the 4558 op is a very noisy opamp
you can change them for the tlo8/7 series dual
opamps
is it a dip or a ziff 9pin ic
as in the korg dss1 they are ziff 9 pins
i exchanged mine for the ones used in the korg
trinity the
UPC4570HA made by nec
jrc are a good make if
you can source them
the 4558 has a very
rubbish slew rate and are noisy
but becuase of this
they make great fx pedals as fast transients can distort
----- Original Message -----From: NickSent: Sunday, January 06, 2013 3:49 PMSubject: [vintagesynthrepair] Re: Roland JX3P FaultyHello all. Yep there were multiple hairline cracks, all fixed now with all control restored.
I do however need to replace the (Sharp)IR94558 op amp in the mixer section (IC1) as it's crackling. I can get a new Sharp IC but it's rather expensive. I'm inclined to stick with sharp but would anyone perhaps suggest using the cheaper JRC or the like?
Thx
--- In vintagesynthrepair@yahoogroups.com, Nick Bell wrote:
>
> Thanks all for your input, really helpful & appreciated. Will report back with any successful/unsuccessful repairs.
>