Vintage push-pull mod - lost at sea...

[Benjamin]

Hi All,

You must field enough of these and I feel like such a dunce, but I am all lost at sea as to how to make this mod work. I have studied every diagram on the Interwebs. Either I just don't understand electronics (partially true) or most of the diagrams show a different kind of push-pull pot - the kind that have all switch lugs below, and pot I/O above.

I ordered the "official" 330K pot from Pick of the Ricks. Sourced a 0.0047uF cap from local electronics store. Here's some pics. Please help!

Edit: This diagram does not make sense to me because I can't clearly make out which tabs are which. No offense to the author of the diagram, I just can't make sense of it.


Edit again: Is this going to be the same? (Pulled from this thread: viewtopic.php?f=2&t=405859&start=0)

[johnallg]

Ben, the diagram is an either/or for the switch. RIC used to supply and use the 6 lug kind and now use the type I added in the top right corner. To cover both, I just added the new type in parallel.

Make your mod like the last picture you posted. FInd the red wire from the toggle switch to the Treble volume pot, cut it, solder the two ends to the two lugs on the switch, then put the cap across the lugs also. Then wire the three lug pot as the one you pulled out.

A poly capacitor would sound better then the ceramic one you bought.

[Benjamin]

I think I understand. It doesn't look like that wire is long enough, but I will figure that out. Will try to find a poly cap also.

In theory I shouldn't need extra wires, just make use of what's there.

Thanks John!

[johnallg]

I think I understand. It doesn't look like that wire is long enough, but I will figure that out. Will try to find a poly cap also.

In theory I shouldn't need extra wires, just make use of what's there.

Thanks John!

Get a short wire, unsolder the red wire from the switch at the volume pot, solder that to one switch tab, take the new wire, solder to the pot tab and the other switch tab.

[Benjamin]

Done! I am in debt to you John!

Now, if I have done it correctly, and the poly 0.0047uF capacitor is right, I should observe (when engaged):

1. A significant volume/bass drop when treble pickup soloed
2. When both pickups are on, more growl and a pronounced midrange

When I roll off the bass pickup volume slightly, it gets a bit more nasty but the beef still remains. Was only able to test going direct to a Behringer desk and a pair of Bose monitors. Tomorrow afternoon I will get the chance to test with GK and Henry 8x8.

Does this sound like success?

[aceonbass]

I know I'm a bit of a component snob, but a ceramic disc capacitor is the last thing I'd use in any instrument. They are easy and cheap to manufacture for a reason, and can be microphonic at times. RIC uses a polyester film axial caps that are better, while I use vintage paper in oil caps.

[cassius987]

...a ceramic disc capacitor is the last thing I'd use in any instrument....can be microphonic at times.

I have experienced microphonic ceramic caps firsthand. Stay away from these! It's such a nuisance.

[Benjamin]

Don't worry guys, I sourced a poly grey and square, cost almost double the ceramic @ 25c each!

So does it sound like I did it right? My previous post is what I observed after the mod.

[aceonbass]

This is a $1500.00+ bass. Why would you put a 25 cent cap in it? You get what you pay for

[Benjamin]

Tell me where else I can get a better cap then? Pick of the Ricks are out of stock. Reputable electronics store do not have five dollar caps...

[aceonbass]

My parts bin.........

[Benjamin]

My parts bin.........

Y'know I have almost one of everything else, in an old franking machine box my friend labelled, "the box where things go to die!". PM received, love your work. Thanks mate!

In the meantime, church gig last night, all I can say is WOW! Combination of Rotos and this mod (even if it isn't quite 100% with the cheaper cap) this bass has kilotons of character. Through my rig there wasn't that much of a volume loss when switching to the cap, treble pickup soloed. It sounded like when I switch to a single coil on my Bart MM equipped Ripper.

[johnallg]

Tone-wise it sounds like you are spot on. Glad my posts helped.

Oh, and don't mind Dane, he's a original 60's oil and paper blue cap snob. Maybe because he came across a box of them.

[aceonbass]

LOL....Actually, I have TWO boxes! A box of .047 NOS Ajax caps for single coil pickus, and a box of .022 NOS Ajax caps for humbuckers. I think I'm gonna go roll around in them on the floor now

[Benjamin]

LOL....Actually, I have TWO boxes! A box of .047 NOS Ajax caps for single coil pickus, and a box of .022 NOS Ajax caps for humbuckers. I think I'm gonna go roll around in them on the floor now

Be careful, you may end up with a cap busted in yo ...!