Quick Juno 106 question...

So, I've had this 106 floating around with myself, various friends, my dad, etc. Picked it up around '94 I would think. I had to replace a couple of buttons, but otherwise it was clean, and worked correctly. After it changed hands the last time, it developed a bit of a problem. I'm pretty sure it's not the standard voice chip thing, but something related. As you hit keys, every so often a note will stick (either either after the decay or sustain phase.) It's hard to tell on any voice that has a low decay level. I have a feeling it's a leaking VCA for one voice, so as it cycles through the polyphony, one will stick, and the next won't. I haven't played with it enough yet (just got it back the other day,) to figure out if it's always the same note count between it doing it, but based on the quick mashing I did, I'd say that's the case. (which is why I think it's a VCA) Messing with the VCA slider will tone down the stuck part a bit. Anyway, what I'm wondering is if this is the case, how easy of a fix is it? I haven't had it apart since a friend and I replaced buttons when I got it the first time. I'll probably open it up soon, but was wondering if anyone had any thoughts. If it's beyond my skills, I've got someone that can help. May as well use it if it's easy to fix...

That's def the start of the dead voice chip syndrome. You'll need to figure out what voice chip is acting up and and have it replaced. There's a way to boot up into a service mode, but i can't remember what it is. I think it's holding down both transpose buttons on start up. But i'm not 100%. You can then cycle through each voice and figure out what one it is.

I have two Juno-106s ... under my bed. One has 5-6 voices ... Another has 3-4 ... The cool thing is their death voices are pretty musical ... I'm either going to consolidate mine or save them for my basement studio project where I can have an area for them ...

While I can't say I regret getting the 106s ... there's just no future in the original chips ... Better off with the Juno-60 (more like the Jup-8 apparently ... ) ... Still, I like mine ... but for now the Fusion's back in the lineup ...

IT'S TOO BAD SHE WON'T LIVE ...

BUT THEN AGAIN, WHO DOES?

Like Acid said, bad VCA/VCF chip (each voice chip is VCA/VCF integrated). This happens to them all, at some point. If you really want to keep the 106 for life, get six replacements (remanufactured, not used) and replace all 6.

Ah.... but she DOES live...

Just as the 106s can. You can buy replacement chips from someone in Europe.

Bladerunner = my FAVE movie of all time!

But the replacements aren't quite the same, I've heard ...

and it's kind of expensive ...

I'm probably going to fix mine ... it's still a very nice sounding synth ...

But this is the year of Jup-8 for me (OK, reallly expensive ... but life is short ... )

.............

BTW ... What do you mean she (Rachel) lives ... ? All those replicants had death dates from what I gathered ... We just don't see hers ...

Yep, should sound different, but wil work for many more years (the only other option is to replace with another 25 years old IC taken from a broken unit, which will probably won't live for long anyway - this is why I suggest this only if you're a 106 keeper...)

As an owner of a Juno 106 that had two 80017A chips die on me, I heard from a reputed Juno Guru who recommended you try to avoid leaving your Juno 106 powered on when you're not playing it. So far, I haven't had a chip die on me since 2006.

Hold down Transpose while turning on the 106. Then press both Poly 1 and 2 together so both are lit. This puts the 106 into the "rotate through the voices" mode. Each note you play uses a different voice, which is shown in the LED. This makes it easy to pinpoint the faulty voice.

Diametro, is the Juno I sold you dying?

Next time I restore a 106 I'm going to try these chips: http://www.analoguerenaissance.com/D80017/#Buy

From what I've heard they're a dead ringer for the originals sound-wise.

Yes, unfortunately.

One voice chip is going ... and it seems like certain keys across the board won't play that voice anymore ...

I have a local tech who can probably fix it ... I may wait a while, though ...

Interesting. Actually I found that most of the 106 *sound* is actually at its amplification/chorus board... In any case I think it will always be best to replace all six for unified sound all over the keyboard. You can always sell the older ones on ebay

I personally got tiered of having the 106 opened up and serviced again and again...

I replaced all 6 chips in a Juno I restored earlier in the year, with clone chips, but not the ones in the link I posted earlier. They match, but they aren't the same as the originals. For example, I had to change a resistor on the board for each voice to get them to calibrate properly, and some differences were evident, especially resonance at lower frequencies. There was some "lag" in the filter cutoff changing too, it wasn't as instantaneous as the originals.

But, regardless of what clones I put in the next one, I will only do all 6 from now on. Not only will it ensure matching, but it will ensure that the Juno won't fry another chip a few weeks/months down the road.

That sounds like the typical voice chip dying. Due to the way the Juno allocates voices, it will give the illusion that some notes don't play. If you pop it into diagnostic mode and select the round-robin (Poly 1+2) mode, you'll be able to tell which voice it is. IIRC, it was voice 5 that I replaced, and I remember seeing that 2 others were replaced prior.

... and full recap while at it !

check ebay item 310076300027 for parts

I, too, have 2 106's, one of which I've already pulled the 5 remaining working filter chips from for eventual use in my other 106. It's kinda sad.

Thanks for the responses! Yeah, I wasn't sure if that would be part of the voice chips or not, so that settles that. I'll take a look around, I'm not that picky as far as getting the exact 106 sound. It's a fun board though, and I have quite a history with this one, so I may fix it up.

I've seen one or two "for parts" 106s on the local CL in the past few days. Have a look, one was only $50.

I have a 106 that had voice 1 go. I replaced it with an Analog Renaissance replacement. I can't tell any difference EXCEPT:

Make sure your Juno is adjusted properly, and that goes BEYOND what they say in the service manual. There is a trim pot for VCF resonance, for which there is no calibration procedure. If this trim pot is set too high, allowing the VCF to self-oscillate with DCOs off, Analog Renaissance's clone will "lock up". You will get NO SOUND at all until the resonance is reduced to a certain point and the voice is retriggered.

That's my experience with it anyways.

Do they know that at Analog Resistance ?

My service manual has a calibration for VCF resonance. It's one of the ones where you adjust the trimmer to get a certain P-P voltage of the sinewave on a scope.

hey folks

i've also been having a weird problem with my Juno-106 in the last week and maybe some of you experts can tell me if it's also a voice chip thing. one (or more) of the keys will suddenly stop working, but only temporarily, and it's not always the same key(s). this phenomenon is also accompanied by a fair bit of intermittent crackling and "crapping out" noise. diagnosis?

thanks in advance!

Classic bad chip symptoms. Sorry, dude.

i see... do you have any idea how complicated the chip-replacement procedure is? (ie: is it something a n00b like myself could do?)

If you've never handled a soldering iron before, then I HIGHLY recommend you let a pro do it. It's not hard, but requires skill.

I'm thinking of picking up a Juno 106 and would eventually buy a set of the clone chips to go with it. In the meantime, if some of the voice chips die, can they be removed and will it just reduce poly, or will it always try to play the bad voice even without the voice chip? Is there a way to "bypass" a bad voice?