Twin T Drums - Practical Electronics January 1978

DIY TWIN T DRUMS?
Im doing next weeks video as a builders livestream TONIGHT :- / lookmumnocomputer
You can watch back the livestream after! needless to say this supports the upcoming museum.
more info on the museum of everything else :-
www.museumofev...
BREADBOARD MOUNTING BOARDS
www.lookmumnoc...
Paypal :-
www.paypal.me/...
ARCHIVE COPY :-
worldradiohist...
other issues here :-
worldradiohist...
#electronics #science #retro

[@THISMUSEUMISNOTOBSOLETE]

Join the livestream of shooting and building the project for next weeks video tonight :-@t December 1972 archive copy :- worldradiohistory.com/UK/Practical-Electronics/70s/Practical-Electronics-1978-01.pdf

[@paulevans4334]

I've got a shit tone of these magazines from the 80' up to the early 2000's

[@zenithparsec]

Very nice video. I like the analysis of the signals in the magazine, showing what the circuit does. Perhaps you could use an oscilloscope to show how each of the stages shapes the signal when demoing it?

[@Ratkill]

Came for the beeps, stayed for the boops.

[@jeremywinnett6352]

Came for the beans, stayed for the toots.

[@ryanmalin]

Bleep bloop

[@ExStaticBass]

I built one of those for me Gran's electric organ in 1988. I found the design in that same issue at the local library after she'd asked me if I knew anything about stuff like that. It didn't turn out like the picture on the front there as things go but it worked well enough. I remember making some real bangers with that and me Gran actually rather liked it oddly enough. Then again she always was a rather odd one.

[@DoodMangSpeaks]

My Dads mom was very creative and really out there. She did a lot of art and loved different cultures. Very stubborn and independant even in her 90's. She drove over an hour when she was 93 years old just to prove my parents that she could still run her own life. She didnt even let us host coffee and lunch with us she just smiled and said love you and got back in her van and left. Those weird grandmas are the best. Haha. Making a beat machine to jam with grandma sounds awesome and somehow reminded me of my grandma.

[@Nukle0n]

Your gran sounds really cool encouraging you to work with electronics.

[@Gin-toki]

The most important rythm is defineltly Bossa Nova. You can't take any rythm machine seriously without a bossa button!

[@maxine2798]

the english translation isn't New Boss but it could be

[@greenaum]

Ideal for those Pixies covers.

[@dykodesigns]

Right on the first page on the lower left corner: A heading with “TV games” and various general instruments AY pong chips listed. I bet many readers of that magazine in 1978 would be building their own version of Pong using these off the shelf chips. A lot of commercial pong clones used the same chips.

[@Bartyron]

I have an Odyssey 2100 with pong from around '78 computerhistorischmuseum.nl/collectie/philips-odyssey-2100/

[@greenaum]

Yup! The later numbered chips had background graphics, like a grid of matchsticks, that they could make basketball hoops out of, and even a primitive Breakout playfield. They were a good bit rarer than plain 4-game "video olympics" models. Dunno why, really, prices weren't much more and infinitely more fun to play.

[@doughankins3996]

Sam. You have inspired so many people including myself. Thank you. I even told my kiddos, "don't be scared to try it". They were making kites. They had a great time. I can't wait to start making more things. Thank you again for your inspiration and sheer enthusiasm for learning and showing others.

[@richardsinger01]

Since you asked, in 1978 I was a teenager reading these magazines, wishing I could afford to build these projects. Everyday Electronics generally had simpler, more affordable projects if I remember correctly.

[@bigjd2k]

The ingenuity of the designers was awesome - it sounds pretty good for such a simple circuit, especially for the time when it’d sound similar to the keyboards (or organs!) of the day.

[@fathomisticfantasy2681]

For all the work you done on the basis of, "free information for all," I really hope your museum is a big hit. May God bless you with a place of tribute to go down in history forever known as Look Mum No Computer. May God watch over you and your country in these difficult times. Amen

[@josemarquez950]

I have been on KZbin for 15 yrs and this is one of the most unexpectedly delightful videos I have ever seen. Your delight when you made the clave 🙌🏼

[@Defecato99]

Nice video !! I pulled the rhythm unit from a T500 Hammond organ that my boss had thrown out. At the moment its composite PCBs are lying on my bench. Theres the switching PCB for rhythm selection ( 15 rhythms which, like you mention, you can super impose by pressing more than 1 button), the tempo and rhythm generator board and the drum voicing board which, like you say, uses a white noise source for the snare, cymbals, hats etc and an oscillator for the bass drum, toms, congas etc which are formanted to make the drum sounds. All passives and transistors. I'm feeding around 24 volts into it and it works !! :) Now, I would like to put it all in a nice enclosure and possibly run it from a 12V supply ... I'm thinking I could supply the required 24 volts using 12v and a boost converter. I alos want to be able to trigger each drum sound seperagtely so I can make myt own rhythms. Not sure how to go about that though. Any thoughts ??

[@andyallan2745]

I’ve been wanting to do some of these old circuits since I got interested in electronics and music. Well 1983 to be exact so thanks for getting around to it for me.

[@ZizoMass]

I loved how you use a drill bit to point things, definitely gonna copy that

[@davidbwn]

The 1974 version will be very interesting. As it would use TTL logic for the sequencing which means you could basically rework the rhythm patterns.

[@THISMUSEUMISNOTOBSOLETE]

bit of a spoiler alert for the next vid ha

[@soejrd24978]

aw heck yes, I might whip this into a Eurorack project

[@hayd7371]

This has just become my favorite KZbin channel

[@edwincancelii2917]

I was in my final year of preschool at age 5 years old, in Coney Island, Brooklyn, New York City, New York, U.S.A.

[@MindlessTurtle]

Excellent video! Love the circuit analysis and signal processing breakdown.

[@baddriddimworkshop]

Gaham Bishop's book "Audio Circuits and Projects" has that rythm generator circuits in it too (not exactly what i would call a quick build for beginners though), and it has the layouts for veroboard mounting too... I wouldnt be surprised if that magazine's project would be grahams (a big name in vintage analog audio electronics design)

[@johncoops6897]

0:17 - where was I in January 1978? I was entering the final year in high school. We were smuggling booze into school, smoking cigarettes and dope, and doing very little school work. Most of the school days was spent in the amusement arcades in the city (Sydney) and we just broke into the school records room to adjust the attendance roll. In our spare time we were building drum machines, sequencers, dimmer racks, strobes, "Musiccolours" (light organs) and other lighting stuff so we could use them at dances. This allowed access to many parties and lots of willing girls. Life was very very good indeed in January 1978.

[@ray_gannon]

in Jan 78 I was buying this magazine!

[@frontier9]

Quality episode - loved it - subscribed

[@demagmusic]

Thanks for the stripboard layout! makes it really easy to try. Awesome vid, per usual

[@profProsky]

Thanks very much Sam! Wish I had found this instead of the wonky Heath kit FM radio I built at 15.

[@8bitwiz_]

Where was I in 1978? I was a kid playing with electronics! And waiting for home computers to happen. Only over here "RS" meant Radio Shack. Too bad I didn't care much about music then as a naive youth, beyond getting a 555 to beep a speaker. Yeah, it looks like the M253AA was the star of this show. That "3072 bits" with the beat patterns was probably 256x12. Twelve sequences at 256 counts per 4/4 bar, or 64 counts per quarter note. Or half that if the sequences were two bars. (3/4 or 6/8? Go take your waltzes somewhere else!) Seems a bit like an unobtainium part now, but it contained the sequence counter and the multiplexers for the beat selects to the outputs. You could build it from discrete parts, but you can't really get a ROM that small these days. At that point you might as well go full Linn! But you could probably get an Arduino to stand in for it. Racking just the oscillators was a good idea.

[@Stuartrusty]

Meter is led, not nixie. I used to get these magazines regularly as a child, it's so good to see them again. Love your enthusiasm for this kind of stuff. Thanks so much.

[@LOOKMUMNOCOMPUTER]

Aaah my bad

[@dj1NM3]

If you wanted to make drum pads that should trigger the sounds, I came up with a design years ago: It's a piece of 1mm sheet steel A5 paper sized, with a piezo transducer epoxied on the underside and some thin craft foam on the striking side. Polarity shouldn't matter, just connect one lead to the trigger and the other to earth/common.

[@Bleats_Sinodai]

You could make a sequencer using a 555 oscillator and a CD4017 Decade counter. 555 determines the play speed, CD4017 steps between each of it's 10 outputs per pulse from the 555.

[@Bleats_Sinodai]

I believe that by connecting the 9th output of the CD4017 to it's reset pin, you'll get an 8 step sequence. I'll have to test it sometime later.

[@cleekersneaker]

I love this. A fresh wiring up of the sound of 78.

[@codewizard58]

I loved the "Ingenuity Unlimited" section in these mags. Some crazy sound circuits in there.

[@sebbothebushnerd]

Literally just released a video of my own using some of these twin-T drum circuits! Spoopy timing! The feedback from these things are so ear shattering! 😬😅

[@stephenparry6811]

i like that you translated prices, 250 quid was about the cost of a zx80 in early 80s & that was an expensive outlay

[@ryanmalin]

Pretty cool circuit project from the past. I also,like you used to say Clavs lol. When you demod the circuit at the end I was surprised at the range that circuit has! Sounded great!

[@mrenglishjawa]

if you havent found it yet in Everyday electronics from june ish 1988 there was a long series of audio modules like phaser /compressor /delay /vco/vcf etc all based round an Lm13600 (now replaced with the 13700 ) using a standard pcb for all the projects. something that may keep you going for a while

[@jrodrigo1984]

Thanks man.

[@AW-Services]

What a great year 1978, I was 3 watching my dad rewiring the home

[@UzumakiNarutoX3]

Wow cool! Been looking for an easy to follow e-drum project for a long time. Deffo gonna give this one a try :)

[@jamhough22]

A little tip - the ringing when tapping on the bench etc is caused by the ceramic capacitors, you should never use ceramic capacitors in audio applications due to this reason. Change them for something like film capacitors (MKS and MKP are brilliant for audio) and you wont have this issue.

[@LOOKMUMNOCOMPUTER]

Cool; will give it a go!

[@THEREALDATALORD]

What a great idea for a series. Top shelf bruv.

[@h2o1969]

That was pretty interesting. Thanks Sam!

[@tylerevans1700]

That was awesome, can't wait to try it out

[@mericseker]

beautiful series, keep going!

[@PexiTheBuilder]

This is just what I need, thanks!

[@elektroarkivet]

The twin-T is a nice little circuit. I did something similar years ago, but with just an NPN transistor as active component instead of digital gates. Will try to do this with vacuum tubes later and get something like a Wurlitzer Sideman. :-)

[@tommyfoley]

Wow, I have been waiting for someone to make something like this. Thank you for sharing!!! In one of your next videos can you show how someone might wire up the triggers like Wolfgang and Karl from Kraftwerk, drum pad drumstick type of configuration?

[@joakimengstrom4924]

He has a video where he does that already!

[@mikeschonebaum1198]

Wow I’m early, love this series!

[@sawsquaresinetube]

Sam, I love this series!!

[@gustavosicaviani7553]

freaking awesome Sam!

[@sammerritt730]

You should try and attach piezo elements to use as triggers for the drums :)

[@TheBananaPlug]

In 1978 that rhythm generator kit was = 2 weeks of my wages! Phonosonics BTW was owned/run by John Becker who in later years became the editor of PE.

[@chrishopkins209]

I hope you have a section dedicated to R A Penfold

[@dominiccarlsson2891]

Ha, I was hoping to build this as described by the magazine but those M253AA chips are hard to come by! Fascinating stuff nonetheless.

[@arsenicjones9125]

One of those oscillators sounds so much like a donkey braying that I got up to go check on my donkey. Kinda wanna build a donkey synth now using this 🤦‍♂️

[@PaulTheSkeptic]

Where was I January of 1978? *slow jazz Ah I remember it like it was yesterday. It was a warm winter. The Pansies were in bloom. And a warm peetey smell drifted upon the breeze. It's my diaper. Time for a change.

[@dogwalker666]

Most of these have been scanned and are available on the internet archive.

[@THISMUSEUMISNOTOBSOLETE]

indeed! check the link in the description whole archive

[@UnauthorisedService]

those magazines are quite some resource !

[@rockpopmando1]

oh yes, these old magazines. I bought a stack of these in 1990 and throw them away in 2000. I found most of them online here: DIY-schematics from the old days ... www.drummachines.de/beatboxer/ritmus1.htm#diy I build the ZX81 Drums which used the ZX81 as the Pattern-Generator. Planned to bring back to life this year.

[@ogasi1798]

when i was a kid this sort of publication was all over - if they did this now their would be more people into it-

[@chrishopkins209]

I was one month old when that magazine came out.

[@rockpopmando1]

a very cool Cymbal-Synth based on nearly the same ICs .. a lot of logic-ICs create a FM-like digital FM-Noise. www.drummachines.de/beatboxer/beatboxer/etihh.htm

[@ManfredGerhard]

Interessant 🧐

[@soejrd24978]

ja

[@greenaum]

Hm I think the claves might sound better a bit lower pitched. Depends on the particular blocks of wood you're after I suppose but your ones do sound a little bit tinny. Also of course if you don't have the right cap, you can always parallel a couple, and add the values. Or else put them in series but I still can't figure out exactly how the maths behind that is supposed to work. If you wanted a more modern-style programmable sequencer, just a Johnson counter producing the sequence, and have an LED on each output. Then a whole lot of diodes and switches leading to the drum triggers.

[@THISMUSEUMISNOTOBSOLETE]

I like em high and tinny it sets em apart from the other sounds. imo.

[@toolzshed]

Whoa sweet!

[@flourfree2K]

Some considerations immetiately jumped in my mind. The 4011 NAND gates are used as inverters. Therefore, any hex inverter chip would rok as well, and they could have made a 6 oscillators drum kit (for the "toned" sounds): For instance: microcontrollerslab.com/74hct04-hex-inverter-ic/ OR, alternatively... an inverter is a single switching transistor, right? Then it could be made by using any NPN you got laying around your desk. OR, alternatively... by using a transistor array in a chip, like the TPQ3904: www.tekkna.it/open2b/var/catalog/product/files/7589.pdf

[@kellymerrill5294]

Just built the Addac T networks 103, it's amazing for plinky plonky drum sounds! Now I can add more!😹

[@pete3897]

2:42 - you're supposed to say spoiler alert BEFORE the spoiler! That's why it's an alert :)

[@hippynurd]

Sam, I like that you get to use your name on this channel

[@fransdebruijn6763]

its not a microprocessor, its a ROM with some added logic.

[@Fifury161]

They published a sound generator based on the AY-3-8910 chip, I'd love to hear the finished product...

[@duckyvirus]

Jan 1978.... i was 1 month old.

[@glenesis]

In Jan 1978 I was freezing 🥶

[@madhatter8508]

Hey, do you know what kind of drum machine Young Marble Giants used? I know it was built out of a magazine kit but I've not been able to find which kit they used.

[@jeffseven2194]

Klaaaahhhh......vaaaaaaaaa.. been pronouncing that wrong for 50 odd years, thanks for straightening me out Sam. Have a fantastic weekend

[@devjock]

I'm betting there's not a lot of folks that know that CGS stands for Cat Girl Synth though.. Ken Stone is such a legend! You can still find the old site at synthpanel dot com

[@slick8086]

oh man i gotta make this

[@LOOKMUMNOCOMPUTER]

Yeyahhhh

[@MrFlint51]

@5:37 -according to Collins' English Dictionary "claves" is pronounced CLAYVES, and is always plural because you need two of them to make a sound

[@johncoops6897]

Of course it's "CLAVES" - what on earth is a "Clarr-vay"??? Claves, Staves, Knaves, Saves, Behaves all use the same letter structure and rhyme

[@positrone]

Does it need to be a CD411? ...or just any other NAND like 74HC20? ...both 5V.. Thanks & cheers

[@ChrisLeeW00]

Would a LPF prevent that feedback?

[@devolutionrc8016]

It would be cool if you built the (High Definition Amplifier) on the previous page as well and combined the Drum Machine into a standard alone kit/module?! 😮😁

[@MeriaDuck]

9:55 scared the h... Thought one of my fire alarms went off.

[@nrdesign1991]

This is *exactly* the kind of circuits I found in old electronics magazines, books and websites when I was a little kid, didnt understand a word of it, but it still seemed awsome. Later I just didnt have the time and patience to try it all out. Thank you so much or letting me sort-of re-live that time :) There's also a few early arcade games that made their sounds without microcontrollers. One of them being *ASTRO BLASTER* which has a few cool sound effects, all built with analog electronics. You should definitely check out its service manual for the complete schematics: files.arcadeinfo.de/Anleitungen%20Spiele%200-9%20A-D/Astro%20Blaster.pdf See PDF page 57 and 58 for the interesting bits. I've tried simulating the sonar and shot sounds, but it was a little too complicated.

[@factorsistemas5396]

Can someone explaine me why the Nand gate?

[@MartynDavies]

Beguine is pronounced like beg-een. Nice video.

[@robotmr]

Cool :) What a Software you used for drawing your Stripboard Layouts?

[@MrMargaretScratcher]

@ 0:16 - ELECECTRONIC FAULT DIAGNOSIS?

[@eatshitgoogle]

9:05 FULL BRIDGE RECTIFIER!!! ... Confirmed.

[@Wobblybob2004]

Have you tried decaf?

[@lagduftothemax]

Hey Sam, is the stripboard layout on one of your websites or is it in on the LMNC patreon?

[@THISMUSEUMISNOTOBSOLETE]

right now just a screenshot of the vid pop it on 4k, this week when I have the rest of the strip board ill make a page for it

[@lagduftothemax]

Ha! That’s exactly what I did. Cheers!

[@brianspenst1374]

Just before 15:00 RIP my ears in my headphones.

[@TheSTONEones]

Ive just got all the parts together to build this too. On project board not vero board. Im going to use my science fair 500 in 1 kit microprocessor to supply the pulses to the drum circuits. It gives you 64 lines x 8bit of code available for user programs. Thats it lol. Thinking 32 lines for drum patterns (8 steps per beat 4/4time) 32 line available to code some kind of sequencer / play user patterns. 8 outputs available to run 8 instruments. World radio history site has all these vintage electronics magazines and more. Its a gold mine. Ive been looking at some of the guitar effects pedals circuits back in the 70/80s. some really cool effects and easy to build. Like your channel, been watching many vids.

[@GlitchyfrogMusic]

how are you making sure that you don't overshoot the Voltage from the Bstp? Is there a way to set the gates to 5V or is your circuit secured?

[@THISMUSEUMISNOTOBSOLETE]

I usually go with the notion if it goes pop it goes pop

[@GlitchyfrogMusic]

@@THISMUSEUMISNOTOBSOLETE hahahaha xD I see :p Asking because I am using the BSP with a AEModular. Wouldn't risk something on this Baby. Smoked my first DIY parts last week :p

[@THISMUSEUMISNOTOBSOLETE]

@@GlitchyfrogMusic aaah cool! tbh the above circuit will take 12v happily without it going pop :)

[@graxjpg]

Jan 1978 my dad was 13!

[@LOOKMUMNOCOMPUTER]

Wheyy same

[@graxjpg]

@@LOOKMUMNOCOMPUTER a few years after this my dad would blast Black Sabbath from his car for the god fearing folks walking home from Catholic Church LOL

[@pardonmysandwich6943]

My dog likes the claves

[@mancavemusician]

Man, what did you do to your Beat step Pro 🤔😲

[@THISMUSEUMISNOTOBSOLETE]

haha that one has been through the mill haha

[@hughman8597]

Double yüüaarr !! Cool !

[@bigsby19]

January 1978 I was 6 and going to school.

[@leftmono1016]

I was only 5 at the time, trying hard to earn new words at school for my word tin. Which still smelled of tobacco.

[@maikmario71]

Very important: I've tried different CD4011BE, it doesn't work! it only works with the CD4011AE !!!!!!!!

[@shagarma_oharim]

Man, I've been trying on and off with the CD4011BE for months using both the LMNC layout and original schematics with little to no succes. It worked once, but only on 1 quarter of the chip, and couldn't replicate it afterwards. Im ordering CD4011AE immediately if thats all there is to it.

[@gartmorn]

I was an Everyday Electronics man myself!

[@Porkcylinder]

You sound like the guy off ‘look mum no computer’?

[@THISMUSEUMISNOTOBSOLETE]

I am the guy off look mum no computer

[@Porkcylinder]

@@THISMUSEUMISNOTOBSOLETE ha! Well how about that? Love your crazy synths wish I had the brains. Btw just took delivery of a korg microsampler today. Just thought I’d mention it 💁🏻‍♂️

[@JG-nx3jg]

The people who wrote these instructions really had their work cut out