Changing the pots on a Bachbird?

[exiledarchangel]

Some people like that slightly treble roll off that 250k pots do to humbuckers, it's up to you really. If you want maximum treble from your bass, then 500k everywhere is the way to go. Again, the difference is minor.

As for cable, I have bought a spool of this, and still have some. That reminds me to go buy some cable too!

http://store.guitarfetish.com/guhoupwi22ga.html

The king of guitar wiring cables is cloth covered cable, like this one here:

http://www.banzaimusic.com/Cloth-covered-wire-RED-50ft.html

Not a big difference soundwise, but more practical, you push back the cloth, make your solderwork and then let the cloth come back again.

[the mojo hobo]

... Some of you claim that a 250k pot for the tone but others claim that they used 500k pots for both the volume and tone pot. Does anyone know for sure? ...

I have some Gibson schematics dated 10-22-74 that show 500k volume and 250k tone, similar to but drawn a little different than this:

[the mojo hobo]

Oh my Bach I have expermented with pots, pickups and caps. I didn't like the Artec with a .1 cap. I do like the .1 cap with the Seymour Duncan pickup that I currently have installed.

[drbassman]

I always used 500k pots for tone controls on humbuckers until last year (or the year before, I can't remember!).  I tried a 250k pot on my 60's NR TB restoration and I loved the treble roll off it achieved.  Now, I only use 250k pots for tone controls with humbuckers.  It's all a matter of taste.  Gibson, I believe, may have used 300k pots for tone (available thru Bass Parts Resources).

It's not absolute.  You have choices and decisions to make.

[chromium]

That schematic posted above labeled "Thunderbird IV (or III?) 1974" is how I've wired my BaCH w/TB+ pickups.  I've been very happy with it.  Doesn't hurt to buy some different value parts and experiment, though!  




Stew-mac sells the braided push-back cloth insulated wire.  I love that stuff for these types of projects, since you can shield a lot of the circuit by soldering the braid to the pot enclosures.  I've rewired my EB-2D, EB-0, Ampeg AEB-1, the BaCH, and Guild JS-II in this manner and never had any noise problems.

It may be hard to justify if this is just a one-time project, but a good soldering station makes such a huge difference.  Something like a Weller WTCPT or Hakko 936 would be a great investment (I have the latter, and there are plenty of other options).  They pop up used on Ebay - saves ya a few bucks.  For solder, I've been using a spool of Kester 44 rosin core.  Take the money you save paying for a tech's labor, and put it into some tools, bulk wire, etc... and the next time you have a project like this it'll cost you next to nothing.  You can also build your own instrument/patch cables with these tools and save a bundle (I built a mother-lode of Canare/Neutrik cables for my home studio setup at an average cost of $4/ea.)

Also, another excellent vendor for parts is Small Bear Electronics in Brooklyn - http://www.smallbearelec.com/StoreFront.bok  They don't stock the CTS brand, unfortunately, but have all the other components that you'd need.  I've dealt with Banzai before too, and they're great.

Good luck!!

[PeterB]

Doesn't hurt to buy some different value parts and experiment, though!  

I agree to that! I've experimented a lot, and it differs a lot per bass.

For example, I ended up wiring my:
* Jazz with ChiSonics (single coils) with 500 K pots for Volume and 300 K for Tone;
* the same Jazz with ChiSonic Humbuckers with 250 K pots for Volume and Tone;
* Darkstar Precision with 500 K pots for Volume and 250 K for Tone.

It's also nice to experiment with the values of capacitors: I've used the traditional .047, but also .033 and 0.1 values.

But as for Orange Drops: not all of them sound good in a bass I found out:
* the 715/400V are THE Orange Drops to use (available in different values), and;
* the 715/200V sound like crap!

[Dave W]

But as for Orange Drops: not all of them sound good in a bass I found out:
* the 715/400V are THE Orange Drops to use (available in different values), and;
* the 715/200V sound like crap!

Why would the voltage capacity make a difference? The actual voltage in the circuit is a small fraction of that.

[exiledarchangel]

Maybe even if they are the same series )715) they are built different? Seems strange to me too. I have never used orange caps with lower voltage than 400v so I don't know about that.



off-topic: I think it is more useful to install a rotary switch on your bass to choose between some different cap values, than to have a cap and a pot, especially if you are an "on-off" tone user.

[PeterB]

Why would the voltage capacity make a difference? The actual voltage in the circuit is a small fraction of that.

Well, I can't give the technical explanation, but my ears are the judge. Really a difference. 

[Highlander]

Why would the voltage capacity make a difference?

iirc, purely down to physical material differences - were bound to have some electronic techies (ie PBG) to explain in detail...

I don't use tone controls, excluding the amp, so I can't be objective here...

[Johnbob]

Wow, a bunch of great information here. Thanks. I think I am going to get the 500k's for the volume and the 250K for the tone but I can't decide which cap to buy. I might go for the orange like the original's but I might also go for the Mallory-150-0-1uF.html film cap. Good thing they are so cheap, I can try one and if I don't like it I could switch it out. I think I am also going to go for the braided wire too. Thanks again everyone.

[the mojo hobo]

Found a link to this interesting article on another board:

http://www.aqdi.com/tonecap.htm

"Our conclusion is that two tone capacitors with the same measured capacitance value and low leakage yield the same tone, regardless of rated voltage, size, dielectric, or price! "

[Johnbob]

OK, so I am finally getting ready to buy my new pots, jack, cap and wire for my Bachbird project. Thanks to everyone that threw in their advice and suggestions. I made a list below of everything I am ordering. Please take a look and check it out and let me know if something looks horribly wrong since I really don't know crap about this stuff. I do have a question about the pots though. Should I be getting split or solid shafts?

I am ordering all this stuff from Bass Parts Resource and I have also listed the prices of everything I am ordering and I was wondering if these prices seem good or if anyone out there has a better suggestion of where to order this stuff from. Keep in mind that I am in the U.S. so obviously it would make sense for me to order from the U.S. Although this stuff seems pretty cheap so I can't imagine it could be much cheaper anywhere else but you never know. Oh, one last thing, I am going to be getting the Seymour Duncun SSB4 pickups just to give you guys an idea of what I will be using. 
 

- 1 SWITCHCRAFT USA 1/4" MONO JACK - $2.49
- 1 SPRAGUE .047mfd ORANGE DROP CAP - $1.99
- 2 500K CTS SOLID SHAFT AUDIO TAPER POTS - $4.69 X2
- 1 250K CTS SOLID SHAFT AUDIO TAPER POT - $4.69
- 1 BRAIDED METAL WIRE (8' Long) Vintage Gibson® style. 22awg - $7.79

[chromium]

Split shaft would be best, as most of the gibby-style knobs are made to fit those knurled split shafts, press-fit style.  For solid shaft, you'd typically need knobs with a set-screw to hold them in place.  Functionally, the pots are no different.

Good luck with it!

[Dave W]

Yep, go with split shaft for Gibson knobs. And you're probably not going to find much difference in price elsewhere unless you're buying in bulk.