right, ive been messing around with envelope/detectors/filters/followers etc etc.. a hell of a lot lately...probably too much.. ::)
anyway its been a breadboard marathon..
1:sound to light, with morley wah.....the 386 makes it noisey
2:sound to light with earthscums lowaht....the 386 makes it noisey
3:nurse quacky....too distorted. and no B+E string response... ::)
4:nurse quacky envelope detector part..
5: and now breaded this @#$%er twice, but no quack (led/ldr)......will this schematic actually work????....i have signal in/out ok, just no quack!!..
http://www.beavisaudio.com/schematics/DOD-440-Envelope-Filter-Schematic.htm
i'm trying to get a 'sensitive' EF so notes will quack with just hammering/tapping notes...without having to whack the ass out of my guitar.. ::)
so
A: will the above schemo work?...anyone tried it?
B: anyone got a 'good' envelope filter with 'subtlety'...but with common parts too.?
C: arggggggggggggggggggggggggggggggghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh........
i have yet to breadboard the
DR Q
phunvgnosis..
cheers guys.
Quote from: deadastronaut on October 20, 2012, 05:58:33 PM
i'm trying to get a 'sensitive' EF so notes will quack with just hammering/tapping notes...without having to whack the ass out of my guitar.. ::)
thats a pain, any envelope detection usually have a treshold range that is fixed for a very specific range on input levels.
I have protoyped that a compander, using common ic like the NE/SA571, can be tapped for a sort of rectified/averaged output signal, and then it could be processed for an appropiate ADSR control for other stages (filter, etc). The nice thing is that this signal is proportional to the rate of the variation in input, but not so much on the input level of that variation. Simply put, would get a similar "bump" by playing a note hard or a gentle tap.
I suggest you to lead research on that..
The only envelope detector circuit I've played with is the Foxx Guitar Synth pedal, which is a glorified Mutron III. I've got two different veros and schematics over on this thread;
http://www.diystompboxes.com/smfforum/index.php?topic=95016.0 (http://www.diystompboxes.com/smfforum/index.php?topic=95016.0)
Might help you.
Maybe get some ideas from the Mad Professor Snow White Auto Wah, seems to work pretty well for me on all strings.
You could try using a comparator to create a gate from your envelope, and then follow that with an attack/release generator. I've had pretty decent results with that method, and you get an even quack across the entire fretboard (depending on how you have the filter set, of course). I've been using a simplified version of the A/R generator in the MFOS subcommander and it works great.
Rob, someone either Mark Hammer or RG Keen gave cap values to get a better b/e string response out of the Nurse Quacky. The sensitivity knob also has a fairly small range where it will work properly with any given guitar ... mine seems to hit the b and e strings fine with the stock values, but it's a pretty bright guitar.
I haven't built the Beavis version of the DOD, but it's not radically different from BYOC's, which I *have* built and it sounds crazy good. It's not subtle at all, though.
Also, Madbean's got a Mutron III derivative coming out in a few weeks, might be worth a look. Not a cheap project, though (it uses two vactrols).
Have you tried just running a boost into the Nurse Quacky? A treble booster especially would probably solve the string definition problems you're having as well. You could combine them in one circuit and adjust the decay to keep it from getting out of hand with the boost running.
Quote from: jaapie on October 20, 2012, 09:20:28 PM
You could try using a comparator to create a gate from your envelope, and then follow that with an attack/release generator. I've had pretty decent results with that method, and you get an even quack across the entire fretboard (depending on how you have the filter set, of course). I've been using a simplified version of the A/R generator in the MFOS subcommander and it works great.
that is almost exactly what i am doing (mfos gate extractor or whatever it is called into yusynth adsr into various synth filters)
my only problem is that if i don't leave a little bit of silence between notes then it won't send a new gate signal so i can't really filter fast licks with it where an envelope follower would work perfect (but then an envelope follower won't give the flexibility of an ADSR)
When I first build the nurse quacky i had a b and e response problem then figured out one of my caps was the wrong value (10pf instead of 10nf if i remember correctly) one I changed it the b string was responsive. I still have a problem with the e string. I tried tweaking the values of the 4n7s to 4n4s but didn't really do much.
The sensitivity of the pedal is determined by the gain of U1A , which is set by the value of VR1. As the total resistance on the ground leg (VR1+R2) gets smaller, gain is increased, to a maximum of 221x.
However, the gain applied is pretty similar for anything 160hz and up. What you'd like to do is create greater gain for higher strings and notes. You can do that by utilizing a 2nd parallel gain-setting path.
If you stick a 6k8 resistor and .033uf cap in series, and place them in parallel with R2/C1, at max sensitivity, the gain of that stage will be 324x for content roughly 710hz and higher. If you drop the cap down to .022uf, that shifts to roughly 1060hz. Max gain for content below that point will still be 221x, as before (actually a little higher for stuff just under the rolloff set by the 2nd pair of components.
To increase sensitivity for everything, regardless of string, consider increasing the value of the feedback resistor R1, from 2.2M to something a little higher, like 2.4M or 2.7M. Another thing you can do is swap diode D2 (shown as a 1N4148) for something with a lower forward voltage, like a germanium or Schottky type.
Mark, would that apply to the nurse quacky as well?
Quote from: Devius on October 21, 2012, 08:22:29 PM
Mark, would that apply to the nurse quacky as well?
Sort of. The Nurse Quacky uses an inverting op-amp configuration for the gain stage before the rectifying diode. The gain is modified in a different manner here. For the Quacky, rather than varying gain, the gain is fixed at [3.3M]/[47k] = 70x, and the sensitivity control adjusts how big or small a signal you apply that gain to.
The rolloff going into the gain stage is set by 47k and .01uf, which is approximately 340hz. So it already tames the low end a bit, relative to the middle and higher strings. But you can still produce the same differential gain thing, if you use a parallel RC pair, alongside the 47k/.01uf pair. Try out 27k and .0056uf (5600pf), which will get you a gain of around 122x (instead of 70x), starting around 1050hz. If that seems a bit much, drop back to 33k and 4700pf, for a bit less gain (100x) startoing around roughly the same point.
cheers for the suggestions/tips guys...that SWAW looks/sounds nice.
i have the beavis EF on breadboard at the mo...have signal but still no quack..ive checked all connections thoroughly
http://www.beavisaudio.com/schematics/DOD-440-Envelope-Filter-Schematic.htm
i am using an led/ldr in place of the vactrol...
e.g. ldr across the 2x 220k's.....led lights up, responds etc.
if i get it going i'll try those mods mark suggested..cheers mark. ;)
.........ldr.........
220k......220k..
going by this schematic its saying ''centre tapped ldr''?....but i'm using 1 x ldr 2 legs...hmmmm...i suspect this is my problem... cure?
http://www.google.co.uk/imgres?imgurl=http://experimentalistsanonymous.com/diy/Schematics/Filters%2520Wahs%2520and%2520VCFs/DOD%2520440%2520Envelope%2520Filter.gif&imgrefurl=http://experimentalistsanonymous.com/diy/Schematics/Filters%2520Wahs%2520and%2520VCFs/&h=481&w=486&sz=6&tbnid=aug6hcpJdUXuYM:&tbnh=90&tbnw=91&prev=/search%3Fq%3Ddod%2Benvelope%2Bfilter%2Bschematic%26tbm%3Disch%26tbo%3Du&zoom=1&q=dod+envelope+filter+schematic&usg=__Mqf_FPFys2cra3bB7Hq910Q0ZJs=&docid=THMqB97guVgAzM&hl=en&sa=X&ei=uxGFULzoOpPB0gWs_4DYBA&ved=0CB8Q9QEwAA&dur=3802
i guess what i'm saying is, can it be converted to use and led/ldr...i dont get the centre tapped thing?...the vactrols ive looked at have 4 legs, 2 for led, 2 for ldr...hmmmm...
here's the recommended one....wtf?
http://www.mammothelectronics.com/VTL5C9-Photoconductive-Cells-and-Analog-Optoisolat-p/400-1109.htm
Quote from: deadastronaut on October 22, 2012, 05:26:43 AM
going by this schematic its saying ''centre tapped ldr''?....but i'm using 1 x ldr 2 legs...hmmmm...i suspect this is my problem... cure?
Ah.
Yes, that's your problem. You need a 5-legged vactrol like the VTL5C4/2 for the DOD project. And they aren't cheap:
http://www.smallbearelec.com/servlet/Detail?no=350
I ... suspect ... you can just use two MATCHED photocells, point them at the same LED, and join two legs together.
yeah i tried 2 ldrs....no joy..
@#$%ing envelope filters......arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ::)
ok i thought i'd post this little problem on here too..
heres what i have at the mo,
the sound to light circuit/EF is fine on its own.....
and the wah is lovely and clean on its own.....in fact its really nice. :icon_cool:
but as soon as i connect the guitar input to both to get the led responding into the ldr it distorts...now i know you guys will spot the problem easily, but i've tried a few things to no avail... :-[
ive been ok with lf'os into this kind of thing, but have never tried the guitar input into both circuits.....any suggestions?
(https://dl.dropbox.com/u/7464107/EFWAH.jpg)
Well, that 4.7M resistor is a TON of gain. You're probably overdriving the envelope's op amp. Why that causes distortion in the audio circuit, I can't say, I just know it does. (I had this problem recently in multiple circuits.) Hopefully someone will jump in and 'splain it.
You should have a divider of some sort (you can't just short the guitar signal to the amplifier and add a resistor to the envelope, you'll never trigger the envelope) along with a series resistor going into the envelope section. You also probably need the hold cap in the circuit all the time -- maybe with the cap going to ground, not in series with the second LED. (I'd ditch the second LED here anyway and match it to the reference LED.)
In that setup, the -ve input pin of IC1a is essentially shunting the guitar input signal to ground (the -ve input of an opamp presents a very low resistance to ground...which loads the guitar signal = much sorrow).....at the very least, you need a high value resistor between C2 & R2.....but even that isn't a particularly good solution.
As an aside, the input impedance of the other opamp is a tad too low (R10 could do with being higher ....same problem...i.e. you're using the -ve opamp input) ....even better use a non-inverting opamp configuration there. You're better following the path followed in the other thread (http://www.diystompboxes.com/smfforum/index.php?topic=90184.60), because the particular LED setup you've adopted above will *never* have a slow release tail (should you seek this)
cheers guys, if only things were as simple as me... ::) :D
ive changed the EF section anyway.. , i ended up pinching the nurse quacky led sectiion.......(i tried lowering the gain on the opamp, but then i lost the led..)..
@G: ok...looks like i'll have to do it properly then.... ;D
ok, had a rummage around, this is from the classic EF mcmeat,
http://www.experimentalistsanonymous.com/diy/Schematics/Filters%20Wahs%20and%20VCFs/Lovetone%20Meatball%20McMeat.pdf
could i just lift the envelope follower from the ''sense''-----to the ''intense''....led. ????
it has attack, decay, etc...
Quote from: deadastronaut on October 24, 2012, 09:06:46 AM
ok, had a rummage around, this is from the classic EF mcmeat,
http://www.experimentalistsanonymous.com/diy/Schematics/Filters%20Wahs%20and%20VCFs/Lovetone%20Meatball%20McMeat.pdf
could i just lift the envelope follower from the ''sense''-----to the ''intense''....led. ????
it has attack, decay, etc...
yeah
btw i don't see how the envelope follower section could be this much of a problem, the way i see it it is just an AC-DC converter/rectifier with some gain and sometimes with some caps for attack/decay. i mean once i used a simple graetz bridge as an envelope follower (that was only on a breadboard) to control a synth filter. I had to boost the incoming AC signal (the guitar) though to get around 5-10VDC swing on the output.
btw after a while the guitar's envelope won't satisfy you i think (i mean the guitar's envelope is generally the same shape all the time, that is why they try to shake up things with the attack/decay cap) that is when you should try triggering an ADSR to control the filter instead of an envelope follower but then there are problems with reliable triggering imo
edit: also when you use an envelope controller your filter cutoff will depend on the input signal's loudness which is not always a good thing imo. When you wanna get huge filter sweeps your signal's loudness will swing quite huge too which a lot of the times not a good thing. (think about it from a mixing engineer's viewpoint)
The problem is that the end device that Rob wants to drive is a LED....that mcmeat is an improvement, but the EF section is biased to ground....& therefore the envelope cap will need to charge up to the fwd voltage of the led before the led will turn on (in other words a 'dead zone'). Same on the release side, as soon as the EF cap discharges below the fwd voltage of the led, it'll extinguish....but in this situation there's still about 1.8V still to discharge on the holding cap.....therefore you miss that 'tail' release aspect. This is why I reckon the led should be biased to 'just off' with no input signal (so for example a RED LED should be biased to 1.7V etc)
Quote from: WhenBoredomPeaks on October 24, 2012, 10:59:02 AM
btw after a while the guitar's envelope won't satisfy you i think (i mean the guitar's envelope is generally the same shape all the time, that is why they try to shake up things with the attack/decay cap) that is when you should try triggering an ADSR to control the filter instead of an envelope follower but then there are problems with reliable triggering imo
Normally, (IMHO) we're not trying to extract/grab the guitar's 'signature' as such....but merely extract the magnitude of the 'plucked' string. Re going for an ADSR type filer, well with most guitar-esque EFs, the 'A' is covered already, the 'D' is too (though confusingly is normally called release)....you can't have an 'S' aspect with a guitar (well, not without a sustainer at least!) & nor can you have the 'R' (release) that follows the 'S'!
But the McMeat's EF section drives a LED too ??? (actually two vactrols and a "status" led or whatever they call it but they are still LEDs)
The speed of the Attack is always the same with a guitar. (basically the pick attack) You can try pick weaker but then you will just get a lower peak but generally the shape of the envelope will be always the same. So it is like having an ASR and you can only change the value of the Sustain (with the strength of picking) Or if i think a little more about it you don't even get sustain, after the really fast pick attack portion of the signal it immediately starts getting weaker till it gets to zero. So it is more like AR. Or you can call it AD but with zero sustain and then the release becomes irrelevant because it goes from zero to zero.
So you can try whatever on a guitar but you will never get an opening filter like sound or complete silence after the attack portion or fast decay or many other sounds that you can do with an ADSR.
(edit: btw the envelope follower section of the Meatball (musicpcb.com) is biased like what you said (not around zero but to some voltage around 1V) so maybe that would be better)
Quote from: WhenBoredomPeaks on October 24, 2012, 12:09:29 PM
But the McMeat's EF section drives a LED too ??? (actually two vactrols and a "status" led or whatever they call it but they are still LEDs)
yes, I realise that ;) , my last post was in response to your comment
"btw i don't see how the envelope follower section could be this much of a problem" I'm basically agreeing that yes an EF section is easy, but a touch more involved if you seek a smooth response especially if the end device being driven doesn't turn even on until it gets 1.8V across it & then turns off when the voltage drops below 1.8V. (i.e a RED LED)
hi guys, i tried the mcmeat EF,
from the 4.7k onwards to led..
i didn't get any response from the led though....with guitar straight in....hmmmm.....i'll give it another go after dinner... :)
(https://dl.dropbox.com/u/7464107/MCMEATEF.jpg)
ive been scouring the threads and web, and what i want seems to be a common problem (quite a few threads on led EF..) , with no definitive solution that i can find anyway... :P
On pin 3 I'd have binned R3 (which biases IC1a to 0V ....which I don't reckon is best) & instead placed a trimpot with one lug at ground, the trimpot wiper to the opamp pin 3 & the top lug of the trimpot to a fixed value resistor which then in turn connects to 9V. The value of the resistor depends on the value of the trimpot you use.....a good starting point would be to use a resistor just under 2x the value of your trimpot.
You can then set the DC level of the opamp output to suit (i.e. tweak it until the LED D3 is *just* off.) IMHO you can lose R17.
YAYYYYYYYYY....whooohooo....
nice one G....
yep that works... 8) 8) 8)
Good. ;)
I'd have used a schottky for D2 as well (you might not even notice the change, but it ought to help in this circuit)...I'd have also thought that R4 is too high - I'd have gone for 470k (probably less)
aha those schottky's come in handy after all... ;D
yep done those... 8)
re: the trims actions:
attack: full on =led on/off. halfway=slightly short swell on.(soft lattack) full CCW led just about on.. :icon_cool: (halfway=very short soft led fade)
decay: (with attack full) : fully CW =dim led,... full CCW= bright led.... on /off action. (no fade)
intense: full = led almost off , full CCW led on/off action (no fade)
(https://dl.dropbox.com/u/7464107/efmcmeat.jpg)
edit as an experiment i swapped the c3 10uf for a 100uf to be extreme :icon_twisted:.....and yes...lovely slow attack fade on and off, :icon_cool:
47uf is cool...too, probably more practical/useable..
now to make it pot adjustable, 8)
edit:
actually the decay pot acts as an varying attack with the 47uf now, when CW its on/off, and when CCW its a nice fade...with fadey goodness in between... :icon_cool:
i could probably lose those other pots....hmmmmm...
defo the best EF yet.....
i'll have a measure up and sort that voltage divider out...cheers G: you the man!!! :icon_cool:
Your mileage may vary, but I'd have thought R1 should be above the trimpot.
In fact, a better arrangement would be something along these lines...
9V
|
22k resistor
|
25k trimpot (wiper to opamp IC1a pin 3)
|
7.5k resistor
|
ground
.....this will allow you to set the bias on IC1a pin3 anywhere between 1.24V & 5.4V ....which should be enough range for any colour LED you put on the output.
You should also have left R16 in situ (say 100R)....this will at least yield some series resistance if your intensity trimpot is set for zero resistance (zero resistance is not good for the LED)...in other words it'll protect the led if the VR5 trimpot is set too low.
Also...a point worth noting....pesky input impedance again....at about 4.7K & not good for connecting direct to a guitar (so use a buffer or preamp to feed IC1a)
BTW this circuit's attack/decay controls are a bit problematic imo, for example if you set the attack higher than the decay it mutes the envelope voltage somehow. (at least this happens with the meatball and meatsphere) Also using a bigger cap instead of the 10uF for more usable decay times makes the attack too slow. I think those problems were some part of the reason why i started looking at ADSRs a while ago.
It,s also why, over the years, I've found that I get more return for my effort on variable decay than variable attack. Some variable Attack functions work well - the MXR Envelope Filter comes to mind immediately - but in many implementations they just eat up too much drive current. Moreover, one needs to eat up a LOT of drive current to yield audibly different attack times. With variable decay, you can easily obtain a 20:1 or higher ratio of decay times without significant impact on the sweep width of the filter. That's much harder to do with attack in simple circuits.
in my rummaging around i found the bassballs circuit, which sounds to me like what i was originally looking for...sort of guitar faux synthy type sound..
to go with an off biased fuzzy synthy sound i have......
anyway i found this remarkably hummy but ''very informative'' video of a guy demonstrating his excellent mods. :icon_mrgreen: :icon_wink:
http://www.youtube.com/watch?v=eoAIKHFGOcQ
i'll definately try this on the breadboard today and see how i get on..i'll leave off the moody fuzz though i think.....sounds great mark!! :icon_wink:
i want to be able to pick softly and harder...dynamically...to go from gently opening, to fully open filter....like a synth...lots of delay etc..
like this clip i did with my dodgy thrown together EF....
https://dl.dropbox.com/u/7464107/SYNTHFUZZ.mp3
i'll let ya know how i get on ok... 8)
i also found this by runoffgroove....minus the fuzz..
http://www.google.co.uk/imgres?imgurl=http://runoffgroove.com/images/attachments/bb.png&imgrefurl=http://www.diystompboxes.com/smfforum/index.php?topic%3D72307.0&h=570&w=700&sz=8&tbnid=7c1BWTGs-CJkGM:&tbnh=87&tbnw=107&prev=/search%3Fq%3Dbassballs%2Bschematic%26tbm%3Disch%26tbo%3Du&zoom=1&q=bassballs+schematic&usg=__w_NZJKFfX36E9PlZsjCYh95TRJg=&docid=EFRM7XO_xjDoNM&hl=en&sa=X&ei=AFGJUPp85crRBdiMgLAE&ved=0CCIQ9QEwAQ&dur=838
The webcam mic is the pits, and the videos are shot right beside the desktop computer and directly under a fluorescent fixture. I could have only made it worse by shaving with an electric razor while talking! That's part of why there haven't been many recent followups.
Fast decay seems to perceptually accentuate the sweep, making it sound more synth-ey. And it's the sense of "action" in the sweep of any filter that seems to appeal to us. Although that "action" comes in the form of both upsweep and downsweep, the series resistance needed to vary the attack diminishes the upsweep, even as it provides more sonic variation.
I've often wondered what you'd get by sweeping the two bandpass filters in the Bass Balls at different rates, with independent envelope followers. My sense is that it would start to get a little more "talk-ey" as the desynchronized filters started to behave more like formants do.
:D...ha ha, shaving too...that's funny.!..
yeah i guess it would end up vowel-ey...
halfway through breading.....i can't wait to tinker with those twin filters....sounds right up my street!!!..
i might try adding my own fuzz after to the out of ic1b...anyway see how it goes.
cheers mark!..some cool mods on that vid, you should do more!....but don't shave at the same time.. ;D
fwiw, rob, the escobedo phunqgnosis worked for me right out of the gate.
do you have it sweeping up, or down? if it's sweeping down, it may not be too noticeable..
just thinking on my feet.
got it going. that fuzz is nasty in a bad way......thats gone! .(the diodes trick was much better though)
i also swapped out the 'gain' 220k for an 82k..
it has much better sensitivity to picking now.. its great on the B+E strings all over too... :icon_cool:
i like that 330k mod...nice and short to really long..
i love how this thing 'phases' the trail off....
anyway still tinkering.....it gets very clippy on certain notes and whack, so i'll tinker with it...but i'll persevere.. :)
https://dl.dropbox.com/u/7464107/guitarBBbollox.mp3
tried my bass for a laugh too...
https://dl.dropbox.com/u/7464107/bassbollox1.mp3
One of the things we tend to forget all too often is that filters need something to filter. If you feed a VCO to a filter, governed by an envelope/transient generator, the harmonic content of the VCO is constant. It only disappears if you filter it out, no matter how long you take to do so.
Not so with guitar. Most of the harmonic content is at the beginning, and fairly quickly dies out. If you come late to the party with your filter, all that's left is a bit of dip and the pieces of cauliflower nobody else wanted. Distortions can help to keep the harmonic content "alive" for a longer period, but the harmonic content can still easily peter out. Moreover, distorting prior to envelope detection results in less dynamics.
So faster decay helps to get in there and filter stuff while there is still stuff to filter; making it a more pleasing and musically interesting sound.
The envelope follower needs something to follow, too!
Which is why it is a best practice to tap a clean signal to send to the envelope follower, and introduce any fuzz (which naturally steals dynamics) after that point.
I've often wondered why envelope based pedals dont provide a Sidechain Thru or something for this reason. What if I want to run my Bluebox into an autowah, f'chrissakes!
> all that's left is a bit of dip and the pieces of cauliflower nobody else wanted.
I just snorted tea all over my keyboard. Thanks, Mark
Quote from: Jazznoise on October 26, 2012, 05:18:52 PM
I've often wondered why envelope based pedals dont provide a Sidechain Thru or something for this reason. What if I want to run my Bluebox into an autowah, f'chrissakes!
The Bass Balls sort of does that by using the rectifier gain stage as a sort of fuzz. It will provide a distorted signal, without impacting on the dynamics too much.
The format you want, though, is the Q-Tron+, which has a send-receive loop that's tapped at the same point where the envelope folower is tapped from. You can stick whatever you want in the loop, and as much of it as will fit, and the filer will be swept by the dynamics at the input to the pedal.
Quote from: R O Tiree on October 26, 2012, 06:15:29 PM
> all that's left is a bit of dip and the pieces of cauliflower nobody else wanted.
I just snorted tea all over my keyboard. Thanks, Mark
I do my best to help people keep their nasal passages clean.
>I do my best to help people keep their nasal passages clean.
AGGGGHHHHHHH - you just did it again!
Mark - I see a whole new career opening up for you!
Quote from: Mark Hammer on October 25, 2012, 10:10:30 AM
It,s also why, over the years, I've found that I get more return for my effort on variable decay than variable attack. Some variable Attack functions work well - the MXR Envelope Filter comes to mind immediately - but in many implementations they just eat up too much drive current. Moreover, one needs to eat up a LOT of drive current to yield audibly different attack times. With variable decay, you can easily obtain a 20:1 or higher ratio of decay times without significant impact on the sweep width of the filter. That's much harder to do with attack in simple circuits.
I think the HSR Fader/Panner/Gate used a trick to minimise current draw during the attack section of the envelope. I have to haul our suitcases containing summer clothes into the attic later today, so I'll try to locate the relevant issue of the mag - from 1988 or so.
We had first frost of the winter overnight!
i kinda prefer a fuzz before envelope followers, seems to track better to me, and sound more...fuzzular. i like fuzz before wahs, too...but like wahs pre distortion, or overdrive.
the colorsound diphonizer i think has the fuzz first, at least it seems like it does.. but again, i prefer that pedal to have a fuzz before, and an overdrive after it. really seems to bring it to life.
if you still play dynamically, you can get a *LOT* of sounds out of them... i often use envelope filters live so i don't need to be tied to my wah, and people don't seem to notice the difference.
Hmmmm....
@mark: i noticed you built the Q-tripper..
i can't find any clips of it though...is it a straight autowah?....does it have good response on all strings?
can it make a cup of tea?... ;)
The Q-Tripper is a bit of an oddball. Instead of selecting filter mode via a switch, as the Dr. Q does, it uses a blend/bleed pot to emphasize which filter mode dominates. The sound is akin to a well-behaved Dr. Q/Quack.
cheers
ive been tinkering with the bassballs, and i have it quite sensitive now, i love the filter sound, very synthy
but i just can't get rid of the 'filter breakup jumping' (not distortion) when letting a chord ring out...rather than a smooth filter fade trail off......
thats got to be the envelope detect part i guess, any thoughts/suggestions mods on that?..
Half-wave rectification is usually more than enough when the event to be followed is fast. When the event to be followed has a protracted fade-out, full-wave rectification may be a smarter path to pursue.
Alternatively, or in conjunction with, it may be wise to have a toggle-selectable time-constant/averaging-cap range switch. So, 10uf when you want things to move along quickly, and 33uf when you want the filter to take a leisurely stroll. The thing with half-wave rectifiers and single averaging caps is that things you do to have a slow decay get in the way of fast attack, and vice versa.
You can also try two-pole averaging - resistor/cap->resistor/cap - for more averaging/filtering of the envelope during the decay phase. I can't speak to how one ought to optimize that, though.
It also bears noting that some of the ripple can addressed at source. For example, older strings, worn a bit at the frets, are more likely to produce "beats" that show up in the envelope, and result in audible ripple.
hmmmm...cheers mark. :icon_cool: (i wouldn't have a clue as to a full wave rect version)..(though i think gurner was pointing me in that direction....i think!)
as of now ive ripped the BB off the breadboard, i just couldn't get a nice trail out of it clean...(shame as i liked the filters sound but hey ho..)
so now my lengthy quest for a good EF has left me with the Q-TRIPPER..
http://www8.plala.or.jp/KandR/cir_q-triper.html
ive breaded it, but alas no quack ::)..i tried 2n5457's/ j201's. with a 4558 ic. ...been over the connections from in to out and all looks ok...all bias points etc..
if i turn the depth trim/pot i can manually sweep the filter, but not auto/quackyness...
note: if i remove Q2 and put it back in i get a hint of quack for a split second...hmmmm...
edit: breaded it twice now...is the above schematic correct?..hmmm..
ok i have j201's/2n5457's...this calls for 2sk30a's..which have a different 'fet' symbol to others going by this strange datasheet pdf.
http://www.on-ele.org/up/2SK30A.pdf
so in the schematic is the input going to the 'source' of Q1.....not gate?....seems weird to me!!!.. ???
This might help you:
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/Q_Triper_LAYOUT.jpg.html
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/Q_Triper_TRANSFER.gif.html
Quote from: deadastronaut on October 30, 2012, 09:37:54 AM
so in the schematic is the input going to the 'source' of Q1.....not gate?....seems weird to me!!!.. ???
I'm not familiar with that particular circuit, but I can say with a fair degree of certainty that the output of the circuit's envelope follower (the wiper of the depth pot) should go to the fet gate (ignore the circuit symbol if this is confusing)...the source goes to bias & the drain goes to junction of c5 & c6.
If as you're saying the filter works when you adjust the depth, then that suggests there's a problem with the envelope detect aspect of the circuit......put your meter across C10 & give your guitar a 'full on' power chord whack.....you should see the DC level across C10 move up a fair bit
@mark, cheers yeah i saw that.
@G: yep thought so, thats how i have it setup...(that datasheet should be banned.. ;D)
D
S
G
on the recommended schemo it calls for 2sk30a's...
however in marks Q tripper build report he mentions considering using 2n5457's ...so i'm trying those....or j201's..maybe.
http://www.diystompboxes.com/smfforum/index.php?topic=83116.0
i gave that C10 / 10uf reading a go...
correct, no change on DMM with a whack...hmmmm...so it is the EF....i'll poke around it..
Quote from: deadastronaut on October 31, 2012, 07:05:22 AM
i gave that C10 / 10uf reading a go...
correct, no change on DMM with a whack...hmmmm...so it is the EF....i'll poke around it..
DC voltages for U1 would be useful. (as would squirting in a sine wave from a sig gen app outta your soundcard)
okey dokey.....4558
1 4.35
2 4.36
3 4.36
4 0.00
5 9.11
6 8.96
7 9.01
8 9.11
Quote from: deadastronaut on October 31, 2012, 07:46:21 AM
okey dokey.....4558
1 4.35
2 4.36
3 4.36
4 0.00
5 9.11
6 8.96
7 9.01
8 9.11
Pin 5 is wrong - it should be sitting at near 'bias' (4.5V) ....put a meter on these ....VR1, R9, R15 ...& post the results
i thought pin 5 looked moody.. :)
ahhh i just found a dodgy connection. the R15 wasn't going to the R9 (covered by a bent lead..) no quack though,
4558
1 4.34
2 4.36
3 4.36
4 0.00
5 4.31
6 6.02
7 6.06
8 9.09
Q1
D 9.09
S 4.86
G 3.97
Q2
D 4.30
S 4.36
G 1.83
Quote from: deadastronaut on October 31, 2012, 08:16:36 AM
i thought pin 5 looked moody.. :)
ahhh i just found a dodgy connection. the R15 wasn't going to the R9 (covered by a bent lead..) no quack though,
What's the voltage across C10 with no signal & also when a full power chord is whacked out on your guitar?
C10/10uf
0.80 with no signal, same with a good whack..
Quote from: deadastronaut on October 31, 2012, 09:17:15 AM
C10/10uf
0.80 with no signal, same with a good whack..
what's the DC voltage on the right leg of C9?
C9 right leg -
really slow drain from 0.99 when turning 9v supply off then on.....slow......slow.................to 0.03...
+ side is 3.84
Quote from: deadastronaut on October 31, 2012, 08:16:36 AM
1 4.34
2 4.36
3 4.36
4 0.00
5 4.31
6 6.02
7 6.06
8 9.09
Something ain't quite right here still ...pin 6 & 7 should measure close to pin 5 ...and also the left leg of C9 should be pretty close to pin 7 which is 6.06V (which as I've just mentioned, I don't think is right!)....but you're saying it's presently 3.84V
this is the point I'd ask you to whip out your scope!
ha ha Mr no scope... ;D
re-measured my pins to be sure...
1 4.35
2 4.37
3 4.36
4 0/00
5 4.32
6 3.59
7 3.60
8 9.11
left of C9 = 3.60
arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh my @#$%ing head....... @#$%ing EF's...arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh....
btw ive ordered some 2sk30a's...but won't get them for a while....china!!!!..too pricey over here!. ::)
looking at this 'verified' layout depth pot 3 goes to source via a 47k..and bias pin3... ???
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/Q_Triper_LAYOUT.jpg.html
hmmmmmm..compared to the schematic.
http://www8.plala.or.jp/KandR/cir_q-triper.html
i have a feeling the schematic isn't really up to it...going by the layout!..arggggggggggghhhhhhhhhhhhhhhh..............one day i'll get an EF working..... :-\
i'll go through the nightmare task of disecting the layout and re-drawing the schematic i think...theres a few anomalies ive spotted comparing etc......@#$%ing @#$% @#$%ers
i may be some time......... ::)
ok i followed the layout and carefully redrew the schematic from it.. ::)....messy but you get the point.. :)
i'll tinker and see if i can get the @#$%er going.....looks pretty much the same apart from pot wiring..
(https://dl.dropbox.com/u/7464107/qtripper%20redrawn.jpg)
edit nope.. ::)