days, promise. I checked and double checked the layout and I am fairly certain it is correct now. As you can see, I am no da Vinci when it comes to layouts but I hope you can make sense of it. If not, feel free to ask and/or complain.
(https://s17.postimg.org/b6eie9jff/The_Quackmire1-1.png) (https://postimg.org/image/b6eie9jff/)
Please let me know if you find errors.
Giggity,
Andy
Quotehad a minute to try to get the gentler touch down. Adding a diode works but as it turns out, so does turning up the Sensitivity a smidge. Then I listened to the sound sample again (later realizing it should have done that earlier) at the points you mentioned (0:14, 0:32, 0:51) and realized that you probably thought that I let the notes ring out when in fact I muted them. When letting notes ring out the filter follows the envelope nicely to zero without any abrupt drop.
Interesting result.
What ever happened to this thing? No schematic link now...
(https://i.postimg.cc/QxPdWKLY/Quackmire.png)
That was quick! My sincerest thanks!
Do you happen to have the layout? I remember there was one on the original post.
I got the schematic from the OP (change .org to .cc), I don't see a layout or any mention of one.
Quote from: Marcos - Munky on December 21, 2018, 10:57:58 AM
Do you happen to have the layout? I remember there was one on the original post.
I've designed this one, but it's still untested.
https://docdro.id/IU4jLXx (https://docdro.id/IU4jLXx)
Fits 1590A.
Quote from: rankot on December 21, 2018, 05:41:34 PM
I've designed this one, but it's still untested.
https://docdro.id/IU4jLXx (https://docdro.id/IU4jLXx)
Fits 1590A.
Really nice layout there, what software do you use for those rad curvy traces?
If I can kick this cold I'll try and etch it out this weekend.
I use free a version of DipTrace, called PCB Creator. https://bayareacircuits.com/pcb-design-layout-software-for-custom-pcb/ (https://bayareacircuits.com/pcb-design-layout-software-for-custom-pcb/)
But be aware that this PCB is untested, please print on paper and check if it fits enclosure first! Also have in mind that power section is a little bit altered, I have added 11V 3W Zener diode for overvoltage and polarity protection, together with 50-100mA PTC. If you don't need this, you can simply omit Zener diode and short PTC, or, in case you can't find such a diode, use 1N4007 instead.
That's a nice layout!
Thanks!
(https://i.postimg.cc/26sd0MdS/Quackmire-PCB-by-Ranko-T.jpg)
Quote from: StephenGiles on November 13, 2017, 06:29:40 AM
Quote from: StephenGiles on November 12, 2017, 07:45:21 AM
I get "internal server error" when I try to download the circuit???
Downloaded OK today - how strange!!
no schematic link even visible, here
Quote from: pinkjimiphoton on January 02, 2019, 05:10:05 PM
no schematic link even visible, here
Quote the OP, rat f the postimg url from that, change .org to .cc
Quote from: thermionix on January 02, 2019, 05:34:25 PM
Quote the OP, rat f the postimg url from that, change .org to .cc
Nice!
I remember there was a layout, but it wasn't on the 1st post:
(https://s17.postimg.cc/b6eie9jff/The_Quackmire1-1.png) (https://postimg.cc/image/b6eie9jff/)
Hi there!
Great to see people still being interested in this little thing.
@rankot
Nice PCB layout indeed! Thanks!
I checked it by retracing the schematic from your PCB and arrived at (almost) the original schematic plus the switching and indicator LED incl. series resistors and a 10µF cap. I'm not sure what the 10µ cap does for the indicator. Save the LED from power supply surges upon power-up? Anyway, it can't hurt. Other than that, only the series diode and resistor in the power supply filter were changed from 1n5817 to BAT85 and 47R to 15R respectively. Neither of these changes should affect the sound or operation of the device, use what you have. The only slight "mistake" I found was that the contact pads on the diodes and polarized caps are a bit confusing. Diodes have a square pad on the minus side and round on the plus side in the layout. For electrolytic caps it is the other way round. I'm not sure if that is some sort of weird convention I am unaware of, may well be. Just be careful and double check the orientations of polar devices when building this. Also: be aware that this is a tight layout. You may need to get particularly small varieties for the large value film caps. Greenies or orange drops or similar will probably not fit, the boxed KEMET caps (the beige ones) should fit, I think. Someone will have to try, I suppose...
EDIT: The original schematic had a trimmer to set the output volume, Rankos PCB has set that fix to max with a 100k resistor, which is probably what 95% of the people want 95% of the time anyway. And one more thing: If you put a switch instead of the time cap C10 that lets you choose between different size caps (1µ, 2µ2, 4µ7, 10µ, 22µ all sound nicely different) you get a much more variable pedal but it will be extremely awkward to put that in a 1590A. The next best thing is to socket this cap and try which value you like best.
Cheers and a happy 2019 to all,
Andy
I'll try this pretty soon, expecting PCB to arrive :)
LED and electrolytic cap pads are confusing, but that's how they are in this application I use.
10uF cap on LED is to avoid popping.
Once I verify this layout, I will release PDF with PCB.
"10uF cap on LED is to avoid popping."
What. Wait. Where.
On the bypass? Ala dead astronaught ?
http://www.muzique.com/lab/led.htm (http://www.muzique.com/lab/led.htm)
I use the second circuit from this page.
Gottya. I was worried you were hanging it on the vactrol led. Phew.
I have used a // small cap before now with the vactrol led. Can't remember why. Something like 100-500pf
Parallel with vactrol LED? Maybe to reduce some flutter?
My memory aint what it used to be. Maybe...... :-\
Never mind, I will try it, once I get PCB.
Built it, works like a charm! Unfortunately, didn't see v1.1 schematics in time, so this is without the switch (although I don't know where'd I put it anyway) :D
(https://i.postimg.cc/CB48x1rD/IMG-20190112-151541376.jpg) (https://postimg.cc/CB48x1rD)
(https://i.postimg.cc/ZvKdBSXQ/IMG-20190112-151605156.jpg) (https://postimg.cc/ZvKdBSXQ)
No gut shots, I forgot to do it when it was naked, now I'm too lazy to pull everything out.
Just to mention, I've rolled my own vactrol (for the first time), used 3mm orange LED with GL5516 photoresistor (bought at Aliexpress). Works fine.
And for those willing to build this baby, here's the PCB:
(https://i.postimg.cc/W15K8StX/Quackmire-PCB.jpg)
I even found some place to put a switch (see faint rectangle below RANGE pot), in that case don't put 10u tantalum on PCB, use 1u there and solder positive leads of 4u7 and 22u to switch poles, connect switch middle to point A and negative leads of those two caps to point B.
Unmarked part above BAT85 is 100mA PTC; above that is 3W 11V Zener diode serving as both overvoltage and reverse voltage protection, if you don't need overvoltage, just put 1n4007 there, or you can omit it completely if you don't need protection (and you can simply short PTC if you don't need that, too).
I suggest you to drill a hole for adjusting volume trim, so you can do it later w/o need to remove PCB from enclosure. In that case, use Piher or similar 5mm trim with top/bottom adjustment screw.
(https://i.postimg.cc/HLJvTy92/IMG-20190112-175551691.jpg)
OK, here are the guts ;D
Hello,
I've got an LM358 IC in stock, would it be a good replacement for the NE5533?
Pin layout seems to be the same.
I'm a complete noob in electronics so, I just ask.
Better use TL072.
https://www.electronicspoint.com/forums/threads/lm358-not-for-audio.243233/ (https://www.electronicspoint.com/forums/threads/lm358-not-for-audio.243233/)
hey ranko,
if ya get any boards burned for this, please let me know, i'd love to try one bro.
thanks!!
@rankot
This is officially awesome! I'll try and back-trace the new schematic as soon as I can. Great that you even found a place for the switch! Gotta get me some new etching solution and make me one myself. My own stripboard build has a bad contact somewhere, which I have not been able to locate yet. So I might as well just do it right.
@sevrien
QuoteI'm a complete noob in electronics so, I just ask.
Wlecone to the game! The LM358 should work (probably). Just build the thing with a socket for the opamp (which is always a good idea) and stick the LM358 in and see if it works. It can't do any harm. Worst case: it does not sound good and you'll have to spent 30 cents on a different opamp. I used the NE5532 in the design because it is a very popular opamp that many diyers keep around. It is cheap, low noise and is good at delivering a decent current into relatively low resistance at its output. If you want to intensify your diying, I would suggest to order some NE5532 next time you order something else anyway. The NE5532A variant has a certified maximum noise, the NE5532 (without the A) does not, but in my experience the difference is negligible in most guitar effects (there may be another letter following, like NE5532P or NE5532AP, where the P denotes the packaging. You normally want P for through hole Dual Inline Package). The TL072 suggested by Ranko is "the other" very popular opamp. It has a JFET input stage and therefore a higher input impedance, which is sometimes important (though not for the Quackmire). So get you some of those as well, they are also cheap. I would advice against the TL072 in the Quackmire, however, because in some settings the opamp may go into clipping and the clipping of the TL072 sounds quite awful (to me) compared to the NE5532. The (now discontinued) JRC4558 would probably also work and is also widely used in diy projects. But really almost any dual opamp can be used in the Quackmire and most should work just fine (there are hundreds of opamps on the market). The ones that I keep around besides the NE5532 and TL072 are NJM2068 (very low noise and relatively modest current draw but less output drive capability than the others), NJM4556 (or JRC4556, same thing different name, bit more noisy, very high output drive capability, good for headphone amps and line drivers and such) and TLC2262 (more expensive, rail-to-rail mosfet opamp that sounds very good when pushed into overdrive).
Cheers,
Andy
To be honest, I used OP275 for Quackmire. Also tried NE5532, but there was no audible difference (not for me). :)
It would be much easier to find a place for a switch if I had that in mind before drilling pot holes, now it is a real challenge! Wish me luck ;)
Quote from: Fancy Lime on January 13, 2019, 04:35:41 PM
I'll try and back-trace the new schematic as soon as I can.
Is this one?
(https://i.postimg.cc/34FTvT52/The-Quackmire1-1.png) (https://postimg.cc/34FTvT52)
weird, can see the graphic here, but it won't actually load so i can snag it!!
For who might be interested
(https://i.imgur.com/rDRHxDZ.png)
Quote from: Marcos - Munky on January 14, 2019, 02:35:52 PM
Quote from: Fancy Lime on January 13, 2019, 04:35:41 PM
I'll try and back-trace the new schematic as soon as I can.
Is this one?
(https://i.postimg.cc/34FTvT52/The-Quackmire1-1.png) (https://postimg.cc/34FTvT52)
Yes, that's the current version and should be the one corresponding to Rankos laste PCB layout, if I understood him correctly.
@Jimi
Maybe it works as a link:
https://postimg.cc/34FTvT52
@sevrien
Ooh, nice, a proto-board layout! I'll try and verify that one as well by back-tracing. Sorry if it may take a while, since I am extremely busy at the moment and hardly have the time to even glance at the forum once or twice a day.
Cheers,
Andy
I actually left one 1N4148 going from IC1a output to ground. Is it needed or not?
i can see the thumbnail here, it links to a page, but the image won't load, if i try to reload it or anything i just get a 404
changing ".org" to ".cc" doesn't work, comes up with an invalid certificate warning.
if you advance, tries to run an executable in the browser window.
be careful with that link. if anyone else has it, and wants to reattach it, i'd be grateful. thanks!
Quote from: rankot on January 14, 2019, 05:39:36 PM
I actually left one 1N4148 going from IC1a output to ground. Is it needed or not?
Nope, that one is not needed, it has no effect. Was a design error in the first version.
@Jimi
Freshly uploaded, see if this works:
(https://i.postimg.cc/GBM8dF1w/The-Quackmire1-1.png) (https://postimg.cc/GBM8dF1w)
Andy
thanks andy and everyone else,
i'm stumped. i can get the thumbnail, but the page won't display the pic ;)
check that... its freekin firefox or something.
got it fine with IE just now.
thanks much!!!
looks like its gonna be fun
andy, you rule dude!! :)
Update,
found a fault in the power supply, corrected in this version
(https://i.imgur.com/OvhcfYm.png)
Finally managed to find a place for capacitor switch - used tantalum 1u, 4u7, 10 and 22u. Sounds cool.
Now I have a little problem with contact at input jack, when I push it to the end it loose contact, but I'm sure I'll fix it.
(https://i.postimg.cc/rpx5JMqM/Quackmire-DSC-0002.jpg)
Quote from: sevrien on January 15, 2019, 08:24:38 AM
Update,
found a fault in the power supply, corrected in this version
(https://i.imgur.com/OvhcfYm.png)
Is someone able to verify this layout on sight?
I know I drew it myself, but, its not working and I don't seem to track down the problem.
I do get a very quiet signal but it sounds distorted and not quacky at all.
I'm using a 2N5088 for Q1,
the LED between pin 3 and 4 of the IC lights up bright, the other faintly and does not flicker when playing.
I assumed there was a short circuit somewhere but I can't find one.
Thanks in advance
Nevermind previous post,
here's a working layout.
Had some serious buzz from the range pot, after grounding the housing it was gone.
Still some 50hz hum in the circuit, not sure where it comes from.
(https://i.imgur.com/CsbxCaB.png)
Anyone made the schematic with the switch? If not, I can make it, but just wanted to save myself some work...
Quote from: jfrabat on September 27, 2019, 08:43:27 PM
Anyone made the schematic with the switch? If not, I can make it, but just wanted to save myself some work...
Here you go:
https://postimg.cc/GBM8dF1w
Cheers,
Andy
Started building one of these for my son's base guitar First time using veroboard for me, and it has been an experience... Anyway, got the board done, but still need to attach all the off board components (pots, switch, jacks, stomp switch, LED, and caps for switch). Hopefully, I did not screw up my soldering and the thing will work!
Hey, guys. Need some help here... Got bored during the quarantine, and decided to have a go at this one (had it pending for my son for some time!). Anyway, I used what I had on hand, so some components are a bit oversized! :D
Anyway, I wired it all up (outside of the box) and I am getting no sound. Now, my intention was to give you some voltages, but, unfortunately, my MM died on me, and Amazon has yet to ship the new one! Not to mention for another week or two to get to Panama, and then maybe see if the forwarder is still delivering goods (by law, we cannot leave the house save for 3 hours a day, 2 days a week!).
Anyway, I thought I would compensate that with lots of pics. Please bear in mind that I am dyslexic, so it is very possible I have switched something other than what I caught during my checks.
I used this as the base:
(https://i.postimg.cc/xCWTBf6p/The-Quackmire1-1.png)
Overview
(https://i.postimg.cc/Bv8LT3W6/20200413_154936.jpg)
This is one correction I had to make, and I was out of holes, so I soldered to the cap leg...
(https://i.postimg.cc/t4vnnTMw/20200413-154955.jpg)
(https://i.postimg.cc/cLL8JYXf/20200413_155013.jpg)
(https://i.postimg.cc/7hr2PWWL/20200413_155029.jpg)
Not exactly ideal size for a pedal, but it what I had...
(https://i.postimg.cc/pTFjHHk7/20200413_155122.jpg)
https://i.postimg.cc/dtvyzgCH/20200413_155139.jpg
Now, the switch I had to go from the schematic; did I get this right?
(https://i.postimg.cc/7Lczd610/20200413_155156.jpg)
(https://i.postimg.cc/v85n2G4x/20200413_155211.jpg)
(https://i.postimg.cc/GtPs4xWx/20200413_155246.jpg)
And, of course, the ugly side of things...
(https://i.postimg.cc/VLRC14BY/20200413_155307.jpg)
So, do you see anything out of place or a wrong value?+
The only thing I see, is that you have installed C11 (1u) twice, once on the board and once at the switch. It is only supposed to be on the board. Only C10 and C12 are supposed t bet on the switch. However, that cannot be the reason for no sound at all. When you say "no sound", do you mean none at all or is there at least noise or something? You can try touching the terminals of the components with a wire or nail or whatever (anything that is conductive and connected to you hand) while the circuit is connected to an amplifier (which is set not too loud). Start from the very end and work your way backward. When touching a trace, there should be a loud BZZZZZZ. As you work your way back from the output along the signal path, at what point does that noise disappear? It's the poor mans audio probe! If you have an audio probe, you can use that as well, of course.
The problem I always have with strip board, is that it is pretty difficult to diagnose problems. There are often shorts or cold connections that are difficult to see but looking at all the solder work with a magnifying glass is usually my first step.
Hope that helps a bit,
Andy
The first thing I always do, when something on vero doesn't work, is to run a stanley knife between the copper traces. Those solder bridges can be almost invisible. That has solved a fair number of problems with non-working builds.
There's a couple of places on the photo of the copper side that looks suspicious.
Before the MM died, I did a connectivity test, so there are no unwanted bridges in the soldering (at least none that I detected at that time). I will go through it with an scratch owl and make sure, but I do not think that is the issue... I will try the audio probe and see what that turns up.
My new MM arrived today!!! YAY!!!
SO, I started checking for bridges (did find two; not really bridges in the solder sense, but actually, when I drilled the breaks, I left a tiny little sliver of copper in 2 places that were providing continuity where there should not have been). Then I found two wiring errors:
1. A jumper was going to the wrong line of the board
2. The output was soldered at line 13 instead of 14 (I believe the is a possibility that this could cause no sound to come out of the output; but I will blame this on the design, as this type of error shoul dhave been foreseen and allowed for!).
Connected the bass again, but no sound still! I really thought I had the problem found when I found the above, but, the problem persists... So, here are a few voltages for your guys:
Input Voltage: 9.52V
Input after D2: 9.27V
Q1:
C: 8.90V
B: 4.99V
E: 4.48V
IC1:
1: 1.319V
2: 1.599V
3: 1.141V
4: 0V
5: 2~2.4V
6: 3~3.3V
7: 2.5~2.8V
8: 8.9V
Anything else I should measure?
Looks like there is something wrong between the emitter of Q1 and pin 5 of the IC. These should be much closer together. Can you take the voltages at all the junctions in between? So after R6, after the range pot, after R7. Does any of this change when the range pot is at maximum vs range at minimum?
Also: With no input signal, the voltage should not vary on pins 5, 6 and 7.
One possible explanation is that the filter opamp half (input at pin 5) sucks too much current. Opamps are somewhat variable and what worked with my NE5532 may not work as well with yours. Although the way the circuit is designed, this should lead to a little unwanted distortion at worst but not to no signal.
At the moment my money is on a bad connection between E of Q1 and pin 5.
Oh and I also just now realized that the Sensitivity pot is connected wrong in both the schematic and the layout. Lug 2 should be tied together with lug 3 instead of with 1. That will only change the direction and characteristic of the Sens control, though.
Hope that helps. Let me know how it goes,
Andy
EDIT: deleting post (duplicated)
Quote from: Fancy Lime on April 21, 2020, 03:03:09 AM
Looks like there is something wrong between the emitter of Q1 and pin 5 of the IC. These should be much closer together. Can you take the voltages at all the junctions in between? So after R6, after the range pot, after R7. Does any of this change when the range pot is at maximum vs range at minimum?
Let me re-measure, just to be sure on the readings. The great advantage of home office is that the pedal is IN the office today! At least ONE good thing from this Pandemic! Here are today's readings (making sure not to touch the board and introduce static into the system!):
Input Voltage: 9.52V
Input after D2: 9.26V
Q1:
C: 8.90V
B: 4.99V
E: 4.48V
R6:
From Q1e: 4.48V
To Range pot: 3.84V
Range Pot
Pin 1+2: 3.83V
Pin 3: 3.33~3.84V (depending on pot position)
R7:
From Range pot: 3.33~3.83V (depending on Range pot position)
To R8: 3.32~3.82V (depending on Range pot position)
R8:
From R7: 3.32~3.82V (depending on Range pot position)
To IC1 5: 3.30~3.80V (depending on Range pot position)
IC1:
1: 1.304~1.311V (depending on Sensitivity pot and making sure not to touch the board; voltage is stable)
2: 1.311~1.599V (depending on Sensitivity pot and making sure not to touch the board; voltage is stable)
3: 0.867~1.150V (depending on Sensitivity pot and making sure not to touch the board; voltage is stable)
4: 0V
5: 3.30~3.79V (depending on Range pot and making sure not to touch the board; voltage is stable)
6: 3.94~4.19V (depending on Range pot and making sure not to touch the board; voltage is stable)
7: 3.94~4.19V (depending on Range pot and making sure not to touch the board; voltage is stable)
8: 8.9V
Mind you, as soon as I introduce some static to the system, voltages start oscillating, which I guess is normal, as it is detecting a signal, right?
Quote from: Fancy Lime on April 21, 2020, 03:03:09 AM
Also: With no input signal, the voltage should not vary on pins 5, 6 and 7.
Yes and no... I was holding the board in my hand, so it could have been getting some static from me.
Quote from: Fancy Lime on April 21, 2020, 03:03:09 AM
Oh and I also just now realized that the Sensitivity pot is connected wrong in both the schematic and the layout. Lug 2 should be tied together with lug 3 instead of with 1. That will only change the direction and characteristic of the Sens control, though.
I will fix that once I get this working. Thanks for the heads up!
Hmmm, those voltages look OK now. So the DC path seems not to be the problem. So let's try to hunt down the problem together.
Do you have alligator (crocodile) clip wires? Those would make this easier but you can also solder temporarily or figure out some other way of making a temporary connection with the gear you have.
1. Try to attach a 4.7k resistor and a red LED in series from the middle pin of the mode switch to ground. If you play something into the input with the sensitivity pot turned half way up, does the LED light up?
If yes, then the problem likely lies in the filter section or the vactrol. If no, it lies in the envelope detector or the input stage.
2. If the LED does light up in the first test: Try to add a parallel 1k to 10k resistor to the resistor side ends of the vactrol (the two wires that meet the two ends of R6) with alligator wires from the vactrol wires. If you play something, do you get output.
3. Check the orientation of the vactrol. Where is the dot? The dot marks the cathode (minus) of the LED side.
4. If the LED in test one does not light up, run an alligator wire from E of Q1 directly to the lowermost leftmost pad on the board (15th row, 1st column). If you play something into the input, do you get signal at the output? Is the trimpot turned up?
Those are the things I can think of right now. I'll let you know if something else pops into my mind.
Cheers and good luck,
Andy
Here's mine that I finally boxed up yesterday.
(https://i.imgur.com/07eCPde.jpg) (https://i.imgur.com/LyCAHHY.jpg)
It's pretty cool. 8) Thanks Andy! If anyone is interested in my vero layout, here it is:
(https://i.imgur.com/wUVGJjh.png)
Watch out for some of the cuts which aren't too obvious: three underneath the 10K in the bottom left, and two under the 33K to its right (I think the rest are reasonably clear). Watch out also for the two slightly kinked wire links. The vero was a scrap piece left over from something else which explains why it's the shape it is, and why some of the controls aren't attached at the edges! BTW, I added the "less peaky" mod ("Q" switch on mine). And I adjusted my volume trimmer to be full blast. :icon_twisted:
(Edited to fix image links.)
Great graphics Marc. Nice work.
Most excellent, Marc! Nice build and way groovy graphics! Thanks for posting the layout!
Groove is in the heart!
Andy
;D Great work! love the Bootsy graphics!
Thanks for sharing. ;)
Quote from: Fancy Lime on April 21, 2020, 02:23:23 PM
Hmmm, those voltages look OK now. So the DC path seems not to be the problem. So let's try to hunt down the problem together.
Do you have alligator (crocodile) clip wires? Those would make this easier but you can also solder temporarily or figure out some other way of making a temporary connection with the gear you have.
1. Try to attach a 4.7k resistor and a red LED in series from the middle pin of the mode switch to ground. If you play something into the input with the sensitivity pot turned half way up, does the LED light up?
If yes, then the problem likely lies in the filter section or the vactrol. If no, it lies in the envelope detector or the input stage.
Like this?
(https://i.postimg.cc/3NYn0Yh8/20200528-153815.jpg)
If so, the LED
DOES light up (not too brightly, but it does light up enough to be clearly seen in daylight in a lighted room).
Quote from: Fancy Lime on April 21, 2020, 02:23:23 PM
2. If the LED does light up in the first test: Try to add a parallel 1k to 10k resistor to the resistor side ends of the vactrol (the two wires that meet the two ends of R6) with alligator wires from the vactrol wires. If you play something, do you get output.
No, I do not (used 10K).
Quote from: Fancy Lime on April 21, 2020, 02:23:23 PM3. Check the orientation of the vactrol. Where is the dot? The dot marks the cathode (minus) of the LED side.
Vactrol is correctly oriented (checked).
Quote from: Fancy Lime on April 21, 2020, 02:23:23 PM4. If the LED in test one does not light up, run an alligator wire from E of Q1 directly to the lowermost leftmost pad on the board (15th row, 1st column). If you play something into the input, do you get signal at the output? Is the trimpot turned up?
Those are the things I can think of right now. I'll let you know if something else pops into my mind.
Cheers and good luck,
Andy
What do I try next? I am stumped...
Bump... Any ideas what to try next?
Quote from: jfrabat on June 02, 2020, 02:45:16 PM
Bump... Any ideas what to try next?
Hi Felipe,
sorry, I missed your last post. Wasn't too active here lately. Anyway... You tried the LED and it lit up and you tried the 10k parallel with the vactrol and that did not give you signal. That means that your problem is somewhere between the vactrol and the output. It is not the power supply pf the opamp, else the LED would stay dark. This suggests that there may be a cold connection or a short to ground somewhere on or between one or several of the following components:
LDR1 (resistor side), Range pot, R6, R7, R8, C4, C5
Can you check the voltages on either side of those components?
Cheers,
Andy
Quote from: Fancy Lime on June 02, 2020, 04:20:43 PM
This suggests that there may be a cold connection or a short to ground somewhere on or between one or several of the following components:
LDR1 (resistor side), Range pot, R6, R7, R8, C4, C5
Thanks, Andy!
I cannot get continuity from these components to GND, so it seems this is not the case.
Quote from: Fancy Lime on June 02, 2020, 04:20:43 PM
Can you check the voltages on either side of those components?
Looking at the ground issue, I noticed that I made an error soldering C5 (I have it in line 7 instead of line 6). I will fix this tomorrow (I am kind of tired today). Will let you know if that fixes the issue!
Quote from: jfrabat on June 03, 2020, 12:12:25 AM
Looking at the ground issue, I noticed that I made an error soldering C5 (I have it in line 7 instead of line 6). I will fix this tomorrow (I am kind of tired today). Will let you know if that fixes the issue!
I honestly believed this would be the source of the issue... But it was not. I also had a lose solder joint in C4, which I corrected, but it was not that either. I mean, both were issues, for sure, but I still get no sound...
Quote from: Fancy Lime on June 02, 2020, 04:20:43 PM
Can you check the voltages on either side of those components?
LDR1 (resistor side)
Range pot
1: 3.83V
2: 3.83V
3: 3.42~3.44V
R6
1: 4.49 (at line 7)
2: 3.91 (line 8)
R7
1: 3.43 (9)
2: 0.884 (10)
R8
1: 0.884 (10)
2: 2.2 (14)
C4
1: 1.328 (12)
2: 3.84 (8)
C5
1: 0 (at line 6; this may be the issue! Now that I connected it to the right row, I get ground here!)
2: 0.884 (10)
What sticks out to me is the 0.884V between R7, R8, and C5 on row 10. It seems that this is the point that drags all the voltages down. Please check the section of row 10 on the right side of the cut (so columns 9-12) very carefully. Are there any accidental connections to ground? You say there is no continuity to ground, from which I assume you tested with the continuity function of a multimeter, yes? Try the resistor function, sometimes there is a very tiny solder bridge that has hundreds of ohms or even a few kilo. Are you sure C5 is good? Sometimes capacitors are faulty (very leaky) and act like a small resistor. This is not very likely for a ceramic cap, but if there are no erroneous connections around row 10, I would try changing C5 for a different capacitor of the same or similar value.
I think we are getting close,
Andy
> I made an error soldering C5 .... I also had a lose solder joint in C4
I'm on a purple drug and not seeing/thinking clearly.
But an old technician says: bad solder/joints run like deer or turkeys: in packs!
(https://i.postimg.cc/w7tfndzN/MPM-DEER-CROSS-ROAD-003-3345189-scaled.jpg) (https://postimg.cc/w7tfndzN)
If you see one deer or bird on the road, slow WAY down, because there are probably more that you have not seen yet.
(https://i.postimg.cc/ZC17SDYM/bab10639427fc8874894b7cd00d0a795.jpg) (https://postimg.cc/ZC17SDYM)
Quote from: PRR on June 03, 2020, 10:38:41 PM
>
I'm on a purple drug and not seeing/thinking clearly.
But an old technician says: bad solder/joints run like deer or turkeys: in packs!
(https://i.postimg.cc/w7tfndzN/MPM-DEER-CROSS-ROAD-003-3345189-scaled.jpg) (https://postimg.cc/w7tfndzN)
If you see one deer or bird on the road, slow WAY down, because there are probably more that you have not seen yet.
(https://i.postimg.cc/ZC17SDYM/bab10639427fc8874894b7cd00d0a795.jpg) (https://postimg.cc/ZC17SDYM)
mmmmmm. purple drug. been years. carry on!
+10000000000000 on solder joints in packs. best bet if in doubt, suck the old stuff out and reflow fresh.
don't use your lips tho ;)
;)
Will any NSL-32 work fine?
I see different ones one the bay... NSL-32SR3, NSL-32SR2...
Quote from: akkar on July 19, 2023, 05:37:40 AM
Will any NSL-32 work fine?
I see different ones one the bay... NSL-32SR3, NSL-32SR2...
Vactrols generally have fairly wide tolerances, so using any type always comes with a big "YMMV". That being said, the Quackmire design attempts to mitigate this a bit by working in a range where many vactrols should work ok. The speed of the vactrol is no big concern here. The dark resistance is also not too critical unless it is below say 200k. As long as the bright resistance isn't too high (<1k is ideal but <3k or so should be fine), it should work as intended.
Beware of fake vactrols on the bay though. Just because it says NSL-32 does not necessarily mean that that is what it is. Some may not be vactrols at all or may be dead devices. If possible, I would recommend buying such specialized devices from a "known reliable source". It may be better to use a different type of vactrol (along the specs outlined above) than to chase an NSL-32 and fall for scammers.
Andy
Thanks for your suggestions!
Another thing, I'm not sure about the mode switch... is it a SPDT with a central off position?
It is actually connected like this?
(https://i.imgur.com/k1ThnpE.png)
Yes, it's an on/off/on switch.
Quote from: akkar on July 21, 2023, 10:52:03 AM
Thanks for your suggestions!
Another thing, I'm not sure about the mode switch... is it a SPDT with a central off position?
It is actually connected like this?
(https://i.imgur.com/k1ThnpE.png)
Precisely so, as the wise bunny already said.
Quote from: akkar on July 21, 2023, 10:52:03 AM
(https://i.imgur.com/k1ThnpE.png)
Weird choice of values though, right?
We've got 1u+4u7 one way, 1u in the middle, and 1u+22u on the other side.
So those are roughly 6, 1, 23 ratios, but excuse me if those seem like odd numbers to choose...;)
Maybe those values are great, and I'm just too twitchy about stuff like this. Those ratios freak me a bit because they don't fit any pattern, although I recognize there's actually no reason why they should.
Yeah, well, life's full of compromises, innit? I liked 1u for the shortest and 22u for the longest time constant. Wanting a small and cheap switch meant on/off/on was the way to go, leaving me with one more value somewhere in the middle. I only had 4u7 and 10u around and wasn't going to combine two caps to get anything more tailored (for simplicity and because electrolytics have ginormous tolerances anyway). Out of the two choices, I liked the 4u7 in parallel with the 1u better. That's all there is to it. If I were to put this in a larger enclosure, I would probably go rotary switch with 1u, 2u2, 4u7, 10u, 22u, 47u, or something like that.
Andy
Quote from: Fancy Lime on July 23, 2023, 03:29:40 AM
Yeah, well, life's full of compromises, innit?
Yep! I guess it is!
Quote
I liked 1u for the shortest and 22u for the longest time constant. Wanting a small and cheap switch meant on/off/on was the way to go, leaving me with one more value somewhere in the middle. I only had 4u7 and 10u around and wasn't going to combine two caps to get anything more tailored (for simplicity and because electrolytics have ginormous tolerances anyway). Out of the two choices, I liked the 4u7 in parallel with the 1u better. That's all there is to it.
Entirely fair enough. As I said, I think I'm just twitchy about stuff like that. Trying it to see what sounds good is a very reliable and well-thought-of method to determine required values, after all..;)
Quote
If I were to put this in a larger enclosure, I would probably go rotary switch with 1u, 2u2, 4u7, 10u, 22u, 47u, or something like that.
Now that sounds like it might be overkill!
Quote from: ElectricDruid on July 22, 2023, 09:02:18 PM
Weird choice of values though, right?
I read it as 1, 5, 25. 5:1 steps. 2+ octaves each, 5 octaves total, half the audible range.
Yes yes I am over-simple. 1, 5.7, 23; 4.6oct. Not that you can be so precise on 1st-order filters.
Anyway, "that's what was in my box!" You think I'm driving to the store for more theoretical or metaphysical values?:icon_eek: Does Hogwarts U. teach a spell for cap-value tweaking? :icon_twisted:
I learned to drive on several 3-speed gearboxes. The ratios were barely logarithmic. "We have a 17-tooth sprocket design on hand, we are using it!" The '42 Plymouth has a loooong jump from 1st to 2nd. A later Honda 5-speed had more uniform steps. The new Toyota 8-speed I dunno what the steps are, it never stays in one very long. ;D
Quote from: ElectricDruid on July 23, 2023, 10:47:33 AM
[...] As I said, I think I'm just twitchy about stuff like that. [...]
Oh, me too, brother, me too! Bugs me to no end when I see this sort of nonsense in someone else's design. Being all reasonable and pragmatic instead of theoretically sound! Ugh! It's a lot easier for me to accept that the rules of neat design sometimes get broken, if I'm the one swinging the bat :icon_mrgreen:
Quote
Now that sounds like it might be overkill!
Right, like that has ever stopped the likes of us 8)
Quote from: PRR on July 23, 2023, 05:01:00 PM
Quote from: ElectricDruid on July 22, 2023, 09:02:18 PM
Weird choice of values though, right?
I read it as 1, 5, 25. 5:1 steps. 2+ octaves each, 5 octaves total, half the audible range.
Yes yes I am over-simple. 1, 5.7, 23; 4.6oct. Not that you can be so precise on 1st-order filters.
Anyway, "that's what was in my box!" You think I'm driving to the store for more theoretical or metaphysical values? Does Hogwarts U. teach a spell for cap-value tweaking?
I learned to drive on several 3-speed gearboxes. The ratios were barely logarithmic. "We have a 17-tooth sprocket design on hand, we are using it!" The '42 Plymouth has a loooong jump from 1st to 2nd. A later Honda 5-speed had more uniform steps. The new Toyota 8-speed I dunno what the steps are, it never stays in one very long.
In hindsight, that's the smart answer that I should have given.