Double Bass Stagg EUB megathread

[TTRCmedia]

Good idea to check first.

Checked - it is working I will add the missing pot and FET so I can connect both piezos as it is intended with that amp.

Just use a very sharp knife and use almost no pressure and move the knive a lot back and forth to cut.

I got some flexible 80mm piezo wires. I think I will not cut them - I did a test how narrow I can lay them into a spiral and that way they fit below the bridge feet.

You don’t need any washers as the wood is thick. There might have been washers on the strings, but I’m pretty sure I have installed strings without them.
BTW, I still have a few sets of the originals strings that I do not use as they color my fingers black.

I ordered some inexpensive strings at Amazon, should be ok for a first try. But they are steel ones - would it be better to use nylon core strings like the original ones?

I noticed that someone already sanded down the bottom of the upper part of the bridge. But it looks like he did it separate for each side, as one side is not flush with the other. I think i´ll have to fix this, as now one of the big thumb nuts is pressed tilted to one side.

 

[DoubleMIDI]

Checked - it is working I will add the missing pot and FET so I can connect both piezos as it is intended with that amp.

Just checked a pic of my Stagg electronics and it is indeed the pot, transistor and jack that are missing. Anything else looks the same on mine.
So you already know that the grey cable is output, the black/red is battery and the jack(s) are the piezos.

I got some flexible 80mm piezo wires. I think I will not cut them - I did a test how narrow I can lay them into a spiral and that way they fit below the bridge feet.

That’s what I would have recommended too.
I think the piezo wire is inside a plastic tube on mine, but it can be the outer isolation. Most were bent in a loop, some others just straight.
There might be a limit how much the piezo wire can be bent, so be careful. It is a synthetic piezo material in the dielectric. Here is a look at the newer bodies at the bridge position.

The piezo wire goes through the hole and is connected to a shielded cable with a 2.5 mm TS plug (Mono-Klinkenstecker). 8 cm seems to be perfectly fine for that.

The cables are shielded with adhesive aluminium foil and pressed to the sides DI the endpin goes above the foil and between the cables:

I ordered some inexpensive strings at Amazon, should be ok for a first try. But they are steel ones - would it be better to use nylon core strings like the original ones?

The originals have a thin solid steel core. If they wouldn’t color my fingers I might have kept playing them. You can order them as replacements (40€), but I rather recommend 4/4 Spirocore (get a used set) since the underlength is longer than on a DB because by if the missing tailpiece. If you want hardly used original strings I can send you a set. Put a sponge below the underlengths to dampen the resonance.

I noticed that someone already sanded down the bottom of the upper part of the bridge. But it looks like he did it separate for each side, as one side is not flush with the other. I think i´ll have to fix this, as now one of the big thumb nuts is pressed tilted to one side.

The lower strings need a higher action than the upper strings. The bridge is originally constructed for equal height which is bad.
Common sense is that the height difference from string to neighbor is one millimeter. On my instruments it is up to 1.5 millimeters. Typical 5/6/7/8 millimeters G to E.
It is not possible to get there with different adjuster heights. Either file down the crown of the bridge on the G-side (swap bridge top if the E-side is lower) or live with a non-optimal setup (or make a new bridge yourself).
If the feet of the top of the bridge are sanded down differently that is of no help, but raising the adjuster on the side where more wood has been removed will correct that. Just cosmetically unpleasant.

Happy tinkering!

 

[TTRCmedia]

If you want hardly used original strings I can send you a set.

I will check if the strings I got from Amazon are long enough - they should be, but I will see it when I have put body and neck together. But first I want to care about the small lacquer damages. I think it´s easier to work on the wood while it is still more compact

If the feet of the top of the bridge are sanded down differently that is of no help

One of the feet is not at a right angle to the adjuster axis anymore - I will have to fix that to get both to be same height and angle, otherwise one side can not sit flush on the adjuster nut.

I received an original bag for the bass, along with the body supports - but the older, non-screw version. Does anybody have an idea what to use to secure the support bars in the body? Mine has the threaded inserts already, I want to keep them in.



I think there must be some standard part that will do the trick if repurposed, but I could not find it. Thread is metric, M10x1.5.

 

[TTRCmedia]

I did not have much time to continue on the bass, but in the meantime I filled & colored the few lacquer chips, completed the electronics, shielded the compartments in the body and added tuners.

One thing I´m curious about: The old headstock on the first version of the EDB was this one, right?



It seems there are two versions of the later, more stable model - one with access to the truss rod from head side, and the other one with access through the end of the finger board. Are there other (important) differences?

 

[farace]

I did not have much time to continue on the bass, but in the meantime I filled & colored the few lacquer chips, completed the electronics, shielded the compartments in the body and added tuners.

One thing I´m curious about: The old headstock on the first version of the EDB was this one, right?

View attachment 7332066

It seems there are two versions of the later, more stable model - one with access to the truss rod from head side, and the other one with access through the end of the finger board. Are there other (important) differences?

View attachment 7332067 View attachment 7332068

It’s my understanding that the problem headstock, prone to breakage, was the early script-logo version. (Photo borrowed from Internet, not mine.)

 

[TTRCmedia]

was the early script-logo version

Oh, so there are four different headstocks :-O

(photos in my last reply were borrowed from the internet, too)

 

[DoubleMIDI]

I‘m not sure if they just have a different text logo but otherwise headstocks see identical.

The headstocks can be stabilized by a backplate fixed well at the headstock. The almost parallel cheeks at the headstock can break easily by a side impact.

 

[farace]

I‘m not sure if they just have a different text logo but otherwise headstocks see identical.

The headstocks can be stabilized by a backplate fixed well at the headstock. The almost parallel cheeks at the headstock can break easily by a side impact.

When I emailed the company to get a replacement tuner (broken gear teeth) they asked me which logo my bass has, so it makes a difference as to what tuners they use, at least. I believe the script logo headstock has thinner sides.

 

[DoubleMIDI]

Interesting.

I know the weaker and newer headstocks have different tuners, but didn‘t know that the cheek thickness differs between the same kind with different text logos.

TalkBass is such a nice resource of knowledge.

 

[mc3r1c]

I am new to this thread. I recently bought a used Stagg EDB for a good price. I've been learning to play upright for a few years and wanted to try an EUB without breaking the bank. I also don't have a lot of experience with modding instruments, so thought this would be a good project bass. Looking for any feedback here if anyone has tried this and has thoughts.

I read the thread, and had the same problems others have mentioned. The string height and spacing was a little low and tight. Biggest issue was playing arco - no output from the middle strings, and the curve profile was not ideal.

I saw some suggestions in the thread to swap out the bridge. I took a bridge from a regular upright bass that a luthier was going to scrap (nice maple, already shaped and slots cut). The bridge is now about 2.75" tall. The bridge base is just flat with the body centered between the normal bridge feet holes. For a pickup, I used a fishman BP-100 I had sitting around, with the piezo elements between the bridge and the body. The bridge base needed to be really flat. I also tried putting the stock cable piezos under the bridge base and using the on-board electronics, but had the same issues with middle string output.

String height, spacing and curve across strings are closer to my regular upright. Tone is much better, especially arco, It does prefer a high-impedance pre-amp. And that is a kitchen sponge acting as string dampener and holding the output jack. I took it to a local jam session and everything stayed in place and still sounded good at the end.

It's definitely not a replacement for an upright, but it seems playable.

Any feedback is appreciated as I know this group has a lot of experience.


.

 

[TTRCmedia]

The reason I´m asking about the differences between the necks used is that I have two of them. The headstocks look identical but the obvious placement of the access to the truss rod - one (left) from the top, the other one from the end of the fingerboard (right).

The nut on the left one feels more like cheap plastic and shows marks of being molded, the one on the right seems to be harder and has an almost wood-like texture.



The screw holes for the tuners are aligned a little bit different - on the right one standard Fender style tuners fit well, the left one came with it´s original tuners with screws placed closer to the cog (length of the headstocks is identical, they are not on the same height on the photo):



The thumb grove on the side is different as well - left one open to the bottom, not on the right one. Oh, and the left neck has no inlays on its side.



The end of the fingerboard has a different thickness:



And the fingerboard surface looks and feels different, too: Left one is almost shiny, right one a little more matte and rough.



I cannot decide which one to use...

 

[farace]

FWIW, mine has the truss rod access as a hole through the headstock rather than the groove, but it also came with the tuners that have the rounded bottom edge to the backing plate. When they sent me a replacement tuner, it was the straight-edge version. The holes lined up, though and it is a drop-in replacement.

I still need to get someone to properly profile my fingerboard. Much of the fingerboard is fine, but I get buzzing on the E and A strings at what would be the second and third fret positions if it had frets, and Bb on the E string “frets out” and is unusable. Other strings are fine at that position. I have the truss rod completely slacked off.

 

[TTRCmedia]

Final parts finished for putting the puzzle together In case someone needs an idea how to connect the old style body supports (or new ones bent from 6mm aluminium rod) to the body with threaded inserts:



I used hose connectors for 10mm hoses with M10x1.5 thread, inner diameter is 6mm. I shortened them, drilled a small hole into the rods and secured everything with wire from a paper clip. Not as nice as the original knurled bolts, but it fits quite well and should work

 

[DoubleMIDI]

Great idea, probably better than the original.

 

[336v]

The stock body supports are so flexible and wobbly, I found them practically useless to hold the instrument in the same position relative to your body as you play. I've replaced the long (right) body support with adjustable rigid link to a wooden pad resting against belly as you play. I play sitting on a high stool, the instrument rests on this support and on inside of my left leg and is very stable. I don't use the left support for the hand at thumb position at all - found there's no need for it. More details on this - on my Stagg page here.
As far as the electronics mentioned a few threads back, someone reported presence of only one channel on his preamp board. I'm the one who traced and posted the schematic of the Stagg preamp, and can tell that both channels are identical. The source followers after input jacks are connected in parallel, e.g. signals from both piezo wires after FETs are mixed (summed up) through fixed 20k resistors before getting loaded to a common volume pot. The Stagg can certainly play with only one channel active and one piezo wire under just one leg of the bridge - the piezo output signal will be somewhat weaker, but more than enough to drive the next stage, which is buffered tone control circuit. You can reconstruct the preamp to the original two channels, but I'd try to use it as is first - it may well be very adequate, and there's good chance you might not notice any difference between one piezo wire under the bridge (usually under E-leg), or both. If you want, you can order complete new preamp board (with or without piezo wires) from EMD music, that is about $40.

 

[DoubleMIDI]

Die to my experience I‘m pretty sure that on a solid body (or even on a DB with a soundpost too close to the bridge foot and too no ich pressure) the strings will not be on the same volume level with only one pickup element.
I also cannot recommend to wire the piezos in parallel in front of the FET.
So I highly recommend adding the missing components.

And, as I remember, each pickup element can be controlled by a pot in volume.

 

[TTRCmedia]

I already filled the gaps on the amplifier board to have both channels, and tested it with two piezos - it works One of the piezos has a lower signal, I think I will have to get new ones at some time. But I did not test it in the instrument, as I currently don´t have much time :-/
I also shielded the cavities for amp, cables and connection socket, and found some nicely fitting screws to put everything together. Hope I can start to have fun with it soon
If the body supports will be too wobbly, I will build new ones from aluminium plates - at least the bottom one - or wood. Or something similar to the support bracket 336v built - I like the adjustability!

 

[336v]

DoubleMIDI, a bit of misunderstanding - I did not mean or suggest to connect piezos (solder piezo wires ends) directly in parallel and THEN connect common junction to a single FET input - while this will produce sound, it's not a good idea. I said that the stock preamp has two input channels in parallel, meaning each FET passes it's own piezo's signal and only outputs of FET"s stage are connected in parallel (mixed) before getting to common for both signals tone control. Similarly to the concept of a multichannel Invalid Link Removed) where you can say all its channels's signals are routed/processed in parallel, but that does not mean the input jacks are directly soldered in parallel. And confirming - on Stagg each piezo element's output level can be adjusted individually by the trim pot on the preamp board before signals get mixed, but this is pre-set and not accessible to the user while playing, only common "volume" pot (knob) is. The location of both trim pots is shown on this rendering - they are blue, marked as VR1 and VR2. You can sure trim the output levels individually yourself if they are uneven, but you'd have to pull the PCB out for that. And yes, restoring missing components is the best option as long as the PCB tracks are not molested, torn away or otherwise are unusable. This reconstruction would be quite simple, but requires basic soldering skill and preferably - familiarity with electronics in general.

 

[mc3r1c]

I'm looking to use the on-board electronics with my new bridge setup. Does anyone know if there are flat disk piezos that terminate with the same cable and plug setup as the stock piezos?

 

[DoubleMIDI]

I'm looking to use the on-board electronics with my new bridge setup. Does anyone know if there are flat disk piezos that terminate with the same cable and plug setup as the stock piezos?

I doubt that you find what you are looking for. Not a big thing to DIY if you know how to solder. Just keep soldering time extremely short on the piezo disk as heat can destroy the piezo ceramic.

But a piezo disk is mainly bending sensitive, the piezo cable used in the Stagg is mainly pressure sensitive. So expect a lower output signal with a piezo disk.

I used large cut to size piezo disks under the bridge feet for my Clevinger pickup. The sound is very nice, but the signal is low. I need an external preamp to amplify the voltage for a useable signal but get some hiss from the high amplification factor if it gets a bit louder.