Questions regarding hacking a Yamaha BC2 magnet

[Tom May]

"Theo" <t.hogers at home.nl> writes:

> ----- Original Message -----
> From: Tom May <tom at synth-diy.you-bastards.com>
> ><snip>
> > I'm guessing this BC2 is from the DX7 era
> > and so could have lost some magnetism over time.
> >
> The BC2 was introduced at the same time as the VL1.
> A magnet loosing strength in merely 10 years looks a little quick to me.

Uh, right, I was getting confused with the BC1, and thinking the guy I
got it from had a DX7.  Although the BC2 is mentioned in my SY77
manual from 1989 which I believe predates the VL1 by a few years.

> > The reason I think it's weak is that I've got to turn the gain all the
> > way up to get a reasonable response curve.
> >
> This sounds like a BC2 alright, only the upper range of the potty is use
> full.
> If the gain is really weak, you may look for other causes.
> I've had similar problems, turned out the connector on my DX was oxidized.

I've cleaned the jack & plug, no difference.  The response is pretty
stable.

> BTW, I found that not all BC work well with all synth models.
> DX100 and DX 27 seem to be among the trouble makers.

Good point.  I'm using an SY77.  I just tried it with a (fairly new)
VL70-m, and I don't have to blow until I'm red in the face to get full
output.  The VL70-m seems to have more internal gain -- the offset pot
on the BC2 is a lot touchier.  I never tried the BC2 with the VL70-m
since I expected to be playing the VL70-m either from a WX5 or from
the keyboard + BC input on the SY77.  So now I'm thinking the BC2 is
normal.  It could still use a gain boost though, either magnetic or
electronic.  Hacking the smd board in its tight location may be
difficult.

> Hope this helps,
> Cheers Theo

Indeed.

Thanks,
fTom.