Prophet 5 Under the Hood w/ Rob Rosen-Clip

We move on to the Prophet 5 which is the first fully programable synthesizer created by Dave Smith by instituting the Z80 chip. Rob Rosen from Rosen Sound gives us a close look at his REV 1 instrument signed by Dave Smith (that was most likely made in his garage). Dave Smith was the first to create a micro controller based instrument that essentially replaced a lot of the complexity in the CS-80. We’ll see the innovative part of the Prophet 5 where the software lives and learn how it controls and interfaces with the sound producing components such as keyboard scanning, voice assigning and sound parameters. We’ll see an early DAC that converts digital into analog and discover temperature compensating resistors. Ribbon cables replace much of the miles of wiring in the CS-80.  We isolate on the Oscillator envelope chips and Rob compares the sound of the REV 1, REV 2 and REV 3 versions. We view the keyboard mechanism with J-wires, a bus bar, and how voices are assigned via a myriad of computerized decision making options.  Rob and I agree that by understanding the way things work on the inside, it can affect the way we play the instrument.

00:00 Prophet 5 History
01:00 Introduction to Prophet 5 Rev 1
02:43 Dave Smith Innovations
03:36 Inside the Prophet 5
08:52 Rev1 vs Rev2 vs Rev3
09:50 Z80 Microprocessor and signal path
12:11 The Keyboard and Computer Calculations
15:23 Why understand how it works?
17:10 From Analog to AI

Follow Rob @rosen_sound on instagram

Anthony's musical touch as both composer and performer is connected with some of the most influential creative minds over the last 40 years. He’s composed and conducted original orchestral scores for over 80 feature films including Young Guns, Internal Affairs, The Man From Elysian Fields, 15 Minutes and Planes, Trains & Automobiles, been commissioned by the Los Angeles Philharmonic for his symphonic work "In the Family Way", written over one thousand TV commercials in a myriad of musical styles, co-founded Levels Audio Post (LA's premiere post production facility) and performed and arranged on big-box-office films and influential hit records such as Michael Jackson's Thriller.

His extensive work as a young arranger, orchestrator and performer for Quincy Jones, Jack Nitzsche, Lamont Dozier, Arthur Rubenstein and Giorgio Moroder was vital in launching his own career. His early years pioneering modular analog synthesizers along with his wide-ranging music scholarship positioned Anthony at the center of the music technology revolution. He attended the University of Southern California School of Music as a piano and composition major.

[gcoudert]

I've had a Rev 4 for three days now and I can't tell you how much I love it!

[jimlemons]

Awesome! Cool Rob mentioned Yellow Magic Orchestra, I love those guys! How cool to hear all the signal paths and processing explained by Rob too!! Great stuff Anthony!

[johnnybegood]

cool closing comment - the individuality of each "dancer" dancing together is what makes it appealing to us (humans ;) 👍

[funkycochise]

Lucky days to be able to watch such kind of amazing contents. Knowing all the background behind the different revisions of such an iconic synth leaves me speechless. Anthony and Rob work perfectly together. Technical and Artistical points of view demonstrates why theses instruments are so fascinating and has some kind of magic in them. Keep going !

[falangistavaleroso]

I got yesterday a SCI Prophet 2002+ sampler from 1985 ( I got 2 in the 90´s). It shocked me for good that the PSU is magnetically shielded. Dave Smith was a genious, perhaps was to avoid the magnetical radiation deleting the diskettes. I got a friend with deep EHS electrosensibility who can´t stand being close to microwaves or magnetical radiation and I borrowed his measurer. I got more recent samplers as E-mu 6400 turbo that are not shielded, either any Ensoniq is. My Akai S3200 is also shielded. I never had any John Carpenter Prophet 5 but I love my Pro one and the Prophet VS. Rest in peace Dave.

[DevanSabaratnam]

Watching all my favourite bands on TV in the early 80's, the Prophet 5 was always standing out on stage, leading me to always wanting one... I still hope to one day get the Prophet 6. Thanks for this breakdown.

[aerickmccullough]

Really love this!

Rev 4 Prophet 10 user here. (rev 4 Prophet 5, 10 voice version)

[touchthatdial]

Took me 40 years or so but I have finally bought myself a Prophet 5 (Rev 4 desktop module) after so many years of wanting one. I absolutely love the thing. It is such a simple synth when compared with more modern alternatives but it is pretty much impossible to get a bad sound out of it. Beautiful piece of work.

[MusicoElectronico]

A masterpiece of electronic design! Love your channel, keep going!!! 🎶 🎵 ❤️

[Goettel]

All the love for old gear and its preservation is amazing and so is all the love that goes into the new gear, hard- or software. Best time for synths in my 40 years using them, use what you have.

[ozhalljr]

Dave Smith was the man, there's no question about it. Not to be forgotten in the design of the Prophet are Dave Rossum and Scott Wedge of E-mu. They were design consultants to Sequential Circuits for the Prophet 5. They received significant royalties on the P5 Revs 1 and 2. The SSM synth chips in the Rev 1 and 2 were designed in consultation with E-mu. The Emu digital scanning polyphonic keyboard (designed by Scott Wedge for the eMu modular) was the basis for the P5 polyphonic keyboard.

[btsndcts]

I get the feeling from Rob that he is a great person to have as a friend.
When he said ' I wouldn't say one is better than the other, just different.'
What a beautiful soul.

[dr.gregoryf.maassen]

Very nice video. It is amazing what we can take for granted these days with computers and VSTs. Thanks for sharing.

[DanielVeglison]

I bought months ago the prophet 5, i have now 7 synthezisers and the p5 is sill my baby his sound is amazing. Warm analog. Smooth and Punchy. So groovee and funky

[baddriddimworkshop]

Two books to cite here: "Musical Applications of Microprocessors" by Hal Chamberlain, and "CMOS Cookbook" by Don Lancaster... reedit: two books that allowed tom oberheim or dave smith too start using ssm chips, being later replaced by more "factory biased" and stable curtis chips, and achieve multiple voicing, and then be able to save voltage or switch settings. And yes "says a lot"; designing gear and reparing it is not the same task and often doesnt require the same skills and/or knowledge... love the channel btw.

[MattWhitehead]

This is really great. I opened my REV3 last weekend after the volume on my P5 disappeared. I’d never actually seen the insides before. Nice to get an idea of how it works.
The downside of these old machines is they do occasionally need servicing.

[brmbkl]

Got off work, loaded up the playlist I saved earlier. Watched this with a good coffee and a Vienna pastry. You made my afternoon.

Your channel is unique, because of who you are. Just discoverd you a month ago, and already the favorite channel on my watchlist.
This is ultimate content, two extremely talented people in their field with zero ego, shooting the breeze and detailing the history of our little niche industry, but make it look like they're just hanging out like two neighbors dropping in on each other.
The vibes are off the charts. Please keep going.

[FPSBird]

I absolutely love these videos exploring the inside of a synth

[globalsquirrel]

Thank you very much for this! Wondered about the inner workings of this synth for years so now I know. Keep up the great work 👍

[nobodynoone]

Great video! Love these deep dives. Wont be as popular as the casio duck bass, but appreciate these a lot!