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Fishman Pro-EQ Platinum Bass pre: Comments, Output level question

Discussion in 'Amps and Cabs [BG]' started by junglebike, Aug 17, 2003.

  1. junglebike


    Feb 14, 2003
    San Diego, CA
    Just picked one of these up from guitar center for $160 to try on for size. I'm looking for something to give me versatile tones for latin, dub, reggae, and jazz with my Pentabuzz.

    I'm amazed -- It's a really good preamp with a fantastic eq section and a really useful compressor that really nails the latin ranchera compressed tone. Anyone else use one of these? Sure kicks the snot out of sansamp (unless you need distortion) and it holds its own (almost) with the higher end DI's.

    A question: I'm driving a power amp with this. Stated output levels from the amp output are -20dBu to +10dBu (1kOhm)

    My amp (Peavey DPC1000) has an input sensitivity of 1V(rms). That works out to about +3dB, so in theory I should be able to clip the poweramp with this pre.

    However, I've not been able to do so, at least not driving a single channel with an 8-ohm cabinet. the Fishman has a noticably lower output level than both my Trace pre and my Summit TD-100 DI.

    What's going on here???
  2. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    heard its great for upright guys, but i guess it'd be fine for your electric boyz, too!
  3. bassmonkeee


    Sep 13, 2000
    Decatur, GA
    I've been using one with both electrics, upright, and Ashbory for a couple of months now--I love it. This is the first compression that I've really liked the sound of--very musical.

    I think it should be standard equipment with the Ashbory. It really improves the response, and tone.

    Are you using the 1/4" output, or the XLR output to drive the poweramp? I use mine as the front end of my Portabass 250 with the 1/4", and send the XLR from the Fishman to the PA, if there is one. I haven't noticed any problems with a low signal, but, then, I'm also not trying to drive a dedicated poweramp.

    Sorry I'm not much help. :meh:
  4. junglebike


    Feb 14, 2003
    San Diego, CA
    I'm using the 1/4" to drive the power amp -- its specified output is 10dBu. The XLR out is lower.

    Yeah, I usually hate compression. But this is fantastic, and very usable. Not for everything, but there are some bass tones that just require compression, I think.
  5. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    Reread the specs in the manual. Input levels are -20 to +6dbV, output is -23 to +3dbV (i.e. 3 db LESS than the input).

    I have two older Fishman pres and at max volume settings they put out the same level as the input give or take a few dB.

    Definitely not enough to fully drive a power amp. Of course, that's not what the device was designed for.
  6. junglebike


    Feb 14, 2003
    San Diego, CA
    Thanks, Brian.

    That info is not in my manual (at least not in those units.)

    Nominal input level for me is -14dBu, input overload level is 10dBu.

    I can get pretty damned close to clipping as it is (possibly thanks to my Pentabuzz's powerful active electronics.)

    Guess I need a boost somewhere, or perhaps one of the Lord Valve input sensitivity mods.

    Why on earth would you make a preamp that isn't capable of driving a power amp? This device strikes me as a fantastic standalone pre. Sucks that I might have to give up on it!
  7. maxvalentino

    maxvalentino Endorsing Artist Godin Guitars/ Thomastik-Infeld

    I also have one..I did the review of it here for TB (check the archives). Yes, it is very nice, and I use it quite a bit (tho' to be fair I like my Raven Labs Pre and DIs better...). And I gree, the compressor it really nice..very musical and flexible. I was quite impressed with that.

    I have had no problem at all using it as a pre to drive either my Mackie or Stewart power amps. I have used both the 1/4" and xlr outs for this...maybe there is some issue of compatibility with the Peavey amp?

  8. kasbrey


    Aug 23, 2002
    Northampton UK
    I mailed Fishman about the stated +10dbu as my unit wasn't driving my QSC RMX850 enough. They explained that this was a nominal rating.
    I do think that the Platinum Pro is a great unit for my electrics and EUB but I'm using it now into a Sansamp RBI and blending the two. Since I bought the RBI all my tone problems have disappeared:D
  9. junglebike


    Feb 14, 2003
    San Diego, CA
    What does "nominal" mean, exactly?

    If it says 10dBu is the max output, and you've got the input gain adjusted correctly and the output volume maxed, I don't understand what factor could make it put out significantly less than 10dBu.

    Input sensitivities From mfg's web sites:

    Mackie m1400: 1.23V (+4dBu)

    Stewart World 2.1: 1V

    Peavey: 1Vrms

    So the Mackie should actually be harder to drive than the Peavey and Stewart. Hmm...

    I've played around with the unit some more, and with everything maxed, I can get the Peavey's clip lights to flicker almost in unison with the input clip light on the Fishman, suggesting that I've got *just barely* enough gain.

    So that means I'm getting about +3dBu, not the +10dBu "nominal", whatever that means...
  10. kasbrey


    Aug 23, 2002
    Northampton UK
    Someone else will correct me I'm sure but I understood it to be like the Peak vs RMS wattage thing. The RBI is also rated +10 dbu but this must be "RMS" as it can easily clip the QSC.
  11. junglebike


    Feb 14, 2003
    San Diego, CA
    I understand peak vs. RMS. RMS = Peak*(sqrt(2)/2)

    If 10 is peak, then RMS =7dBu, or about 2Vrms, twice what's needed to clip the Peavey.

    I think I'll send an e-mail off to Fishman.
  12. kasbrey


    Aug 23, 2002
    Northampton UK
    I'm sorry - I only meant it as a vague comparison.
    That formula probably doesn't hold water in this instance. Please don't quote me.
  13. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Not exactly on topic, but not far off.....

    Check out the Aphex Bass Exciter DI pedals.

    Ive demo'd that one and the acoustic version for customers in my GC and they were both badass.

    It really phattens up the low end without letting it get boomy or muddy and gives the tob end a nice crisp sound without it being brittle.

    Im gonna try to do a side by side with the Fishman tomorrow if I have a chance and let you guys know what I think.

  14. maxvalentino

    maxvalentino Endorsing Artist Godin Guitars/ Thomastik-Infeld

    I have both the Fishman DI/pre and the Aphex pedal, and comparing the two is not realy a fair proposal. Quiet different animals, altogether.
    I bought both the Aphex Bass Xciter and Acoustic Xciter, I returned the Bass model, as I found it to be a bit aggressive in both the low and high end, and a bit "un-natural" sounding (although I think for aggresiive playing styles it would be wonderful). The Acoustic pedal is a bit more refined sounding, open and natural.
    Yet, the Aphex pedal is more of an aural exciter with the added on feature of a balanced DI. Yes, it does have a wet/dry bal. output switch, but it really does not match the smoother sound quality of bona-fide DIs.
    The Fishman is designed primarily as a DI, and as such offers quite a few signal routing options. It has the further bonus of being a bass-optimized preamp. It has far greater headroom than the Aphex, tho the Aphex xciter offers a sparkle (and boom) the Fishman does not.
    The Fishman EQ is exceptionally good, well voiced, and useful, as is the opto-compresor (which is surprisingly good! II have a nfew high end compressors for recording, but really like the over-all musical quality the Fishman imparts).

    I do like the Aphex Acoustic pedal, and it works exceptionally on bass, but it does not "replace" or supercede the Fishman, which I find myself using quite a bit with my semi-acoustic Godins, running straight to power amp.

    Now, the original problem was someone was not getting the Fishman the clip their Peavey power amp......not being an electronics whiz, by any means (although I understand the specs), might I ask why you want to to clip the amp? I find the Fishman has enough juice to drive my power amps, cleanly and efficiently, without clipping.
    The Fishman does have ample headroom to drive a signal from active, passive, and piezo basses, without clipping (which is a harmful road to travel).
    I am not sure I understand just why you would want to drive your amp to clip...please explain, if only for my own edification.

  15. junglebike


    Feb 14, 2003
    San Diego, CA

    First of all, thanks a lot for your posts, here and elsewhere. They've opened me up into a new (and expensive;) ) world of quality DI's!

    Being able to drive the amp to clipping is important not because you'd ever want do do so, but rather because you want to be sure you have enough output to get the maximum power from your amp.

    If your pre can't drive to clip, it likely cannot drive to *almost* clipping, which is where you get the most volume.

    Basically, I want to avoid spending, say $1100 on a 3000W PLX, and use a preamp that can only drive it to 750W!

    Looks like the Fishman is *just enough* for my Peavey. I'd like to have a little more gain, but I think it'll do. I'd be worried with PLX's though, since they are harder to drive.
  16. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    Maybe Bob Lee could weigh in here.

    According to specs on the PLX amps, you need to drive the higher wattage ones with more signal (check the input sensitivity spec). In other words a given voltage into any PLX amp yields the same output as they all have the same voltage gain factor (40x, 32 dB).
  17. kasbrey


    Aug 23, 2002
    Northampton UK
    The stated input sensitivity of my QSC RMX 850 is 1.15v. However, the way I understand it is that this figure is relevant only if you run the power amp at high settings. Therefore the quieter you set the power amp the more juice you require from the pre.
    I tried every combination possible with my Bass Pod Pro (+4db output) and RMX and could not get a punchy sound without putting a mixer in between to boost the signal. The BPP used to sound OK when I plugged it into the back of an Eden head I used to have. The higher output of the Sansamp RBI means I can set the power/pre balance either way and still sound punchy.
  18. GooseYArd

    GooseYArd Guest

    May 15, 2003

    The gain attenuator controls on power amplifiers don't affect how much the amplifier amplifies the input signal, they're simple attenuators that reduce the input signal. So the input sensitivity of the amplifier is always the same, its just that turning up the input attenuator has the effect of reducing the input signal.

    I also use one of these Fishman Platinum EQ preamps. I noticed Brianrost mentioned that the input levels were -20dbBv/+6dBv, I think those are the values for the guitar version of the preamp. That's the manual in pdf form on Fishmans site.

    Jungle, the "nominal output" level tells you the output level when the input level is 0dB, so .775V for dBu. Since +10dBu works out to about 2.5V, if the input clip light on the Fishman is just lighting, and the output volume control is all the way open, and the gain attenuators on your amp are not turned down, you'd be well into clipping. In fact I think you'd need to set the gain attenuator on the amp to about -6dBu to keep it from clipping.

    You also mentioned wanting to keep the signal close to clipping to get maximum volume. The challenge there would be the dynamic range of your bass. Because the output levels of the bass vary so wildly, if you set things up so that playing at a normal, fingerstyle level, you were very close to causing the power amplifier to clip, if you slapped a string or something, you would definitely cause clipping. About the only way you could keep your power amp performing very near maximum undistorted levels would be to use a compressor to narrow the dynamic range- the bass itself is just too erratic.

    hope that helps!

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