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[piscineatokyo]

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One hell of a restoration project... (cont') . HURRAAAAAYYYYYY!!!! 😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊 . The Prophet-5 Rev1 has come back to life, again... at least has the CPU and logic sections, thanks to the addition of the "Tune Mod" board (for compatibility with the v5.2C software EPROMs)!!!! I am SO relieved... 😊😊😊👍👍👍 . Nonetheless, there are still three main things to solve before the restoration can be completed (with the alignment of the whole unit): first, only three keyswitches of the front panel do not respond; second (naturally), will all the audio synthesis section work correctly? and last but not least: does the restored keyboard work too? . So, stay tuned... if I may say 😉 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BmULKwhgUX5/?utm_source=ig_tumblr_share&igshid=7kdjtqbgoez2

[piscineatokyo]

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. . One hell of a restoration project... (cont') . EUREKA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! . Après presque sept heures ininterrompues de travail, le voilà enfin qui sonne pour la première fois correctement, ce Prophet-5 Rev1 !!!!!!!!!!!!!! 😊😊😊😊😊😊😊😊😊😊 . Que de pannes déjà solutionnées (rien qu'aujourd'hui : encore une puce HS, une piste coupée, une autre pastille coupée également, des capas de bypass ajoutées pour éliminer des parasites sur les signaux des potards...) pour arriver à le faire ENFIN sonner !!! . Bien évidemment il reste encore beaucoup de soucis ici et là. Mais c'est déjà un TRÈS grand pas en avant, vu d'où il venait ! ☺️☺️☺️ . ------------------ . EUREKA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! . After almost seven hours full of work, the Prophet-5 Rev1 is FINALLY SOUNDING!!!!!!!!!!!! 😊😊😊😊😊😊😊😊😊😊 . SO MUCH faults already fixed (just for today: another dead chip, one cut track here, one cut pad there, bypass caps added to eliminate parasitic pulses on the pots' signals...) to make it sound, AT LAST!!! . Of course, there are still A LOT of faults yet to be fixed, here and there. But it's already a huge step forward, because the synth is coming a LOOONG way! 😊😊😊 . #SequentialCircuits #DaveSmith #JohnBowen #SequentialCircuitsInc #SCI #DaveSmithInstruments #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BqkRnIglx03/?utm_source=ig_tumblr_share&igshid=n35l5rhlfcw8

[piscineatokyo]

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One hell of a restoration project... (cont') . HURRAAAAAYYYYYY (again)!!!! 😊😊😊 . Finally fixed those three keyswitches that did not respond to presses because of a bad solder joint on the Molex female receptacle of the CPU board that connects to the Panel board: now they're working like a charm! 👌 . I will at last be able to go one BIG step forward: testing the sound synthesis section! 😊😊😊 . So, once more: stay tuned... if I may say 😉 . @dalgaard @johandalgaard . . #SequentialCircuits #DaveSmith #JohnBowen #SequentialCircuitsInc #SCI #DaveSmithInstruments #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BnDmXZtAmzW/?utm_source=ig_tumblr_share&igshid=s02udpgzm0j8

[piscineatokyo]

One hell of a restoration project... (cont') . Preparating one small PCB that should make things much better... hopefully! . 😊😊😊 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager

[piscineatokyo]

One hell of a restoration project... (cont') . Keyboard restoration is now complete!!! . 😊😊😊 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager

[piscineatokyo]

One hell of a restoration project... (cont') . Fresh-new J-wires have been put into place after soldering onto the keyboard PCB. Of course, all eight bus bars have been cleaned thoroughly one by one, as well as the J-wires' plastic holders. . Next step in the keyboard restoration process will be the last one, actually: screwing back the cleaned key tops onto their respective key support 😉 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager

[piscineatokyo]

. . One hell of a restoration project... (cont') . De temps en temps je remets le Rev1 sur la table de travail, pour tenter de trouver ce qui 1/ le fait régulièrement planter (un faux-contact sur la carte CPU semble-t-il... mais OÙ????), 2/ déstabilise en permanence la fréquence de tous les oscillateurs, et 3/ le fait planter si le clavier est connecté. . Mes tests de ce matin me montre que le problème d'instabilité semble véritablement venir de la section "Osc Master Summers" (sur la carte CPU). Va falloir investiguer ça de très près... . Au moins, je suis sûr que TOUTES les puces SSM2030 (les oscillateurs) de 1977 sont ok : OUF ! 👌👍👌👍👌 . . From time to time I put this dodgy Rev1 on the work bench, trying to find out why 1/ the CPU crashes here and there (looks like there's an intermittent on Board 2... but WHERE????), 2/ all the oscillators' frequencies are permanently unstable, and 3/ the keyboard crashes the CPU when it's connected. . This morning, tests show that the Osc Master Summers section (on the CPU board) is faulty. Need to investigate that further... . At least, I checked that ALL 1977-manufactured SSM2030 oscillator chips are GOOD!!!! 👌👍👌👍👌👍 . #SequentialCircuits #DaveSmith #JohnBowen #SequentialCircuitsInc #SCI #DaveSmithInstruments #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BqhO9oJFelq/?utm_source=ig_tumblr_share&igshid=18e832ztptxgv

[piscineatokyo]

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One hell of a restoration project... (cont') . HURRAAAAAYYYYYY (once again)!!!! 😊😊😊 . Finally fixed the start-up issue where the CPU wouldn't go on its own down to the end of the auto-tune procedure at boot-up! Had to "manually" make it think all oscillators were ok... 😪 . Because a f*cking 4066 CMOS transmission gate in the Common Analog section was dead, forcing the OSC1 Master Summer output to the maximum, that is, preventig all OSC1's frequencies to be ajusted by the CPU, then eventually freezing it at the end of the start-up procedure because it was waiting for the OSC1s to be tuned... 😰 . Now that the gate has been replaced with a new one, boot-up is fine and takes less than 3 seconds to complete, at LAST!!! (and after three whole days of work to find the culprit...) 👌👌👌☺️☺️☺️😊😊😊 . . Nonetheless, there's just one thing to solve in the logic section of the synth that I noticed when trying to change the synthesis parameters with their knobs: almost none of the potentiometers are registered by the CPU when moved... 😥 First investigations show that the Vmux signal is not correctly being generated by the POTMUXes on the Panel board 2. . Hopefully this will be the very last fault to solve before delving into the synthesis section... Crossing fingers! ☺️ . @johandalgaard @dalgaard . #SequentialCircuits #DaveSmith #JohnBowen #SequentialCircuitsInc #SCI #DaveSmithInstruments #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BnL6lc9g9XZ/?utm_source=ig_tumblr_share&igshid=1b3u0ci1dka5o

[piscineatokyo]

One hell of a restoration project... (cont') . The new "Tune Mod" board freshly populated and just installed in the socket of the "ROM 0" EPROM. . Will this P-5 Rev1 finally start-up correctly with v5.2 software, thanks to the small piggy-back PCB? That is the frightening question indeed... 😞 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BmUKjLsAf4g/?utm_source=ig_tumblr_share&igshid=uz0zb7f5kvjy

[piscineatokyo]

One hell of a restoration project... (cont') . Just got in the mail this morning the (manufactured) one small PCB that should make things much better... hopefully! . 😊😊😊 . #SequentialCircuits #SequentialCircuitsInc #SCI #Prophet5 #SequentialCircuitsProphet5 #SCIProphet5 #Prophet5Rev1 #VintageAnalogSynthesizer #AnalogSynthesizerRestoration #VintageElectronics #Restoration #Repair #JohanDalgaard #StudioPiscineATokyo #TheGoodDoctorPrager https://www.instagram.com/p/BmOMh3RARuw/?utm_source=ig_tumblr_share&igshid=1oc6r04lpbhn4