Thunderbird Tone Control Mod Question

stiles72 · March 13, 2010, 01:28:08 PM

When I got my Gibson Blackbird bass, it was allready modded and set up like a Les Paul with 2 vol, 2 tones, and 3 way switch. 90% of the time, I run it with both pickups engaged and the tone knob rolled off on the neck pickup.

I also have a stock Gibson Thunderbird IV, and would like to mod it's controls to achieve the same result as the Balckbird - but without drilling any new holes for extra pots/switches. My idea is to have the first knob be the tone control for the neck pickup - followed by the three way switch - then a master volume which would affect anything coming from the 3 way switch. The bridge pickup would have no tone roll off - and would just be wired "hot" all the time.

One thing also to note - the capacitor in my Thunderbird IV is the stock small orange one. The ones in the Blackbird look like Green Chicklet gum. I know that's not a very technical description - but thought I'd mention it.

Can anyone show me a simple diagram of how I would wire this?

drbassman · March 13, 2010, 02:01:40 PM

You could use stacked knobs and not have to drill any more holes. Smaller mini switches also wouldn't require larger holes like standard 3-ways. The green caps are just a different brand. What do they have printed on them, if anything?

stiles72 · March 17, 2010, 07:32:12 AM

Just took a look inside both, and the Blackbird has chicklet shaped capacitors that are a light orange in color - not green - and they say 473K 100M: on them. The pots say EP086 500K 9936.

In the Thunderbird IV, the pots just say Gibson and the capacitor is about the size of a sewing push pin, is mustard goldish in color, and says 223.

Could I simply disconnect the two brown wires on the first post of the bridge pickup volume knob (middle pot), and tie them together - then run a seperate wire from that post directly to the output jack? Essentially bypassing the tone pot for the bridge pickup? It wouldnt have a threeway switch right now - but would that work?

the mojo hobo · March 17, 2010, 09:13:23 AM

Quote from: stiles72 on March 17, 2010, 07:32:12 AM

Could I simply disconnect the two brown wires on the first post of the bridge pickup volume knob (middle pot), and tie them together - then run a seperate wire from that post directly to the output jack? Essentially bypassing the tone pot for the bridge pickup? It wouldnt have a threeway switch right now - but would that work?

It would work, but it would work exactly as it does now, just tied at the output jack instead of the middle pot. What you could do is move the brown wire that goes from the tone pot to the output jack to the middle lug of the bridge pickup, and the wire that goes from the left lug of the middle pot to the tone pot would be moved to the output jack. (The left lug of each volume pot goes to the output, and a wire goes from the middle lug of the middle pot to the tone control pot.) This would make the tone control affect the bridge pickup before it's volume control, minimizing it's effect on the neck pickup.

exiledarchangel · March 17, 2010, 09:28:59 AM

Quote from: stiles72 on March 17, 2010, 07:32:12 AM
Just took a look inside both, and the Blackbird has chicklet shaped capacitors that are a light orange in color - not green - and they say 473K 100M: on them.

473 = 0.047uF cap

stiles72 · March 17, 2010, 11:01:49 AM

Is there a way to wire it so that only the neck pickup is affected by the tone control?

exiledarchangel · March 17, 2010, 11:30:42 AM

Something like that must work.

the mojo hobo · March 18, 2010, 05:10:35 AM

Quote from: stiles72 on March 17, 2010, 11:01:49 AM
Is there a way to wire it so that only the neck pickup is affected by the tone control?

Sorry, I misread your question. Instead of "The left lug of each volume pot goes to the output, and a wire goes from the middle lug of the middle pot to the tone control pot" it would be "The left lug of each volume pot goes to the output, and a wire goes from the middle lug of the first (neck pickup) pot to the tone control pot"

stiles72 · March 18, 2010, 07:08:48 AM

Thanks - I'll give that a shot

TBird1958 · March 18, 2010, 08:55:16 AM

Hey Clint,

That sounds like my old Blackbird, does it have a white PG? Pics of it by chance?

bassvirtuoso · March 18, 2010, 01:14:39 PM

Quote from: TBird1958 on March 18, 2010, 08:55:16 AM

Hey Clint,

That sounds like my old Blackbird, does it have a white PG? Pics of it by chance?

I've been thinking the same thing...

stiles72 · March 19, 2010, 11:29:37 AM

I bought the Blackbird off Ebay back in '04, and it had the original sales slip dated May '02 from Musicians Friend in the case. It was originally sold to a lady in Pennsylvania for (Gassppp) $699. According to another receipt in the case - it was taken to an authorized Gibson repair shop a month later and the strap buttons were moved, the old holes filled, and the tone controls were modded like a Les Paul. This is the bass where I got the crazy idea to move my strap buttons even further away from the heel and further towards the back fin to give it even more of an "upright" stance. One of the best sounding basses I've ever had - both plugged in and acoustically. Another interesting thing about it - it appears to only have a 3 ply neck. On one of the other forums the subjuct of Gibson using a 3 vs 9 ply neck on painted models came up and mine has it. Enough paint has worn off the back of the neck that you can see there is no walnut in the neck. Just mahogany. The pups also seem more robust and a bit louder than my IV. Not sure if they really are different, or just a result of the tone control mods.

Nocturnal · March 19, 2010, 12:00:06 PM

My ebony 2001 Bird has the walnut plys in the neck. You can see them in the finish, and when I popped a pickup put you could see it in the cavity as well. The original listing for Blackbirds listed it as a 3 piece neck. I thought they just messed up the info.

I wish I had bought one of these when they were $700 with case, delivered!! My wife told me to buy one, but I had just bought a bass for the same amount so I was being nice and said no, I don't need it. I am such a dumb ass sometimes!!!

stiles72 · March 19, 2010, 12:08:41 PM

Quote from: the mojo hobo on March 18, 2010, 05:10:35 AM
Sorry, I misread your question. Instead of "The left lug of each volume pot goes to the output, and a wire goes from the middle lug of the middle pot to the tone control pot" it would be "The left lug of each volume pot goes to the output, and a wire goes from the middle lug of the first (neck pickup) pot to the tone control pot"

Just finished - and yes it works - neck tone rolled off, bridge unaffected. Thanks for the help! While I was at it, I swapped the stock 223 capacitor with a 473 that came from (I think) an old Epiphone P-bass so that it would be the same value as the Blackbird. Wow, what a difference. The neck pup now sounds much warmer and rounder than before. Now I'm going to have to go and do this mod to my 5 string!