SDIY Class # 5 - Pocket Passive Patch Pals and the JFET Delight

Spring fertility special :) A bunch of easy useful passive thingies, including a really awesome Jfet waveshaper/VCA/ring mod!
Video and Music by Quincas Moreira
If you like the music you can buy it here: quincas.bandcamp.com/album/gr...
And please support me on Patreon! / quincas

[@stardustjustlikeyou]

I really like this concept. It's like building blocks even smaller than the modules themselves. Didn't have any of the JFETs you've got here but I grabbed a J201 JFET and managed to make something similar to yours! Mine has more bleedthrough and less waveshaping, and doesn't play as well with negative voltages, but hey! It works! Took me like 15 minutes so I'm not complaining.

[@QuincasMoreira]

cool :) Yeah, I keep thinking of more of these, wich I had a big factory in china to roll these out :)

[@circuitben]

That JFET thing is really special :)

[@QuincasMoreira]

Ain't it though? :)

[@Vaxoid]

Absolutely great and helpful video. Thanks!

[@Synthikat]

Awesome Video! Cool small tools. Ty for uploading!

[@OB1techno]

Made the JFET delight. Works a treat 🖤

[@geargabbilly]

I can't wait for the weekend to try making a few of these, especially the Jfet. Thanks!

[@Vult-DSP]

Very cool! thanks for sharing this

[@demagmusic]

Great video as usual! Whenever I build something without a PCB I use a dab of hot glue on the components so they can't shift around under the heat shrink and short out later on (If someone were to squeeze it too tightly, etc). Keep the great ideas coming

[@QuincasMoreira]

Good idea! Thanks :)

[@jasonleiter7557]

This is really inspiring stuff man. Great channel.

[@QuincasMoreira]

Thanks!

[@afi6061]

Brilliant video! Just kind of thing I need! 👏👍

[@QuincasMoreira]

Cool, enjoy!

[@Malice_in_Wonderland]

love your video's! thanks for the inspiration!

[@QuincasMoreira]

Thank you for watching!

[@jeanse27]

Just made a jfet delight and I love it! So simple! Thanx diy guy!!

[@QuincasMoreira]

Great! You're very welcome!

[@gorillaau]

For preventing shorts, you can also use hot glue... I have done this when making a custom ribbon cables which is the soldered to header pins. Oh. Forgot to mention that you can shape the hot blob glue with a wet finger or two.

[@QuincasMoreira]

good idea!

[@MisterNiles]

You are inspiring man! That JFET thing! I need to do an order. I'm making all of these. Great video. Thanks.

[@QuincasMoreira]

Hey, thanks!

[@RaccoonEatingCacti]

Found a couple of bags of JFETs from last year's order. Couldn't remember what I got them for (aside from being great to have) but I think it was this actually! Thank you! Elegant, simple, good. I think I was also going to use them to make circuit bent items CV compatible.

[@KiR_3d]

Funny! I've thought about some similar thing (a passive attenuator) when I've bought Neutron ~ year ago :) Will try your ideas when I'll have time! Thanks for the video!

[@QuincasMoreira]

Cool! Yeah, these are kinda obvious, somebody's gonna make them into products some day, I'm sure :)

[@unsoundmethodology]

I built a couple of the simpler ones of these about a year ago, when I was building some homebrew modules, but since I recently got a MiniBrute 2S I sat down today to build an IamO. Had to wrap it in that rubber tape that molds to itself since I didn't have large enough heatshrink on hand (now I think of it, Sugru could have worked well too). It does what it's supposed to beautifully! These are such a nice companion to a semi-modular setup, as you can tote them around and not have to build them into a case.

[@flaminggarlic]

Damn dude, IamO is a pretty novel little circuit. Cant wait to get this put in a panel.

[@dillipphunbar7924]

Superb...just what I wanted..trying a passive LPG based on your other video , to fill up the remaining space in the rack, and these little "beans" will be awesome companions. Thanks

[@QuincasMoreira]

Glad it helped!

[@mewantgoodmusic]

thank you

[@Tharsismusic]

J201 works very well for the fet

[@QuincasMoreira]

good to know, rhanks!

[@churchofaggressiveaudio6498]

Coolest thing ever!

[@QuincasMoreira]

thanks :)

[@shinrinyoku69]

/me googles JFET sampler pack. Thanks for the inspiration! What a nice model for micro-scale DIY hacking.

[@QuincasMoreira]

thanks Brian :)

[@1951split]

I made a bunch of these too. They really come in handy at times. I got the idea when I needed to remove the DC offset from an output signal, so I just put a cap in line with two jacks. I love your heatshrink solution btw, mine look a bit crude...

[@QuincasMoreira]

Jean-Jacques de Balzac cool, thanks!

[@pantalalabs]

very good!

[@QuincasMoreira]

Gibran Curtiss thank you :)

[@obsessive_discipline]

tight, just got a delivery of my first JFETs, gonna try

[@QuincasMoreira]

cool, have fun!

[@synkrotron]

Thank you again Quincas for some excellent ideas. I really like the JFET thing that you build with the 2N5474 transistor. They appear to be obsolete now, at least the Faichild ones are. So I need to research if there is a suitable replacement. cheers andy

Did you find a good substitute? Im trying to start doing some DIY but is really hard to know to components to start those things

[@synkrotron]

@ Hi André :-) I am afraid that I didn't manage to get to look further into that. Sorry! But as soon as I do I will reply back here. It may be some time as I do not have any funds at the moment. cheers andy

[@bloubear2557]

@ try a 2n5486

[@vitriolix]

looks like a cool way to get into DIY, any chance you have a part list and/or schematic for these?

[@Lea_Der_777]

Very cool tutorial, thanks a lot for sharing! And which delay you used for sound demo of IAMO module? Very clear and beautiful sound of delay...

[@BadChizzle]

Just watched this one again. I Dig all of these and have been making doodads this last week or so. Created a Cool vactrol gate, low pass gate, attenuators and so on. Even did the diode one a couple times. Currently working on a plate reverb DIY... and many other things at once. When i get balled up on one project, i just switch over to another for a bit. Also started a passive ring modulator with two transformers and four diodes last-night. Yeah... I’ve been busy! Sheesh... you should see the mess!!! 🤷🏻‍♂️🤣

[@QuincasMoreira]

keepin' busy Chaz!

[@BadChizzle]

Synth Diy Guy Ok yeah... don’t what else I’d say to that, either. Thanks for the response!

[@enekolorentebilbao1746]

what kind of transformers do you use? whenever I look for how to make a ring modulator, I can't find what kind of transformers to use

[@BadChizzle]

Eneko Lorente Bilbao I picked a few 7k to 10k audio isolation transformers, but one to one will work ok too. One in and one out. I think anything called an isolation transformer for audio will work... but ask around anyway, I could be wrong.

[@enekolorentebilbao1746]

@@BadChizzle Thanks for the info

[@TheHalpap]

Great Work! Very Inspiring! Keep doing great stuff! You make me want to start doing with these things to. You show that its not that hard to to that kind of things. Very nice man!!! Where do you get inspired? Where do you get the schematics and things?

[@QuincasMoreira]

Hey thanks :) I originally got most my inspiration from guys like Ray Wilson (RIP) and his site MFOS, as well as Ken Stone (CGS), Yves Yusson (Yusynth) and others. Building some of their designs got me started in electronics for music and that sparked my interest, curiosity and creativity to start experimenting with my own ideas. Nowadays I'm very inspired by all the kits I get to review. It's less creative to build a full kit but it teaches me things I can then use on my own creative endeavors. Thanks for watching and stay noisy!

[@ekkoflok]

Thanks for the video :) a passive vcf (vactrol + cap) is also very suitable to this mini format. Enjoyed your video, nice setup! Perhaps you could get some sponsor money from Arturia and Make Noise, as you made me consider buying both :p Cheers!

[@QuincasMoreira]

Hey Thanks! I already did a video on the LPG: kzbin.info/www/bejne/bnOyn6mJhtWifbs I do get all my Arturia stuff for free from them, and do beta testing for Make Noise, maybe when I'm raking in millions of views they'll pitch in :D

[@zannfilm9645]

Great video. Very inspiring to see what can be done with such a small number of components.

[@QuincasMoreira]

Thanks!

[@zannfilm9645]

@@QuincasMoreira have you written these up? As great as t hey are I find it difficult to follow via video

[@QuincasMoreira]

@@zannfilm9645 Pause on the schematics page!

[@zannfilm9645]

@@QuincasMoreira Got It!

[@modularbeats2661]

Great video! but can you explain me, how the "i am o" works? what is the capacitor doing? an what kind of signal must go into the modulation input? Thank you!

[@QuincasMoreira]

E Sessions , the cap is for AC coupling, so the audio comes out centered around 0v, no offset. The Jfet needs a good bit of juice to work well, a full 10v swing from modular sources is recommended. Works with bipolar as waveshaper and ring mod, and positive only or negative only as a pseudo VCA. It's basically a clipping amplifier where we're using cv to power it. Thanks for watching!

[@thefrogsucker7663]

Nice video! Thanks for sharing thos usefull and cheap devices, also wich pot did you use for the attenuator?

[@QuincasMoreira]

Thanks! Any pot from 10k to 100k should work!

[@thefrogsucker7663]

👌👍👍

[@Dekkie61]

This is just great... I was wondering: can the little mixer be used for accurate cv? I am building a little switch for +1/0/-1 octave. I wanted to to mod my lil erebus to connect it internally, but it would be even better if I could sum it to a 1v/oct signal: 1v/oct input, switch, and a smed 1v/oct out. Would that work, or would the sum not be precise?

[@QuincasMoreira]

Hey, actually there is a bit of voltage drop and interaction between channels on a passive mixer, so no, it's not recommended for precise applications such as VCO tuning. Better use an active mixer for that :)

[@maybury78]

Great thanks for this. I am planning to put a couple of the I AM O's and a couple of attenuators into a panel this week. What Pots do you use 50k Ohms?

[@QuincasMoreira]

Great! I use 10k pots, but anything between 10k and 100k will be fine

[@maybury78]

@@QuincasMoreira That's great thanks for your swift reply. For the 100nF cap in the I AM O, does it need to be more specific than 100nF, do I need to use a ceramic or electrolytic? sorry I am new to electronic components.

[@QuincasMoreira]

@@maybury78 no worries. Electrolyticas are generally used for values above 1uf, so you can assume values below that are ceramic or polyester 99% of the time!

[@maybury78]

@@QuincasMoreira That's very helpful thanks. D

[@SantiagoReil]

Congrats on your videos. Really liked these passive tools. Would be cool to put the tools used. I know most of them, but for instance, I'm not very familiar with heat shrink tube. Which size did you use? And less important, but may be useful, which brand. And, as Spanish is my native language, how would you call it in Spanish? Thanks.

[@QuincasMoreira]

Hey, thanks! I used the largest Heat Shrink I could find, 1 1/4¨ (about 3 cm). En español le dicen Termofit (al menos en Mexico), lo que segun yo es un fabricante. EL nombre correcto seria tubo termo retráctil ;) Saludos!

[@SantiagoReil]

Muchas Gracias!

[@livelooper]

Thanks for a brilliant series of vids. The only patch pal type of idea I already had was to put a diode into a home made patch cable. (fix fro a problem with a Behringer Neutron, but also a good tone modifier). Maybe for simplest patch pal things it's better to make up a special cable. Anyway, totally inspired by your stuff. Incidentally, do you have a music channel? (that background music is great)

[@QuincasMoreira]

Thanks! The reason I like to do it like this is you can then use whatever length cable you need, whereas with a specialty cable you're kind of stuck. Check out my website, there's most of my music work in there: www.quincasmoreira.com Cheers!

[@livelooper]

all too true, I made my cables long enough for a specific function...then suffered. Of course, could always replace just one of the sockets with a cable. Another thing I made was to add a 2 colour led to a jack, wired so it would show green for positive and red for negative. ...bet you did that already though.

[@QuincasMoreira]

@@livelooper It's a cool effect ! I haven't done it myself, but I may do it with a bicolor LED :)

[@lordzombie]

Could you build the passive attenuators with a single cable instead of the jack? Like just a dedicated attenuators cable?

[@QuincasMoreira]

of course! I only do them like this because I like to choose the right length cables for each application. If you make them into cables then you're sort of stuck to that cable's length

[@quollism]

These are the coolest! :) I found PJ301BM jacks at Thonk and saw you're using 1 1/4" (~3cm) heatshrink in another comment, but what's the resistance of the potentiometer? :)

[@QuincasMoreira]

10 k pots! thanks :)

[@QuincasMoreira]

anything from 10k to 100k will work just fine though. Since they are wired as dividers, what matters is the ratio between each resistor in the divider. There is some impedance variation but if you stay within the 10k to 100k range it won't matter.

[@quollism]

Synth Diy Guy thanks! :)

[@quollism]

Also wanted to ask: is there anything special about the 2N5457 JFET which makes it better suited for this purpose than an alternative JFET? Is it in a sweet spot between doing nothing and popping when it gets modular-level signals fed into it?

[@QuincasMoreira]

I just happen to have 5457's in my drawer because they are used in a lot of MFOS designs! I think it would work with other JFETs and even BJTs, with some variation in sound I would expect.

[@daneguitarist1]

dude! those are amazing can i buy like a bundle of them.. like 1 of each i am not quite at the level to make my own, i can do the full diy kits, but everytime i build something it doesnt seem to work, like i miss some little thing

[@daneguitarist1]

also, im a composer for my day job, maybe we could collab in some aspect -Dane www.imdb.com/name/nm8068897/ [e-mail]

[@QuincasMoreira]

@@daneguitarist1 Hi Dane! Cool, what kind of composition work do you do? I don't make anything to sell, I'm afraid, no time. You can do it though, these are easy ;)

[@daneguitarist1]

@@QuincasMoreira hah you hope in my abilities to follow something step by step gives me hope for the future hah I usually do thrillers, but horror and documentary and really whatever nowadays I just woke up did I post my links? I'd love to collab or at least jam at some point in life I'm in kansas -Dane www.imdb.com/name/nm8068897/ www.soundcloud.com/gerbilhamstercompositions (film) www.soundcloud.com/gerbilhamster-records (record label) [e-mail]

[@davidschessl129]

i have a question about the ringmod: what would be the difference if i would use a BC546 instead of the JFET?

[@QuincasMoreira]

I don't know! You'll have to try it and find out :) Please report back so we know!

[@davidschessl129]

it is working! it may sound different, i can't tell i also changed the 100k resistor to a 470ohm resistor in series with a 100k pot, so i have a dry/wet pot with strange behavior ;)

[@QuincasMoreira]

awesome! I'm gonna try too :) Thanks!

[@akaleri]

I'd love to hear the results when you guys are done. c:

[@Fedor_Tkachev_Music]

Hey Quincas! Will I get a phase reverse if I made a patch pal that simply connects two sockets in reverse, I mean plus to minus?

[@QuincasMoreira]

Hi! You mean polarity, not phase reversed. Well, no, because the "negative" side of a switch or jack has to be ground. So on a bipolar signal both positive and negative are on the "live" or tip, and ground is the reference 0v. If you invert passively, what you'll get is a unipolar output of only the negative side (I think) as positive on the other end. For unipolar positive signals, you'd be draining the entire signal to ground, and grounding the destination's input, so you'll get just 0v. Some engineer please correct me if I'm wrong! Cheers!

[@Fedor_Tkachev_Music]

@@QuincasMoreira so there's no passive way to reserve phase?

[@QuincasMoreira]

@@Fedor_Tkachev_Music Again, you mean polarity, not phase ;) Not that I know of no. Unless you're dealing with balanced signals, or the output puts out positive and negative separately on T and R of a TRS cable, and the destination input receives the same signal arrangement. Then you can invert T and R and get polarity reversal. Ground is there too on the Sleve though! www.pro-tools-expert.com/production-expert-1/2019/4/25/how-to-check-and-correct-phase-in-your-recordings-expert-tutorial#:~:text=Polarity%20inversion%20is%20the%20reversal,becomes%20negative%20and%20vice%20versa.

[@Fedor_Tkachev_Music]

@@QuincasMoreira right, makes sense, thank you!

[@pickleboysupreme]

Commenting a bit late, but from what I remember, all filters introduce a phase shift, meaning theoretically you could have a low pass with a really high cutoff to change the phase, although I don't think it would be that practical and I can't say for sure that's what happens. I did however find an active one that is relatively simple to make, and it's shown in this link www.allaboutcircuits.com/technical-articles/focusing-on-phase-the-all-pass-filter/ hope that helps!

[@liamkramer-white4228]

Noticed that cv doesn’t work as an input signal, any easy fix for this?

[@ignaciodelvillararce4925]

Donde consigues los componentes en México?

[@QuincasMoreira]

Algunos en Republica del Salvador en el centro, pero es mejor pedir en línea de Mouser, Digikey, Tayda, Thonk, Synthcube, Small Bear, etc...

[@ignaciodelvillararce4925]

Muchas gracias por la información. Tardan mucho tiempo en llegarte ? Te cobran muchos impuestos por traer ese tipo de cosas a México?

[@QuincasMoreira]

@@ignaciodelvillararce4925 La verdad no, Mexico es de los mejores lugares en latino america para eso, talvez por la cercania al gabacho y NAFTA, quien sabe... suelen ser 16% de importacion, Mouser entrega en un dia con flete gratis si pides mas de 40 dolares.

[@stefan1024]

It's great what you're doing here, but it would be very very helpful, if you write some keywords down. As a non native speaker I still don't understand what those modules (except the JFET) do. What's the first one? An "ateniorator"? "Antantoater"? I googled several variations and still don't have a clue. I'm not a lazy student but I need something useful to start with. Anyway, great work!

[@QuincasMoreira]

Hi, thanks! I thought I explained them pretty well in the video! But here goes: Attenuator, Gate Combiner (multiple Or Gate) , Passive Mixer, Passive Mult, Resistors, Capacitors, Diode. The Jfet does bipolar VCA, Waveshaper and Ring Modulator duties. Hope this helps, cheers!

[@stefan1024]

Thanks so much! It wasn't the explanation per se, just the words :)

[@schmeraldgukk332]

Rammels du auch gerne Schildkröten oder Enten babys

[@olGrandpaby]

I’m very new to diy electronics so I’ll hope you’ll forgive my ignorance but I was wondering if that vca/waveshaper/ring mod would work the same way if used with a synth that runs on 0-5v unipolar (the AE modular by tangible waves).

[@QuincasMoreira]

Hi! The Jfet delight thrives on strong bipolar voltages for modulation. You can send it a 5v audio source but a 5v positive only EG or LFO will be less than ideal. It'll work, just not the same as in the video.

[@olGrandpaby]

@@QuincasMoreira Thanks for the info. Since the parts are so cheap I might give it a try on the breadboard anyway just to see what happens. There’s no risk of damaging anything in my system if the circuit is passive right?

[@QuincasMoreira]

@@olGrandpaby yeah, do it! no risk :)

[@dannyroessler]

@@olGrandpaby How did it work for you on the single 5V system?