Double Bass K&K preamp very low volume

[cacio]

Hi,
i have K&K Bass Master Rockabilly set that i use on my laminate strung with Gutalike strings.
The problem is that I have big issues in volume.
If i connect my passive p and the upright to a radial big shot i/o pedal,i thought I had to connect the K&K to the 2nd channel,and decrease the volume in the way the manual explain.
But to uneven the output i have to connect th upright in the 1st ch and the passive p in the 2nd and deacrease to 2 (from 10) the volume.
It's the K&K very low output with nylan strings or maybe my preamp has some problem?

Thanks

 

[DoubleMIDI]

Battery?

 

[Ric Vice]

Since the K&K Preamps use 9 volt batteries. It could be that it's dropped below the voltage required to run the PreAmp.

 

[Don Hergert]

In my experience with the K&K Dual Channel Pro ST (which is supposedly a re-labeled K&K Bass Master Rockabilly pre-amp) this problem should not be related to using synthetic strings; piezo pickups should work well with either synthetic (including nylon) strings or metal strings.

Things you've probably already done, but just in case:

1) Replace the pre-amp's 9V battery, just to be sure (rated at ~60 hours of life by K&K, but batteries can self-deplete over time).

2) Check the pickup connections to the pre-amp (work it, unplug, plug back in, gently twist and turn a few times to remove contact condensation). At this time also verify that the correct plugs are plugged into the correct sockets on the pre-amp.

3) Verify that the piezos are still working (they tend to have a limited life of between 6 and 10 years in the best circumstances). With amplification connected and turned on and your pre-amp powered up, rub each of the piezos with your finger to verify that they still pick up vibration; you should hear this loudly through your amp. If they do still pick up vibration, check the bridge wing mount to make sure it is snug but not over-tight. Varying humidity conditions can affect this snug fit and cause changes in pickup performance. Also check that the fingerboard piezo is properly attached to the underside of the fingerboard.

4) Make sure that the pre-amp internal EQ and Gain pots for both channels are set as you like them. They shouldn't move about on their own, but it's worth checking. (Because these pots are not easily accessible, I usually keep the internal EQ pots to flat-high settings and Gain to somewhere between +1/4 to +1/3rd, and then do my real time EQ and Gain settings on my amp.) Also verify that you're turning the external blending volume controls in the right directions when you need to -- I know I've mixed those up sometimes.

5) Make sure your amp and your connections to it are working properly.

Lastly, sending a message to K&K wouldn't be a bad idea. They may have suggestions and/or remedies specifically for your situation.

Good luck with all this!

(My piezo pickup config: Vic's Model C bridge wing and fingerboard pickup system => K&K Dual Channel Pro ST. For strings I'm using Innovation SilverSlaps E and A under Superior BassWorks Deluxe Dirty Guts medium gauge D and G.)

P.S. In looking at the K&K Bass Master Rockabilly pre-amp at the K&K site, it looks like there may be at least some labeled socket-related differences from the K&K Dual Channel Pro ST. That said, most or all of my fairly generic recommendations above still apply.

 

[cacio]

Thanks to all.
Battery is not the problem,piezo is working great as my amp.To have a similar volume to a passive fender i have to put all the gain and the eq to max
I’ll try with an email to k&k,but i’m in Italy…i don’t know what they can do

 

[Francois Blais]

What pickup do you actually use?
A BassMax in the bridge wing?

 

[Don Hergert]

Is the Fender amp expecting a mic to be plugged into that input socket?

Also, how long has this configuration been in place? Is it newly installed or has it worked, and/or possibly worked better at one time in the past?

 

[Sam Reese]

Did you open up your preamp and mess around with the Gain? You'll need a small screwdriver.

 

[cacio]

Yes,the gain is at max.
The only way to have an output similar to a passive bass is to max eq and gain on the bridge pu.

 

[Mark Gollihur]

Hi,
i have K&K Bass Master Rockabilly set that i use on my laminate strung with Gutalike strings.
The problem is that I have big issues in volume.
If i connect my passive p and the upright to a radial big shot i/o pedal,i thought I had to connect the K&K to the 2nd channel,and decrease the volume in the way the manual explain.
But to uneven the output i have to connect th upright in the 1st ch and the passive p in the 2nd and deacrease to 2 (from 10) the volume.
It's the K&K very low output with nylan strings or maybe my preamp has some problem?

Thanks

Yeah, this doesn't make sense at all - the K&K Preamp is capable of 10x gain, so you should be able to achieve a VERY hot signal. At the very least, it should be like putting a passive bass guitar and an active bass guitar into the bigshot.
Without the bigshot, does the K&K system "sound good" to you? Is it otherwise working well?

 

[Keith Rawlings]

Are you using stereo cables? I noticed that standard guitar cables don’t have the kind of output that stereo cables do with the K&K. I also use a Vic’s Model C with mine.

 

[Mark Gollihur]

Are you using stereo cables? I noticed that standard guitar cables don’t have the kind of output that stereo cables do with the K&K. I also use a Vic’s Model C with mine.

You would only use a stereo cable from the output of the pickups to the input of the preamp. Using a stereo cable from the OUTPUT of the preamp will result in the preamplifier not being turned on/powered. This could actually be the issue, if the OP is using a TRS/stereo cable from the preamp to the pedal.

 

[Keith Rawlings]

You would only use a stereo cable from the output of the pickups to the input of the preamp. Using a stereo cable from the OUTPUT of the preamp will result in the preamplifier not being turned on/powered. This could actually be the issue, if the OP is using a TRS/stereo cable from the preamp to the pedal.

I meant from the pickup. I should have been more specific.

 

[Don Hergert]

The K&K Dual Channel Pro ST actually expects a stereo input from the pickups. At least according to the K&K specs, it looks like the Bass Master Rockabilly pre-amp does too. Both of them also specify mono blended output, with a separate mono output for each channel if that is desired to be used.

 

[Mark Gollihur]

The K&K Dual Channel Pro ST actually expects a stereo input from the pickups. At least according to the K&K specs, it looks like the Bass Master Rockabilly pre-amp does too. Both of them also specify mono blended output, with a separate mono output for each channel if that is desired to be used.

Absolutely correct. Using a mono cable from the pickup to the preamp will cause one of the pickups (usually the clicky) to be completely silenced.

 

[cacio]

I use stereo cables,and otherwise is everything ok.It sounds good.But the problem is there,i have low volume in the radial,in the amps,in the daw
Is it possible that with the GutALike strings the doublebass has a very low volume acustically and this made the piezo signal so low?

 

[Mark Gollihur]

I use stereo cables,and otherwise is everything ok.It sounds good.But the problem is there,i have low volume in the radial,in the amps,in the daw
Is it possible that with the GutALike strings the doublebass has a very low volume acustically and this made the piezo signal so low?

You use stereo cables? as in TWO? Again:

• DON'T use a stereo/TRS cable from the preamp to the amp.
  
• DO use a stereo/TRS cable from the pickups to the preamp.

If you're using a stereo cable for both connections, that is what is causing your volume problem.

 

[Don Hergert]

I use stereo cables. ...
... Is it possible that with the GutALike strings the doublebass has a very low volume acustically and this made the piezo signal so low?

And no, the strings make no difference. I'm using strings similar to GutAlike and have no problems with the piezo/pre-amp combination.

As Mark Gollihur (of Gullihur Music, who sells and installs these items) has indicated, your problem is very likely your stereo cable feed from your pre-amp to your amp. That should be a mono (not "TRS") cable. If you correct that you should have a full signal going to your amp and full volume available.

 

[cacio]

Ok,cables are not the problem.Trust me.And with another double bass the preamp seems to work well.
So the problem it seems to come from the piezo in the bridge,maybe there isnt enough conctact with the wood

 

[Mark Gollihur]

Ok,cables are not the problem.Trust me.And with another double bass the preamp seems to work well.
So the problem it seems to come from the piezo in the bridge,maybe there isnt enough conctact with the wood

Cool. From our instructions (FWIW, the Bass Master Rockabilly was co-developed by my father, @Bob Gollihur, working with the folks at K&K) :

The wing pickup is a Bass Max, and is easy to install, but it is important to take the time necessary to get a good fit to get the best sound. You must prepare the bridge properly for the best results — do not force the pickup into the bridge wing, or damage can result, voiding the K&K Sound warranty. The pickup includes piezo-ceramic elements that can be broken or cracked just like any other ceramic material.

The Bass Max needs about a ¼ inch opening in the bridge “wing”, and the surfaces should be parallel to each other for the best results. Both K&K Sound and I recommend that it be installed on the E string side, as the sound is usually balanced best in that position. However, feel free to try the G string side and make your own determination.

If your bridge opening is:

• Too narrow? Most bridge wings are too narrow, so you will have to widen the opening. I use a thin, flat file most of the time, but you can also wrap various weights of sandpaper around a flat ruler or stick, to sand away wood, in your mission to create a flat surface for the pickup. Sand both sides; the wood must be smooth on both sides so it doesn’t tear the rubber jacket.
• Shaped without parallel surfaces? If the upper side of the wing is not flat (file it flat) or is very small, it can be a good idea to install a shim on that side to improve contact surface. You can sand away as much material as necessary to accommodate your shim. Once fitted, it’s a good idea to put a spot of wood glue on the shim and bridge to make the structure stable.
  
• Too wide? Like above, you can make a shim to take up the space needed for the best fit. I prefer to use a thin slice of wood, a sax reed, or a piece of wood you can cut and sand to fit a particular bridge. As with the prior example, adding some glue to stabilize the fit can be a good idea. Guitar picks in various gauges can provide the ability to easily test-fit various thicknesses of shims.

How tight should the fit be? My rule of thumb is, the pickup should not move if tapped with your finger, but if you grasp it firmly with thumb and forefinger it should readily be able to be repositioned or removed. If your Bass Max is too loose, you are inviting a boomy sound that feeds back more quickly. Too tight, and the sound is choked and flat, and you could possibly break the transducers inside the pickup. You will also often find differences in sound depending on the position of the pickup within the wing – experiment!