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Wishlist for URB Piezo preamp

Discussion in 'Amps, Mics & Pickups [DB]' started by flatback, Jan 31, 2018.

  1. flatback


    May 6, 2004
    I have spent many years (like most of you) cycling thru different gear looking for a sound that is at once clear to hear: pitch, intonation, rhythmic accuracy, punch/thump etc. and yet not unlike the actual instrument we play (realistic neuance). Toward that end I have ended up mixing a mic in with a piezo to get the best of both the piezo qualities and the mic qualities.
    Lately I have been thinking that with all the fancy preamps that are on the market there isn't one that is the ultimate Upright piezo preamp. We all have piezo's even if we rely on a mic or contact mic for a lot of the sound and though there are preamps out there that do a damn good job (Felix, Headway, etc.) they are all aimed at a wider group of instrumentalists and therefor have compromises that make them not perfect for upright bass using a piezo.
    So what would the perfect piezo preamp look like? Is it something like the ToneDexter that emulates a mic? Or could a preamp be made to really specifically address the upright bass's way of amplifying a piezo and tailoring to its needs.
    Here's what I would want in one based on what I have had or tried in different preamps, none of which has all the features on it's own:
    Variable Impedance
    Variable phase
    HPF filter and seperate
    Notch filter
    Tube presence/warmth
    quack centered eq - so that those quack frequencies can be rolled out easily and intuitively (although variable imp and phase go along way in that direction)
    a tuner built in.
    a DI

    What else? What would make the Ideal one channel URB piezo preamp?
    Scott Lynch likes this.
  2. shwashwa


    Aug 30, 2003
    Just wondering what a variable input impedance would provide that a high pass filter would not provide. The way I understand it, and I could be completely wrong, with a Piezo pickup as you lower the the input impedance you raise the corner of the resultant high pass filter that is created thus creating The Sweet Spot that you mentioned, but if you keep the input impedance High and let all the bass frequencies through can you not achieve the same effect with the high pass filter?
    flatback likes this.
  3. Dr. Love

    Dr. Love Supporting Member

    Nov 5, 2008
    Lubbock, TX
    A mute switch for set breaks, sudden wild feedback, etc.
    cdavisshannon likes this.
  4. flatback


    May 6, 2004
    Yeah maybe just maxing out the imp and then dialing it back is the solution (it has been mine especially with the Felix...I put the toggle to 20m and then HPF off the flabby bottom. (And BTW ,what I don't know about electronics is everything...I turn knobs to make the sound right and only remember some of it)
    But I thought I heard somewhere here that there is an Ideal imp for each different pickup.
    to get rid of the quack on the Felix (piezo channel) I either turn UP the mids but adjust the freq knob so that it is the LOW mids thereby overcoming the nasty 3000-to 3500 range that seems to me to be quack central on most piezos..or I notch that out (but then I cant use the HPF) or I cut it with the eq. But it isnt a system it is a bunch of knob twiddling until it sounds right.
    I think that the ideal preamp for a piezo should, when you plug it in, be pretty close to the ideal.
    WHat I like about the variable phase (if you have a two element pickup like a Yamahiko) is that just that one knob tunes you right in pretty good with everything else flat. A friend of mine showed me this in some digital audio program. My Felix allows you to invert either channel, but you can hear easily that the sweet spot is somewhere in between. Mike Arnopol first made me aware of this on the Yamahiko thread. THat pickup with two sides (G and E legs) bridged causes phasing which thins the sound and makes it super electric sounding. You can eq it back to pretty good, but if you invert the phase on one of them, it becomes too boxy and thumpy. Again you can eq that back to pretty damn good. I end up using one or the other a lot (although on really loud gigs I sometimes just bridge them and enjoy the vintage 70's twang) Both are really good by themselves....
    But like all Piezos it can sound pretty good or downright awful.

    Yeah a mute switch...always.
  5. sevenyearsdown

    sevenyearsdown Supporting Member

    Jan 29, 2008
    Sanborn, NY
    I think that for starters, this preamp should be tailored for upright bass first, and not a one-size-fits all "acoustic/piezo pickup" preamp. The idea that the same set of features will pleasantly accommodate any instrument with a piezo on it is hogwash in my book.
  6. Ric Vice

    Ric Vice Supporting Member

    Jul 2, 2005
    Olivette, Missouri
    Agreed, but it would likely have to be a custom build to justify the cost. Acoustic Image, Euphonic Audio, and Walter Woods already incorporate DB friendly preamps into their amps. Grace, Headway, et all work very well with DB. Just my take of course. I’m selling a lot of my gear to simplify my setup.

  7. flatback


    May 6, 2004
    thats what I'm saying.
  8. sevenyearsdown

    sevenyearsdown Supporting Member

    Jan 29, 2008
    Sanborn, NY
    I'll expand a bit (about the piezo side).

    I understand that manufacturers can't be bothered to make a preamp specific for each acoustic instrument. It just wouldn't be cost effective. It does kind of make me chuckle now (with the benefit of experience) when I see one of these "full featured" acoustic preamps for piezos.....like a piezo on a mandolin is going to require the same tone shaping/voicing as an upright bass. I'm probably in the minority, but I much prefer "voiced" preamps so far as they have a pleasant voice for my instrument.

    The total transparency idea with piezos has always bugged me, as I've stated many times before. A piezo sounds like crap, and not like an acoustic instrument at all - so why would I want a preamp that leaves that signal uncolored with a dead flat EQ section. The best piezos with the best preamps still sound like piezos. So give me something already voiced for upright bass, not a glorified mixer input.

    So here are a couple/three of gotta haves:

    1. variable input impedance for obvious reasons
    2. the ability to set the center frequency for the mid band
    3. make all the switches/knobs easily accessible. nobody want to mess with tiny dip switches, recessed pot screws, or anything like that on a gig.

    One thing I think would be super cool is a selection of modeling voicings. I was once dead set against this type of processing in my signal chain, but recent advancements have changed my mind. Recently I started using a TC Electronics Bodyrez in my chain, and I really like it. I wrote a lengthy review about it. I'm not sure if this is exactly modeling or not, but it would awesome to have a group of selections to choose from similar to what Fishamn does on it's Aura Spectrum (but for UB instead of geetar). I mentioned this in the tonedexter thread as well, but they weren't keen on the idea.
    massimo and flatback like this.
  9. shwashwa


    Aug 30, 2003
    I do not see what the obvious reason for a variable input impedance. I do see the obvious reason for a high input impedance. Lowering the input impedance creates a high pass filter. Why can't we let all the bass frequencies through and adjust with a dedicated high pass filter instead of artificially creating a high pass filter with an impedance sweep? Add a good EQ section and a phase switch and you've got all coloring you need combined with your amps tone controls to boot. There's actually already many on the market that have these features
  10. sevenyearsdown

    sevenyearsdown Supporting Member

    Jan 29, 2008
    Sanborn, NY
    I'm not going pretend to know all of the science behind it, but we've all tried different pickups and preamps with different input impedances and had different results. While there is a baseline and general range most of them fall into, we know that some combinations just sound better to our ears. I'm not proposing a huge range - just the basic 3 selections that are most common.

    High pass filtering doesn't do much for me. I've had an fdeck and a Broughton Audio, sold them both. I've found the bass knob on my preamp does a good enough job of reducing low frequencies for me.

    This is where you and would differ. I run my preamp into the effects return on my head, thereby turning it into just a power amp. I hate running a preamp into.....another preamp. Two gain stages, two seperate EQ's - sometimes fighting for the same frequency ranges, sometime not....too complicated for me. I much prefer the use of a single preamp, and more importantly (to me) a single gain stage.

    Phase switching is also something I have never found a use for. I must be lucky because I've never had to use HPF'ing or phase switching to ditch feedback.

    But hey we're talking about a wish list here, so I'll wish whatever I want of my fictitious preamp (humor intended here).

    Oh and while we are at it - NO STOMP BOX FORMAT! Make a nice enclosure with rubber feet to sit squarely on top of a head, or mic stand mount. I can't be holding the bass, plucking notes, and turning knobs with my preamp on the floor! I'm 6'-5" and play on stages the size of a postage stamp sometimes. Anything that's out of arm's reach once the gig starts isn't getting attention until the gigs over! I have a Boss TU2 that's older than dirt I stomp on for muting. If I need a boost, I lean back and turn the master volume up on my head.
  11. flatback


    May 6, 2004
    I guess part of my wish list really goes to what sevenyearsdown is saying: these preamps all do a lot of things for a lot of different applications....too many things. On the Felix I have about a hundred ways of getting similar sounds. And that is just on the pickup channel.
    I would love to be able to plug a series of upright piezo's into a preamp and at least get the minimum pretty quick and intuitively and simply...It's what I really like about the ToneDexter concept.
    sevenyearsdown likes this.
  12. I love brainstorming, so just throwing in my 2c, despite not using a piezo for several years.

    Ultra high input impedance can contribute to cable noise - e.g. look at the ehrlund thread.

    Phase or polarity is not just for preventing/halting feedback.. my check list for the sound check has 'test 0deg and 180deg polarity for best sound' - often this is the difference between a thin vs a full sound, or a nice vs a tubby sound. This was dead easy with the dyn-b switch on the afterlengths. Now I have to bend down to the EDB1 when I check this out.

    HPF vs using bass tone control.. adding HPF can let you boost the bass control for warmth, and yet cut out off mud at some point between say 80Hz and the E fundamental, i.e. the use of the bass control is not compromised by increased muddiness. Sometimes the default 40Hz HPF of the Headway 'bass' setting or built into the ART Tube MP is all it takes to make a difference.

    If a modular/expandable design preamp was feasible who would be interested? - add a plugin notch filter or a DI output, etc.. like using inserts but without the cables
  13. Jon Mush

    Jon Mush

    Jun 3, 2015
    Winnipeg, MB
    Yeah. I agree wholeheartedly. I tried the Felix angainst my Headway. Different flavour of great. Both had tonal merits the other lacked.

    I said this in the Audiosprockets thread too, but with preamps as we’ve known them, it comes down to a pristine audio path, great headroom, surgical EQ and a bunch of other bits that all add conveniences on a gig. But, in the end we’re polishing a turd. It’s the same as mics or any other studio gear. Bad source into a great pre doesn’t equal great.

    Not that the ToneDexter (or the state of our grasp on the tech) doesn’t have its limitations, but it’s so much closer to letting us have the sound of a great mic in a room with a dude playing a bass in it than anything I’ve tried before. The limitation we’ve all struggled with up to now is how to get that mic/acoustic sound without bleed and feedback. Tone Dexter does that better for me than anything else I’ve tried.

    In the PA world things are changing for the better at a fast pace with digital processing and filtering to correct (as much as possible), the inherent flaws due to physical limitations, etc., within the speaker enclosures. I really think this is the next step in preamp design.

    We can all debate about how much we hate the idea of a fake tone with all this processing, but at least it’s high tech. A piezo pickup is about as refined as a sledgehammer. Albeit, thus far, the best and most realistic option for many of us.

    My playing circumstances don’t allow me to use the Ischell/MSP, or the DPA/Remic/AMT route. I’m constantly looking for better ways of faking that sound. Pretty soon it’s just gonna come down to me playing better...I’m running out of other ideas!:D
    Last edited: Feb 2, 2018
    Chris Fitzgerald likes this.
  14. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator Gold Supporting Member

    Oct 19, 2000
    Louisville, KY
    I love the idea of the Tonedexter and would love to experiment with one. No idea if it would work for me, but it's intriguing.

    I also do not completely understand the technical aspects of the variable input impedance versus a HP filter. But since I can buy a HP filter in a simple little box for cheap, I'm going with that. Years ago I borrowed a Summit TD-100 with variable impedance to try out. I expected the holy grail, but didn't find it. I like the "Phil Jones Sound + Fdeck" a lot with a piezo. No idea what part of the amp is really the heart of that sound. I suspect it's some combination of the 5 MegOhm input impedance, the little speakers, and the cabinet design. It's good enough to make music with.

    I've tried a lot of preamps, and each has something that I like and some things that I dislike. In the end, it comes down to what I can live with that lets me forget about the pickup and amp and lets me focus on the music making itself, which is the reason I'm there in the first place. When I stumble onto the next great thing that makes the gig a lot easier without a lot of fuss or schlep, I'll go with that and be happy. Until then, the one thing I know I can do is work to improve the acoustic an musical end of the signal chain. No matter what I'm running that through, it's always the fountainhead of the rest.
  15. sevenyearsdown

    sevenyearsdown Supporting Member

    Jan 29, 2008
    Sanborn, NY
    This has more/less been my argument regarding piezo pickups for years. Some sound better, though none sound good in comparison to an acoustic instruments tone. For whatever reason a lot of folks are convinced that they are some great "acoustic" pickup, when they are not - just another form of electronic pickup.

    The whole Tone Dexter concept intrigues me as well. It would intrigue me a whole more if they had a mid band adjustment and presets though. The argument against having a mid band adjustment on any acoustic preamp is short cited by the builder, no matter how great they think their modeling is. They are kidding themselves if they think that modeling will correct the need to adjust that frequency in a live setting. I twiddle knobs at almost every gig, and I never know which ones I'll need. I hadn't touched my mid knob for months, then at loud gig last weekend - boom needed more mid clarity. Even though I'm a CUT THE MIDS kind of guy, sometimes you need to put some back into the mix.

    I would love to see a preamp with an average EQ section, along with some common preset modeling. The Tone Dexter guys pretty well ignored me when I brought it up, but I think it would be awesome to have presets with stuff like: Vintage Kay w/guts, Carved German w/Steels, etc., etc., etc. Like go ahead and pick 6 very common, desirable upright bass tones and have a pro do your modeling training. Like @flatback said, I just want to plug in and find a decent tone quickly - with any preamp.

    Some of the EQ sections on the higher end ones scare the ca-rap out of me....so many knobs. Might as well be a graphic EQ. They look like studio tools, not live boxes. I'm sure guys get used to them, but I really like as little as possible to worry about on a gig.

    So I guess I'll update my wish list. Here is my piezo only preamp.

    1. variable input impedance
    2. 3-band EQ with adjustable center frequency for mid band
    3. fully accessible switches and knobs top mounted, with no recessed controls
    4. 6-10 modeling selections with wet/dry control
    5. free standing or mic stand mountable. no stomp box format.
    6. hot enough output to drive a power amp easily.

    So who's gonna build the Jay Super Deluxe Upright Bass Preamp huh? If you build it, I will try it out free of charge to me! I'm screen shooting this post as proof of concept. The coffee is strong this morning.
  16. Jon Mush

    Jon Mush

    Jun 3, 2015
    Winnipeg, MB
    I get what you’re saying about the mids. That’s where the most important info is. I typically try to get the most accurate acoustic-like tone out of my pre to send to FOH and then use my amp controls to tailor my stage sound. And lately most DB gigs have been in-ear monitors.

    The thing so far is that with the TD the mids are much closer to where I want than ever before. The shelving EQ points are pretty well thought out so that rolling back will make the mids pop pretty well.

    I’ve seen friends with the Aura setup and they do add something special. The JD dobro setup is the best I’ve heard. It uses a specific pickup and on a great guitar sounds wonderful. The more generic Aura stuff is just that and doesn’t work well with everything. The beauty of the TD is that it tailors the specific waveform of your bass output. When you make a good WaveMap it’s such a win. It took me days of experimenting before I got one or two that I’d consider keepers

    The beauty is that James and the folks at AudioSprockets are constantly innovating. It’s worth reading the low-down after each firmware release. Soon there will be the ability to export our WaveMaps, so we are likely to have a trading card like community of crowd-sourced WaveMaps that we can experiment with. However, I truly believe that the process will always be closest when utilized self-trained. I’m not sure how the Aura tech is, but my understanding of the AudioSprockets filtering would make it necessary to use your bass in the training for optimum results. I really like that it’s very specific in the training. (A few years back I did a gig that Jim Hurst was also playing at, and we spoke of the Aura setup on his guitar. He wasn’t happy until they tailored a setting to his tastes. I can’t remember if they even had his guitar in the lab, but I believe they did.)
  17. statsc

    statsc Supporting Member

    Apr 23, 2010
    Burlington, VT
    ToneDexter solves the feedback and bleed problem!
  18. Jon Mush

    Jon Mush

    Jun 3, 2015
    Winnipeg, MB
    Indeed. I edited my above post for clarity (my bad). The TD is my new fav, and I think I am less prone to feedback or tonal issues than before—even though the control set is more spartan.
  19. sevenyearsdown

    sevenyearsdown Supporting Member

    Jan 29, 2008
    Sanborn, NY
    I do get it. They definitely have a niche, and a very cool concept developing. He seems to focus on the software much more so than the hardware, which I guess is to be expected given the nature of how the product functions. Some of the product demos are incredible, and I dig that they are pushing the boundaries on this stuff.

    Where I think we'd have to agree to disagree is the idea that you don't need at least a three band EQ to tweak things room to room in live settings. Regardless of how well it mimics your acoustic tone, you are still amplifying and will run into situations where you need to cut or boost some frequencies. That's not an indictment on the preamp, but a reality of amplifying upright bass in a variety of venues IME.
  20. shwashwa


    Aug 30, 2003
    I personally would rather him focus on what he's good at. And if I need a 3-band EQ there are a hundred pedals I could put after it. Yes you do end up carrying one more thing about the size of a cigarette pack but doesn't really bother me. having said that I don't own a tone Dexter and don't really plan to but I do carry an EQ pedal that I use if I get a tough room
    DoubleMIDI likes this.

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