Roland Alpha Juno 1 and 2 Overview and Repair

This is part 1 of 2 where I look at the classic Roland Alpha Juno Synths. I compare the Alpha Juno 1 to the Alpha Juno 2 and do some repairs on the Alpha Juno 1.

[@lundsweden]

I've owned: Juno 106, Alpha Juno 1, JX8P and JP8000. They are all good synths, I can't pick a favorite really. But my sound now is more towards the smoother and mellow, and I think the Alpha has that area covered best.

[@drumhead96]

Thanks for taking the time to put this video together. Very informative

[@janntucek]

Thanks Brad, awesome. Have both of these and really helps understand the workings. Love the channel!

[@DoItYourselfMusician]

Man those ads bring back memories. I remember those from the Roland Users Group magazine. So cool.

[@lassel1644]

Cant believe why this dude does not got more followers. He is very skillfull in the area

[@DestroyER82]

Had both of em (sold JU-2 and kept Juno-1 because for its size and its more handier). I find it absolutely awesome and usefull for all kinds of genres (both older and modern). Since I never get programmer (its rare and expensive as you mentioned) im using programmer throught midi from my PC and its pretty easy, fast and awesome. Also you can use use both velocity and AT on Juno-1 when externally controlled. Also to mention. DX7 was about 2k$, JU-1/2 were priced against cheaper DX serie 4op's versions. Have fun with your synths and all the best! :)

[@_P_M_]

I've been waiting for this. Thanks!

[@buildstoys]

Nice work, looking forward to part 2!

[@BobsBand]

Me too. I need to take my RAJ2 apart. It was vandalised twice by UPS.

[@simonsorensen5405]

Perfect timing. Just recently opened up my JU-1

[@vinyljunkie07]

Another interesting video! I never knew the JU-2 had a totally different board, does seem weird! I have the HS-10 Synth Plus 10 which is simply labelled as a JU1 on the board and only the EPROM and outer casing are different. The presets also whilst the same, they actually sound different on the HS-10, I learned this when playing my friends actual JU1. Things like Organ 1 sound totally different. I ripped the inverter out of mine and put in one of those cheap Chinese LED displays some years ago, it's not a direct replacement due to the dimensions but you can do it with some made up brackets.

[@ashleybrownau]

Awesome video man, makes me want to ship my Alpha Juno 2 all the way over to the US so I can get it serviced by someone who know’s their stuff!!

[@BIM0X]

great video. thanks :)

[@kiko1935]

Love the history of these, I have 0 soldering experience and it's so cool to get this history of my favorite synth. I KNEW it was the same filter as the JX8p! That liquidy filter sound is uncanny, but I think it sounds better on the Alpha Juno. man if you got a blue OLED display for them that would be sexy AF!

[@waheex]

@bookmarkthis ebay check out 16x1 or get a new EL panel for the original display, both look great

[@electrowayne2918]

I would agree love both ..Having both .. the alpha does sound better then the 8p to me .

[@stoopkid7647]

Thank you for this helpful video. I just bought an alpha juno 1 and noticed a clicking sound when the chorus was on. I did some research and found out I need to replace my BBD chip. I know I need to replace the two MN3009 but I was wondering if I would also need to replace the two MN3101. I just want to make sure before I purchase the replacements.

[@juanpablosalmoiraghi1683]

Great video, as always! I have a weird issue with my AJ1 that's messing up all of the presets: VCF cutoff and resonace as well as the VCA make a "jump" at some point. So for example if I sweep the cutoff frequency (also in test mode) from the max value of 127 down to 0, the frequency goes down until the value 63 and then it jumps back to it's max value, then from 63 to 0 works fine. Same sweeping the reso and VCA. It's not a problem of the alpha dial because it works fine (the numbers on the display go from 127 to 0 correctly). Making the same test and checking the voltage at the cutoff frequency pin of the VCF chips the voltage goes suddenly up as the jump occurr. Do you have any clue on what could it be? It's very annoying because all those jumps appear when I use the Envelope Generator as well. Thanks man!

[@hansb6885]

Hi Brad, I enjoyed this repair tutorial, very helpful. Since a couple of weeks I have a beautiful Juno 1 and want to changeout the capacitors from the power supply, just as you did. I saw that there are two 1000uf/35V, one 3300uf/25V caps, but I didn’t get the values of the five? small ones, can you help me out here?

[@makers1958]

(Ref ~1:10) At that time (1985), the DX7 listed for $1995, and the DX9 for $1495. Maybe the Alpha Junos were meant to compete with the lower priced 4 operator Yamaha FM synths (DX100, DX27, DX27S, & DX21)?

[@solidaudio6764]

Very good work/comparison. Which kind of epoxy do you use? Can you give me a good tip? Thx and greetings from Germany.

[@michelcury]

Great video!!! Do you know that the rubber key contact of juno 1 is the same as the juno 2?

[@alphanumeric1529]

Can I ask a q: My HomeSynth 10, AJ1, every now and again makes a sound like a record scratching, briefly, maybe 1 second, maybe less. I think it is related to the chorus. It only happens on the right channel. It sounds like something is trying to catch up, like a signal lagged and then zip it catches up. It happens when the synth is sitting idle, can't recall if it happens when the synth is active. I've been using the AJ to do most of the synth work on a track, so have been printing many parts from the AJ, and I don't recall the little zip noise happening in any of the recordings. Any ideas? And my apologies for the vague fact pattern!

[@m.abrill.7407]

Brad, by chance, do you know the model (serial) no of the volume knob potentiometer of the Alpha Juno-1?. It was replaced (I think so) and the volume is very low on the synth and I want to replace it.

[@resynthesizer4565]

AJ-1s always seem to have broken plastic on the back. Also, their keybed circuit boards are prone to corrosion. Backlights are spotty on both models. AJ-2 build quality is much better. Pitch bend is often broken, and the plastic "hinge" on the pitch bend mech will eventually crack. Always wise to rebuild the power supply. AJ-2 is a little harder to work on as the main circuit board is tucked up inside under the keybed.

[@michaelpierce3264]

hi curious if the resonance can be adjusted like the jx3p?

[@wiktorgruszka3783]

Great video. Is Juno Alpha 2 basically the same synth as the Juno Alpha 1? I mean - are electric components are the same?

[@MrCshmn]

Can you change the input voltage on these transformers? Or will they need a transformer change to permanently change one from 120v to 240v?

[@thirfytash7286]

Is changing the battery in the Juno 1 pretty easy for someone who has hardly ever soldered?

[@sebastiandior1315]

What brand of plastic cleaner was that?

[@jockeyshift4124]

Am looking at a -2.most all keys have no sound and am thinkin that because the battery is dead/near as some keys are very weak and seems random. Its got physically issues as well ,but not like your-1.Do you recall how many strips of plastic you laminated in on one hole? I know its a year plus,no big deal was just curious.Let me know if you have -2 with good cheek blocksor if another model fits,which i doubt but.....

[@fadzamakehappy]

Nice video man, inspiring to see how well you know the gear. I got myself an Alpha Juno 1 recently and it is showing a “check battery” message when i turn it on. Wonder what kind of battery it is exactly so i can replace it. Cheers

[@bradthx]

The battery is a standard CR2032 3V lithium cell with solder leads. If you want to order from digikey, part number P659-ND. Lots of other suppliers have this cell as well. Thanks for watching!

[@fadzamakehappy]

thanks for the info

[@intelligenceservices]

if the plastic is ABS there's always the acetone method to fix broken pieces

[@louiseisobel]

@9:20 "this does have digital oscillators" ... so to confirm they are NOT DCO's ?

[@TEHBILB]

I expect you carried on watching but at 13:00 he says he misspoke and that they are DCOs

[@louiseisobel]

@@TEHBILB thanks

[@ageshero]

These things are getting expensive now, in 2022