BluesHawk Bass

[shadowcastaz]

http://www.bluemoonexoticwood.com/cuban_mahogany.html
nuff said.

[Dave W]

So it's the Cuban mahogany species but it's from the Pacific Rim.

[Barklessdog]

I was going to get some several years ago, but never had the need. Although in todays day & age, investing in exotic hard wood would be better than 90% of stock investments today.

[Barklessdog]

This bass switching system seems pretty complicated. I'm not sure what wire goes where on the double sided switch. To make matter worse I can't really read a schematic, but I do understand it somewhat, but it does not indicate where on the toggle switch the wires go. To complicate matters further the switch when in a position, contacts are spread around on the switch!

I'm lost on what goes where?

The switch


a diagram I made on what makes contact in each position-



Gibson's schematic

[Barklessdog]

An explanation of its function

"The main feature of the BluesHawk is that you can obtain a good single-coil, fast attack-type sound with hum-cancelling capability," Riboloff said, "With the hum-cancelling mechanism in place, it also makes the pickups more efficient and makes them more powerful."
The secret of Riboloff "Blues-90" pickup system is a dummy coil, placed away from the strings to cancel hum without interfering with the working pickups. He explained how the hum-cancelling mechanism works.
"The 'dummy' pickup is basically another pickup, but it doesn't have the magnetic core in it," Riboloff said. "It cancels out opposing sides of the A/C signal and provides a path for the other side of the signal to travel through to prevent the hum." - the blueshawk thinks this is a pretty inarticulate explanation of what is admittedly a difficult thing to explain. Riboloff notes that the idea of a dummy coil is not new, but his use of the technology is. "Dummy coils have been used in the past, but I've never seen it used in the manner that I used it in," he said. "It's wired into the circuit in a unique fashion to where it knows to get out of its own way when it's not needed."
"The user doesn't have to worry about turning it on or off; it automatically happens when he selects his pickups normal with the normal three-way pickup selector. When you are in the middle position, for example, the two normal pickups cancel each other out and the dummy coil is automatically inoperative. The pickups are 360 degrees out of phase with each other, which makes them actually in phase but opposite polarity. One pickup is picking up the top side of the sine wave and the other pickup is picking up the bottom half." - the blueshawk says - this is the same principle at work in humbucking pickups.

[Barklessdog]

Another Gibson drawing



Where is Granny Gremlin when you need him?

[drbassman]

Yikes, that looks like wiring for a NASA control module!!!

[Barklessdog]

"Dummy coils have been used in the past, but I've never seen it used in the manner that I used it in," he said. "It's wired into the circuit in a unique fashion to where it knows to get out of its own way when it's not needed."

That was one of the things that I thought was cool about this project.  I think I have it figured out- In the schematic you see a 123 sets that indicate wiring for each position on the switch. Each position has 6 contacts on two sides of the switch.

So I believe all I need to do is wire the sets on their positions, plus the neck position with the "Bleed Network" which is a capacitor & resistor together

[sniper]

Where is Granny Gremlin when you need him?

thought i would pass this on, an email i got less than 2 weeks ago:

'Hey Bill, been a while.

Congrats on the grandchild. I've been busy in a family way myself - just bought a house and am getting married in September...... Jake"

BTW looking good on that build!

[chromium]

Based on the numbering on your diagram, I think this would work:



You see how there are two layers to that switch?  That what the labels "disc 1" and "disc 2" refer to.

That would give you:
Position 1:  Treble pickup and dummy coil
Position 2:  Treble and neck pickup
Position 3:  Neck pickup and dummy coil

Looks like one section of that switch (pins 7-10, in this case) will remain unused.

Let me know how that works, or if you have questions on it.

[Barklessdog]

Thanks.

With both pickups on, the Dummy coil should be inactive.

On a parts labeled drawing it lists a 100K resistor for the "bleed network", but it does not give any other info on what kind or watt rating?

I have some 100K 1/4 watt  2% metal film resistors. Would that work?

I found this place that sells audio resistors

http://www.angela.com/catalog/resistors/Resistors.html

[chromium]

I don't think you'd need or realize any great benefit from using precision resistors there.  If I was doing it, I'd just use those 2% metal films that you already have.  It's safe to assume 1/4-watt rating throughout.

If you ever do need or want them, I buy parts from these guys.  They have good pricing on precisions ($2.95 for a bag of 100):

   http://www.action-electronics.com/resist1p.htm

That's a cool circuit, btw!  Short of wiring it initially, it strikes me as very simple to use and should yield a lot of different tones.

What did you use for the dummy coil?  Another G-3 pickup?

[Barklessdog]

yes I bought three of the Bill lawrence G-3 / S-1 pickups from GreatDealz and sent them to Lindy Fralin to demagnetize one of them.

I bought a Bid D varitone, the new model, which uses Orange Drop Capacitors which are huge!

The more OI found out about the guitar the more I though its a cool idea for a bass. The G-3 pickups are probably the best single coil high output picks they made, which the guitar feature high output single coils as well.

[Barklessdog]

Did the second staining today.



I still need to sand the excess stain from the wood faux PRS style binding. I clear coated it before I stained it so the seepage stain will remove easily.



thanks to Shadowcastaz about staining it black first. That really popped the grain without looking really like black. The poplar stained really well. Thanks to dave for linking me the article about leaving polar in the sun to turn it brown.

[ramone57]

very nice, that's really going to look sweet when it's done!  you did a good job bookmatching the top, too.