Behrenger AD121 Vtone Preamp/DI

[markbaptiste]

Anybody had any experience with a Behringer AD121 Vtone preamp/DI with a mandolin with a passive piezo pickup (like Epiphone MM30E) diectly plugged into a PA?
thanks
mark

[almeriastrings]

Works quite well. Surprisingly well considering the incredibly low price. It has a 1M input impedance and adequate gain. You can use it with the 'modelling' turned off, as a straight-forward DI. The 'modelling' is nothing too special, and is not to be compared to a Fishman Aura. Used as a basic piezo DI, however, it gets the job done. My wife has one that she uses on her mountain dulcimer, which is fitted with a passive piezo transducer. It sounds fine and she's had it a few years, with no issues.

[Jim]

I've been using one for about 3 months now and am quite satisfied. I've been using it with mandolin and guitar in some noisy environments where I couldn't mic the instruments and went direct into a Kustom 4 channel PA. The sound was quite nice. Also have used it with Behringer and Epiphone Acoustic amps where it wasn't absolutely necessary nut helped "warm up" the tone and gave me volume and tone control by my foot instead of having to walk over to the amp.

[markbaptiste]

Thanks for the replies.
Very helpful
mark

[RichardF]

I tried two of these devices, with both passive and active pick ups. In each case I found the output of the XLR to be ridiculously high. The speakers of the PA were flapping in and out when the devices were just plugged in never mind being used. No amount of adjusting the mixer's gain control would solve the problem, even when set to zero. Both went back to the retailer.

[markbaptiste]

I tried two of these devices, with both passive and active pick ups. In each case I found the output of the XLR to be ridiculously high. The speakers of the PA were flapping in and out when the devices were just plugged in never mind being used. No amount of adjusting the mixer's gain control would solve the problem, even when set to zero. Both went back to the retailer.

Wow, that's scary. Thanks for the input.
mark

[Mike Bunting]

I tried two of these devices, with both passive and active pick ups. In each case I found the output of the XLR to be ridiculously high. The speakers of the PA were flapping in and out when the devices were just plugged in never mind being used. No amount of adjusting the mixer's gain control would solve the problem, even when set to zero. Both went back to the retailer.

Did you turn down the gain on the device itself?

[almeriastrings]

I tried two of these devices, with both passive and active pick ups. In each case I found the output of the XLR to be ridiculously high. The speakers of the PA were flapping in and out when the devices were just plugged in never mind being used. No amount of adjusting the mixer's gain control would solve the problem, even when set to zero. Both went back to the retailer.

What you are describing is not a symptom of a "ridiculously high" XLR output.

The XLR output on these is at standard microphone level. Not even line level.

The symptom described is suggestive of some form of general electrical instability in the system, possibly related to a serious ground-fault issue . A faulty cable or plug would be one likely suspect.

If it was simply a level issue (which I guarantee you it was not), nulling the channel gain would have solved it. Instead, you must have been getting spurious low frequency signals arising as far down the signal chain as the output stages. It is a parasitic oscillation that can have several causes, from failing capacitors, to poor connections, unwanted inductances, RF pickup, poor PSU regulation, and so-on.

[RichardF]

Well I no longer have the AD121s in question so I can't try out any suggestions. All I can say is that these were the symptoms I observed when the device was used as a direct replacement for a Behringer Ultra Active Di in to 3 different systems. The systems worked well with the Ultra Di and not the AD121. However, I'm prepared to admit that I may have had two rogue units. Who knows? And yes I did start with the gain on zero.

[almeriastrings]

Unfortunately, with Behringer - two defective units is much more probable than if they'd been built by, say, Radial! All of the ones I've encountered have been fine. A defective battery can also produce that symptom in some circuits as well.

[kkmm]

I use a Behringer AT-108 (for acoustic guitar) and it works well with pick-up with preamp and also with simple glue on piezo pickup without the need for a preamp. I had 3 instruments with this glue-on pickup and they all sound great thru this Behringer AT-108. To get some chorus effect, and simply insert a chorus effect box in between.
This little amp is rated at 15 watts but it sound much louder than other brand amp rated at 30 watts.

[markbaptiste]

I've been using a Seymour Duncan SFX1 pickup boost, but have never been totally happy with the sound of the mandolin through it plugged directly into a PA, especially outdoors. I think it was really meant for an electric guitar. I'm going trade it back for store credit, and get a Behrenger ADI 21 to try. Thanks again for all the advice.
mark

[KanMando]

I use a Behringer ADI 21 for my mandolin with an LR Baggs Radius stick-on pickup and an acoustic guitar with a piezo pickup direct into our Yamaha board. It really helps to open up the sound of the Baggs pickup and seems to get rid of most of the typical "quack" from the piezo pickup (with the built-in Fishman preamp on the guitar). I've never experienced an issue with the DI level overloading the board input. No problems in two years of regular use.

[Jim]

I use a Behringer AT-108 (for acoustic guitar) and it works well with pick-up with preamp and also with simple glue on piezo pickup without the need for a preamp. I had 3 instruments with this glue-on pickup and they all sound great thru this Behringer AT-108. To get some chorus effect, and simply insert a chorus effect box in between.
This little amp is rated at 15 watts but it sound much louder than other brand amp rated at 30 watts.

That's my experience with the little 15watt Behringer acoustic amp too. I've used it in coffee shops and similar gigs and it was more than enough power, sounds great with the AD121 as well. Can carry in that amp , a small bag with cords and the pre amp, a guitar and a mandolin in one trip from my vehicle.

[markbaptiste]

Just got the ADI21. I like it. The mandolin sounds pretty good through it plugged into the PA. I've had a little trouble getting rid of a hum (probably from the mandolin pickup as it does not hum with guitar). With enough fiddling with the knobs (mostly lowering base), I can get rid of most of the the hum. Plenty of volume. I think with some more experience it will work ok. Better than anything else I've tried.

[almeriastrings]

Hum pickup can be a real problem with passive transducer installations. The wiring is critical. You need to ensure that the ground connections and shielding are up to the job. Also, use as short a cable as possible from the instrument to the preamp. This too needs to be of very high quality (low capacitance cable, preferably Neutrik or Switchcraft connectors). If you have any poor cable or connectors, this will certainly add to hum/noise problems. Some transducers themselves can be susceptible... you can sometimes cure this by covering with grounded adhesive copper foil (as used in electric guitar pickup installations). Also, see if the 'Ground Lift' switch has any impact.

[markbaptiste]

Hum pickup can be a real problem with passive transducer installations. The wiring is critical. You need to ensure that the ground connections and shielding are up to the job. Also, use as short a cable as possible from the instrument to the preamp. This too needs to be of very high quality (low capacitance cable, preferably Neutrik or Switchcraft connectors). If you have any poor cable or connectors, this will certainly add to hum/noise problems. Some transducers themselves can be susceptible... you can sometimes cure this by covering with grounded adhesive copper foil (as used in electric guitar pickup installations). Also, see if the 'Ground Lift' switch has any impact.

Thanks very much for the advice. Ground Lift has no impact, but I can cut hum to an acceptable level by dialing down the base.
mark