Carvin FLess, SGD / Bartolini EZQ mod

[RedLeg]

Hello all,

Thanks to ChrisCassisi I was able to score a late 90's LB75 Fretless in great condition and at a great price. The bass came modified for EMG DC40's and without pups or a pre. Perfect project bass!


Here is the plan. I am going with SGD Sidewinders for pickups and a bartolini ezq for the pre in an 18v config. Here is the link to the schematic I will be using (it is on the last page with the switchable Q and bass boost). I will most likely change the "Q switch" option with a 50K linear pot (a la Alembic CVQ style) due to there being 5 pots. Also I will replace the 250K blend with a 500K. If everything goes as planned the control layout should be:
Vol - Blend - Filter Freq - Variable Q - Bass Boost

I will get back home to Japan in a 2 weeks and I can begin. I will post pics of the process and I will get some sound clips posted when everything is done. I really have to thank the wife for such a nice xmas gift.

[RedLeg]

Well almost everything has made it to me. I am waiting on a few pickups to arrive. I have noticed that the old carvin/wilkinson bridges are prone to malfunction probably due to design flaw. So I am sourcing a .687 pitch Hipshot A bridge in black/aluminum with gold saddles. I have the preamp circuit wired up. I am going to try the switched Q first.

[RedLeg]

OK. Got a gold Hipshot bridge installed. I tried the switched Q and wasn't feeling it. I am sourcing some Dual 50K Linear Pots with enough thread lendgh to get through the maple top. This is no easy feat! I found something that I hope will work on mouser. Also, the shaft size on the stock 50k pots are not compatible with just about any knob I own!
I did get the SGD pickups and the bass boost feature wired up (guts hanging out, lol) with the variable Q option and I gotta say it is the best of both worlds having a bass boost and a filter based preamp with a variable Q. Definitely better suited for a fretless than a traditional shelving preamp. The final wiring schematic will be Vol - Vol - Filter - Variable Q - Bass Boost. I am kinda going my own way by using the first page of the instructions and adding the bass boost of the last page and using hints of standard jazz bass. I do love my tinker toys!

[RedLeg]

I am a little worried that I cannot achieve 34" from nut to saddle (saddles fully extended). It seems that I am about an 1/8 inch shy.

What say you TB community?
do I need to relocate the bridge 1/4 to 3/8 inches closer to the nut so that I can get the G string to a perfect 34 inches with a little wiggle room?
or
an 1/8 no big deal on a fretless because after all intonation is dynamic on a fretless!

[MarkA]

Originally Posted by RedLeg

I am a little worried that I cannot achieve 34" from nut to saddle (saddles fully extended). It seems that I am about an 1/8 inch shy.

What say you TB community?
do I need to relocate the bridge 1/4 to 3/8 inches closer to the nut so that I can get the G string to a perfect 34 inches with a little wiggle room?
or
an 1/8 no big deal on a fretless because after all intonation is dynamic on a fretless!

Can you get the octave harmonic to line up with the fingered note when you play right on the 12th "fret" line, or does it seem noticeably off?

[RedLeg]

not noticeably off, seems pretty darn close.instead of edge of finger it is a little closer to middle.

[RedLeg]

Everything is wired up and how I want it. 500KΩ 's wired to the SGD sidewinders in series in a volume / volume config. Bass boost, filter, and variable Q. I got those dual 50KΩ pots from mouser and they work, but they were tricky to wire and I had to modify the bass to get them to fit, but they're in (with the help of my dremel!)


I am really impressed with the pickups and the preamp. A filter pre is much better suited to a fretless, I cannot say that enough. I can dial in the sickest jaco tones and the fattest P bass thump with ease. The final thing I will do is the string through body mod. I need to get some time in the wood shop this weekend.

[RedLeg]

Wholly Crap!
I just got the coolest news from bourns audio. I inquired about sourcing some dual 50k pots that would fit my instrument and they responded with a full set of pots to match the schematic! free of charge! They now will be offering a bartolini EZQ kit, so fear not my fellow TBer's. If you want a cheaper alternative to an ACG or Alembic, it now is within your means!

[testing1two]

Originally Posted by RedLeg

Wholly Crap!
I just got the coolest news from bourns audio. I inquired about sourcing some dual 50k pots that would fit my instrument and they responded with a full set of pots to match the schematic! free of charge! They now will be offering a bartolini EZQ kit, so fear not my fellow TBer's. If you want a cheaper alternative to an ACG or Alembic, it now is within your means!

How can I order this kit?

[RedLeg]

PROAUDIO@bourns.com
is the email I have been corresponding with. I guess you would ask for the bartolini EZQ kit? They are very helpful.

[MysticMichael]

Originally Posted by RedLeg

I am a little worried that I cannot achieve 34" from nut to saddle (saddles fully extended). It seems that I am about an 1/8 inch shy.

What say you TB community?
do I need to relocate the bridge 1/4 to 3/8 inches closer to the nut so that I can get the G string to a perfect 34 inches with a little wiggle room?
or
an 1/8 no big deal on a fretless because after all intonation is dynamic on a fretless!

I understand the hassle involved in having to reposition the bridge. But my feeling is that anything worth doing is worth doing right - especially when every other part of this project has been so well thought-out and well-executed.

An eighth of a inch is a significant amount of territory for a fretless bass. Personally, it would drive me completely nuts to have to remind myself to play slightly sharp on the "G" string in order to compensate, for as long as I own the instrument. It even makes me slightly OCD - just sitting here thinking about it.

Playing sliding double stops and triple stops on a fretless is difficult enough - even when the instrument is perfectly intonated and perfectly tuned. Having a "G" string that's off the mark by 1/8" would make doing so all but impossible.

You know what to do...

MM

[RedLeg]

argh. you are correct Mystic! My inner OCDness would eat away at me over time as well. Sadly, it is not only the G string, it affects all of them
My intonation will suffer on a 34 1/8 " scale when the lines are 34" scale.
So here is the plan!

1. score new mounting holes 3/16" or 1/4" closer to the nut
B. drill out original mounting holes and fill with dowel stock; glued in and sanded flush.
*. drill out scored holes.

Should be a snap. Measure 2x, drill 1x is the plan! Curse you bad designed wilkinson bridge!

EDIT, just had a thought, maybe just get longer saddle screws? they shouldnt be that difficult to source?

[Joe Kyle]

looks nice! Those bridges are killer, have one on a 6 string peavey cirrus.

[MysticMichael]

Originally Posted by RedLeg

Curse you bad designed wilkinson bridge!

EDIT, just had a thought, maybe just get longer saddle screws? they shouldnt be that difficult to source?

Obviously the key issue is where the bridge saddles lie relative to the scale length - not necessarily where the bridge is positioned (although there's obviously not much maneuvering room unless the bridge is at least close). So whatever works for you..

Regardless, it's well worth it to get rid of that POS Wilkinson bridge. My first Carvin bass guitar - a 1992 LB70 - came straight from the factory with the Wilkinson installed. At first I didn't want to believe that the bridge was the source of all the tone suck...especially since Carvin talked it up so much in their catalog. (They can't even be bothered to run their catalog copy through a spell check & grammar check - so the same errors get repeated, edition after edition, year after year. That should have told me something... )

At length, I came to my senses and replaced that turkey with a new Quan BadAss II...and that made all the difference. She was a wonderful player ever after...

MM

[RedLeg]

Damnit!
What is going in the world these days. First I ask bourns to source some obscure pots and they totally go out of their way and put together a kit and get it in the mail free of charge. Now Hipshot emails me saying that they will send me some saddle screws 3/16ths longer than stock free of charge as well! To make things more suspicious, I wake up and it is snowing in Sagamihara, so work gets canceled! Sometimes it is just a good month. I should remember this for when times get rough.