Like the title says, I'm installing a John East preamp in my Ibby SR605. At some point I'd like to put some Nordstrand pickups in as well but for now, I have the amp to hand courtesy of @rk7. He kindly gave me the old East pre from his Overwater bass after he had it upgraded whilst having the bass chambered. The build thread is here.
I have been happy enough with the Ibanez from a playability aspect but the output is a bit bland with its current pre and licenced Bartolinis. I'm exited to see if the East brings out anything interesting.
It is a five knob J-Retro (I think). I'm winging it as far as resistance values and such are concerned. Maybe it won't like the humbuckers that I'm going to couple up to it... we'll see. It's already looking like a tight squeeze unless I remove some body wood. There is scope for that within the existing control cavity.
The John East Preamp with its long PCB
The Ibanez Preamp in its tiny cavity
The first important thing was to label the wires and photograph where necessary for reference for if I want to reinstall it.
Labelling
Pickup wire positions
I removed the control knobs and spindle nuts
Then with a few dabs of a hot iron to de-solder, the old preamp comes out (on the left). After applying copper tape to the cavity to ground the control spindles as recommended by the East pdf, the new one goes in for a rough fit.
The board is too long to fit as is. There is sufficient meat in the body adjacent to the output socket for me to carve out a niche for it (I think). There should be no need for a larger cavity cover.
I put the East Knobs on to get a feel for it. It's nice. Beautiful action on the detents, the stacked knobs and the push pull knob for passive tone. I only hope I can get some sound out of it too.
There is an empty hole where the mid frequency select switch went that I might fill with a dummy switch like Lee Sklar does. He says that flicking it makes recording engineers think he's tweaked something too subtle for their ears to hear but like with the Emperor's new clothes they daren't admit it.
I'll leave off for now. It's far too late to start carving wood.