MF#36 Vintage analog Synthesizer 1981 E&MM Spectrum Repair
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- Опубліковано 29 жов 2014
- A repair of a rare vintage 1981 synthesizer suffering from sample & hold drift and badly corroded key switch gear. these were Home made synths that was a project from a 1981 magazine. very few were ever completed. Tardis VFX at 21:30
I have to buy most items myself to make these video's so any help would be greatly appreciated "become a Patreon" / markusfuller
I built one back in the day when I was 18. It was that or driving lessons - the synth won! Designed and built a Z80 based CV-trigger sequencer for it as my final year project at uni, both still work but the Spectrum needs a bit of TLC.It got me a job at Calrec audio then AMS-Neve on assignable analogue broadcast consoles. You've inspired me to get it out and restore it to its hey day. Thanks, great video.
Did you get it out and restore it? :)
Fantastic channel, thank goodness there's something on the internet still worth watching, thank you!
wow Thankyou very much
Love the dr who and sonic screwdriver bit. Such enjoyable vids you make
+Michael Bauers Thanks Michael. the video after this one shows how to do the video effects.
Amazing video, completely jealous of your skills!!! And please don't EVER think that i video might be too long, or be boring, i would have watched 3 hours of you troubleshooting this synth without a problem!. Keep up the amazing work Markus, cheers from Argentina!
me too I loved it very enjoyable video.
I can't do what you do, but I love watching you bring these things to life...Great stuff.
thankyou magikroom. Im pleased you like them. I enjoy making them in the hope that people will have a go at some repairs themselves.
Tanks for your tear downs. After watching a few of your videos I was able to take apart my Novation Impulse49 and fix 5 non playing keys.
My dog ran away when you played that thing at the beginning.
Charles Blakely used to live outside of Blackpool in the 1970s and in the late 1970s early 1980s I bought a lot of his Digisound80 modules (run via a Tangerine computer).... I met him once as he helped me solve a problem with the keyboard interface... I also bout a EMM (Electronic Music Magazine) Maplin kit and my mate who works as an instrument designer at British Leyland set it up for me, and he was amazed at the stability/accuracy of the module. Since then I have caught up with a guy who worked with Charles in the early days desigming the modiles
You still have that gear?
The "envelope shaper" board has two parts; the CEM3310 chips generate a control voltage, which then controls the gain of the two VCAs in the CEM 3330 chips. The audio goes through these VCAs to produce the Attack, Decay, Sustain and Release phases of the sound. The control voltage, or "envelope" is also used to sweep the frequency of the filters.
This video was worth it for the Dr Who sketch alone! Love it! :)
this is by far and away the nerdiest video i've seen on youtube. great stuff!
You certainly got the Nerd bit right :-)
Really love your channel! I'm very happy to see these machines coming back to life. And you explain things so well! Thank you!
I loved E&MM... I couldn't afford to make their projects but it was an endless source of fantasies... that eventually got to come true.
Your best video yet, and your best car boot find yet !
I remember the kits being for sale in Maplins back in the day, i wonder how many were started but never finished ?
You did a fantastic job getting her back to the point of making decent sounds again and i am sure with a little more work she can sing again.
Great work and well done on the repair of this rare old beast of a synth from the past.
I notice the ZX81 on the workbench, i found 2 of those at a garage sale last week with the 16k ram pack and an Alphacom printer !
Hi Neil. Thankyou very much. took me days to repair but I think I need another going over on the main control pots or maybe maybe change a few for new but other than that she sounds pretty sweet now. best wishes from Markus.
I would say that the contact bar tarnish could be a conductive silver oxide, but perhaps I am wrong... Otherwise, great work, as always. Kudos!
Super cool find, thanks for sharing
Nice repair & well done Markus .I always wondered why Dave jones doesn't interested to tearing down synthesizers & musical stuffs then I found your satisfying channel .
PS, the screwdriver humor was epic :D
Really nice score. Thanks for sharing.
what a brilliant repair job !!! thanks markus.
The sample and hold circuit usre a CA3240E Op-amp with a JFET input stage(IC 5). This gives it an input impedance of 1.5Tohms(!), so that it draws virtually no current from the capacitor that is holding the keyboard control voltage. The pitch drift is therefore caused by leakage through the capacitor.
That was brilliant!!!
Brilliant video as always Marcus, even though that Dr fella turns-up & pretends to help :p
Great to see (& now hear) one of those E&MMs after looking at many of the magazines back in the day, and it's brilliant to know this bit of electronics history is in good hands.
Thanks for all your help sharing your knowledge & skills - You deserve that feline cat-span & hope to see you find 8 more treasures :)
Thanks brickscratch. at the moment Im trying to make some sounds with it using the CV gates etc. I think I still have a little bit more work on it yet before its back to its original intention. A couple of the switches need replacing or taking apart for full clean up but this is a keeper for me. best wishes from Markus
Glad you enjoyed the Spectrum. Great video! Thanks.
Well, damn you, you've made me dig out my original Maplin 4600 synth which I built back in the early 80's. Believe it or not, but it was my first ever electronics project. At the time I was doing an electronics apprenticeship at Boscombe Down (MoD).
Now am going to have to spend hours getting to it again. Will probably have to replace all the caps and fix all the switches that are looking very crusty. I've still got the build manual with all the schematics. Maybe I'll make a video of bringing her back to life...
Did you restore it?
Great find! great video Markus, reminds me of the Transcendent kits you could also buy at the time, i always wanted to build one but could never afford.Sounds great, loved the Tardis bit too..he he ;-)
You need some DeOxit. That stuff is amazing for cleaning and deoxidizing electronics. It's made by Caig. Absolute miracle for stuff like this.
I remember that magazine. Because Autocar and motor where separate magazines. Now only Autocar
that was really enjoyable, and the synth sounds fantastic.
Great video! Hilarious. Thanks. I'm glad it was you that found her I would not have had the time to make her shine. See you at the car boots
Hi James, This one came from the last Adur car boot. see you in the new years sales, Best wishes...
The bus bars should be palladium plated, but they were stupidly expensive and I can imagine some builders might have used something cheaper
A friend of mine built a Spectrum when we were at school; I don't know what happened to it, but sadly he's no longer with us.
Wow, this 'make you own synthesizer' took me back to my early teens. I used to get that magazine. Never built the synth though. :) Great video. Loved the Tardis.
The sound those keys make when struck is similar to when the garbage truck picks up and empties your bin..lop.
Wow, that brings back lots of memories of me as a 14 year old kid lusting after this in E&MM and the Maplin's catalogue. That and the Powertran Transcendent 2000 in ETI. I ended up with a VL-Tone instead. Im still hoping one day I will pick up an ARP 2500 from a confused old granny that thought it was a telephone exchange from wartime.
Excellent travail. Congratulations.
Cool video. I just dug mine out of the loft.
Amazing find...I've heard of these but never seen one
Thank you for all this videos Markus, it's great to see all these synths inside, I specially like when you talk about synth architecture and specific chips and their utility, im learning a lot! I'm studing electronics for the last 4 years. When I finish my studies I want to work on music technology... Watching your videos I realize I know nothing about electronics in audio/synthesizers. Could you suggest me some blogs, books etc to learn about this please?
Every boot sale I have been to just has a collection of knackered Yamaha PSS rubbish.
You are one lucky man! - cue solo!
Yes theres always plenty of Yamaha & Casio home keyboards on the bootsales but I never pick them up as I do not think they would make a very good repair or teardown.
Hi Rickteven, thats a good Idea. I could easily convert these to a much smaller eurorack design. and use the CV gate to control them. I don't know what the keyboard is worth as in would it be better to make it smaller or has it more value as the original synth ?.
I just picked up a PSS 460 this morning from the car boot sale. actually it sounds surprisingly good.
got to get there earlier!
You blow my mind........in a fantastic way!
amazing recovery
Had one of these in the 80's...gave it away!
Very nice! Such skills, and then the bit at 22:00 lol!
Amazing work!
very enjoyable video thank you.
Thank you :-)
Fantastic video!
Great video Markus, found it by searching for the Maplin Spectrum Synthesizer on Google as I've just got mine down out of the garage loft ready to sell on Ebay. Hope to switch it on and test it this week, I also built the 1 volt/octave pedal board featured in E&MM to control it. I'm now looking forward to setting them all up again, from what I remember mine always drifted so your video will come in very handy in checking it out. Also have the complete set of E&MM magazines from April 1981 through to May 1985. Although haven't located April 1985 yet but it will be in the garage somewhere.
I loved, loved this video. Thank you.
Wow! Very ,interesting, thanx for making the effort of putting all this over footage. you got yourslef a new subscriber. way to go man....
I repaired a (relatively) old Roland in the 70's by replacing those springs with heavy gauge guitar string. It actually used bronze wire busses.
Thanks Mark! great vid!
Nice Video, Markus, many thanx for sharing!
Be aware of that the absolute maximum ratings of the CEM ICs power rails are +/- 15V. You better go for +/-12V rails, or you may accidently kill these CEMs due to sudden over/under voltage by less than half a volt. Of course you have to do the calibration again, but it´s worth it, otherwhise you may need to replace one or more CEMs in the future.
One thing on this synth that i found rather interesting is that the Keyboard CV is viceVersa to all others. As the key CV should go up as you play higher notes. In this case here it is inverted, as it goes *up* when you play from high to low notes.... If you gonna use this thing with a midi/cv interface it will not be playable.....
Hi Tubical. I have not tested what the CV & Gate jack plugs deliver. maybe they are the other way around to the internal circuit ???. I will have to check them out.
That Tardis Skit was impressive! :]
Brilliant vid, very enjoyable and well explained, I've got an old Korg M500 s it's a bit unpredictable, perhaps I'll take it to bits tonight, ha ha lol, keep an eye on eBay it will probably be on spares or repairs.....ha.
I've had trouble with those poly layer caps in S&H circuits before. No measurable leakage, but they just won't stabilize.
Very interesting video.
Oh wow Markus! Brilliant video, funny, informative and damn interesting!
I think you found yourself a bit of a rare diamond there - sure it looks like it was a fair bit of work to get going but now you have a CEM analogue synth! Im very jealous! Congrats & enjoy mate!
Thanks mCKENIC. when i first fired it up I thought it was going to be stripped for parts and the CEM chips for ebay. Im glad I got it going though if you look at the clock in the video you will see it took several days but well worth it. It sounds a little crusty on some of the pots but I will give them another clean, But wow what an amazing analog sound it has. this is certainly staying in my collection. Best wishes from Markus
Holy crap this synth sounds good
Nihil & Void where did u hear it sound good??
Really interesting piece of synth history! I've picked up a few on car boot sales, I think my best find was a Yamaha CS10, which I paid £10 for...
Excellent. Thats a very good find especially for £10. just shows there some treasures to find on the car boot sales but luck is also required. right place at the right time :-)
Love this one !
Man, I sure would like to find some of these 'car boot' markets you're frequenting
it's more than a year and no one dislike this?
How about now?
I'm amazed to find this video!
I bought and built the Spectrum when I was at Uni (not really what my student grant was intended for!) and it was an amazing synth. When it worked (not that often) it sounded incredible - especially when heard through a decent amp and big speakers :-)
The worst part of the design by far were the keyboard contacts. Those f***ing springs were a complete bastard to solder so they all lay at the same height over the bus bars. I can fully understand why they had been glued to the keys in your Spectrum synth. The best part was that it was stereo and you could pan the right-left via the LFO. That made it sound HUUUGE!
Thanks for the video. Do you still have the Spectrum? Would you sell it...?
Great vid!
This is pretty much your masterpiece video.
you are a boss Markus!!
I have a similar multimeter to that. The MX54, can't find any good info on it online, nice meter though, one I use the most. Nice bit of vintage analog tech there, I do like musical instruments although I can't play them to save my life.
This video put a smile on my face. How'd you do that Tardis trick...lol!!
+finimo Hi finimo the tardis trick is explained in the next video that follows this one. ua-cam.com/video/V57np_DKfko/v-deo.html
That Doctor Who scene was fucking stupid and amazing at the same time, love it!
I was momentarily distracted by the ZX-81 behind.
+edgeeffect Ah the ZX-81 yes it is on my shelf. I just cannot throw it out as I keep thinking I could use it one day. I have owned it since 1982 but seem to have lost the 16K rampack
I would love to buy one as mine got stolen!
thank you for that deep explaining ! Awesome informations for ressurecting analog synths. As you scrap with the screwdriver along the busbar I got goosebumps - do you not afraid to destroy a gold or silver coating here ?
I built one in 81. It was great but the keyboard was a bit of a nightmare.
please make these videos very long and boring, love them..
Use Tarnex. it will have amazing results without any scrubbing or scraping
i spent hours drooling over the magazine but couldn't afford the kit
+davegetsspam Yes it was still quite an expensive Kit back in those days. I wonder just how many they actually sold.
+markusfuller well i am in australia so it cost a bundle to ship but i met the 1st editor (or 2nd) a aussie guitarist who stuck his photo on the cover of the 3rd or 4th edition with guitar and their latest guitar project.
Great channel
What is the situation between address lines and data lines.? What I want to know is why do I get these segments? My drum machine has 16 switches or pads but when I take my prodding tool to the bottom row I always hear the top row instead.
I only watch these videos for the special effects ....
wow wow
At 14:09 - are a few board labeled "MAS". I have encountered the same manufacturer in my Italian made "Jen SX1000" monophonic single DCO synthesizer, which I bought second hand for $19.
till-kopper.de/jen/jen_sx1000_inside3.jpg
Hi I do not know who MAS was but i too have seen them in other synths. A friend of mine had the Jen SX1000 but would not sell it to me :-( and I offered a lot more than whet you paid . Good bargain at $19
markusfuller Thanks. I only had to replace one LF353N opamp on the LFO board and order a replacement "E" key as one was broken. I managed to score one on eBay for 6EUR from an Italian seller to which I "made an offer he could not refuse" (ending an auction): lh3.googleusercontent.com/-bRBLKJAGYlY/VHy2MtL8efI/AAAAAAAADXw/ukc0mYTOJBM/s716/Untitled.jpg
Hi Markus, what is the resolution of your multimeter? I need one with a high precision to calibrate and check voltages in my Eurorack. Cheers!
bahaha the screwdriver bit killed me. This was really awesome, is the magazine/manual online? I'm curious as to how involved this build is.
Hello. I did manage to find some PDF copies of the original magazine that this was published in but could never find the whole series as it was placed bit by bit in the magazines that maplin published some years ago. Mainly the whole thing could be built today but im not sure if there were a few vintage chips involved that would be quite difficult to track down now.
markusfuller ahhh I was worried that'd be the case. Not too surprised...luckily I have my Axoloti board to keep me busy for now (diy "modular" digital synth board...you might find them interesting! )
Thank You very much, Markus! Really nice video, esp. cool idea with a phone booth)) I`m looking Yours videos during long time and finally subscribed now =)
Markus, if You`ll once time get a Roland JP-8000 - make the teardown video of it, please. It would be very pleasure for me to know with what chips, components it was built.
Cheers from Russia, Vladimir.
=sorry for the grammar=
Vladimir Q-Trinity Hi Vladimir i will certainly open up a jp8000 if only i could get my hands on one for the right price :-)
Great.Thank You, Markus. I`ll waiting for this sweet moment =)
I was kinda interested in listening to how VCA/ADSR sounds. Most 3340 synths I have have software generated envelopes. :) Oh well... Great video anyways!
TheLT Sorry I sold that spectrum synthesizer several years ago. I should have kept it but did not have the space.
So does this have an Oberheim-style filter? SVF?
great video. Loved the Tardis cameo. How in the world did you do that video trick?
Hi Stefan. the Tardis is bigger on the inside :-) LOL. actually it took me over an hour to put that bit together.
what piano was used in the song "flashback" By "Imagination"?
You would be so helpful if you could answer this or know what brand of piano made that synth lead. This was in 1981 when the song was popular.
Hi Alex. the cover of the album looks like a steinway model B piano. but I think the instrument you are referring to was a clavinet through a bit of studio effects. I have seen one of them in use on Leee Johns Imaginaton concerts. but then there was also a rhodes piano and a couple of other old synths which I could not identify.
Hi Markus,
Unrelated question if you don't mind , have you any idea on how to service / check a Behringer MDX2200 COMPOSER PRO ?
Where would you start as I have similar test equiptment for servicing HF tranceivers ?
Much appreciated.
😊
@@andrewverran6998 Hi Andrew. I am sorry but I have no idea or info on the Behringer Composer Pro. I do not know how to help you other than the usual dig around google for info. my apologies.
@markusfuller no worries Markus, ULI doesn't make things easy.
✌️.
Didnt bernard sumner build one during the early joy division times?
Yes I think I read that somewhere when i was digging around the net for info. Im working on the big brother at the moment Maplin 5600s but its becoming a difficult rebuild as it had never been completed by the original builder. but Im on my second week of trying to work through the many problems.
the computer in the background isnt a Spectrum, but close enough ;)
Tardis vfx at 21:50 not 21:30
Hi.
I have this synthesizer. It's in perfect working condition now. I'm trying to find out it's value/ price. Can anyone of you guys help me out?
Thanks
Electronics & Music Maker archived : www.muzines.co.uk/mags/emm
I'm clearly going to the wrong car boot sales. All I get is pot ornaments, old clothes and food poisoning from half cooked burgers...
;-) In Kit ?
This video is great hahaha :)
Another one in operation here at Hale Studios, London. :)
instagram.com/p/lZ7v6xTds0/?modal=true
Hi Markus
Do you repair Synthesizers as a hobby, or can anyone bring their keyboard to you and use your services for a price of course?
regards
phil
Hi Phil. Synths Keyboards and electronics are really my hobby now as I have different work. I use to work repairing them years ago but I just cannot find the time now, the last repair I did for a customer took ages and I think he got annoyed because it wasn't repaired instantly. However If I can help with information then I will try my best for you. what seems to be the problem ?.
markusfuller Nothing really, But I had to get my Kronos investigated for a scratchy key, and couldn't find anyone local to Worthing/Brighton, to look at it, eventually found someone in Eastbourne..But thanks anyway...
ok Phil. Glad you found someone. Im just so bogged down with work at the moment it would have sat here for ages. sorry about that.
Even back then you had the horrible VAT? Such an insult to liberty I wouldn't stand for it. Anyway, nice find. Are there still some people out there that have not heard of eBay and sell things like this at trunk sales? Not around here. Everyone checks eBay.
I was amazed to see this. like I said I think this is a once in a lifetime find. (Hmmm I hope we humans get 9 lives like cats do ) there could be another 8 vintage synths for me to find.
I'm clearly going to the wrong car boot sales. All I get is pot ornaments, old clothes and food poisoning from dodgy burgers...