Experimental Delay & AmpMod from Noise Workshop

Started by knutolai, January 05, 2016, 06:35:17 PM

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knutolai

Hi and happy new year! Hope everyone is doing well!

November last year I held a pedal-building workshop for Bergen Improstorband, a musicians collective which comes together to do experimental improvised music. I thought I'd share them here for those of you who like their sound noisy and lo-fi  :icon_twisted:

I designed two circuits with a emphasis on expressivity and a minimal BOM. There's a PT2399 delay and a LM567 pseudo ringmod. The circuits are of course based on countless other similar circuits, but add some interesting features that set them apart.

Lo-fi delay with selfmodulation and extended delay range:

This is a delay using a combfilter architecture which combines the Feedback and Delay Level into one parameter. There's also the option to let the delay modulate itself which can sound very strange. Like a parasitic, squirmy ringmod-esque effect.

Odd Amplitude Modulator/Noise Synth:

This one is kinda unpredictable and unexplainable on my part. Very much the result of a "what happpens if I do this?"-approach. The parameters are very interactive, so there is a lot of noisy exploration to do. It features a voltage starve and a feedback loop with some form of crossover distortion (went silent without the diodes). Be careful not to power it with more than 9 volt as you might burn the LM567 with a higher voltage.

Here are a full documentation of the projects with GERBER-files for anyone interested in building these:
https://pladaskelektrisk.com/wp-content/uploads/2016/01/Documentation.zip

The PCBs will easily fit into 125B enclosures if you use the layout shown in the documentation. Enjoy!

PRR

Interesting.

The Odd Mod may be more predictable if the external source comes through some resistance, so it does not fight the feedback but mixes nicely. 100K from IN to C3, R1 raised to 100K or to whatever works.

Experimentation needed.

"More predictable" may NOT be more interesting to the musicians.
  • SUPPORTER

duck_arse

don't make me draw another line.

duck_arse

knutolai - I haven't breadborded the messy delay yet, but I have a perf layout (should fit 1590A, for people who can accurate measure) if anyone is interested. it is 99% ready to show.

and, the link to your docs returns "Unable to complete secure transaction", seemingly because of the https. http worked ok.
and and, on your circuit dias - the AmpMod schem shows "9V" and "+9V" either side of D1, but the delay shows "+9V" either side of D1, which won't work right.
don't make me draw another line.

knutolai

I'm on my phone atm. Not cooperating well with diystomp.. The "+9V"/"9V" markings on the positive end of the reverse polarity protection diode is just the power supply connector. Should not be connected with the "+9V"-net. Realize it's confusing. It could be labeled "power" instead for instance. Interested in seeing your layout!

Cozybuilder

Quote from: knutolai Lo-fi delay with selfmodulation and extended delay range:


This is a delay using a combfilter architecture which combines the Feedback and Delay Level into one parameter. There's also the option to let the delay modulate itself which can sound very strange. Like a parasitic, squirmy ringmod-esque effect.

Odd Amplitude Modulator/Noise Synth:

This one is kinda unpredictable and unexplainable on my part. Very much the result of a "what happpens if I do this?"-approach. The parameters are very interactive, so there is a lot of noisy exploration to do. It features a voltage starve and a feedback loop with some form of crossover distortion (went silent without the diodes). Be careful not to power it with more than 9 volt as you might burn the LM567 with a higher voltage.

Thanks for posting a couple of circuits that I intend do have some fun with.

There is a problem with the orientation of the LED and Resistor in the Millennium Bypass, they should be located on the drain, not the source. I've had intermittent luck when wired as above.

Here is a quote from the Geofex article:
  "The Millenium 2 circuit is an inverter, not a follower like the Millenium 1, so the LED must be in the drain circuit of the device, and there must be a current limiting resistor in series with it."

You can read the whole article here:
http://www.geofex.com/article_folders/millenium/millen.htm
Some people drink from the fountain of knowledge, others just gargle.

knutolai

#6
Still on phone, don't know how to quote, but the LED circuit works as is. I've used this setup (borrowed from Valvewizards Engineer thumb (thanks!)) many times with no issue. Don't know how it compares to the Millennium bypass, but it definitely does work.

EDIT: incomplete sentence

duck_arse

blast! topology arguments. oh well, for those interested here is the circuit, redrawn, and (MY EYES!) for the colour adverse, both match knutolais dia. e&oe. if any found, please let me know.

here is the latest completed game of tetris (b&w by request only), needs check and verify. I do like to fill the mt spaces .....



board has no notches or mounting holes, but is small enough that you can add board where you like. a bit hectic in some places, and note the 2 shorter resistors. there should be joggle space for other-sized parts, plan ahead.
don't make me draw another line.

knutolai

Quoteblast! topology arguments.

Lets settle with saying there's a lot of ways to toggle a LED. The whole MOSFET LED switching circuit could be removed by using a 3PDT footswitch (I just hate offboard wires!).

duck_arse

ahh, well, an alternate layout to suit the millenium bypass can be seen here.
don't make me draw another line.

lethargytartare


knutolai

Could try to have a short clip of the delay up before Friday. I don't have the AmpMod myself unfortunately.

lethargytartare

Quote from: knutolai on January 11, 2016, 12:36:26 PM
Could try to have a short clip of the delay up before Friday. I don't have the AmpMod myself unfortunately.

Well, ok, then I guess I'm gonna have to breadboard it :-)

knutolai

Yeah sorry.. Was not supposed to have the delay either, but there just happened to be enough parts for one after the workshop

duck_arse

I have this on the bb today. let me say, I haven't heard a "residents" record for maybe 30 years now. and once all the farting noises* were dispensed with (there are lots), and you find a sweetish spot where it starts feeding itself, and start noodling, AND THEN just barely bump the delay knob, either way ...... well, it's "duck stab" all over again.

and if you've ever "heard me play", duck stab is the first thing you think of.

if there was a way to add that knob-bump function, it would be a real winner.




* they are not the good farting noises either, more like the wet-ones.
don't make me draw another line.

knutolai

I'll take that as a compliment!  Love duckstab!

knutolai

#16
Here's a track of the Ekko. A lot of random noodling around, but it should showcase most of the available sounds:
https://soundcloud.com/knutolai/workshop-ekko

Sorry for the annoying swoshing-sounds and terrible recording-technique. Don't have a proper setup at the moment. Phone-recording.

moid

Hi there

I've just joined the forum, so I apologise if this is the wrong place to ask my questions. First of all thanks to Knutolai for posting this and to duck_arse for his layout. I'm interested in building this delay but I wish to build it on vero. I've had a go at drawing the schematic out on vero and I'd be really grateful if someone could have a look at it and see if there are any mistakes that are visible. It's the first time I've tried to draw a vero layout from a schematic (first time I've tried to read a schematic!) and I've only built a few pedals from vero layouts so far, so there might be mistakes or silly ways of doing things that I'm happy to be corrected in. I've decided to use a standard true bypass 3PDT switch to activate the pedal. I drew all the cables connecting the pots because it helps me not make mistakes when I build the pedal.

I do have a question about how I've connected lots of cables to ground. The schematic seems to require lots of these cables all to (presumably) join up at the ground on the dc jack, and I'm wondering if anyone has any advice for connecting such a huge mass of cables together in a slightly neater form?

Thanks for your help or suggestions, sorry the below image is large, but any smaller and it was hard to read. If you right click and choose Open Image in New Tab it should display in full I think


Mushrooms in Shampoo -  Amidst the Ox Eyes - our new album!

https://mushroomsinshampoo.bandcamp.com/album/amidst-the-ox-eyes

duck_arse

moid - hello and welcome to the forum. and this is certainly the best place for a question on this circuit at the moment.

your layout. you don't need to run all the earth wires to the same point. on the pots, for example, you can link across the 2 grounding pins, and then run a wire back to the veroboard, anywhere along the bottom row will do. a sleeve to sleeve to dc jack wire is good.

I'll look closer to your board overnight, but: are we to assume there is a cut under the right most 1uF cap? and, I always preach '"double links" are are a bad idea, and to be avoided', especially seeing you have so much room on this board. me, myself, I'd put a shorting to the left of pins 3 and 4, then run a longer link to bottom row under the IC.

nice use of colour, except you've used the same green to 4 different spots on the same side of the dia.

and: your regulator. see if you can shift it right across to the IC pin1, and up 3 rows. (or, invert and shift across same level, about 3 or 4 rows from the IC.)

if you shift the 220nF and 1k left 2, you'll save some more, but this is only a quick look, and you'll make some changes, so I'll look again when you show rev2.
don't make me draw another line.

duck_arse

an update: the 1k from pin12 shows wrong. if you turn it 90 degrees, and cut under, it will be korrekt. there also needs to be a cut between the left hand 1k and pin8, if it is there, it's not visible.

I see no other errors.
don't make me draw another line.