Thoughts on the PJB Double Four?

Discussion in 'Amps and Cabs [BG]' started by misterCRUSH, Jul 15, 2021.

  1. misterCRUSH

    misterCRUSH It's all's ALL jazz...

    Dec 27, 2015
    Fayetteville, Arkansas
    Not looking for gigging, just a clean, nice sounding amp to take on vacations...
    bassface69 likes this.
  2. ColdEye

    ColdEye Supporting Member

    Oct 22, 2015
    San Diego, CA
    For that intent I think its good. There are cheaper options of course but the D4 is nice, had it twice but ultimately sold it off. It can also be powered by a laptop battery pack, there are some threads here that go into detail about it. It gets pretty loud for home use, AND its a very nice music playback system.
    misterCRUSH likes this.
  3. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006
    I have had one for years for exactly that purpose and love it. IMHE it's the optimal travel rig because it's light and flat enough to fit in a legal carry on bag, sounds pretty good, and can be run on a laptop battery (there's a thread for that around somewhere) if desired and has phones out/aux in . Mine has been all over this crazy, communal, flying rock. I am not a fan of PJB's larger offerings, but the D4 is a great (highly specialized) product. PJB stuff has top shelf fit/finish as well.
    bassface69 and misterCRUSH like this.
  4. lug

    lug Supporting Member

    Feb 11, 2005
    League City, Tx

    Simply put, Phil Jones has learned how to ignore physics. :D
  5. Aloe


    Apr 10, 2016
    I have one for five years and I find it very good. it works nicely with a 5-string and with a right preamp/compressor it's able to stand up to a moderately loud drum kit.

    it's ported on the back, so loudness and frequency response will differ depending on room/stage. it's not boomy (like the briefcase), but clean and rather bright as all Phil Jones gear. when you push the gain, it adds up a nice grit to sound, but breaks up on loud notes pretty fast. headphone output is very decent.

    I power mine with a 20v DeWalt battery, powerbanks didn't the trick for me (it was cutting out and powering off).
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  6. ColdEye

    ColdEye Supporting Member

    Oct 22, 2015
    San Diego, CA

    How do you power yours with a dewalt battery? Any pics of what the leads/plug looks like?
  7. Robf

    Robf Supporting Member

    Feb 14, 2007
    Fremont, CA, USA
  8. Aloe


    Apr 10, 2016
    look at this post and some next ones

    and yes, it's not 12v, it's 20v
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  9. ColdEye

    ColdEye Supporting Member

    Oct 22, 2015
    San Diego, CA
    Thats awesome, better than the expensive laptop battery packs.
  10. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    I love mine. I bought it because I bought a Blackstar Fly 3 which turned out to be a POS which I donated to Goodwill promptly. I wanted something that sounded better. It's plenty loud enough to practice at home and certainly loud enough to put an ABG to the level of acoustic guitars. I use mine all the time and take it on trips, take it to the office and on work trips if I drive and bring a bass. It's crystal clear, EQ is good. It sounds like a bass amp, just not as loud as a bunch of 12" speakers. I use the aux. input for my RDM app sometimes. I would buy it again, no hesitation. I got the white one because it's cool and wife approved.
    If you like PJB gear you'll love it for the ultra-portability. It fits in a carry on or a backpack. If you like a little warmth or grit maybe stick a preamp in front of it. The tone is very clean. Great home practice amp. Great for backyard jams or if you're one of the 75% of TB members who say they want to take a bass to a campfire (campfires and bass guitars don't mix, friends). I have seen people busking with these and a battery pack.
    Other useful features, high and low settings/inputs and a standby switch. And separate level control for the aux input. Get one.
    misterCRUSH, ColdEye and bassface69 like this.
  11. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    My take is that PJB has fully vetted engineers evaluating every step of the design of all their products. Not ignoring physics but capitalizing on the physics. By this, I mean that many cab manufacturers simply ape existing designs. In order to make very high quality and reliable bass amps in such small and non-traditional form factors they have had to rethink everything. Kudos to them. The design of the Double Four is really creative.
  12. lug

    lug Supporting Member

    Feb 11, 2005
    League City, Tx
    I used to believe this as well until I took ownership of a Double 4. After spending time with it, I have come to the conclusion that Phil Jones went down to the crossroads and made a deal with someone to create the greatest small bass amp the world has ever known. That, and the brilliant use of a passive radiator make it so. :D
  13. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    Yeah! Pretty convenient location in St. Louis, near the confluence with the Mississippi. He could easily catch a barge downstream to Clarksdale, MS to make that deal.
    lug likes this.
  14. Love it. I got one of the first ones released into Canada and am still rockin it to this day!! Made many campfires a true party with this as it’s my vacation rig. Boat or camping has never been easier with a bass.


    One thing.... don’t get it wet. It’s made of MDF which acts like a sponge and soaks up water which cracks that hard finish. Don’t ask me how I know.

    It’s been functionally fine ever since it dried out but there’s cosmetic traces it’s had an accident.
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  15. iagtrplyr


    Apr 1, 2013
    Clinton, IA
    As said above, one of the nicest-built small combos ever thought up. It does defy common sense in that it sounds a lot louder than it should and still offer clean (and I mean clean) bass that articulates your notes as I've never heard before in my other amps. No coloration at all.

    Now if you like a little baked-in tone goodness you won't find it here, but if you're fine about plugging in, turning it up, and hearing your fingers plucking the strings this is the combo for you. And yes, it does play with pedals nicely. Look for deals, but be prepared to pay some cash 'cuz no one is giving these away, nor should they. Good hunting!

    PBJ and P 10.2020.JPG
    Last edited: Jul 18, 2021
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  16. Sorry to revamp the thread
    How good the PJB D4 handle drop tune?
    I play 5str Dingwall and sometimes drop the low B to low G#
    I'm looking small amp to practice on my bedroom, doesn't need to get loud, but at least the firmness of solid low G# is still there
  17. el murdoque

    el murdoque

    Mar 10, 2013
    If you ask me, there is no better amp than the D4 for that purpose .
    I can run mine off the external battery for my dell XPS laptop, which provides 19V through USB-C. There is an adapter that turns USB-C into the fitting barrel plug. This is especially nice on vacation because you don't need to find a spot close to an outlet. You can simply place it wherever you want and it runs for hours.
    When you play for yourself or with an unamplified acoustic guitar, it does not shy away from the lows and even does a credible low B.

    If money is not an issue, the other option I'd consider would be a barefaced one10 cabinet with a Hughes & Kettner Bass Master head. These are somewhat hard to find these days since they stopped making them somewhere in the eighties, but it's a tube driven 5W amp with the form factor of a modern (smallish) class D amp. It all fits nicely into a small Cajon bag and weigs in at less than 20lbs, but it's much bigger than the D4.
    You can expect more mojo here and it is totally capable of giving you more of an oldschool tone, though.

    I'm quite convinced that this has to be the case.
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