[sdiy] Non-DIY, but looking for repair advice...

[Shawn Rakestraw]

I bought a Roland JV-1080 from someone locally a few years ago and noticed
on the back that it showed 100V input power. I read online that the
internal transformer has taps for 100V or 120V. It worked fine, but I
opened it up and switched one wire on the transformer to "modify" it for
120V and then placed a sticker on the back with the date and info regarding
my mod. I wonder if your Yamaha has a similar transformer that has been
wired slightly different for US power by someone along the way.

On Sun, May 12, 2024 at 8:03 PM John Ames via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Slightly not-strictly-OT here, I s'pose, but I'm looking for hints/
> advice - I've got a Yamaha CS-5 that's mostly in good working order, but
> has two (possibly related) issues. One is that there's a slight 60 Hz
> buzz from the PSU - it's present even with the mixer sources turned
> off, but the filter can remove it. The other is that the output is very
> weak; running direct into my recording workstation, the maximum
> amplitude is lower than -30dB! Of course I could pre-amplify it...but
> then that boosts the AC hum from "not really audible" to "far too
> noticeable" :/
>
> Now, I haven't had it open yet; before I go poking around willy-nilly I
> thought I'd ask for any advice, and raise what may well be an important
> point. This is, or was, a Japanese import model, and the print on the
> back near the power cord lists it as a 100V device - but somewhere
> along the line someone covered that over with masking tape and Sharpied
> "115V" on it. I've never had problems running 100V equipment on US line
> voltages before, but admittedly it's almost all been digital gear; is
> that potentially an issue? And someone might have done a mod to adapt
> this thing for that already; any ideas what to look for if I open it up?
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20240512/13a04abd/attachment.htm>