Noisy Analog Section

Forum for the JD-XA.
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Jedi_mastaa
Posts: 2
Joined: 07:44, 4 February 2018

Noisy Analog Section

Post by Jedi_mastaa »

There’s a rather large amount of noise before the filter section that ruins just about any patch that isn’t very full of harmonic content. It doesn’t occur using digital parts, and it isn’t a 60hz hum (covers my entire spectrograph) and I’ve tried multiple power supplies at multiple locations, which I hoped it would be.

While it does get boosted with mixer and drive, it doesn’t disappear all the way even with oscillators totally mixed out, which totally ruins even using just the self-resonating filter as a sine.

I bought it second hand without original proof of purchase and after many emails back and forth with rather painful support, they told me to take it in for diagnostic at their authorized shop nearby because they were stumped. They first said they couldn’t hear it and wouldn’t believe the scope images were from the JD-XA, so I had to record a video and edit in the example’s audio being run through a spectrograph side by side; to which they finally conceded something was wrong but wouldn’t provide any warranty information.

Is this noise something you folks have? There aren’t any demo units or folks in possession of one near me to do an A/B with, so I’d rather know if it’s normal, and it’s just a noisy synth. I love this buddy and have been incredibly inspired by it, so it’s a pity.

Is it possible to get schematics for any of the newer gear? It’s doubly frustrating because I’m comfortable with schematics and SMT rework and I just don’t have the information to go off of.

Thanks a bunch,
Michael
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pelican
Posts: 9
Joined: 10:52, 3 September 2016

Re: Noisy Analog Section

Post by pelican »

no noise here at all
mimoid
Posts: 151
Joined: 19:20, 3 January 2016

Re: Noisy Analog Section

Post by mimoid »

Funny you should write this as I just recently noticed the exact same thing.

Especially with It sounds like a really crusty digital aliasing. It can make it difficult to play bass arpeggios with smooth filter settings. Also bass-rich high resonance sounds like analog kick drums are easily ruined by this aliasing noise. Here is an example of how it sounds:

https://soundcloud.com/lunarstructures/ ... alog-noise
https://soundcloud.com/lunarstructures/ ... og-noise-1

(Disregard the compression related degradation with SoundCloud).

TBH, I don't think there is any point in sending the unit back to Roland, it will just come back as "according to spec". Personally I just write it down to a slightly dirty analog filter.
Laximus
Posts: 5
Joined: 14:31, 14 July 2018

Re: Noisy Analog Section

Post by Laximus »

I have exactly the same, I sent it to the Roland service here in Hungary. Hope they can fix it. I heard that maybe because of a capacitor problem, what also causes that clicking sound.
MattFosterMusic
Posts: 6
Joined: 10:54, 8 October 2018

Re: Noisy Analog Section

Post by MattFosterMusic »

Did you guys ever get a resolve, I am having the same issues too with noise pre analog filter

Some examples up on Soundcloud

https://soundcloud.com/matthewfoster/se ... ise-issues
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