1st Biuld - HB-4S violin bass

[Rabbit]

I'm expecting the machine heads to come in on Friday, and the other stuff I have been waiting on today. I went through all 87 "pages" of thread titles to track down other builds of the HB-4 and 4S and found 9. BassGuy must have done a second, undocumented build, since the one he used in the sound demo was not the "Golum" build :P.

Nearly every wiring diagram for the other kits has the bridge earthed. Obviously you can't earth a timber bridge, tommycng did earth his to the tail. Whilst there is no other earth in the wiring diagram, before I button everything up, do you reckon earthing to the tail is a good idea anyway?

[fender3x]

Nearly every wiring diagram for the other kits has the bridge earthed. Obviously you can't earth a timber bridge, tommycng did earth his to the tail. Whilst there is no other earth in the wiring diagram, before I button everything up, do you reckon earthing to the tail is a good idea anyway?

Absolutely! Odd that it's in none of the diagrams.

[Simon Barden]

If they originally came with those black plastic-coated flat-wound strings as standard, then there wouldn't have been much point in grounding the ends of them as the strings themselves would be insulated. But it’s worth doing if you are using standard round- or flat-wounds.

[Rabbit]

Absolutely! Odd that it's in none of the diagrams.

If they originally came with those black plastic-coated flat-wound strings as standard, then there wouldn't have been much point in grounding the ends of them as the strings themselves would be insulated. But it’s worth doing if you are using standard round- or flat-wounds.

Simon: The kit comes with a set of round wounds as standard, I believe your mate Sir Paul likes flats, but I've actually gone the route you intimated, tape wounds! I'm realy curious to see if they produce that upright tone on an electric that everyone claims. That and I couldn't find short scale coated flats. On my current bass I use a mix of DR red devils and black beauties. Very happy with those, but I don't think they are a good fit with a violin bass. The whole point is to have a bass that has it's own character and voice. Since it's no drama in earthing the tail anyways, and Fender3x seems to be hinting that it may be an idea, I guess I'll do that.. Even though the tape wounds may fit the colour scheme, it could turn out to be an expensive flop, and then I try out a set of flats, with the system earthed ready for them. Thank you both for your advice .

[guitalias]

An ooon with the shew!


Once that's resolved, the next question is glue choice. Will PVA such as Titebond be good enough, or should I go industrial with boat builders epoxy?

Titebond original is good, but it is a Aliphatic resin emulsion, rather than a PVA. From what I've read it is a better adhesive for guitars than PVA.

See this https://www.buildyourownguitar.com.a...ead.php?t=1630

[Rabbit]

Titebond original is good, but it is a Aliphatic resin emulsion, rather than a PVA. From what I've read it is a better adhesive for guitars than PVA.

Right you are. I actually went with Titebond II which is " a shelf stable, one part (pre-catalysed) cross-linking PVA adhesive" :

And back to topic of earthing. fender3x seemed to be enthusiastic about it's presence, the wiring diagram for the HB-4 doesn't show it, and tommycng didn't elaborate on how he did it too fully. There are several ways it could be done, but I thought I'd share with the forum how I did it.

I grabbed a piece of stray hookup wire I had floating around, stripped one end of insulation fairly long. I twisted that , then wrapped it around a small screwdriver. The excess was twisted around the main wire. This was then tinned with solder to form a stiff loop. whilst a lug could be soldered or crimped on to the end instead, I wanted to keep things simple. I'm not sure if the tail piece is chromed brass. If so, the wire could have also been soldered to the tail piece after some of the chrome had been removed. Since I already had some extra holes in the body (I had to move the tail piece so the strings lined up), I enlarged the original centre hole to poke the wire through, and bent the loop to 90 degrees:



The new centre screw location goes through the loop, pressing the loop between the tail and the body.
I soldered the other end of the wire to the same pad as the neck pickup. You can see the hot wire for the pickup, and just below it the pad used for the earth. Next to that pad is the pad the socket is ground to, which is the location the wiring diagram says to earth the two pickups to. What isn't clear in the photo below is there are two tracks linking the pad I used and the pad the diagram recommends. I just thought it was less cluttered that way.



I'll post final pics once the rest of the stuff I ordered get here

[Rabbit]

Aaaand, we're done. It sounds ok. There is a bit of hum when you fiddle with the volume controls, but not much, and it settles down. There is also some hum when the switch is set to the solo position. The "bass" and "treble" switches seem to be more "bridge" and "neck" since when only the treble switch is on, it only responds to the volume control of the neck pickup and visa versa. You may also notice the bridge is at a slight angle. Getting the intonation right was a real pain. When you got it correct for one string, it was slightly off on other strings. I had to fiddle with it to get it "mostly right" . As for playing, it took me a while to work out that you needed to attach the front side of the neck strap to the button rather than the back the way you normally would. This lessens the tendency for it to want to roll away from you. Whist playable, it still feels a bit awkward, mostly because of the cut away that gives it that violin shape.







Even though it is clearly not a Hoffner, I've decided to name it "The Hoff" .

[fender3x]

Looks great!

You can get a pretty nasty hum if the strings are not grounded. On steel covered strings a lot of the hum will go away once you touch the strings, which means your body is acting as the ground.

I didn't know that the originals came with tape wounds, but I would think that would be an even better reason to ground the tailpiece. The string core is still ferrous. I have a set of D'Addario tape wounds on an ES bass with a tailpiece. The "ball" on the bass end is colored metal which is conductive. The metal string core wraps around the ball, so a grounded tailpiece will ground the string, even if tape wound. The wrap is also pretty loose on the G string, so I am pretty sure it would ground at the bridge as well.

As to sound, YMMV, but I would not count on them sounding like an upright. I had a set of Fender tape-wounds that sounded a LOT like a fresh set of round wounds on my Frankenbass. You could play slap with them. The D'Addarios are far less lively, but still don't sound that much like an upright to my ear. Flat wounds sound more like an upright to me...and it's what my old upright actually had ;-)

BTW if you do get tapewounds, I'd stay away from the Fenders. Only bass string I have had in years that broke on me. I don't think I got more than a few months out of them.

[fender3x]

There is also some hum when the switch is set to the solo position. The "bass" and "treble" switches seem to be more "bridge" and "neck" since when only the treble switch is on, it only responds to the volume control of the neck pickup and visa versa.

My guess is that the setting that the solo position drops the cap out of the circuit. When the cap is engaged, it's filtering out some of the high frequencies where most of the hum is. Not sure why else it would do that.

The "bass" switch *should* turn the neck pickup on/off, and the treble switch should turn the bridge pickup on/off. A little odd, but what isn't a little odd in a Hofner?

[Rabbit]

[

You can get a pretty nasty hum if the strings are not grounded. On steel covered strings a lot of the hum will go away once you touch the strings, which means your body is acting as the ground.

I didn't know that the originals came with tape wounds, but I would think that would be an even better reason to ground the tailpiece. The string core is still ferrous. I have a set of D'Addario tape wounds on an ES bass with a tailpiece. The "ball" on the bass end is colored metal which is conductive. The metal string core wraps around the ball, so a grounded tailpiece will ground the string, even if tape wound. The wrap is also pretty loose on the G string, so I am pretty sure it would ground at the bridge as well. .

I don't think tape wounds existed when the Hoffners came out. The kit comes with standard round wounds. I thought I'd try tape wounds for something different, but I believe flats are the preferred strings. I have a set of Pyramid short scale strings on there. They are a very heavy gauge.. they don't give you a choice.. 55, 75, 95, 112 hehe... I normally go for 45, 65, 85, 105 . As per my previous previous post, the metal core of the strings *are* earthed. And yeh, the treble/bass switches are on/off switches for the pickups....not sure where treble and bass fits into that <chuckle> .