(new) BONGO piezo - trimmers

[Golem]

ok...so if the trimmers are:

1-general
2-G
3-D
4-A
5-E

6-B

I have some troubles since the E string is still louder than the others....even with the trim all counterclockwise...

any suggestions? It is normal that the trimmer does not cut off completly the volume when closed?

am I doing right?

thanks

and

Yes, normal .... these are trimmers, not volume pots.
They only do about +/- 6db.

[walkerci]

Yes, normal .... these are trimmers, not volume pots.
They only do about +/- 6db.

So what is the solution then?

With the E string noticably louder than the others when panned all the way to the piezo, this effectively renders the piezo pickups worthless. I would call it a product defect.

I don't want to try to EQ the problem away on the amp either because:

1. I need to change the panning live.

2. I will switch between the SR5 fretless and my L2500 fretted when gigging.

I can't be walking over the amp to change the EQ mid performance and I'm not about to buy pedals to compensate for this either.

[Golem]

So what is the solution then?

With the E string noticably louder than the others when panned
all the way to the piezo, this effectively renders the piezo pickups
worthless. I would call it a product defect.

.........

Piezos are finicky buggars. Since you previously mentioned that
the H PU does NOT suffer from Loud E-String Syndrome, [LESS]
it seems clear enuf that it's not your string set thaz causing your
LESS problem. So .... tricks to quiet a single string would not be
helpful, as then you'd have QESS playing the H-PU [Q="Quiet"].

So, the only option is to address the way the E-string's piezo is
responding. The trim pots are rather twitchy, sometimes jumpy
in their response to small adjustments. They're not wire wound
resistor pots but are "carbon pots" [or something similar], and
the wiper is tracking across a very small distance. Did you try
pot spray, or tuner cleaner, or any such cleaning product ? I'd
try that, first thing.

The piezo saddle elements respond to vibrations, but they are
"preloaded" by the constant pressure of the string. Sometimes
messing with the break angle [string crossing the saddle] will
tame this effect .... sometimes. You can't re-angle the saddle,
but you can make sure that the thick string is not arcing over
it rather than laying along it.

You can also use small scraps of shielding foil [aluminum or
copper adhesive foil] to "pad" or cushion the contact area of
the string along the piezo element. This should not have a
detectable effect on the unplugged loudness of the string, so
you're NOT damping the string [which would provoke QESS
with the H-PU]. You're only reducing the degree of direct
pressure the string exerts on the piezo, thus reducing the
"pre-loading" effect.

Nothing else occurs to me. There's always EBMM customer
service .... piezos are finicky, which is sometimes a PITA.

[walkerci]

Thanks for the long explanation. I'm of the engineering mindset, so what I could understand of your reponse made sense to me.

Those preamp "boards" are WAY to small for me to be fooling with.
I can't even tell if the trim pots are sealed or have an opening.

I probably should have gone with an SR5 HH, but I was simply taken with this bass.
When I tried it out I used the wrong approach.

I fooled with the controls until I could get several tones that I liked.
Must have been with the piezos panned out partially.
I should have spent more time with it and several other basses before deciding...

[Golem]

`

Do spray the trim pots, esp the E.

Remember, pots reduce volume by bleeding
signal to ground. IOW the position of LEAST
resistance is the quietest, NOT the loudest,
cuz the position of least resistance bleeds
off MORE signal to ground. If the pot is not
clean, the position of least resitance has
more resistance than intended by design.