Barbera transducer with WW amp

Discussion in 'Amps, Mics & Pickups [DB]' started by Stefan Boeters, Nov 25, 2002.

  1. Since a couple of weeks I've been trying the combination of a Barbera transducer (integrated in a custom made bridge) and a WW (100 W) amp with my double bass. Given the high quality of both products, I'm somewhat disappointed with the sound results until now.

    The WW has to input jacks: one for "hi" and one for "lo" impedance. Normally I would expect a piezo pickup like the Barbera one to work best with the high impedance input (and this is also what Rich Barbera confirms). Actually, when I use the high-input, I get a loud, fat sound. But I'm not quite satisfied with the sound characteristics. To my ears, the sound has far too much mids and is, all in all, too electric-sounding (even after EQ adjustment). Interestingly, when I use the low-input, the sound is a lot more natural, but the signal is significantly weaker, so that I have difficulties to stand up to a drummer with my equipment.

    I hope that there might be a way of getting the advantages of the two inputs: the high input level of the "hi" and the good sound of the "lo". I think about using a preamp an then going into the low-input. Has anybody here experienced similar problems with the Barbera transducer? Do you know bassists who use this pickup together with a preamp? Any suggestions what I might try?

  2. Sam Sherry

    Sam Sherry Inadvertent Microtonalist Supporting Member

    Sep 26, 2001
    Portland, ME
    Euphonic Audio "Player"
    Ah, brother, that's Hi gain and Lo gain. What you're hearing is that the sound tends to "warm up" a bit as you increase the gain.

    Try this: Set the master volume to about 1:30, tone controls at 12:00, and channel gain to about 10:00. Plug into "Hi" and gradually increase the channel gain until you're hearing the level of "warmth" you like. Now, fine-adjust with the tone controls, then use the master volume to get as much sound as you need.

    Hope this helps.
  3. I have a Barbera, and I've tried a couple of preamps, but I find it's better without one. Considering the price of the Barbera, I was a little disappointed too. I was using Spirocore Weich and D'Addario Helicore strings, and always thought it was a little bit too "electric" sounding. However I recently changed to Velvet Garbo strings, and the difference is HUGE. This pickup system really seems to like gut strings. My sound is suddenly very acoustic and open. I really got them for my country/rockabilly gigs, but I did a jazz gig the other night and got told I had the best acoustic bass sound of any bassist they had ever used. Needless to say, I was somewhat pleased!
    For what it's worth, on jazz gigs I use a GK MB150E112 amp, and generally run all the EQ knobs at 10 o'clock, in other words, with some cut.
  4. Thanks, Samuel, for your suggestion -- I'll try it as you proposed. However, I'm a little confused about the "hi" and "lo" input:

    As I understand it, "hi" and "lo" gain would mean that I should get the same sound result whether I use the "hi" input with the gain control turned down or the "lo" input with the gain control turned up. But this is clearly not the case. As I said, the sound quality differs a lot. (And my guess was that this has to do with input impedance matching.) I like the sound I get with the "lo" input a lot more. And this is why I looked for a solution where I can use this input.

  5. davideo


    Mar 24, 2016
    I use the Barbera transducer as well and used to fight the sound a bit. Too much percussive sound from the string and not enough body and character of the bass. But no feedback at higher volumes. I recent found a fantastic solution. First you should know I firmly believe an upright bass cannot be amplified very loudly without losing the character of the instrument. So I don't turn it up any louder than I need to hear myself and can match a jazz drummer's volume. My solution is based on my Acoustic Image's ability to use both inputs at the same time. I don't know that many amps can do that. I run the Barbera straight into the high imp input. But I also run a good condenser mic positioned between the bridge and g side f hole thru an ART preamp and into the low imp input. It easily blends in phase with the transducer and supplements the sound perfectly. All this comes out an ACME B-1 or B-2.
  6. Ric Vice

    Ric Vice Supporting Member

    Jul 2, 2005
    Olivette, Missouri
    Your Walter Woods has an input impedance of 1 Megohm. Channel 2 is voiced for Double Bass while Channel 1 is voiced for Electric Bass. My guess is that the Barbera needs to see a higher input impedance. Unfortunately, IME the HPF/Buffer Preamp built by Francis Deck ( a great piece of gear) and the Walter Woods aren't a great match, I have no Idea why this so. If you haven't already tried switching to Channel 2 on the Woods, I'd reccommend giving it a shot.

  7. Stephan,

    first the disclaimer: I have never used the Barbera pickup, nor have I gathered any experience with the HPF-pre. So read my post as educated guesses, at least when it comes to the pickup (and the preamp).
    However, I own a WW MI100-8 amp (likely similar to yours). So that part of the chain, I have some experience with.

    First, if you have any chance, I would try to play through another amp into the same cab. I don't insinuate that the amp is the culprit, rather the opposite, but whatever sound results you achieve there, can tell you if the following is true or not: Impedance aside, I am guessing from the design of the Barbera that its sound characteristic is system-immanent. Being piezo elements really close to the string, they will most likely pick up the string and not much else. That often results in a rather electric, artificial tone. So, if you're hearing the same through another amp, chances are it's the pickup design. Bear in mind that pickups work vastly different from player to player and from bass to bass.

    If what you're hearing through the other amp is more to your taste and expectations, try and check if the input impedance on your comparison amp is different (higher) than the WW's 1Mohm.

    As to possible voicing differences between the Woods' channels, I personally can't hear or measure (or see in the schematic) ANY difference at all on my specific WW amp. I have said before and will say again, that I would consider it rather strange of WW to put the phase switch on the dedicated ELECTRIC channel, where it is of no use. I do acknowledge that many players say otherwise and claim there IS a difference in the channels, and that may very well be true, all I'm saying is my experience and measurements tells me otherwise.

    You can always try and use any preamp with an input impedance higher than 1Mohm, and see if that gives better results through the WW. I am using my own home-grown preamp (with 5,7Mohm impedance and some gain, but nothing else- granted I use another pickup) and it works very well on the WW's inputs.

  8. Francois Blais

    Francois Blais Supporting Member

    Dec 11, 1999
    Québec, Canada
    Stefan didn't come back on TB since 12 years now, just FYI.
  9. Oops, good to know. Well, he probably figured something out... Next time, I'll make sure to read the date stamp :)

  10. Francois Blais

    Francois Blais Supporting Member

    Dec 11, 1999
    Québec, Canada
    No worries!
    The info may be helpful to someone else. ;)