fDeck HPF-Pre V1 w/active basses

Discussion in 'Effects [BG]' started by odineye, Dec 1, 2012.

  1. odineye


    Dec 29, 2011
    Bear DE
    Yes, after a couple of years of her sitting on the shelf, I'm in the process of resurrecting my overly abused sm-400. No, I can't explain fully why I decided to put her up in the first place. :confused: Of course, it's fairly well known these things have an issue with trying to reproduce continent shifting, bowel loosening low frequencies that are doing nothing more than wasting precious power and trying to pin my cones to the back wall. But the tone... Oh the tone... :cool:

    So, in an effort to save my power amp, speakers and foundations of my home and any venues I play, I've been looking into high pass filters. I've seen the [sfx] Thumpinator and at some point in the future there WILL be one on my board but at the moment budget is a primary factor. So that brings me to the only other real alternative I've seen... the fDeck HPF-pre, specifically V1.

    The one question I have about them is; Seeing as they were developed for upright basses and piezo pickups, is there anyone out there who has experience using one with an active bass? Has it worked out? Or was the 2:1 volume bump just too much for an effects chain or amp input to handle? I would presumably be using one after my bass and in front of my effects, mostly due the positive effect it can have on compressors... or at least so I've read. And yes, I do know there is a 2nd version with a volume control but, I've seen a couple of REALLY good deals on the V1 and was hoping it would be a viable alternative.
  2. Jim C

    Jim C Spector#496:More curves than Sophia + better sound

    Nov 29, 2008
    Check the amp forum for a complete run down.
    I will be getting the V3 version that has no volume control, offers 24 dB attenuation at 35Hz, and then offers 12dB up to something like 150 Hz. and is in a metal case.
    They seem to work well either in line between the bass and the amp or in the effects loop which is where I would think they would be most beneficial for an SWR.
  3. steelbed45

    steelbed45 TRemington Supporting Member

    Feb 23, 2011
    Nolanville, TX
    +1 to the thread link above and the version 3. Nice metal case, I power it with a onespot, and it has both volume and rolloff knobs.
  4. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    I've had great results on electric with the Series 3.

    The second filter (the variable one) really lets you tune the rig to the room.

    Yeah, read through that thread; well worth the time.
  5. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    I figure Francis won't mind if I copy something from his web site. These are meant to help you choose which model best suits your needs; #4 describes the Series 3 version. (But do visit his site; there's more info there.)

    Which one to choose? Here are some pointers:
    1. For typical double bass amplification, such as jazz at moderate volume levels, Series 1 and 2 both get the job done, and are not obsolete. If you have one of these preamps and are happy with your sound, then you don't need to upgrade. Or, if you don't have extreme cone control problems on an electric bass rig, then Series 1 or 2 are an economical choice.

    2. The volume control on Series 2 and 3 is handy when you can't reach the volume control on your amp. This gives you the option of moving your amp away from your bass to help control feedback.

    3. The plastic case is rugged, but it's indisputable that the metal case is more rugged.

    4. The "12+12" filter curve is two filters in one. The first filter has a fixed corner frequency of 35 Hz, and 12 dB/octave slope. The second filter is adjustable from 35 to 140 Hz, and also has a 12 dB/oct slope. Thus it always has 24 dB/oct slope below 35 Hz. I designed the Series 1 and 2 filter (same circuit in both) for double bass amplification, to tame the infrasonic "thump" produced by the acoustic instrument, which interacts poorly with the low frequency excursion behavior of ported speakers. Interest in a 24 dB/oct filter came from electric bassists who are experimenting with the latest high-performance speakers, to avoid driving the system at frequencies below the port tuning frequency. I designed the "12+12" filter with the same input conditions and "front panel" as Series 2, so that either could be used for double bass.

    5. Maybe you don't need a preamp! Since I consider the HPF-Pre to be a problem solving tool, it's worth investigating whether your rig suffers from the problems that it purports to solve. A bit of research is always worthwhile. There are a number of credible people on the TalkBass and Greenboy forums, including engineers and reps from some of the major gear makers, who regularly provide competent and honest answers to technical questions asked by bassists.
  6. odineye


    Dec 29, 2011
    Bear DE
    Thanks for the replies guys, I truly do appreciate the effort, but I had been hoping to get some information on version 1. Trust me, I'll waste a whole lot of my time before I start taking up everyone else's with easily answered questions. I had been through the thread in the link above (two mentions of V1, neither pertaining to my proposed situation), a dozen others and a pretty good Google search outside of TB. All to no avail, which is why I figured I'd ask here if anyone else had a similar experience.

    fDeck HPF-pre Version 1 with active basses? Anyone?

    Thanks again all...
  7. Wild Rice Chris

    Wild Rice Chris

    May 7, 2005
    Palatine, IL
    Rice Custom Guitars, Inc
    I've loaned my v1 and v2 to friends with active basses before. No problems with an Ibanez 6-string or a G&L L-2000 at 3-4 gigs. I love the HPF-Pres!