Double Bass Homebuilt EUB build thread

[Jeff Siddall]

I am building the 5 channel version. I think that one has the circuit that you are referring to?

Yes

 

[DoubleMIDI]

The yellow capacitors could be ceramic ones, but I doubt it. It's not a question of capacity value but of the right selection of building type.
In Europe I would use a Wima (manufacturer name) foil capacitor, but there are other types that would work too. To make a good selection check your suppliers and read about good and bad choices for audio use.

 

[Videojunkie]

@DoubleMIDI , nah they're cheap ceramic caps. I bought a selection kit from Amazon. But now I know which ones need to be upgraded, and I will order the proper replacements from mouser.

 

[bassically_eli]

Seems like it might be preferable to leave out the limiter part of the circuit.

 

[Videojunkie]

Seems like it might be preferable to leave out the limiter part of the circuit.

If I understand correctly, that's more a protection circuit for the 2nd op amp than a real limiter. So if something hits a bass string hard (or you drop the bass!) It doesn't blow up your circuit.

I am going to see how it works out, and then decide how to proceed.

 

[Jeff Siddall]

If I understand correctly, that's more a protection circuit for the 2nd op amp than a real limiter. So if something hits a bass string hard (or you drop the bass!) It doesn't blow up your circuit.

I am going to see how it works out, and then decide how to proceed.

No, those limiters are there only to make nice sounding distortion. Since all the op amps are powered from the same rails they won't fry each other so you don't need to worry about the circuit damaging itself.

 

[aesopslyre]

A thought. 34" is pretty close to the 4th - 5th fret of 4/4 scale length. In theory, using an E - C set Tuned B - G, the string tension should be similar?

There are several options for DB strings for 1/4 size basses that are 36” in length. So you might want to reconceive your approach to scale

 

[Videojunkie]

There are several options for DB strings for 1/4 size basses that are 36” in length. So you might want to reconceive your approach to scale

I think @DoubleMIDI and I pretty well hashed this out before I applied saw to wood (in any case adding 2" to the scale at this point is impossible). But I am thinking about extending the bridge holes through the body (there is a support brace in place for this) so that longer strings are an option.

I am hoping that I can find a 'cheap' set of 1/4 scale DB strings to try on this thing, but I am leaning towards EB flats designed for fretless playing. Will I be able to bow them properly? probably not, but I am looking forward to getting this bass finished and ready to play!

 

[aesopslyre]

I think @DoubleMIDI and I pretty well hashed this out before I applied saw to wood (in any case adding 2" to the scale at this point is impossible). But I am thinking about extending the bridge holes through the body (there is a support brace in place for this) so that longer strings are an option.

I am hoping that I can find a 'cheap' set of 1/4 scale DB strings to try on this thing, but I am leaning towards EB flats designed for fretless playing. Will I be able to bow them properly? probably not, but I am looking forward to getting this bass finished and ready to play!

Try eBay, I got 1/4 size a set of D’addario Helicore for under $70. I successfully use 1/4 size DB strings on a a very small DB with a mensur of 34”. But they don’t compare to Spirocore if your’e doing primarily pizz

 

[Videojunkie]

Whew, After nearly 6 weeks on the road, I am finally able to make some real progress on the bass again...



Started carving the volute. In keeping with the style of the headstock, I had a bit of fun with the design. I am not quite sure how I want to finish the bottom of the part that sticks out so opinions are welcome...

I am at a critical decision point. I either need to finish the neck while the body is square, or finish the body while the neck is square. There are pros and cons both ways. I am thinking that I might try and bridge the best of both worlds by finishing the headstock and that end of the neck, then finish the joint at the body, build the body, and then come back to finish the rest of the neck.

Any advice is welcome.

 

[Videojunkie]

Started cutting the end of the neck. How thin should this be? Right now it's about 1.5" including the fingerboard. I think it wants to be thinner, but I am not sure how thin to go.

 

[DoubleMIDI]

Neck thickness including fingerboard directly in front of the pegbox heel:

Stagg EUB: 38mm
4/4 5-string DB: 41mm

BTW, the Stagg has a truss rod but I haven’t found that is does anything.
DBs don’t have truss rods, the neck together with the glued on fingerboard are strong enough to hold the tension and to not being able to bend it by a truss rod.

Check your left hand when playing horizontally (BG) and vertically (DB). I found for me that I’m more comfortable with a thinner neck horizontally and a thicker neck vertically.

 

[Videojunkie]

Working on the heel of the neck today (yay for four day weekends!)

I'm pretty happy with how this is shaping up.

I know shinto files are the new hotness for shaping necks, but I have used a draw knife since I built my first guitar in the late 80s.

 

[Videojunkie]

Sometimes you have to go old school.

Bookmatching the top and front. It's about 1" too wide for my bandsaw, so I cut both sides as deep as the tablesaw would go, and I get to cut the remaining 2" or so of wood. At least with the guide cuts on both sides, it is going smoothly.

 

[Videojunkie]

While certainly not grade A wood, this ain't bad for box store off the rack.

(Just a bit of water..)

 

[ctmullins]

Wish my box store had some of that….

 

[Videojunkie]

Wish my box store had some of that….

I lucked into it... there was only one like it in the whole shelf of maple at Menards. It just happened to grab the light as I flipped through the boards, and I recognized the pattern.

I am really excited about how it's going to look when I finish it...

 

[Videojunkie]

So I am playing around with cardboard to mock up the sound box.

Turning 2D drawings into 3D reality is fun!

 

[Videojunkie]

Apparently I have some geometry to figure out.

I think I am going to bevel the center curved section so that it better intersects with the side.

Anyone else have a suggestion?

 

[Jeff Siddall]

Apparently I have some geometry to figure out.

View attachment 4285444
I think I am going to bevel the center curved section so that it better intersects with the side.

Anyone else have a suggestion?

Sorry, I can't answer your question because I was laughing that you used a lego box to mock up a 3D shape!