envelope filter

[12bar13]

i am looking for a good envelope filter project.  i love the q-tron but i don't really want to shell out the cash.  the best that i've found seems to be the dod 440 but all the review say that the power drop is pretty bad.  any sugestions?

[snoof]

if you like the qtron, try the neutron at General Guitar Gadgets.  That and the McMeat are the only circuits of that caliber for DIY IMHO.

[12bar13]

thanks i was just looking at the pdf for the neutron and saw that they offer several options for the photocell. what is the difference between them? i'm looking for a midrangy funky sound with just a touch of distortion if that helps.

here is a link to the pdf
http://www.generalguitargadgets.com/diagrams/neutron_filter.pdf

do you have a resource for the McMeat?

thanks a lot

[merc]

If you're looking for a funky sound, you might want to check out Phuncgnosis.  It may or may not be what you're looking for, but that's the pedal I think of when I hear "funk." 

You can find it at the Circuit Snippets page, (http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html) which also has other great schematics.  If you're interested in the Phuncgnosis or any of the others, the actual layouts are pretty simple to find.

[12bar13]

If you're looking for a funky sound, you might want to check out Phuncgnosis.  It may or may not be what you're looking for, but that's the pedal I think of when I hear "funk." 

You can find it at the Circuit Snippets page, (http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html) which also has other great schematics.  If you're interested in the Phuncgnosis or any of the others, the actual layouts are pretty simple to find.

do you know where i can find a sound clip of this?

[12bar13]

nevermind, i just found the clip on the link you gave me.  have you used this one? it sounded pretty top heavy. is the tone adjustable on this?

thanks

[Gila_Crisis]

check out the meatball!!!

[12bar13]

do you have a good link to a good schematic for the meatball?

[mdh]

thanks i was just looking at the pdf for the neutron and saw that they offer several options for the photocell. what is the difference between them? i'm looking for a midrangy funky sound with just a touch of distortion if that helps.

Ideally, all of the optocoupler options should sound the same.  My understanding is that in practice, the photo-FET optocouplers can be fiddly, and that it can be hard to get rid of envelope ripple in the decay.  I built one of these using the dual-LDR optocoupler available from Small Bear.  This is the easiest way to go, but I'm sure you could also achieve a good result by "rolling your own" with 2 LDRs and an LED.

The question of the range of the filter has more to do with the capacitors in the feedback paths of the op-amps that are actually doing the filtering.  Looking at the Neutron schematic, for example, C6 and C8 are in the circuit when the range switch is in the "high" position, whereas the "low" position puts C5 and C7 in parallel with C6 and C8, respectively, making for larger total capacitances, and filters that sweep over a lower range of frequencies.  The great thing about this is that it makes it pretty easy to tweak the circuit to give you a sweep over a range that you like.  If it's too trebly, increase the values of those capacitors; too bassy, decrease the values.

I'm not absolutely certain about the 1-stage filter in the Phuncgnosis, but I think that to make it more midrangey, you can increase the two 680 pF caps.  Try nearby values such as 820 pF and 1 nF to start.  If you have a breadboard, this is definitely a good circuit to play around with and tweak.  I'm not sure of your level of experience, but if you're sort of new to this, the Phuncgnosis is going to be easier to build than the Neutron, and though it's not as flexible, it can be quite satisfying, especially since you can tweak it to your needs.

[snoof]

do you have a good link to a good schematic for the meatball?

the McMeat is a clone of the meatball.  using the search function will reveal lots of hits

[merc]

nevermind, i just found the clip on the link you gave me.  have you used this one? it sounded pretty top heavy. is the tone adjustable on this?

Nah, I haven't used it yet.  I'm trying to get my PCB built for the Chaos.  As soon as that's done, though, I will be ordering parts for the Phuncgnosis.  But considering shipping from Futurlec takes two weeks, it will probably be a while until I have a completed Phuncgnosis.  In the meantime, I'm trying to keep an open mind, since I'm not completely committed to the Phuncgnosis yet.

[12bar13]

i think that i'm leaning a little towards the mcmeat/meatball.  anyone out there that can give me some first person perspective on this pedal?

[Gila_Crisis]

http://www.pisotones.com/Meatball/psst/meatball-psst.html

[axg20202]

My last major build was a McMeat - it's a hell of a lot of fun (to play, but not to build!) - it's a complex build, mainly because of the extensive off-board wiring, but well worth the effort IMO.

[bleubleu]

The DOD EF440 is a ridiculously simple project, something like 20 or 25 components & 2pots. Check it out on GGG.
It does sound very well to my ear, but I dont know how it compares to other EF. This is only one I built.

Mat

[12bar13]

The DOD EF440 is a ridiculously simple project, something like 20 or 25 components & 2pots. Check it out on GGG.
It does sound very well to my ear, but I dont know how it compares to other EF. This is only one I built.

Mat

i really liked the clips that i heard too, but i was scared off by the review claiming that there is a severe volume drop off in the pedal. it it really as bad as they are saying or is it overstated?

[12bar13]

http://www.pisotones.com/Meatball/psst/meatball-psst.html

there doesn't happen to be an english translation of this does there?

[12bar13]

nevermind i found one here it is for anyone you wants it

http://translate.google.com/translate?hl=en&sl=es&u=http://www.pisotones.com/Meatball/psst/meatball-psst.html&sa=X&oi=translate&resnum=2&ct=result&prev=/search%3Fq%3Dlovetone%2Bmeatball%2Bdiy%26hl%3Den%26rlz%3D1T4ADBF_enUS256US256

[Transmogrifox]

The DOD EF440 is a ridiculously simple project, something like 20 or 25 components & 2pots. Check it out on GGG.
It does sound very well to my ear, but I dont know how it compares to other EF. This is only one I built.

Mat

i really liked the clips that i heard too, but i was scared off by the review claiming that there is a severe volume drop off in the pedal. it it really as bad as they are saying or is it overstated?

One could mitigate the volume drop by building a booster circuit onto the output of the filter.  I would have to study the filter topology more to see if it could be done without adding many parts, but I think a direct filter gain increase would also increase the filter resonance (which may not be what you want). 

An experiment I tried a while back is I bought a DOD FX25 envelope filter for $25 off eBay.  It only took some minor mods to become good sounding and flexible.  That kind of circuit leaves a lot of flexibility for tweaking with minor parts changes.

You could look for a schematic for the FX25 and I could show you some of the mods.  Unfortunately there are a lot of inaccurate schematics for this floating around the internet. 

Another experiment I tried was to convert the Morley Bad Horsie into an envelope filter.  This also turned out relatively well.  You can find the BH schematic at morleypedals.com.  This circuit is pretty much a crybaby that is controlled by an LDR.   If you have a BH, there is plenty of room inside the box to add all kinds of circuits.  To convert it to an EF, you only need to add an envelope follower (like on the EF440) and take a tap from the input buffer to drive it.  I think this route best fits your description of "somewhat distorted".  Just think about an envelope controlled Crybaby.

I had the Phuncnosis built on my breadboard once.  I didn't care for it very much.  It's too distorted to my ear.

The State Variable Filter based EF's like the Neutron and McMeat are what I would call "smooth" and "synthy" sounding.  I don't consider them so much as "funk".  Filters like Dr. Quack, phuncnosis and DOD FX25/B type filters are closer to what I would consider "funk".

[gijimmbo]

i just have to say that i just finished my Neutron last weekend and it sounds AMAZING.  maybe a more intermediate build than the (advanced?) Meatball but still with lots of sonic potential.  totally worth the time debugging... and it did take me a while