Restoring TWO Sequential Circuits Prophet 10 synths and stacking them with MIDI (40 Oscillators)!

The techs at Bell Tone Synth Works vintage synth repair workshop recently restored TWO amazing Sequential Circuits Prophet 10s and since we also retrofitted both with MIDI, we decided to chain them together to create a 20-voice, 40-oscillator monster polysynth! Here's an overview of what goes into restoring one of them, and a demonstration of the "Prophet 20" in action, also featuring our lovely Hawk HE-2150 stereo tape echo. This is like playing FOUR Prophet 5s at the same time!
Sound demonstration starts at 6:42
(in case you don't care about the "tech stuff")
Bell Tone Synth Works is an electronic musical instrument repair workshop in Philadelphia, PA specializing in restoration and repair of vintage synthesizers and organs. Please email us with synth restoration inquiries at [e-mail].
Website: belltonesynthworks.com
Instagram: / belltonesynthworks
Facebook: / belltonesynthworks
Video by Alison and Stout and Darian Scatton, May 2020.

[@buckdiablo7907]

I worked at SCI from 1978 to 1987, this was a trip down memory lane! I built, tested, tuned and repaired quite a few P10's. Compared to SMT electronics in use today, these were a lot easier to work on - you can actually see the components! Now I solder under a microscope down to 0201 size components. (smaller than a grain of sand).

[@blimolhm2790]

That's so cool. I have a SCI MAX here in Australia with a few spare CEM3394s. Much respect to anyone who worked at SCI, I've been meaning to get a hold of the book which explains the history!

[@sasarasa88]

great to see someone who can FIX vintage synths and also PLAY them. It seems to me that there's a lot of passion in this work and I highly respect that

[@kohlemainen]

The world is a better place because of people like you, restoring these wonderful instruments. Love it!

[@gordon7462]

The drones sound better than the shite on bandcamp.

[@Fopenplop]

if i send you my parents can you make them into vintage wurlitzers thanks

[@BellToneSynthWorks]

thank you for your perplexing comment

[@alanhaynes418]

@@BellToneSynthWorks When you see how difficult it is to find a beige/red/green Wurlitzer 200, and how expensive they are, you can understand why Fopenplop asks this question.

[@hot88s23]

@@alanhaynes418 I had a red Wurlitzer. Are you saying it was valuable?

[@eddievanheinous666]

@@hot88s23 Heavens no. And if anyone else has any in working condition they need getting rid of, just PM me and I'll "haul them to the dump" for you for free.

[@Tadesan]

@@BellToneSynthWorks I feel like they were trying to say they liked you... Now I'm perplexed...

[@natevizzi2901]

Dude … that outro was like legendary …. You are unbelievably talented

[@davebellamy4867]

10:07 That keynote! Bzzzz! Gorgeous

[@ZTAudio]

I played a P10 for about 30 minutes back in the day. The idea of having TWO of them blows my mind.

[@philipclayberg4928]

Now I can see and hear why Prophet synths were such an integral part of Robert Rich's early to mid-1980s sound palette. Thank you for restoring these two synths. I hope that they get used for many years to come.

[@Denver_Risley]

Holy moly! 2 Prophet 10's in the same room? I considered myself lucky to see two in the same decade.

[@BellToneSynthWorks]

believe me, so do I!

[@LonnySarao64]

chief tp I wish I could get my prophet to make a sound

[@davebellamy4867]

Someone in the UK also has two. Not me!!

[@fedesartorio]

It’s so conforting to know there’s people out there who know how to fix these things! Great video!

[@Wayne_Robinson]

That was a great troubleshooting story! Your mention of Curtis chips got me reading a bit about them and made me notice how similar some Prophet sounds are to Oberheim OB-Xa and probably other users of those chips. As a complete amateur I'm happy with soft synths triggered from a controller with knobs because they fit my music-gear budget but I really admire vintage hardware. Thanks for demonstrating those sounds which got me to crank my speakers up.

[@wa4aos]

Simply amazing. As an engineer, I am very aware of how early power regulator circuits could fail and pass the source voltage b4 regulation and fry many components. That and Tantalum caps add to the headache. I hope you have some good desolderIng equipment like a Hakko or my favorite is Air Vac.. What a headache it must have been to FINALLY clear all of the faults.. Thank you for the persistence, knowledge and labor to allow this instrument to be played for years to come !! Bravo !!

[@goodun2974]

Your fellow You Tuber Fran Blanche of FranLab is also in Philly somewhere; she builds guitar effects pedals and all kinds of other unusual repairs, builds and rebuilds. When this insanity is over, perhaps you two should meet. Kindred Spirits?

[@Petertronic]

I was wondering if she knew Fran

[@bogdan449]

That drone at the end is the greatest thing I've heard. It's elemental.

[@globalgulag5586]

I had my 1964 Farfisa Compact restored recently. It was in the shop six months. Thanks for explaining how difficult this kind of work is. Labor of Love ❤️

[@davebellamy4867]

In UK or USA?

[@mathumphreys]

Wow - two prophet 10s in one room!!

[@maker-matt]

I actually met Dave in the early years. He was building the "Programmer" the "sequencer" and the P-5 was JUST in production - San Jose in 1976 If I remember correctly

[@Zinfidel1]

That is a beastly synth! You could add some wheels and drive it around. "Honey, I'm taking the Prophet to work.' "Okay! Don't forget the camping gear in the trunk!"

[@holdenapplegate7080]

Fixing and playing synthesizers: the best job in the Universe! I'm amazed by Your enthusiasm.

[@jhowe5571]

You just made the jaws drop and eyes go crazy for every synth afficiano, geek and nut who instantly clicked on the vid link!!! 😱😵😜🎉🎊

[@ssssssssssss885]

Love DIL/DIP IC's. Thanks for showing these holy monsters from the inside to those that will never afford them.

[@SGMGRecords]

Thanks so much for taking the time to share some of this arcane knowledge. Amazing work as always!

[@PaulDonnaErik]

Great work. So nice to see equipment like this lovingly and professionally restored. Also enjoyed the 40 oscillator drone - bonus.

[@samikalastaja]

Very cool to see inside of this synth and thanks for telling about the restoration process.

[@crolodon8024]

Awesome and very nice job. Would love to hear more and see more synths!

[@discodave6153]

Incredible restoration, beautiful synths and lovely playing. Thank you

[@MelissaAtwell]

Absolutely fascinating! Thank you for sharing this. Congratulations on the restorations!

[@jcamp3606]

Huge thumbs up! Amazing restoration!

[@tonaltti]

That drone sounds really good. I wish I could replicate it with VST stuff.

[@matthewghere7765]

This video is my exact niche. I would love to see much more of your work!

[@RandyPiscione]

Wow! I feel like I'm a teen in the 1970s again, amazing stuff! Thanks!

[@thefool2007]

This is fantastic. You’re an awesome person. Brilliance meets art.

[@ZOOTSUITBEATNICK1]

Ahhh...thanks so much for reminding me of the great time I had with my SC Pro One all those years ago. Wish I still had it.

[@adrianreyes4702]

You are such an excellent, well versed instructor! Thank you for sharing!

[@molochlight]

Good information thanks for posting. I always heard about the problems with prophet 10's. That's a real labor of love getting to those up to working order again.

[@mschorer]

Excellent repair job! I once repaired a Polymoog where one broken UA741 took down the whole synth. Its those repairs you‘ll remember forever 😅

[@pablofarago]

Such a wonderfull synth!!! Vangelis used to play one of those, thank you!!

[@FransvandenBergeMuziekschuur]

Just love the way you explain these very complex instruments.

[@danbient]

Great work Alison!!! And a lot of it!

[@Skootavision]

Got to be my dream job! I enjoyed this very much, thank you. Have never even seen one of these in person but TWO whaaa?! Awesome

[@hidude1130]

Great video! I'm glad i found this channel as an audio enthusiast and electronic engineering student.

[@michaell431]

Very cool video, and how awesome these Prophet's sound. I'm very much into synthesizers and the "tech stuff" for decades.. BTSW, You really know your sht.! Thanks for sharing video's about it, much respect.

[@davebellamy4867]

Wonderful job! Replaced almost everything!

[@wajobu]

The foundation of Tony Banks's sound all through the 1980s and into the 1990s. Amazing--Pratt-Read keyboards used to be made in my little village!

[@cotton7960]

There's a moment in his music video for This Is Love where he nearly drops his Prophet 10 and it's terrifying to watch

[@TryptychUK]

That would be Ivoryton, Connecticut? I used to deal with Pratt-Read a lot. They made all the keyboards for the American synths, SCI, Moog, ARP, Oberheim, EMU

[@arcsound]

You must be in southeastern CT, once the ivory piano key industry hub.

[@arcsound]

rowan cotton I would carry mine up and down a spiral staircase, praying I didn't lose my grip or stumble. Not fun.

[@joselares9031]

Very nice Sound...¡¡¡ Stunning reverb...Great Job...YEAH...

[@pianicolas5896]

What an amazing work! it sounds sooooo good!!

[@fallingmanjutsu]

Thank you for this video and for posting videos again in general. I am very much looking forward to more content from your channel! I'm at a loss for words for 2 prophet 10's in the same room. I really believe instruments have some kind of weird destiny thing where they are alive and seek out the right owners and doctors, in this case.....Wizards!

[@clutchbasket5764]

Please make more videos of your work. This was outstanding!

[@blackwatch_TV]

extraordinary tech work and descriptive breakdown! judging by the views, reactions and likes this video has well deserved momentum - Subscribed

[@Rhythmicons]

Absolutely loving this, especially after 10:58.

[@devaux1904]

Thanks so much for sharing the inside and out... Amazing!

[@notahat]

That’s some very impressive restoration work!

[@guitarstringman7403]

Very, Very Impressive. Well done!

[@boombap28]

They worked wonders on my SP-12 a few years ago!

[@subtropical-yearning]

I'm so glad to see this amazing channel posting videos again! I know it probably gets in the way of your actual work, but it does make my day.

[@BellToneSynthWorks]

Glad you enjoy it! We're trying to find time to do more.

[@pauldncn1]

Thank you it's great to see Inside one of these. I did wonder how they put them together Thank you from the UK

[@Godzilla2k69]

Reminds me of my days at EV in Buchanan repairing mixers, amps, EQ's, x-overs and so on. Yes. The IDC ribbon cables cause many problems. That was a wonderful time for music and hardware development.

[@kevinnolan3592]

Absolutely amazing work and a magnificent video - thank you. I've just received my restored and (Winecountrysequential MIDI-fied) Prophet 10 back from Kent Spong. Owner of two T8s too. Passed through some chorus and a modern reverb, they are all immense.

[@officialmikethompson]

2 T8's eh? Wow. I hosed mine last year while re-socketing chips on the digital board... :-(

[@dan_remaincalm]

this is incredible amazing work

[@ghavinga]

Very impressive, really good to know, see and hear it is possible to repair the 'old' electronics inside a classis synth.

[@flippinguitars6566]

Love the technobabble on the repair!

[@rolandmarckwort]

Wow - incredible killer sounding beasts!!

[@lbcsrw]

Thanks so much for sharing this. What a treat!

[@peterbronez1188]

Solid Tame Impala vibes around 10:00!

[@vocoloco8731]

Currents 💜

[@OPTIONALWATCH]

Very entertaining. I also loved what you played.

[@brianostube]

VERY cool, appreciate all the techie details you provide showing how these keyboard instruments were put together! Great work - I know who to contact if I ever need any synth repairs!

[@davidfreeman4808]

WOW! Thanks for bringing TWO P10s back from the other side :-)

[@ELEKTROGOWK]

Great work!!!

[@albertoduran1955]

Amazing work! Congrats! :D

[@fickfehler3866]

You are Synth Goddess ! Your knowledge & quality of work is tremendous ! It's a shame 90% of music these days is thru mouse clicks, quantizing, and autotune ! There's a reason why music from decades ago will still outlast anything made today ! Keep these precious babies alive !

[@Transterra55]

Super Cool....such resonance!

[@superphatal]

Ace repair shop. Made my Juno sing!

[@robertsyrett1992]

I love how they printed little drawings on the circuit boards of those old prophets.

[@yaniv-nos-tubes]

love those hypno sounds!

[@plp9894]

Sounds like the sounds they may have used on "blakes 7" an old British Sci fi show from the 70's.

[@raheemhosein-isolate333]

I was wondering what it reminded me of- Yes good call mate.

[@stationlightyears1532]

@@raheemhosein-isolate333 Yamaha GX1 used extensively by Dudley Simpson on that show! Not sure about P10, but definitely big Yamaha sounds in there. Great soundtrack to those shows!

[@GNeuman]

Haha... Spot on! Great music but the worst not-so-special effects and wooden acting in BBC scifi history. 😂😂😂

[@zazoomatt]

What a Project !

[@marienbad2]

Please make more videos, this was ace! Also, "Spooky Gary Numan sound" was spookily accurate!

[@mattjbyron2010]

that bit at 1145 is insane. great work.

[@johnthrob2486]

You are seriously cool. Cheers. More please!

[@tears_of_heck]

Allison you are awesome!

[@videomove]

thanks for this! you are too cool... and i love the demo, too.! 😊🙏🏼

[@DreamlordRecordings]

Wow ! That reminded me of Blake's 7 !! Awesome !

[@sounddoctorin]

cool work Alison!

[@eeddingt]

“A digital-side apocalyptic event the likes of which we’d never seen before.” Lol. Oooo, this is getting good!

[@basehead617]

Awesome video

[@claudiostano]

Thank you for this video !

[@thegreaterconundrum]

Brilliant!

[@artrprod9620]

Very well explained! Thx!

[@conquerantofficiel]

Congratulations, you made a very great job. 😮

[@nreyntje]

Very cool!!

[@VimyScout]

Lovely to hear

[@leukostad1592]

Such a distinct sound. There was so much wrong with that instrument, I admire the work that went into it.

[@SeansMusicVault]

This was fun! I see a mellotron vid from ya'all as well. Heading on over! [edit] That 40 oscillator drone had my studio rumbling. Beautiful!

[@expandingknowledge8269]

Only saw one, Prophet 10, in a vintage guitar 🎸 shop in Keene N.H., And it was in rough shape. Sure love 💘 the old analogs. 😃

[@melodikmusic]

Wow! Just wow!

[@kenny.maytum]

Brilliant! Dave Smith would be proud.

[@buddhabillybob]

Fascinating video! Thank you. I love slightly outdated computers! I can understand them...

[@OCEANSINSPACE]

this is amazing and very unique! you rule!

[@johnforguites4800]

nice work and great trouble shooting

[@Pauleyh2]

Not only do you have awesome knowledge your also an amazing keyboardist wow!!