5 string fretless: "Ignis 3"

[T-34]

Hello, guys, wanted to share my last build with you.
I am building this bass for a friend, the design is of my last build 6 years ago ( ), the 6 str fretless bass "Ignis" "Ignis" 6 str fretless singlecut

this one will have one string less, have different woods and two pickups



specifications:
* mahogany body with imbuia top
* roasted ash (hi temp treated) multilam neck with ebony fretboard, unlined, neck-through
* 1 trussrod, 2 carbon stiffener rods
* not sure what pickups yet
* weirdo homebuilt electronics, more on this later


you'll probably ask: where's Ignis 2? You'll be right: it is in the works but not advanced far yet

[T-34]

Top wood and fretboard from LMII:


Neck wood:


Laminating maple separation layer to imbuia top



Blues or Reds?


Nice figure popping out after wetting the top with some water:


Laminating the neck (four pieces of roasted ash separated by fine maple accent layers):

[Beauchene Implements]

Very nice, T-34. I like the design, but I'm an even bigger fan of "weirdo homebuilt electronics," can't wait to see/hear! Thanks for the help last year on my own weirdo electronics, btw

[T-34]

Yeah, bizarre mix of passive and active, you'll like that

[joeyl]

if it is going to be as nice as the Ignis 6 string, I am excited to see the rest!

J'attends la suite avec impatience!

[T-34]

Thank you, I (and future owner) sure do hope it turns out well!

Mr Beauchene, do you speak french too?

[Beauchene Implements]

Originally Posted by T-34

Thank you, I (and future owner) sure do hope it turns out well!

Mr Beauchene, do you speak french too?

Unfortunately, no- but it's on my to-do list. My last name is by way of Canada, and I'm aware that it's a good last name for somebody who likes to make stuff out of wood

[T-34]

Proper woodworker name for sure

Once I worked in Russia, company's network admin's last name was Loginov, no kidding

[joeyl]

Originally Posted by T-34

Proper woodworker name for sure

Once I worked in Russia, company's network admin's last name was Loginov, no kidding

hahaha

[Stealth]

Originally Posted by Beauchene Implements

Very nice, T-34. I like the design, but I'm an even bigger fan of "weirdo homebuilt electronics," can't wait to see/hear! Thanks for the help last year on my own weirdo electronics, btw

Ditto. Love the design but it's the circuitry that piques my curiosity the most.

Not to derail the thread, but, Beauchene, can you link to your own wierdo electronics?

Originally Posted by T-34

Once I worked in Russia, company's network admin's last name was Loginov, no kidding

[joeyl]

5 string fretless showcase: Habanero V

[T-34]

So, speaking about my electronics.

This bass will have two passive tone controls, one per pickup (home-built multi-capacitor selector using 10-position rotary switch, I call it "Megatone") followed by two-channel buffer preamp with no EQ. This way it'll be possible to use "Megatones" independently unlike in full-passive circuit where tone controls cannot be separated properly without the loss of signal.

Here is the schematics I designed


detailed view for Megatone part:


normal/boost switch changes the control's behaviour a bit, I'll post simulated frequency response curves later to show the difference.
R1 to R9 are 2Meg, needed to keep capacitors discharged and avoid "pops" when switching caps.

[T-34]

Now the graphs,
Top diagram showing "boost mode", bottom - "normal", each of 10 curves representing one of 10 positions of the rotary selector.



So basically this is a low-pass resonant LCR filter, inductance L defined by pickup and C choosen by rotary selector and R by boost switch.
Looks promising

[T-34]

For comparison sake: this is what the frequency curve of conventional tone control looks like (0.047 capacitor, 250K log pot):

[Beauchene Implements]

Originally Posted by T-34

Now the graphs,
Top diagram showing "boost mode", bottom - "normal", each of 10 curves representing one of 10 positions of the rotary selector.



So basically this is a low-pass resonant LCR filter, inductance L defined by pickup and C choosen by rotary selector and R by boost switch.
Looks promising

Wow, that's really cool! It looks like a 5-10dB boost that's sweepable from 1-10k and lops off everything higher. Do you think, though, that those last two positions, as you get close to 10k, might just be letting more noise than signal through? Could you change component values to drive the whole graph left, so the 'presence' boost selection could start at 100hz? just a thought. Very freakin' cool.

[threadjack] Stealth, joeyl posted the link, my first attempt at a preamp is about halfway through. I've changed it since then, but I'll make my own thread to tell you about it. [/threadjack]

...aaaaaand subbed!

[T-34]

No, the mid boost peak cannot be moved more to the left easily, to accomplish that you'll need pickup with more inductance. I've made my simulation taking an "average" figure of 4H, that's inductance of an average PB pickup. Moodbucker or Fender '72 tele humbucker will yield about twice inductance as that, moving frequency boost one octave lower.

About the noise at higher positions: keep in mind the baseline signal is still there, what you have is just a resonant peak boosting some produced frequencies, still letting others be there. The filter is passive so no additional noise at all will be produced (unlike traditional active EQ circuits), meaning the peak is NOT accompanied by the raise of the noise at this frequency.

[T-34]

Back to wood stuff

roasted ash and maple separators glued together; sipo body wings

[Beauchene Implements]

Originally Posted by T-34

No, the mid boost peak cannot be moved more to the left easily, to accomplish that you'll need pickup with more inductance. I've made my simulation taking an "average" figure of 4H, that's inductance of an average PB pickup. Moodbucker or Fender '72 tele humbucker will yield about twice inductance as that, moving frequency boost one octave lower.

About the noise at higher positions: keep in mind the baseline signal is still there, what you have is just a resonant peak boosting some produced frequencies, still letting others be there. The filter is passive so no additional noise at all will be produced (unlike traditional active EQ circuits), meaning the peak is NOT accompanied by the raise of the noise at this frequency.

Ah, I see. I'm just getting more into winding pickups. I see an inductance meter in my future. Great, more tool GAS. Wood choices look great!

[T-34]

Looks like I've completely neglected the updates in this topic...

Will try to catch up with the updates accumulated since last time I've posted!

June 2012
Body wings roughly cut


Prepping tilted headstock surface


thinning down Imbuia for matched headstock, gluing



Installing double-action truss rod and two carbon rods

[T-34]

July 2012

Gluing body wings to the neck


Cutting rough neck shape