[Roland] [Juno 106] – [Hearing oscillators with filter closed
Hi,
I wanted to check with you if it is normal to hear the oscillators (VERY LOW LEVEL) even with filters completely close. With volume set to 50% or above, filter and envelope at 0%, i can hear very faintly but clearly all of the oscillators together, SAW, SQUARE and SUB though not sure about the noise.
In a separate matter, i repaired one of my voice chips a while ago by striping the coating using acetone but now i can hear some crackling noise coming from that particular chip, also, when i turn off the oscillators and gradually drive the filters to self oscillating level, that particular chip oscillates before the others. Do you think it’s a calibration issue or simply the chip is giving up ? I have a new set of chip and can swap them but just wanted to be sure.
I should’ve kept the 60 instead of the 106🤦♂️..
Thanks
I have a 106 and never noticed that myself and I constantly can’t not help but notice phantom sounds so I think I would have noticed that. As far as the crackling yea probably replace the chips, probably wouldn’t be bad to take find a small electronics repair guy who could give the capacitors a check. Of course you could do what I did when I finally got fed up fixing my 106 and go on eBay and buy a Juno-X 
. Which reminds me, anyone interested in buying a Juno 106? 
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I can agree you should have kept your 60 and fitted the Tubutec midi!
I see, so pretty there should be audio whatsoever unless the filter is open. Thanks
Yea i hear you. It’s not a show stopper so all is good. The 106 is in a mint condition so once fixed, it should be good for many years to come.
Definitely check all the capacitors on the main power P.C. board and any other P.C board. Make sure none are leaking fluid. You may want to purchase a can of Deoxit D5 from Sweetwater Sound. Spray the Deoxit into the output jack, Put a 1/4” cable in & out about 20 to 30 times after spraying to check that your main output jack is clean and not oxidized. You can use a patch cable. I had this problem on my Soundcraft Ghost console. You just spray a short qick spray and then insert and remove the jack 20 to 30 times. Make sure your Juno 106 is disconnected from power.. You may have to repeat this process at least twice to rule out the output jack itself isn’t the problem. You can also spray it’s sliders with Deoxit D5 and quickly move the faders up & down 20 to 30 times. Especialy your volume knob or slider. I belive one or all of these need to be sprayed considering it’s age. The Deoxit D5 will also lubricate your knobs and faders. I bet this is your problem…. Bro I had to do my Entire Soundcraft Ghost! I just removed every knob and sprayed every button as well. That took me 2 days. About 8 hours each day. It will take you about 30 minutes. P.S. First remove each plastic slider cap and plastic knob before spraying each knob button and slider make sure you have a roll of paper towel right by your side to wipe any excess spray off the Juno 106’s faceplate. The Deoxit D5 comes with a straw so you can target a specific area. Spray at the base of any circular knob so it get’s into the tight crease. The faders can be prayed anywhere in it’s crease but you must move the knob and faders at least 30 times each. Like I said before. It will remove any crackling and some may need to be sprayed twice. Finally when you do all this. Before connecting back to power on and testing it out. You need to wait at least 20 minutes. I have complete signal flow on my Ghost now… every single knob and button is ultra smooth plus zero crackling on the entire console.
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Sounds good, i’ll start with the simple stuff yiu’ve mentioned. With that being said , you gave me an idea to actually check if the filter fader is actually going to 0% electronically when all the way down.
Regarding recapping, i’m actually not very convinced of the wide spread practice of recapping everything . After fixing many synths, old and new, and also working on vintage tube radios and some vintage solid state audio equipment, I barely ever came across any that required recapping. The only caps i really had to replace were the 90s era Roland main boards, korg M3-RADIAS board and M50 plus misc here and there. My observation comes after properly checking voltage ripples, ESR, leaks, ……
The above is based on my own experience and i do it for a hobby so other full time repair techs might have different opinions.
cheers
Synth tech here, I’ve done many Juno 106’s and their relatives. What you’re describing is kind of common on both the 106 and the 6/60, although less so on the 106. The exact cause isn’t totally clear. I’d make sure you do the full calibration according to the service manual. Also if you did the acetone method this isn’t completely reliable and it could be some of your chips bleeding through even with the filter closed. Another possibility are the transistors that control the VCA’s if they’re the 2603/1115 series. I completely agree with your recapping statement, I’ve never had to do this on 80s Roland stuff, and not usually with other brands unless I see physically leaking caps which does happen on Korgs of that era. Stuff from the 90s and later with surface mounted electrolytics yes they’re always worth checking for that.
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Thanks for the details. Much appreciated. i actually recalibrated it and it resolved the audio issue.
Also, i think the voice chip noise i had was due to it not being seated properly
. It was a little loose. Fixed it before starting the calibration procedure.
After addressing the above. I played the juno for an extended time and then ran the test mode, activated test 3 and held all 6 voices ON( all waves, pwm LFO cycling, sub, noise) for a few hours in unison mode to stress them. The original voice chip in question worked flawlessly but i found another chip (#1) acting up(something that i suspected a while ago but never had time to do a thorough test for). It’s sitting in paint thinner now .
I have a full set of Borish chips to upgarde the synth if needed but want to see if this works. It’s my personal synth hence can experiment on it